Tag Archives: global warming

At least 97% of experts agree that climate change is real and caused by humans. But only 3% of the 3% of climate change deniers are actually qualified in climate science

Credit: Pixabay.

Analyses of over 12,000 studies studying the effect of global warming suggest that 97% of the authors endorse the consensus that climate change is real and a result of human activity. But the remaining 3% of studies, whose methodologies and author affiliations are dubious, to say the least, have been greatly amplified by conservative think tanks and other groups with an interest in distorting an otherwise crystal clear scientific picture and polarizing society.

Studies that run counter to the established consensus of anthropogenic global warming serve as ammunition for conservative leaders with an agenda to subvert climate mitigation policies. To the uninformed public, a study being published in a scientific journal must mean that the arguments of the ‘other side’ are worth hearing or can weigh just as much as the consensus. Of course, not all studies are equal. Some are better than others, while some are downright awful and pseudoscientific.

And while appealing to authority is a logical fallacy, one can’t help but point out the findings of a new study published this week by researchers at the Georgia Gwinnett College, USA. Laura Young and Erin Fitz analyzed climate change contrarians from multi-signatory documents and discovered that out of the 3% of scientists who don’t agree on anthropogenic global warming, the overwhelming majority aren’t qualified to assess it.

“As politicians use contrarian arguments as a reason to justify inaction against climate change, it is important not only to understand who these contrarians are, but also to establish what links, if any, they have to organizations and industries that work tirelessly to prevent climate mitigation efforts. Exploring these connections may help explain why these individuals continue to argue against the climate science consensus,” the authors wrote.

Only 3% of the 3% of climate change deniers are actually qualified in climate science or at least some related field. The remaining 97% do not meet expert criteria and are also involved with organizations and industries affiliated with the climate change countermovement. To qualify as a climate expert, the signatory must have “a minimum of 20 climate-related, peer-reviewed publications as the base to establish expertise”.  What’s more, most contrarians are aged 65 or older, an age group that is more prone to entrenching world views.

The names of the individuals whose expertise was analyzed in the present study were drawn from the Bali Open Letter, Manhattan Declaration, Paris Climate Challenge, Lindzen Petition, and Climate Scientists’ Register. These documents serve as an official challenge to the global climate discussion and often target specific global policy initiatives. 

“Almost none of the individuals who signed the documents have a degree directly related to climate science. In fact, less than 1 percent of the individuals in the sample have a degree deemed relevant to climate science, with relevance defined as individuals having a degree in climatology or a similar field. A total of 77 percent of contrarians, however, have a scientific degree that could provide some knowledge related to climatology, for example, physics, geography, or engineering. Just under 23 percent of contrarians have a degree with no direct relation to science, for example, statistics, economics, international relations, and those related to the humanities,” the researchers reported in their study published in the British Journal of Political Science.

Since the 2013 study was released which first reported the “97% expert consensus figure” over anthropogenic climate change, expert consensus may have now climbed to 99%. But despite the near-unanimous consensus, climate change deniers are often given as much exposure in the media, if not more, than legitimate climate scientists.

It is thus important that we place more emphasis “on distinguishing between the consensus among 97 percent of scientists and the rhetoric spread by the 3 percent of contrarians,” the American researchers wrote.

The recently published Intergovernmental Panel for Climate Change (IPCC) Synthesis Report claims “it is unequivocal that human influence has warmed the atmosphere, ocean and land”, and warns that the Paris Agreement goals of 1.5℃ and 2℃ above pre-industrial levels will be exceeded during this century without dramatic emissions reductions.

G20 leaders promise big climate efforts but make few tangible commitments

There’s a distinct irony to Boris Johnson calling out world leaders for their hollow promises on climate change.

The UK Prime Minister, who said these promises are “starting to sound hollow” and that the commitments are “drops in a rapidly warming ocean”, is familiar to hollow promises himself. Johnson has often been criticized for his failure to deliver on a number of topics, including climate. The UK recently announced its plan to transition to zero emissions, but many have pointed out that the plan is also short on specifics and rings hollow at different places.

So when, after intense all-night negotiations, world leaders finally agreed to a joint declaration on climate change, we can probably be excused for not getting our hopes up.

Sure, on paper, things look good. Not only did the leaders of G20 (which accounts for 80% of the world’s emissions and includes the European Union plus the world’s 19 richest countries) reiterate their support of the Paris Agreement to limit climate warming within 2°C, but they even made a push for 1.5°C.

“We remain committed to the Paris Agreement goal to hold the global average temperature increase well below 2°C and to pursue efforts to limit it to 1.5°C above pre-industrial levels, also as a means to enable the achievement of the 2030 Agenda,” the leaders said in a statement. “We recognize that the impacts of climate change at 1.5°C are much lower than at 2°C.”

But ultimately, the agreement made few concrete commitments. US President Joe Biden said there were a “series of very productive meetings”, but he rightly pointed out that China and Russia (among the world’s biggest polluters) “basically didn’t show up” on matters of the climate. In fact, China and Russia, along with India and Australia, made a push against a firm statement about ending the use of coal. European diplomats were pushing on a firm target to end the use of coal, but supporters of fossil fuel could not be budged.

The leaders agreed to end international public financing of new coal power by the end of this year, but domestic financing of coal plants was not addressed — let alone ending the use of coal altogether. This political stalemate does not bode well for COP26 — the global climate summit that starts today.

Five years ago, at the 21th COP in Paris, we got the Paris Agreement — the landmark international climate pact in which all countries agreed to limit their emissions to keep temperature rise to within 2 degrees Celsius — and now it’s time for countries to update their national plans to reduce emissions — hopefully with more ambitious plans.

But this doesn’t seem to be the case. Even if current committments are respected (which is already a big ‘if’) that only puts us on a trajectory for a warming of 3 degrees Celsius.

So if we are to avoid catastrophic climate change, we need more tangible action and we need it now. There seems to be an impending feeling of “now or never” in the air, with Boris Johnson telling G20 leaders that “If Glasgow fails, then the whole thing fails.” Unfortunately, many felt that the G20 didn’t deliver. Oscar Soria, of the activist network Avaaz, told the agency there was “little sense of urgency” coming from the group, adding: “There is no more time for vague wish lists, we need concrete commitments and action.”

Even António Guterres, Secretary-General of the United Nations expressed his disappointment with the result, saying his hopes are “unfulfilled” but at least “not buried.”

Still, not all is lost yet. France’s President Emmanuel Macron told newspaper Journal du Dimanche that “nothing is ever written before a COP”, while a US official told reporters that G20 was about “helping build momentum” before the leaders head to Glasgow for COP. With the conference kicking off today, the message of G20 leaders is expected to set the tone for negotiations and lend a push for the uphill battle of fighting climate change.

We’ve seen in the pandemic that the world can take decisive action quickly with the right drive, and climate change is a challenge equal in scale (or even greater) than the pandemic. Hopefully, world leaders will manage to recreate that same drive and put the world on a path that avoids some of the worst effects of climate change.

The scientific consensus is that if global temperatures rise by 2 degrees Celsius, the likelihood of climate catastrophes increases substantially. This translates into increased global hunger, water crises, disease, and conflict. Even 1.5 degrees would be problematic, but it is much more manageable than 2 degrees. Meanwhile, the 3 degrees warming we’re currently headed for would be catastrophic, bringing devastating loss of life and economic decline across all of the planet. It’s pretty much our last chance to take action that avoids all these negative effects. If we don’t act, the window of opportunity may soon be closed.

How global warming causes both extreme heat and cold weather

Texas Guardsmen assist a motorist stuck on snow and ice on February 17, 2021 in Abilene, Texas.  Photo: Texas Army National Guard/Staff Sgt. Yvonne Ontiveros

It’s obvious how global warming can lead to record-breaking surface temperatures and heatwaves. After all, there’s “warming” in the term that describes the rise of global average temperatures as a result of more heat-trapping greenhouse gases emitted into the atmosphere. But the same process is responsible for driving record-low temperatures as well, which seems counterintuitive. A new study explains how global warming can drive both sweltering heat waves and frostbiting blizzards by analyzing three extreme events from the past winter.

Harsh winters and blazing summers: what’s the connection

On February 26, 2015, Senator James Inhofe (R-Okla.), who quite ironically used to be the chair of the Senate Environment and Public Works Committee, appeared with a snowball on the Senate floor to demonstrate, once and for all, that climate change is a hoax.

“You know what this is?’” asked Inhofe, the author of The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future. “It’s a snowball, from outside here. So it’s very, very cold out. Very unseasonable.” Then he tossed it to a congressional page.

This tasteless stunt occurred during a period when it happened to be very cold in the eastern United States. Since then, June 2021 has officially become the hottest June on record in North America while July 2021 was the worst for wildfires since records began.

But while global warming and extreme cold might sound antithetic, they’re actually quite well connected. And if Inhofe would have been of good faith and listened to climate scientists, he would have known this, too.

