Tag Archives: Climate

Gas stoves leak methane even when not in use

Methane, a powerful greenhouse gas, is leaking from your stove even when it is not in use. In fact, most of the methane they leak happens while the stoves are not being used. Although individually, each stove doesn’t leak much of the gas, the effect adds up tremendously over the whole USA.

Image via Pixabay.

Leaky troubles

“Simply owning a natural gas stove, and having natural gas pipes and fittings in your home, leads to more emissions over 24 hours than the amount emitted while the burners are on,” says Stanford Professor of Earth Sciences Rob Jackson, co-author of the study.

The team measured the methane released from the cooking stoves in 53 homes in the state of California. They recorded the quantity of methane that leaked whenever the knobs of the stove were turned, in the moments before the gas lit on fire. They also recorded how much methane escaped unburned during cooking. However, the main advantage of this study over comparative ones is that it also measured how much methane was released when the stoves were not in use.

According to the results, a surprising 80% of the methane leaks recorded during the study were observed while the stoves were not in use. These came from loose couplings and fittings between the stove and gas distribution pipes. Eric Lebel, the study’s lead author, says that their results come to address the lack of data on “incomplete combustion from appliances,” offering up a valuable piece of the climate change puzzle.

The stoves and cooktops studied in this study belonged to 18 different brands, and varied in age from between 3 to 30 years old. Stoves using pilot lights leaked more than those equipped with an electronic sparker.

According to the measurements, the team estimates that around 1.3% of the gas used in a stove leaks into the atmosphere — which, individually, is a small quantity. Added up over the more than 40 million gas stoves in the U.S., however, this amounts to a significant quantity of greenhouse gas. Overall, the climate-warming effect of this quantity of methane would be equivalent to the emissions of 500,000 gasoline-powered cars.

Such leaks become important when considering the global push against greenhouse gas emissions. The E.P.A. estimates that buildings account for more than 10% of the greenhouse gas emissions in the USA.

The authors advocate that switching to electric stoves would help slash these emissions. It would also help in the broader sense that making a switch here would make people more comfortable to switching other, larger sources of domestic emissions such as the furnace, water heater, and clothes dryer.

That being said, they are aware that such a switch isn’t viable for many people, such as renters as those who can’t afford to purchase an electric stove. In these cases, there is a simple step everyone can take to limit methane emissions in their home:

“Pull the stove out from the wall and tighten the connectors to the stove and to the nearby pipes,” Jackson says.

In order to remove these emissions completely, however, the team underlines that the only real option is to switch to an electric stove entirely.

The paper “Methane and NOx Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes” has been published in the journal Energy and Climate.

One-third of Americans are “alarmed” about climate change, and over half are at least “concerned”

Americans are more concerned about global warming than ever, according to the latest results from the long-running Climate Change in the American Mind survey on public opinion.

Image credits Andrea Spallanzani.

Researchers at Yale University and George Mason University (GMU) report that, as part of the results from a twice-a-year US-wide survey, around 59% of people in the country are either “alarmed” or “concerned” regarding climate change. They also responded to feeling more engaged with and supportive of policies meant to reduce pollution and the warming of the climate.

A full one-third (33%) of Americans were “alarmed” by the issue, adds a news release from GMU.

Heating up

With the effects of climate change ramping up throughout the world, the public is increasingly concerned about how our way of life is impacting the health of the planet and our own wellbeing. The recent increase in freak weather, heatwaves, droughts, and wildfires are prime examples of how shifts in the climate can wreak havoc on our communities.

Public opinion is increasingly aware of these changes, and there is a general shift in interest against damaging practices and a growing demand for solutions. The recent results of this survey, and a comparison between them and results in past years perfectly illustrates this shift.

Climate change is fueled by emissions of greenhouse gases, primarily carbon dioxide from the burning of fossil fuels. Other man-made sources of such gases include methane, nitrous oxide, and even water vapor. Various industrial, commercial, and domestic practices generate these emissions. Apart from that, human activity further promotes climate change through the destruction of natural ecosystems — which work to keep the current balance through the recycling of various gases, — replacement of natural landscapes, overconsumption, and various types of pollution.

As things are going now, these problems remain poorly addressed. Climate change, then, is very likely going to persist in the near to mid-future, and its effects will become evermore dire as mean temperatures increase.