Research has connected the collapse of the polar vortex — a huge ring of low-pressure, cold winds in Earth’s stratosphere above the North Pole — with extreme sub-zero temperature events. This is owed to the polar vortex’s connection with the jet stream, a band of strong air currents flowing from west to east about 10 kilometers above the surface. When the temperature abruptly increases due to global warming, the interaction between the polar vortex and jet stream can be dramatically altered. The resulting extreme weather due to the interplay can be further amplified by changes in ocean temperature or Arctic Ocean sea ice.

Researchers led by Xiangdong Zhang, a professor of climate and atmospheric sciences at the University of Alaska Fairbanks, showed this effect in action when they examined two record-setting cold air outbreaks in China from late December 2020 to mid-January 2021. During this time, the cities of Beijing and Tiajin saw their lowest temperatures in 54 years at -19.7°C (-3.46°F) and -19.9°C (-3.82°F), respectively.

Record-breaking cold weather in North America’s midwest and deep south in February 2021 was also examined, which saw the coldest recorded temperatures in almost a century in Texas and Austin, at -13.3°C (8°F) and -8.3°C (17°F), respectively.

Using observational data from the past 42 winters, the researchers plugged temperature readings into climate models that simulated how sea and atmospheric events may impact extreme weather.

“Even though global warming and loss of Arctic Sea ice occurs every year, such extreme weather events that we investigate are intermittent — they do not occur every year,” said co-author James Overland, research oceanographer at the National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory in the U.S. “This is because they are caused by a combination of new global warming and extreme, but naturally occurring, precursor weather conditions in the jet stream and polar vortex.”

“The overarching problem to solve is why extreme weather events have more frequently occurred in a warming climate during recent decades and if the Arctic warming amplification plays a leading driving role,” Zhang added. “The extreme events of the 2020-21 winter provide a unique opportunity to examine what physical processes or mechanisms drive these events.”

The results suggest that all three events were linked to sudden stratospheric warming, although the downstream effects were different for each scenario. During the first East Asia cold event, polar air modulated the midlatitude jet stream, steering cold air southward. In the second event, the polar vortex split, deepening the region of low pressure driving more cooler Arctic air into the region. Finally, in North America, the polar vortex also split but this time the low-pressure atmosphere settled more deeply over the south.

The study shows that large-scale atmospheric circulation and temperature anomalies can lead to extreme weather across the world, but due to slightly different factors. Satellite remote sensing may help validate these model simulations; and if that’s the case, scientists may use these models to better predict how precursor events influence the monsoon season in East Asia and other weather events. But whatever may be the case, the common denominator is global heating.

“By studying these record-breaking cold spells, we can see the ’big picture‘ of extreme weather events.” said co-author, Zhe Han, scientist in the Institute of Atmospheric Physics, Chinese Academy of Sciences. “Though the events can be different, they might share similar underlying mechanisms that are related to global warming. Along with the warming, the Arctic amplification and intensified ocean thermal anomalies may interact with the atmospheric circulation, such as the polar vortex and sudden stratospheric warming, to cause the occurrence of extreme cold or hot events.”

The findings appeared in the journal Advances in Atmospheric Sciences.

Climate change literally shifted Earth’s axis

Credit: Flickr, Derek Keats.

Earth’s axis is an invisible line that connects the planet’s geographic north and south poles. However, this axis isn’t fixed since it is a function of the planet’s center of mass, or barycenter, which can change if the planet’s mass is significantly redistributed. This is exactly what happened in the last three decades as a result of global warming, which has melted hundreds of billions of tonnes of ice from the poles, especially the north pole.

According to a new study published in the journal Geophysical Research Letters, since 1980, the position of the two poles has shifted by about 4 meters.

That may not sound like a lot. In truth, this shift in the geographic poles doesn’t affect our lives or the course of nature in any way. It doesn’t even have an effect on navigation, which relies on locating the magnetic poles.

However, in the grand scheme of things, it is yet another damning testament to humanity’s planetary-alternating power.

Previously, the Gravity Recovery and Climate Experiment (GRACE) satellite, jointly operated by NASA and the German Aerospace Center (DLR), provided reliable gravity data showing that glacial melting was responsible for movements of the geographic poles between 2005 and 2012.

In this new study, Shanshan Deng and colleagues from the Institute of Geographic Sciences and Natural Resources Research at the Chinese Academy of Sciences extended this link to before the satellite’s launch in 2002. They showed that the direction of polar drift shifted from southward to eastward, and this has been going on since 1981.

The average speed of polar drift has accelerated in recent years. The researchers found that the drift from 1995 to 2020 was 17 times faster than from 1981 to 1995. This period also coincides with massive melts in the Arctic and Antarctica.

“The faster ice melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s,” said Deng.

But it’s not only melting polar ice that’s been driving this slight polar drift. Any sizable redistribution of mass can change the planet’s barycenter. For instance, the researchers found that humans have extracted more than 18 trillion tons of water from deep underground reservoirs over the past 50 years. All of this mass that used to be stored and concentrated in certain locations has now been spread out into the world’s oceans and seas. Certainly, the pumping of groundwater must have also made a contribution to the drifting of the poles, the researchers noted.

The analysis showed that the greatest changes in water stored under land were in areas like California, northern Texas, Beijing, and northern India. All of these regions have pumped copious amounts of groundwater for agricultural use.

“The findings offer a clue for studying past climate-driven polar motion,” said Suxia Liu, a hydrologist at the Institute of Geographic Sciences and Natural Resources Research at the Chinese Academy of Sciences and the corresponding author of the new study. “The goal of this project, funded by the Ministry of Science and Technology of China is to explore the relationship between the water and polar motion.”

Both groundwater depletion and the melting of polar glaciers are due to unsustainable human activity. This shows that humans aren’t an insignificant force on this planet. On the contrary, humans have a profound impact on the planet, so much so that scientists have proclaimed a new geological epoch — the Anthropocene, or ‘the age of man’. 

NASA just released the first direct evidence that humans are causing climate change

A simplified animation of Earth’s planetary energy balance: A planet’s energy budget is balanced between incoming (yellow) and outgoing radiation (red). Credit: NASA.

By now it should be no surprise to learn that the planet is warming very rapidly. The vast majority of this warming is not natural, over 99% of scientists say, but rather the result of heat-trapping greenhouse gases released by human activity such as burning fossil fuels.

Yet with all the thousands of studies about climate change and its connection with human activity, it was only recently that researchers at NASA have provided direct observations of the driving force of climate change.

Since the Industrial Revolution in the mid-19th century when humans’ appetite for coal and other fossil fuels was first stirred, the concentration of CO2 in the atmosphere has skyrocketed from 280 parts per million (ppm) to over 415 ppm today.

We know beyond a doubt that greenhouse gases such as CO2, methane, or water vapor trap heat in the atmosphere, thereby raising surface temperatures. We also know that CO2 in the atmosphere is increasing at a pace 100 times faster than it should naturally.

At the same time, human activity is also responsible for air pollution, such as particulate matter that we all know is detrimental to our health, as well as that of wildlife. But some of this air pollution is in the form of aerosols, which are minute particles suspended in the atmosphere where they reflect incoming sunlight back into space. In other words, this kind of pollution has a global cooling effect.

Aerosols are thus a force of cooling, whereas greenhouse gases produce heating. The difference between the energy absorbed by the atmosphere, of which greenhouse gases are a major contributing factor, and the energy radiated back to space by factors such as aerosols is known as “radiative forcing”.

When radiative forcing is zero, this means that the planet’s energy system is in balance, so the atmosphere shouldn’t warm nor should it cool. When radiative forcing is positive, this means that Earth’s system is off balance and warming.

What NASA has done in its recent study is to quantify the individual radiative forcings using satellite observations in order to determine exactly how much each component warms or cools the planet.

For decades, scientists have devised models of climate change predicting how the temperature will change as a function of greenhouse gases in the atmosphere. Unsurprisingly, the new NASA study found that radiative forces match these models after it combined data from NASA’s Clouds and the Earth’s Radiant Energy System (CERES), which studies the flow of radiation at the top of Earth’s atmosphere, with other data sources such as ocean heat measurements.

“This is the first calculation of the total radiative forcing of Earth using global observations, accounting for the effects of aerosols and greenhouse gases,” said Ryan Kramer, first author on the paper and a researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, Baltimore County. “It’s direct evidence that human activities are causing changes to Earth’s energy budget.”

Another nail in the coffin

Scientists unanimously agree that human activity is the only thing that can explain the steep rise in the average global temperature on Earth, which has increased by a little more than 1° Celsius (2° Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.

Although the evidence for anthropogenic global warming is overwhelming, this was actually the first study to present direct rather than indirect evidence in favor of this explanation for the warming we’re currently experiencing. Up until now, direct evidence that changes in greenhouse gases affect the atmosphere’s ability to transfer heat was only available in localized settings.

According to the study, human activities have caused radiative forcing on Earth to increase by about 0.5 Watts/square meter between 2003 to 2018.

“Creating a direct record of radiative forcing calculated from observations will allow us to evaluate how well climate models can simulate these forcings,” said Gavin Schmidt, director of NASA’s Goddard Institute of Space Studies (GISS) in New York City. “This will allow us to make more confident projections about how the climate will change in the future.”

The findings appeared in the journal Geophysical Research Letters.

Ocean warming is a wrecking ball for coral reef systems. This researcher wants to understand it all

Year in and year out, scientist Thomas DeCarlo saw the writing on the wall — the wall of coral reefs, that is — and his findings are sounding the alarm: ocean warming and acidification could spell doom for coral reef ecosystems.

Coral reefs are vital for the health of the oceans. Image credits: Olga Tsai.

Billion-dollar buffers

“Ocean temperatures are now approaching one degree above what they were in industrial times, with a projected increase of two to four degrees, which could have terrible consequences for corals,” DeCarlo says.

DeCarlo has studied the history of monsoon upwelling, wind patterns, and other weather factors affecting coral reef ecosystems in the Red Sea. His research shows that reefs are essential not just to the corals themselves, but to the entire surrounding ecosystems, and human society as well.

If reefs collapse, so too do biodiverse life systems that rely on them to survive — and the damage will continue to cascade. Coral reefs are a nursery to different marine species, they provide fish for humans, and they buffer shores from storms.

That storm-buffer feature is apparently quite significant in dollars. In a US Geological Survey report, coral reef barriers as a force in flood protection protect $1.8 billion worth of coastal infrastructure and economic activity in the US and trust territories alone. Reefs reduce the energy of the waves as they wash ashore, which prevents or limits coastal erosion, flooding, and water surges.

DeCarlo’s detailed explorations use microsope, climate models, coral cores, and computerized tomography (CT) analysis, to study the relationship between climate stressors, bleaching, and calcification. He’s not the first scientist to study the environmental impact of coral reefs but he has taken a special look at instances where the upwelling of nutrient levels can be toxic to corals.

Composite photo shows samples of coral cores alongside CT scans of coral skeletal cores showing annual pairs of light and dark bands of high and low density. Photo: Thomas DeCarlo.

His plan, he says, is to build a global database of the history of coral bleaching events, helping to fill the gaps in our knowledge of coral resilience and vulnerability. But to do that, we first need to understand how the climate is affecting corals.

High, hot, and deadly

Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away, a process known as “upwelling,” explains the National Ocean Service (NOS). The water that rises to the surface is typically colder and is rich in nutrients, which “fertilize” surface waters, and have high biological productivity.

For corals, upwelling can be a blessing or a curse. According to DeCarlo knows, nutrient-dense waters can spell good news or bad news. It depends.

“Summer monsoons circulate nutrient-dense waters from the Gulf of Aden to the Red Sea. The symbiotic algae that live in corals thrive on these nutrients. In return, they provide food and energy for the corals to grow,” said DeCarlo. “But warmer waters create more nutrients, which create more algae, which create more oxygen and waste build-up in corals. When high waste conditions combine with high heat, this situation causes bleaching, which could turn deadly.”

According to the NOS, bleaching events might or might not be a dire threat for coral. If stress caused bleaching is not severe, the coral may recover. But if (1) there is prolonged algae loss and (2) continued stress, coral eventually dies.

There’s much work to be done, and DeCarlo has no intentions of stopping anytime soon. From King Abdullah University of Science and Technology (KAUST) and now on to Hawaii, at Hawaii Pacific University, his work offered valuable insight into the life of corals, but there’s much more research to be done, especially in regards to global warming. DeCarlo’s website states that “global warming is driving an increase in the frequency of mass coral bleaching events worldwide.”

Healthy coral reef and marine life in the central Red Sea of Saudi Arabia. Photo: KAUST.

It took the researcher 4 years to finish his PhD studying corals, an accomplishment he says he is “especially proud of,” since it was a first of its kind comprehensive study.

One important takeaway from this research is that coral reef environments are not a cookie-cutter affair. One-sized conclusions and conservation measures cannot address and fix everything. One must recognize the complexities due to what are the oceanographic settings of any individual coral reef.

Disentangling these oceanographic processes will help us predict when and where we may find coral reefs that are relatively resistant to rising temperatures, and this information will be critical to informing local management decisions.”

Climate change. Facts and figures behind mankind’s greatest challenge

It’s real, it’s happening and it’s caused by human activity. Climate change has already started showing its effects around the world. From extreme weather to rising sea levels, climate change is already upon us — and there’s an overwhelming body of scientific evidence demonstrating it.

Image credits: Joe Brusky / Flickr (CC BY-NC 2.0).

What exactly is climate change and how are man-made greenhouse gases causing it? Who is to blame for this and how can we tackle it? Should we tackle it? We’ll take a dive into all these questions and many others to provide an accurate look into the facts and figures behind the world’s greatest challenge.

A changing planet

First of all, climate shouldn’t be confused with the weather. Climate is the general weather conditions of a place over many years — it’s essentially a long-term average of weather.

Climate change, therefore, isn’t a hot day or a hot summer. It’s a significant variation of average weather conditions over several decades or more. The longer-term trend is what differentiates climate change from natural weather variability.

Climate change also isn’t necessarily an artificial process — this climate change is, but there have been many previous climate change events throughout Earth’s history.

The Earth has had seven cycles of glacial advance and retreat over the last 650,000 years, with the last ice age ending about 11,700 years ago and marking the start of the modern climate era.

Image credits: NASA.

Most of these climatic changes are linked to variations in Earth’s orbit, changing the amount of solar energy the planet gets. Other events like volcanic eruptions or large meteorite impacts can also affect the planet’s climate — but that’s not the case with the current warming trend. It’s essentially clear (>95% certainty) that this is the result of human activity.

Humans are the driving force behind the changing climate of the planet; specifically, it’s the greenhouse gases that we’ve been producing for the past century and a half. Carbon dioxide (CO2) is responsible for most of the global warming we are causing, with methane (CH4) and nitrous oxide (N2O) behind it.

It works like this. The Earth’s atmosphere absorbs some of the Sun’s energy, and reflects some of it away. The amount that is absorbed/reflected depends on the chemical make-up of the atmosphere. The more greenhouse gases there are in the atmosphere, the more energy is absorbed, thus causing the atmosphere (and the planet itself) to heat up.

This is called the greenhouse effect.

The amount of greenhouse gases that we generate has skyrocketed in recent decades, and this shows in the atmospheric composition. Concentrations of CO2, CH4, and N2O have increased to “unprecedented levels” in the last 800,000 years, according to the Intergovernmental Panel on Climate Change (IPCC).

The radiative forcing (warming influence) of greenhouse gases in the Earth’s atmosphere is growing at an accelerated pace. Around 30% of the industrial-era increase has occurred over just the past 30 years. Image credits: NASA / NOAA.
  • Carbon dioxide (CO2). It’s released through natural processes such as volcanic eruptions and also through human activities such as burning fossil fuels. It’s the most important man-made greenhouse gas — although it’s not the most potent of the greenhouse gases, it’s long-lived and very abundant.
  • Methane (CH4). It’s a hydrocarbon gas produced by natural sources and human activities such as agriculture. It’s much more active than CO2 on a molecular basis but also less abundant in the atmosphere.
  • Nitrous oxide (N20). It’s a very powerful greenhouse gas, caused by soil cultivation practices such as the use of fertilizers, biomass burning, and fossil fuel combustion. It’s 300 times more potent than CO2 but it’s produced in lower quantities than CO2 and stays in the atmosphere for 114 years, while CO2 can remain for up to 1000 years.
  • Water vapor. It accounts for the largest percentage of the greenhouse effect, but it isn’t directly affected by human activity (at the global scale, at least). It increases as the Earth’s atmosphere warms, but so does the possibility of clouds and precipitation. Human activity is altering water vapor circulation, but this is not usually considered a cause of global warming, rather a reinforcement mechanism.
  • Chlorofluorocarbons (CFCs). They are synthetic compounds of industrial origin used in many applications. They are now regulated in production and release to the atmosphere by an international agreement.

This is proven by a large body of data collected over the years by scientists and climate experts, who can now get the big picture thanks to satellites orbiting around the Earth and other technological advances. And even predict future trends, using climate models, an extension of weather forecasting.

The global warming trend seen since the mid-20th century is linked to the human expansion of the greenhouse gas effect, which happens when the atmosphere traps heat radiating from the Earth. While this is important in keeping the planet warm enough to inhabit, greenhouse gases in the atmosphere have skyrocketed in recent decades.

How we know it’s humans

We’ve said it before: climate change has happened in the past, far before humans emerged on Earth. The very emergence of photosynthesis is thought to have caused a major climate change event, more than 2 billion years ago. So how do we know it’s humans that are causing it now, or that it’s even happening?

For starters, it’s abundantly clear that temperatures are rising. We’ve been measuring temperatures for over a century, with increasing coverage and precision. Climate change isn’t uniform — some places can heat up dramatically, while others can heat up far less, or even cool down a bit. But we have enough global temperature mapping to say with certainty that, on average, temperatures are increasing significantly and steadily. According to the NOAA (which is just one of the many sources with similar data), the combined land and ocean temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880. In recent decades, the average rate of increase has more than doubled to 0.18°C (0.32°F) per decade.

To see what’s causing this warming, we only need to look a bit further.

The first big clue comes from the extra greenhouse gases in the atmosphere. We can measure these emissions in two ways: we either measure them directly (with satellites, for instance) or we calculate approximately how much emissions our activities produce (which we can do with decent accuracy). All the existing data shows that greenhouse gases (and CO2 especially) are rising spectacularly. We’ve just passed a landmark 400 parts per million concentration of atmospheric CO2 — from about 280 before the industrial revolution. That’s a whopping 46% increase.

This doesn’t mean that temperatures also increase by 46%. Emissions of greenhouse gases are normally balanced out to a natural equilibrium. As a result, greenhouse gas concentrations and temperatures have been fairly stable for a long time. This is no longer the case as carbon sinks such as the planet’s forests and oceans can’t simply keep up with the growing emissions of CO2. But CO2 isn’t the only greenhouse gas, and the processes that govern climate change are more complex, so while the correlation is definitely there, it’s not a perfect correlation.

The CO2/temperature correlation, from NASA data.

This has already been known for a while. Despite what some would have you believe, scientists have known that human activities are driving climate change, but communicating this has proven to be a bumpy road. It’s a bit like the smoking-cancer connection: it took decades for people to follow the scientific evidence rather than the disinformation campaign by lobby groups.

To put it this way, man-made global warming looks like a duck, walks like a duck, and quacks like a duck. We may not know exactly how big its eyes are or how many feathers it has, but it’s definitely a duck.

The IPCC, which groups global climate experts, concluded in its Fifth Assessment Report from 2014 that there’s a more than 95% probability that human activities over the past 50 years have warmed our planet, rising atmospheric CO2 levels from 280 parts per million to 414 parts per million in the last 150 years.

The main source of human greenhouse emissions is the burning of fossil fuels such as coal and gas (for electricity, heat, and transportation). Deforestation ranks second, releasing sequestered carbon into the air. Other activities that generate emissions are fertilizer use, livestock production, and some industrial processes.

While humans are the main factor influencing the Earth’s climate, it’s not the only one. Variation in solar radiation, the Earth’s position relative to the sun, volcanic eruptions and large-scale weather patterns such as El Niño can also drive changes in the climate of the planet. But their significance is much lower than that of human activities, and in fact, analyses have suggested that over the past centuries, natural factors were actually causing a slight climate cooling — which emphasizes even more that we’ve been overheating the planet.

We’re already seeing the effects

When many adults were growing up, it seemed that global warming was something far away to be dealt with by future generations. That’s not the case.

While it may seem we have plenty of time to deal with its consequences, climate change has already become a severe problem across the world, with observable effects all over the place. The world is already 1ºC warmer than before industrialization, with the 20 warmest years on record all happening within the past 22 years.

More than 90% of the warming that happened on Earth between 1971 and 2010 occurred in the ocean, according to the State of the Climate report. Increasing ocean heat content is contributing to sea-level rise, ocean heatwaves and coral bleaching, and melting of ocean-terminating glaciers and ice sheets.

The acidity of surface ocean waters has increased by about 30% since the beginning of the industrial revolution. This is the result of increasing emissions of CO2 into the atmosphere and more being absorbed into the oceans. The amount of CO2 absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.

Across the globe, sea level rose about 8 inches (20cm) in the last century. The rate over the last two decades has been almost double that of the last century and is accelerating slightly every year. This has been driven by an increase in water volume as it heats up but also by the retreat of glaciers around the world.

Credit GPA Photo Archive. Flickr

Worldwide, most glaciers are shrinking or disappearing altogether. Between 1980 and 2018, glaciers tracked by the World Glacier Monitoring Service have lost ice equivalent to 21.7 meters of liquid water, the equivalent of cutting a 24-meter (79-foot) thick slice off the top of each glacier.

Ice sheets in Greenland and Antarctica have significantly decreased in mass. Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period, according to NASA’s Gravity Recovery and Climate Experiment.

Finally, the number of record-high temperature events has been increasing, while the number of record low-temperature events has been decreasing. A map by Carbon Brief found that 69% of 355 extreme weather events and trends were made more likely or more severe by human-caused climate change.

All this is costing us in many ways. Increased heat, drought, declining water supplies, hurricanes, reduced agricultural yields, extreme weather, sea level rise, changing insect outbreaks, ecosystem destruction — to list just a few of the effects of climate change — are already taking a toll. From human health and famine to climate refugees, we’re already feeling the impact, and the effect is due to increase as time passes. It’s hard to put a price tag on climate change but according to recent studies, climate change has cost U.S. taxpayers more than $350 billion over the past decade, and if we look at hidden costs such as its health impact, that figure grows dramatically. But even that is peanuts compared to what’s to come. Climate change could cost the developed world up to 10% of its GDP a year, one analysis found.

The problem is you can’t just hit the brakes on climate change. Even if you somehow, magically stop all emissions today, you’d still witness a bit of heating over the next century. But the more we delay action, the greater the damage. The longer we wait, the more painful (and expensive) the consequences will be.

What can we expect for the future?

Scientists have a high level of confidence that global temperatures will continue to rise for decades to come. The IPPC predicts a temperature rise of 3ºC to 4ºC by the end of the century if the world follows its current trajectory. That’s why activists and experts call for further climate action.

The extent of the climate change effects on each region of the world will change over time, with some countries more capable than others of adapting to changes in weather patterns. Overall, the net damage costs of climate change are likely to be very significant and to increase over time, according to the IPCC.

Projections put sea level from 30 centimeters to 2.4 meters by 2100 as the result of added water from melting land ice and the expansion of seawater. This will be combined with high tides, land subsidence, and storm surges, increasing flooding in many parts of the world and even forcing climate migration.

The Arctic Ocean may become essentially ice-free in the summer before mid-century, according to a study published this year. Researchers analyzed results from 40 different climate models and in most of them, the Arctic sea-ice was reduced to less than a million square kilometers, a level that they described as practically sea-ice free.

How can we stop it?

To stop a global challenge such as climate change, we need global cooperation and collaboration. There’s no real way around it.

In 2015, 195 countries committed to the Paris Agreement to limit global temperature rise to no more than 2°C above pre-industrial levels, doing everything within their power not to exceed a 1.5º temperature increase. Nevertheless, the initial pledges are insufficient to meet any of those targets and to make matters even worse, virtually all countries are failing in their commitments.

We’ve also seen how flimsy these commitments can be. All it takes is one administration that doesn’t care about climate change to take one step back instead of forward. Case in point: Donald Trump has withdrawn the US from the Paris Agreement. The president-elect has vowed to rejoin the agreement as soon as possible, but some damage has already been done.

But there’s still hope. As part of their commitment in Paris, countries have to update their climate pledges every five years and now it’s the time to do so. A few have already presented theirs but many are still pending. The Climate Action Tracker (CAT) regularly assesses countries’ climate pledges. Morocco, India, Costa Rica and the European Union are highlighted among the most ambitious ones, while China and the United Kingdom show some promise. On the bottom of the list ranks Russia, Saudi Arabia, and the United States.

Progress is also coming from other levels. A global covenant of mayors is offering a platform for cities to share initiatives, ideas, and support each other. The private sector can also support sustainable change, especially with a healthy policy in place.

The status of the new climate pledges. Credit CAT

Ultimately, all of us can make a significant difference. Individual behavior won’t save the world by itself, but if we support politicians and companies who are invested in climate change action, we can make a difference — and even a small difference could be crucial.

A temperature increase of 2ºC is considered the gateway to severe effects of climate change. If we could limit that to 1.5ºC, it could make a world of a difference.

At 1.5°C, over 70% of coral reefs will die, but at 2°C, almost all reefs will be lost, the IPCC projects. At the same time, with a warming of 1.5ºC versus 2ºC, the proportion of the population exposed to water scarcity due to climate change could be reduced by more than 50%.

This half of a degree could be pivotal for mankind and countless other species. But it won’t be easy. A report by the IPCC in 2018 said the 1.5ºC target would require “fast, far-reaching and unprecedented” changes. Whether or not we can accomplish these unprecedented changes remains to be seen.

Investors that manage $47 trillion urge companies to commit to net-zero emissions pathway

A leading group of investors has sent a letter to the boards of the world’s largest corporate emitters of greenhouse gases, asking them to produce a strategy to move their business to net-zero carbon emissions by 2050 or sooner. The investors will now follow the progress of such strategies based on a group of 30 indicators.

Credit John Englart Flickr

The Climate Action 100+ initiative was launched in 2017 and includes more than 500 global investors that collectively manage over $47 trillion in assets. They targeted 161 companies in their letter, which are collectively responsible for up to 80% of global industrial greenhouse gas emissions.

“Companies across all sectors need to take more ambitious action to ensure otherwise devastating impacts of climate change are avoided while they still can be,” Stephanie Pfeifer, CEO of Institutional Investors Group on Climate Change and a member of the Climate Action 100+, said in a statement. “A broader step change is urgently required.”

The investor group’s companies of interest are from various sectors, including oil and gas, utilities and power producers, transportation, mining and minerals, construction materials, industrials, chemicals, and food, beverages, and forestry. The lists include Dow, Nestlé, BP and Walmart, with over two-thirds based in Europe and the US.

These companies have made some progress on climate action, the investors acknowledged. More than 100 of them have a board member with the explicit responsibility overseeing climate-friendly action, while 50 have net-zero emission targets by 2050 or sooner. Nevertheless, this isn’t enough, they argued, asking for companies to be more ambitious.

“There are urgency and seriousness with which investors are looking for progress,” Pfeifer said. “We welcome the progress made so far but we really want to see further progress. When you’ve made a commitment we want to see the details of how that is going to be implemented, and when you haven’t made a commitment yet we want to see that as soon as possible.”

Following their letter, the Climate Action 100+ will soon judge progress by companies based on 30 indicators. They are currently developing the Climate Action 100+ Net-Zero Company Benchmark, which will be released next year. Some of the indicators will include capital alignment, governance, just transition, targets and goals and decarbonization strategy.

The indicators will be designed to clarify investor expectations and show which companies are leading the transition to net-zero emissions. The investor group asked companies to provide disclosures consistent with the benchmark “to enable investors to assess your company’s potential for long-term value.”

Human activity may turn Earth into a “Hothouse” — a warm climate it hasn’t seen for millions of years

A group of climate scientists have compiled a high-fidelity and continuous record of variations in Earth’s climate extending 66 million into the past, and the results aren’t optimistic. The planet could eventually warm to levels it hasn’t seen in 34 million years as a result of climate change, they argued.

Credit Flickr Klem@s

The new global “climate reference curve” created by the team was achieved by bringing together research from twelve international laboratories. They used sample material from the ocean floor collected over more than five decades of international scientific drilling expeditions around the world.

While the framework of a global climate reference curve has existed since 2001, climate records from many new sediment cores greatly improved in recent years. Over the last two decades, scientific drilling specifically targeted older geological strata, giving researchers access to better material to reconstruct the climate many years into Earth’s history.

The sediments analyzed in the study, some 66 million years old, are packed with the preserved shells of tiny organisms that can tell scientists about the temperature and chemical composition of the ocean when they were formed. The researchers used these proxies to reconstruct Earth’s climate history, going all the way back to the time when dinosaurs were still alive.

Using advanced mathematical analysis, the researchers identified four climatic states, classified as Hothouse, Warmhouse, Coolhouse and Icehouse. The distinctive climate pattern of each state is defined by greenhouse gas concentration and polar ice volume, with high CO2 and little ice volume during Hothouse and Warmhouse.

Temperatures on Earth during the warmest of the climate states in the past were more than 10ºC hotter than they are today, the study showed. It took the planet thousands or even millions of years to reach those levels, in sharp contrast to the climate change the world is now experiencing as a consequence of human activity.

The world has been in an icehouse state for several million years but that’s now changing. If we don’t act to reduce our greenhouse gas emissions, in a few centuries the Earth could once again break a threshold, moving to a Hothouse state. Global warming has already caused temperatures to go up over 1ºC compared to pre-industrial levels.

“If you look at the worst-case scenario [by 2300], the change in mean global temperature is larger than most of the natural variability going back over the last 66 million years related to changes in the Earth’s orbit,” Jim Zachos, a paleoclimatologist at the University of California, Santa Cruz, and a co-author of the study, told Scientific American.

The researchers warned that without immediate and stringent action Earth will face some of the strongest and fastest climate change the planet has ever seen. Countries have committed to limit the temperature increase to 2ºC as part of the Paris Agreement but almost everyone is lagging behind on that target.

“It’s a significant advance in Earth science,” said Zachos, claiming that the study provides a valuable framework for many areas of research. It will be useful to test climate models but also for geophysicists studying different aspects of Earth dynamics and paleontologists studying how changing environments drive the evolution of species.

The study was published in the journal Science.

Algae are turning the Italian Alps pink, raising concerns over rapid melting

Citizens and tourists in Italy were surprised by the appearance of pink glacial ice in the Alps, a phenomenon that is usually caused by algae that speed up climate change. Researchers will now study the algae to better understand where it came from.

Credit Fickr

Biagio Di Mauro, a scientist at Italy’s National Research Council, said the pink snow observed on parts of the Presena glacier is likely caused by a plant that had been previously found in Greenland. He said the algae is not dangerous and described it as a natural phenomenon that happens in middle latitudes and at the Poles.

The algae, known as Ancylonema nordenskioeldii, is also present in Greenland’s so-called Dark Zone, where the ice is also melting. Usually, ice reflects more than 80% of the sun’s radiation back into the atmosphere, but as algae appear, they darken the ice so that it absorbs the heat and melts more quickly.

More algae appear as the ice melts more rapidly due to the higher availability of liquid water. In the process, they also color the white ice at the Passo Gavia in red tones. Passo Gavia is a high mountain pass in the Italian Alps located at an altitude of 2,618 meters (8,590 feet).

“Everything that darkens the snow causes it to melt because it accelerates the absorption of radiation,” Di Mauro, told AFP. “We are trying to quantify the effect of other phenomena besides the human one on the overheating of the Earth,” said Di Mauro, claiming that tourism could be having an impact on the algae.

Meanwhile, tourists in the area regretted the impacts of climate change to the glacier. “Overheating of the planet is a problem, the last thing we needed was algae,” tourist Marta Durante told AFP. “Unfortunately we are doing irreversible damage. We are already at the point of no return, I think.”

Elisa Pongini from Florence also told AFP that she felt the Earth was “giving us back everything we have done to it.” She said this year was a special one as “terrible things” have happened, claiming atmospheric phenomena are worsening and that climate change is “increasingly evident.”

The pink glacial ice isn’t actually something new. The phenomenon was observed by the first arctic explorers, and it was initially believed to be caused by iron oxides permeating the snow. Since then, however, it was established that the hue is a product of algae that bloom in frozen water.

Previous studies have shown that these blooms are causing the snow to melt faster and they’re only going to grow more frequently as climate change increases snowmelt. In 2017, researchers argued microbial communities, including the algae, contributed to more than a sixth of the snowmelt in the locations they were present.

The last 150 years of global warming undid 6,500 years of cooling

The global warming experienced by the planet over the past 150 years has undone all the global cooling that happened over the past six millennia, according to a new study. The findings reinforce the role of mankind in climate change and the urgency to take action to avoid its worst consequences.

Credit Flickr

The millennial-scale cooling of the planet began approximately 6,500 years ago when the long-term average global temperature topped out at around 0.7°C warmer than the mid-19th century, the researchers argued – just as the Industrial Revolution, which had begun in Britain, began to take hold across Europe and America.

The period before industrialization represented the lowest global temperatures since the last Ice Age, culminating in a so-called “little ice age” in recent centuries, the study found. Since then, increasing greenhouse gas emissions from industrialized economies have contributed to global average temperatures 1ºC above the mid-19th century.

Researchers from Northern Arizona University’s School of Earth and Sustainability (SES) led the study and worked with scientists from research institutions all over the world, reconstructing the global average temperature over the Holocene Epoch. This was the period following the Ice Age and beginning about 12,000 years ago.

“Previous work showed that the world naturally and slowly cooled for 1,000 years prior to the middle of the 19th century, when temperatures reversed course due to growing greenhouse gases,” said Darell Kaufman, led author, in a statement. “This study shows more confidently than ever that the millennial-scale global cooling began approximately 6,500 years ago.”

An international group of 93 paleoclimate scientists from 23 countries, including Kaufman and his team, published earlier this year the most comprehensive set of paleoclimate data ever compiled for the past 12,000 years, compressing 1,319 data records based on samples taken from 679 sites globally.

At each site, the researchers analyzed ecological, geochemical and biophysical evidence from both marine and terrestrial archives, such as lake deposits, marine sediments, peat and glacier ice, to infer past temperature changes.

“The rate of cooling that followed the peak warmth was subtle, only around 0.1°C per 1,000 years. This cooling seems to be driven by slow cycles in the Earth’s orbit, which reduced the amount of summer sunlight in the Northern Hemisphere, culminating in the ‘Little Ice Age’ of recent centuries,” said Michael Erb, co-author who analyzed the temperature reconstructions.

Since the mid-19th century, global warming has climbed to about 1°C, suggesting that the global average temperature of the last decade (2010-2019) was warmer than at any time during the present post-glacial period. Nicholas McKay, a co-author, said individual decades are not resolved in the 12,000-year-long temperature reconstruction, making it difficult to compare it with any recent decade.

“On the other hand, this past decade was likely cooler than what the average temperatures will be for the rest of this century and beyond, which are very likely to continue to exceed 1°C above pre-industrial temperatures,” McKay said.

The researchers argued that investigating the patterns of natural temperature changes over space and time helps understand and quantify the processes that cause the climate to change, which is important as the world prepares for the full range of future climatic shifts due to both human and natural causes.

Countries have agreed in the Paris Agreement in 2015 to avoid temperature increase past 2ºC degrees. Nevertheless, the plans so far presented are far from ambitious and put the world in a 3ºC to 4ºC global warming trajectory.

The study was published in the journal Scientific Data.

Temperatures in the UK could exceed 40°C by the end of the century

Temperatures exceeding 40°C in the UK sounds unfathomable today, but this could become the new norm by the end of the century under current greenhouse gas emissions trends. Researchers at the Met Office in the UK devised a mathematical model that suggests temperatures in excess of 40°C may be reached every 3.5 to 15 years by 2100.

In 2019, the UK registered its highest ever temperature, when weather stations in Cambridge recorded 38.7°C. Typically, Britons would only see this kind of dramatic heat during their summer trips to Spain or Italy. Now, heatwaves are hitting closer to home than many would have liked — and the consequences can be devastating.

During that summer heatwave, 900 extra deaths were recorded in England alone, according to statistics released by Public Health England. In the last four years, 3,400 people have died early during periods of extreme temperature in England.

Many more preventable deaths are expected by the end of the century, as a result of rising temperatures fueled by greenhouse gas emissions.

Nikolaos Christidis, senior scientist at the Met Office Hadley Centre in Exeter, and colleagues estimated changes in surface temperatures in the UK for medium- and high-emission scenarios.

“While attribution studies have provided plenty of evidence that heatwaves in Europe and the UK have been increasing in both frequency and intensity under the effect of human influence, one major challenge in attribution research is examining changes on small local scales. Such analyses would require regional models, which would need to be evaluated against local observations that are not always available,” Christidis told ZME Science.

Unlike other studies that estimated changes in temperature based on emissions trends, the new research employed high-resolution datasets that allowed the researchers to “relate local to UK-mean changes in extremes.”

“We then apply these observationally-based relationships to downscale data from global climate models and assess changes in the chances of extremes everywhere in the UK. It was very interesting producing maps of the changing risk of extremes in the UK, which can display in remarkable detail local features like the effects of orography,” Christidis added. Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region’s elevated terrain.

Man-made climate change increased the probability of 40°C in the UK by about 10 times

The climate model showed that higher emissions increased the odds of temperatures above 35°C becoming increasingly common. The effect was most pronounced in the southeast of the country, where temperatures above 35°C could occur every year by 2100, rather than every five years today.

Meanwhile, the north of the country, which is known for its chilly weather, can expect 30°C up to once a decade by 2100. 

An outside temperature of 40°C or more is a freak occurrence in the UK, estimated to only occur every 100 to 300 years. However, these scorching hot levels could be seen every 15 years under a medium-emissions scenario and as frequently as every 3.5 years under a high-emissions scenario.

“There is always a probability that we may hit 40° C in the UK, but this probability would have been exceptionally low without human-caused climate change. Climate change is estimated to have increased the probability up to about 10 times, though the event is still rare in the current climate with a return time of a few hundred years. Going forward, the probability is rapidly increasing and by the end of the century, 40 degrees may be observed every 3-15 years depending on the pathway of future greenhouse gas emissions. Looking at the observational record we see that some areas in the southeast have seen warming trends as high as 1 degree per decade. Temperatures at the end of the century will depend on whether warming will continue at the same rate, or whether we will see higher/lower trends,” Christidis told ZME Science.

These bleak projections suggest that the UK might become unbearably hot during some summer days by the end of the century, with important consequences for public health and the economy.

“We know from past extreme events that heatwaves are associated with a range of adverse impacts like spikes in mortality, detrimental impacts on transport infrastructure, agriculture, water availability, etc. The severity of future impacts would of course depend on how well society will have adapted to more frequent and intense heat extremes,” Christidis warned.

Almost every year ahead of us will become a ‘record-breaking’ one in terms of temperature. Such studies underscore the urgency of cutting back on fossil fuels in favor of emissions-free alternatives, such as wind or solar. But for such a transition to occur within a sensible timeframe, all stakeholders have to be involved — from policymakers and industry to regular people.

“We also aim to keep a global perspective looking at changes happening around the world. Having reliable scientific information on how climate change has influenced extremes so far and how it may do so in the future is important not only to decision-makers, but also to the public that needs to build its resilience to weather and climate extremes.”

The findings were reported in the journal Nature Communications.

Climate change is making marine species migrate towards the poles faster than those on land

Rising temperatures, shifts in precipitation patterns, and changes in vegetations, all direct effects of a warmer world, are changing the range and distribution of many species — they are now forced flee from their normal habitats to find more suitable places.

Credit Flickr

This doesn’t occur equally for all species. Marine species are actually moving to the poles six times faster than those on land, according to a recent meta-analysis that compared over 30,000 habitat shifts in more than 12,000 species.

Land species are moving closer to the poles as the planet heats up but this shift is “at a pace that is much slower than expected, especially in areas with warm climates,” the authors wrote. Instead, marine species are following global thermal shifts much closer, they argued.

Marine species were found to move towards the poles at an average pace of six kilometers per year, while land animals showed a pace of almost 1.8 meters per year – which is faster than previous estimates but still much slower than marine species. This might be due to air sensitivity, the authors argue. Air transports heat less effectively than water and land animals can easily regulate their body temperature.

This means marine species are more susceptible to the changing temperatures on the planet due to global warming. At the same time, animals in the water are capable to migrate easier when they have to, while on land the movement of animals is more difficult due to human activities and geography.

When animals are subject to a high degree of disturbances from human activities, the authors found they tended to move against the thermal grain and not with it. This agrees with the general idea that land use and climate change may force species in opposite directions.

“Habitat loss and fragmentation due to land-use changes may impede the ability of terrestrial species to track shifting isotherms,” the authors wrote. “These complex interactions need to be accounted for to improve scenarios of biodiversity redistribution and its consequences on human well-being.”

The fact that marine life is following temperatures changes more closely could have big repercussions, some of which the world has seen before, the authors argued. During the Permian-Triassic Extinction, the most calamitous event in Earth’s history, very few marine organisms stayed in the same habitat as oxygen levels declined.

Today, animals are already swimming towards the poles and are at risk of running out of cooler water, competing with each other. This is happening on land too, with animals going up in the mountains. But in the water, this phenomenon seems to be happening faster, according to the researchers.

“Commercial fishing may speed up the displacement of marine species distribution through resource depletion and population crashes at the trailing edge, whereas low constraints on dispersal in the oceans may allow marine species living close to their upper thermal limits to better track climate warming at the leading edge,” the authors predicted.

The study was published in the journal Nature Ecology & Evolution.

More than a billion people could live in Sahara-like unbearable heat within 50 years

Credit: Pixabay.

We like to think of ourselves as a highly adaptive species, which is true to a degree. However, it is also true that humans have historically preferred to settle in habitats where the temperature is just right for both comfort and food production. But rapidly accelerating climate change is disrupting many regions that momentarily enjoy equilibrium, potentially threatening the livelihoods of billions of people.

Hotter than the Sahara for more than a billion people by mid-century

For many creatures, their habitat is predicated on temperature — this is also one of the reasons why abrupt climate change is so dangerous.

Warmer water temperatures cause declines in the populations of trout, salmon, and many other species that require cold water to survive.

Many species take their cues about when to migrate, flower, nest, or mate from seasonal changes in temperature, precipitation, and daylight. Climate change is confusing those signals and forcing wildlife to alter their behavior.

Professor Marten Scheffer of Wageningen University, Netherlands, and colleagues investigated the effects of climate change projected for the future from a curious angle. Instead of calculating the economic impact or going too much into the physics of climate change like other climate models, the researchers wanted to see how rising temperatures will affect human habitats.

According to the researchers, the vast majority of the population lives in regions where the average annual temperature is between 6°C (43°F) and 28°C (82°F). It has been this way for the last 6,000 years or so.

By the end of the century, global average temperatures are expected to increase by an additional 3°C. However, that’s the average. Some terrestrial regions might heat by as much as 7.5°C, which could make certain habitats unbearably hot.

The modeling work performed by the researchers, which was described in the journal Proceedings of the National Academy of Sciences, suggests that a third of the world’s population will live in areas that are as hot as the Sahara within the next 50 years under the worst-case scenario.

In the best-case scenario (3°C of warming by the end of the century), 1.2 billion people will live outside their “climate niche”, experiencing average annual temperatures over 29°C (84°F).

The worst affected countries will be India, Nigeria, Pakistan, Indonesia, Sudan, Niger, Philippines, Bangladesh, Burkina Faso, and Thailand, in this order.

Some of these effects can be mitigated by technology, particularly air conditioning. We’ve seen this work in seemingly inhospitable places such as urban UAE or Saudi Arabia. However, air conditioning is a luxury that the vast majority of people cannot afford, not to mention the fact that the energy required to cool homes and office spaces drives even more global heating.

Instead, what will likely end up happening is mass migration towards cooler regions. Additionally, regions that will experience temperatures past historically comfortable levels will also suffer significant impairments to their food supply, driving even more migration possibly conflict.

“I think it is fair to say that average temperatures over 29C are unliveable. You’d have to move or adapt. But there are limits to adaptation. If you have enough money and energy, you can use air conditioning and fly in food and then you might be OK. But that is not the case for most people,” Prof Marten Scheffer of Wageningen University told The Guardian.

The coronavirus pandemic has caused an unprecedented dip in greenhouse gas emissions that hasn’t been seen since World War II. However, emissions are bound to rebound and return to their usual upward trend once restrictions lift for good.

A U.N. report issued in 2019 found that global emissions would have to drop by 7.6% year-to-year, on average, if we’re to stand a chance at limiting global temperature rise to 1.5 degrees Celsius.

Crises like the coronavirus show just how fragile our economies and livelihoods can be in the face of global calamities. But in contrast to a pandemic, global heating is slow to develop, which gives the impression that things aren’t that bad — not yet at least.

These findings might, hopefully, motivate policymakers to stick to their Paris Agreement pledges, otherwise billions may find themselves living in misery. 

California, and the world at large, will contend with longer, hotter, drier wildfire seasons

Climate change is going to put California at risk of longer, more dangerous, and more destructive wildfire seasons reports a new study from the Stanford School of Earth, Energy & Environmental Sciences

Australian wildfire photographed in 2019.
Image credits Sippakorn Yamkasikorn.

The authors hope their work will guide authorities to implement more effective strategies for wildfire risk mitigation and land management, as well as to spur better resource allocation for the fighting of wildfires.

Wilderfires

“Many factors influence wildfire risk, but this study shows that long-term warming, coupled with decreasing autumn precipitation, is already increasing the odds of the kinds of extreme fire weather conditions that have proved so destructive in both northern and southern California in recent years,” said study senior author Noah Diffenbaugh, the Kara J Foundation professor at Stanford’s School of Earth, Energy & Environmental Sciences.

The team reports that autumn days with weather conditions conducive to extreme fires have doubled in frequency since the early 1980s in California, while rainfall during the wildfire season has dropped by about 30%. At the same time, the average temperature has risen by over 2 degrees Fahrenheit (more than 1 degree Celsius) over the same timeframe, with late summer and early autumn showing the highest increases. All in all, these factors work together to create very dry plant material in forests and grasslands that can act as tinder during the same parts of the year when dry “Diablo” and “Santa Ana” winds blow throughout northern and southern California.

This is what has been feeding the large and fast-spreading wildfires seen across the state in recent years, the team explains. And their effect has been seen over the past few years: California recorded its deadliest wildfire, its two largest wildfires, and its two most destructive wildfires so far during 2017 and 2018, the team explains, which collectively caused more than $50 billion in damage and claimed over 150 lives.

File:2017 California wildfires.png
Map of 2017 California wildfires from January 1 to October 11.
Image credits Wikimedia.

The paper analyses the November 2018 Camp Fire in the Northern Sierra Nevada foothills and the Woolsey Fire around the same time near Los Angeles. Both were fueled by strong seasonal winds and dry plant material created during the state’s hottest summer on record (in 2018). The outcomes of the fire were worsened due to the state’s limited emergency response resources, which were put under immense strain trying to contain the fires raging across different areas.

Local data, global problem

For the study, the team looked at historic temperature and rain gauge records to determine the risk of extreme wildfires throughout the year. Autumn showed an especially pronounced increase, with a doubling in conditions that foster such events over the past four decades. A suite of climate model simulations showed that human-caused climate change is at the root of this change in conditions.

“Autumn is of particular concern since warmer, drier conditions may coincide with the strong offshore wind events which tend to occur in the September to November period,” said Michael Goss, the study’s lead author and a postdoctoral scholar in Diffenbaugh’s Climate and Earth System Dynamics Group.

As for solutions, the team showed that the proposed reductions in emissions under the United Nations’ Paris agreement would help to slow down the rate at which wildfire risks increase — however, even in this scenario, much of California will likely still experience a rise in extreme wildfires in the future. The findings are “yet another piece of evidence that climate change is already having a discernible influence on day-to-day life in California,” according to Daniel Swain, a research fellow at UCLA, the National Center for Atmospheric Research and The Nature Conservancy, a study coauthor.

While the study focused on California, the findings are broadly applicable to any regions that are historically fire-prone, the team explains. This further exacerbates the problem, as global firefighting resources need to be spread over a larger area, limiting their effectiveness.

Apart from curbing our emissions, the team recommends controlled burning to reduce available fuel, upgrades to emergency communications and response systems, the development and implementations of community-level protective fire breaks, and changes to zoning and building codes meant to promote fire-resistant construction.

The paper “Climate change is increasing the risk of extreme autumn wildfire conditions across California” has been published in the journal Environmental Research Letters.

Coronavirus crisis might trigger biggest drop in CO2 emissions since WWII

Credit: Pixabay.

Around 2.6 billion people — one-third of the world’s population — are currently under strict orders to stay at home in order to curb the spread of the coronavirus. That’s roughly the world’s population during WWII, one of the rare times when global carbon emissions saw a dent in their otherwise ever-increasing trend. We’re living another rare such moment, as nation-wide quarantines have shut down factories, grounded airplanes, and kept vehicles gathering dust in parking lots.

According to Rob Jackson, the chair of the Global Carbon Project, a scientific organization that seeks to quantify global greenhouse gas emissions and their causes, carbon output could fall by 5% this year.

This would make it the first dip in global carbon emissions since the 2008 financial crisis when there was a 1.4% year-to-year decrease in carbon output.

“I wouldn’t be shocked to see a 5% or more drop in carbon dioxide emissions this year, something not seen since the end of World War Two,” Jackson, who is a professor of Earth system science at Stanford University in California, told Reuters.

“Neither the fall of the Soviet Union nor the various oil or savings and loan crises of the past 50 years are likely to have affected emissions the way this crisis is,” he added.

This might sound like good news, only it isn’t really.

Although climate change is the most menacing existential threat to both human civilization and wildlife, it is a slow-developing peril that we tend to not take as seriously as more pressing concerns.

The world has slowed down its carbon output greatly due to the pandemic. China alone saw a 25% reduction in its carbon emissions earlier this year after it shut down factories across the country. Once gray skylines are now sunny and reductions in pollution levels can be seen from space.

However, this otherwise welcome breather is not of our choice. The dent in carbon emissions due to all the wrong reasons. Once the pandemic is over, and life goes back to ‘normal’ — whatever that might entail — there is nothing to stop us from resuming our ever-increasing carbon output trajectory — or even accelerate it, as we try to make up for lost economic time.

According to Jackson, after the economy tanked during the 2007-2008 financial crisis, carbon emissions expectedly fell. However, they shot back up with fury, registering a 5.1% increase during the recovery.

Even this year’s forecasted drop in emissions is not enough to avert potentially catastrophic climate change. A U.N. report issued in 2019 found that global emissions would have to drop by 7.6% year-to-year, on average, if we’re to stand a chance to limit global temperature rise to 1.5 degrees Celsius.

We’re already 1 degree Celsius over Industrial Age levels. Today, global carbon emissions are roughly 150 times greater than during the 1850s.

So, in the grand scheme of things, this year’s drop in emissions isn’t really significant — even during this period of inactivity, emissions levels are still up to par with those experienced just a couple of years ago.

“Even if there is a decline in emissions in 2020, let’s say 10% or 20%, it’s not negligible, it’s important, but from a climate point of view, it would be a small dent if emissions go back to pre-COVID-19 crisis levels in 2021,” Pierre Friedlingstein, chair in mathematical modelling of the climate system at the University of Exeter in southwest England, told Reuters.

No doubt, we’re living in troubled times. Our focus needs to be on solving the current crisis. But once it inevitably fades away, the world cannot ignore the silent forces of destruction that scientists have warned about for years — pollution and global warming.

No one could predict the current coronavirus crisis, but scientists have warned that something like this might happen in the future given the extent of human encroachment on animal habitats — including those known to harbor viral reservoirs, such as bats — and globalization. Their warnings fell on deaf ears. Over 99% of climate scientists believe that climate change is due to human activity and represents a huge threat that needs to be urgently addressed. Will we listen now?

Climate crisis is making migration harder for nightingales

The common nightingale is one of the world’s most beloved songbirds and is capable of producing over 1,000 different sounds. It breeds in Europe and parts of Asia and migrates to sub-Saharan Africa. But, like many other species, it is being affected by climate change.

Credit Wikipedia Commons

Natural selection driven by global warming is causing these iconic birds to evolve shorter wings, which might make them less likely to survive their annual migration, according to a new study by Spanish researchers.

The authors looked at the changes experienced in two populations of nightingales from central Spain over a 20-year period, focusing on the variation in the shape of the wings and the survival of the bids.

They discovered that the average wing length of the nightingales in relation to body size has decreased in the last two decades, affecting their ability to migrate. Birds with shorter wings were less likely to return to their breeding ground after their first-round trip to Africa.

In recent decades, the timing of spring has shifted in central Spain and summer droughts have become longer and more intense, leaving nightingales with a shorter window in which to raise their young, according to the researchers.

This means the most successful birds maybe those that lay smaller clutches of eggs, giving them fewer young to care for. And if natural selection is favoring smaller clutches, it may simultaneously push nightingales away from all of the linked traits in the “migratory gene package.”

“Our results show that spring is delayed and the intensity of the summer drought is higher, which means a shorter optimal breeding period for the birds,” said Dr. Carolina Remacha, who led the study, in a statement. “We find the unique possibility that shorter wings are being favoured.”

The researchers believe that birds like the nightingale normally adapt to the demands of migration by having longer wings, larger clutch size, and a shorter lifespan. However, the changing temperatures are interfering with this and provoking a response from the birds.

Faced with a shorter breeding season, Remacha and the group of researchers believe the most successful birds are having smaller families with smaller wings. Nevertheless, these adaptations are likely to come at a price, they argued.

“If these changes are the response to the new environment, then obviously the ones that have been selected, the ones with shorter wings, are the optimal nightingales for the new situation,” said co-author Prof Javier Perez-Tris also from Complutense University.

One in every four species currently faces extinction and much of their vulnerability is linked to climate change, which brings higher temperatures, sea-level rise, more variable conditions, and more extreme weather, among many other effects. Animals react to climate change in three ways: they can move, adapt, or die. Many are moving to higher elevations and latitudes to escape warming temperatures, but climate change may be happening too quickly for most species to outrun it.

The study was published in The Auk: Ornithological Advances.

Research station in East Antarctica reports its first heatwave

Among the many consequences of climate change, extreme weather events are usually on top of the list. Heatwaves, flooding, and droughts, among many others, are already becoming more frequent and impactful across the globe, and Antarctica is no exception.

Credit Wikipedia Commons

Researchers at the Australian Antarctic Program reported the first recorded heatwave event at the Casey research station in East Antarctica. The event, which took place during the 2019-2020 summer, is likely to have impacted biological systems across the continent and accelerated ice melt.

Heatwaves happen when three consecutive days with both extreme and minimum temperatures are reported. Between January 23rd and 26th, the research station recorded minimum temperatures above zero and maximum above 7.5º (45.5 ºF), with the highest m9.2º C (48.5 ºF), being recorded on the 24th. The highest minimum, 2.5º C (36.5 ºF) was recorded the following morning.

The maximum is 6.9º C (44.4 ºF) higher than average for the station, while the minimum is 0.2º C (32.3 ºF) above average.

Land-based meteorological stations in Antarctica have measured temperatures as low as −89.2 °C (−128.6 °F) in the past. Satellites identified even lower temperatures, of -93.2 °C (−135.8 °F). Australian Antarctic Division applied Antarctic ecologist, Dr. Dana Bergstrom, and a group of researchers said that in the past a large part of East Antarctica had been spared from climate warming due to ozone depletion, which cools surface temperature and creates strong winds.

But these record-breaking temperatures seem long gone. The warmer temperatures reported on by the station can be linked to higher than average temperatures across different parts of Antarctica and to other meteorological patterns during the spring and summer of 2019 in the Southern Hemisphere, all influenced by the early breakup of the ozone hole in 2019.

“The upper levels of the atmosphere at the edge of Antarctica were strongly disturbed in the spring of 2019, and effects of this likely further influenced the lower atmosphere over Antarctica during the summer,” Dr Andrew Klekociuk said in a statement, adding there are now international controls working to close the ozone hole.

The researchers believe that the warm summer reported in Antarctica will likely lead to long-term disruption to local populations, communities, and the broader ecosystem. This disruption could be both positive and negative.

“Most life exists in small ice-free oases in Antarctica, and largely depends on melting snow and ice for their water supply,” Dr Bergstrom said in a statement. “Meltwater flooding can provide additional water to these desert ecosystems, leading to increased growth and reproduction of mosses, lichens, microbes, and invertebrates.”

Nevertheless, according to Bergstrom, excessive flooding can displace plants and alter the composition of invertebrates and microbial mats. “If the ice melts completely, early in the season, then ecosystems will suffer drought for the rest of the season,” she added.

The study was published in Global Change Biology.

Greenland lost 600 billion tons of ice last summer, satellite data shows

For many scientists, Greenland is considered “ground zero” for climate change, a place where the effects of global warming are most evident – including growing temperatures, warming oceans, and melting ice.

Last summer, Greenland went through an exceptionally warm season with record-breaking temperatures. This led to the loss of 600 billion tons of ice, which is enough to raise global sea levels 2.2 millimeters in two months, according to a new study.

NASA’s Jet Propulsion Laboratory (JPL) and the University of California looked at satellite data, which showed the surprising rate loss of ice in the area. Last year was the hottest on record for the Arctic, with the annual minimum extent of sea ice in the region its second-lowest on record.

“We knew this past summer had been particularly warm in Greenland, melting every corner of the ice sheet,” lead author Isabella Velicogna, senior project scientist at NASA’s JPL and a professor at the University of California, Irvine, said in a statement. “But the numbers really are enormous.”

The study took its data from satellites that were designed to measure changes to the Earth’s gravitational pull that result from changes in mass, including water. It showed that the ice losses registered last summer are more than double Greenland’s 2002-2019 yearly average.

But it’s not just Greenland. Antarctica continues to lose mass as well, the researchers said. “In Antarctica, the mass loss in the west proceeds unabated, which will lead to an even further increase in sea-level rise,” Velicogna said, claiming they also saw a mass gain in East Antarctica due to an uptick in snowfall.

Glaciers around the world are melting because of global warming, with Greenland as one of the most affected areas. Last year, a study showed ice is being lost from Greenland seven times faster than it was in the 1990s. This means 400 million people could be at risk of flooding every year by the end of the century due to sea-level rise.

Greenland’s ice sheet is experiencing an increase in ice slab thickness in its interior regions, another study showed. These ice sheets are normally porous, allowing meltwater to percolate (drain through) them, but the extra thickness makes them impermeable — so all the meltwater is draining into the ocean.

With most attention now focused on the coronavirus, the study helps to show the consequences that further global warming would have across the world. Countries agreed through the Paris Agreement to limit the temperature increase to 2 degrees Celsius, but much further action is needed to meet that goal.

The study was published in the journal Geophysical Research Letters.

Climate crisis is accelerating, shows growing impacts, UN warns

Global warming and its impact on ecosystems and people grew in 2019, according to a study by the United Nations, which warned more ambitious action is needed by all countries as fast as possible.

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The Statement on the State of the Global Climate, prepared each year by the World Meteorological Organization (WMO), a UN body, confirmed that the last year was the second warmest in history at a global level since recordkeeping began, with a temperature increase of 1.1 degrees Celsius above preindustrial levels.

“The indications are crystal clear. Global warming is accelerating,” the head of the United Nations, António Guterres, said in a news conference.

According to the analysis, the five-year period 2015-2019 includes was the warmest recorded and the decade that ended in 2019 was the one with the highest temperatures known so far. Last year was the second warmest year there is a record of, surpassed only by 2016, when a very intense episode of El Niño shot temperatures up. The WMO predicts that temperatures will continue to rise and, for the time being, points out that this January was already the warmest on record.

“Since greenhouse gas concentrations continue to increase, warming will continue,” said the secretary-general of WMO, Petteri Taalas. At a press conference, Taalas said the projections suggest that temperatures will continue to rise over the next ten years and will be between 1.1 and 1.65 degrees Celsius above pre-industrial levels.

UN scientists consider it vital to limit the rise in the planet’s temperature to a maximum of 1.5 degrees. That’s one of the goals included in the Paris Agreement, signed in 2015. But the latest data suggest that the world is not doing what is necessary to achieve it.

“We need all countries to demonstrate that they can reduce emissions this decade by 45% compared to 2010 levels and that we will achieve emission neutrality by mid-century. This is the only way to limit global warming to 1.5 degrees,” Guterres said.

According to Taalas, if nothing is done, the temperature would rise between 3 and 5 degrees Celsius by the end of the century and 8 degrees by the end of the next. For that to change, much more ambitious climate plans (and action) is needed from countries around the world.

Impacts of the warming planet

One of the problems higher temperatures cause is an increase in the risk of large forest fires, which in turn give off large amounts of carbon dioxide, which continues to fuel the heating cycle. This has happened with the large fires registered in Australia, Canada, or Siberia, which have triggered a spike in emissions, according to the report.

At the same time, the oceans are absorbing much of the heat from global warming and, as a consequence, continue to increase in temperature, breaking new records in 2019. The consequences of this are polar ice thaw, a rise in sea level, changes in ocean currents, changes in marine wildlife cycles, and changes in marine storms and other meteorological disasters.

The oceans absorb carbon dioxide, which dampens the effects of climate change but also increases the acidity of the waters and affects marine life, threatening, for example, a good part of coral reefs.

The report also highlighted the enormous impact on health that climate change is already having, with thousands of deaths linked to the increasingly frequent heatwaves recorded. According to WMO, up to 220 million people were exposed to great heat waves last year. In France, for example, up to 20,000 people were treated in the emergency room due to heat problems during the past summer and about 1,500 related deaths were recorded.

Globally, Taalas stressed that the “figures are much higher than those of the coronavirus”. To this is added the expansion of diseases transmitted by mosquitoes such as dengue, which in 2019 experienced a large peak of cases.

The coronavirus

WMO confirmed that in China an improvement in air quality was seen in January as a result of the coronavirus, which shows the impact that human activity has on the climate.

Guterres, however, urged “not to overestimate” the reduction of emissions linked to the decline in economic activity by the virus, as it will be temporary, and insisted that the fight against the disease should not distract from the need to continue taking measures against climate change.

“We are not going to fight climate change with a virus,” warned Guterres, who insisted that countries have to reach the necessary commitments at COP26, scheduled for November in Glasgow.