Truth be told, uncoupling our way of life from fossil fuels completely is a massive challenge from a practical point of view. These substances keep our societies running, in a very literal sense, on nearly every level. Although there have been incredible advancements in the field of renewable energy and a lot of progress in implementing them, it would still take a lot of work to replace fossil fuels with renewable energy completely — and quite substantial upfront costs.

That being said, it’s becoming ever clearer that we don’t really have a way around it. Public opinion seems to be swinging around to that view as well, judging from these findings. And, although completing such a transition is a huge task, policymakers and governments have been doing painfully little to get it started. The end of the pandemic has also brought about a re-increase in emissions, as our economies grind back into gear, showcasing how little progress has actually been made up to now.

China, the US, and the EU, as the largest emitters of greenhouse gases in the world, have the most work to do. We can hope that, with public opinion breathing down their necks, the US government will start to make more meaningful strides in this regard. The EU has been making some laudable efforts, although they, too, have a ways to go. China, due to its political regime, is a wildcard as to how it will progress in regard to climate change; authoritarian regimes tend not to deal very well with global issues.

The United States’ largest (to date) step towards fighting climate change is the $555 billion “Build Back Better” bill, which aims to invest in renewable energy and clean transportation. At the time of writing this, it is still awaiting approval by Congress.

This “shockingly big jump” in public concern for climate change mirrors the increase in the proportion of Americans who believe climate change and freak weather are linked, says Anthony Leiserowitz, who directs the Yale Program on Climate Change Communication. This program has been conducting the survey for the last 14 years. The realization that weather can and does harm people, and the fact that Americans are starting to feel its effects on themselves, are likely driving this increase in awareness. 

“You’re beginning to see the coalescing of a powerful citizens’ movement demanding that leaders act, both business leaders and government leaders,” he says.

European Space Agency launches new mission to measure climate change in unprecedented detail

Artist’s impression of TRUTHS. (Image: ESA and Airbus)

The European Space Agency (ESA) has new plans to study the Earth’s energy balance, in an effort to better understand and combat climate change. The Earth energy balance is the point between incoming energy from the Sun and outgoing energy from the Earth. As we emit more greenhouse gases, our planet’s atmosphere traps more heat, which is triggering global warming.

Named TRUTHS (Traceable Radiometry Underpinning Terrestrial- and Helio- Studies), the project is currently in the planning stages by the European Space Agency and its nations and will measure the amount of heat that gets trapped in the Earth’s atmosphere.

The plan for the small satellite mission was introduced at the UN Climate Change Conference (COP26) in Glasgow, Scotland by the United Kingdom Space Agency (UKSA). Conceived by the UK’s National Physical Laboratory (NPL), it will enable a space-based climate observing system which will “set a benchmark to detect changes in Earth’s climate system.”

“The mission will play a vital role in improving how we monitor climate change using satellite data and support the decisive climate action that global nations are negotiating at COP26,” said Beth Greenaway, head of Earth observation and climate at the UK Space Agency.

As well as establishing a new benchmark, the mission will create a climate and calibration observatory that will reduce some of the uncertainty in the Earth-observing data, creating a sort of space-based calibration lab. The benchmark is important because the more heat that the Earth keeps in, the warmer it gets, so it’s probably a good thing if scientists knew that point. TRUTHS will build additional confidence in climate studies by providing an element of a space-based climate observing system tied unequivocally to international standards. It will also enable researchers to better calibrate existing climate satellites.

“TRUTHS is an important mission as it will provide the gold standard of calibration for space-based Earth observation – a kind of ‘standards laboratory in space’,” said Justin Byrne, Head of Earth Observation and Science at Airbus Defence and Space UK. “With TRUTHS we also have the opportunity to further develop important areas of industrial capabilities across the UK space sector.”

Two main instruments would piggyback aboard the satellite: the Cryogenic Solar Absolute Radiometer and the Hyperspectral Imaging Spectrometer. These two pieces of equipment will gauge the incoming and reflected solar radiation to help detect alterations in Earth’s climate more quickly as well as generate the super-accurate reference system employing the benchmark level for other measurements and climate models.

“TRUTHS meets calls from the world’s satellite and climate community for robust high accuracy SI traceability (SI is an internationally recognized reference system that supports comparability of chemical measurements across a broad range of industries and sectors),” said Nigel Fox, United Kingdom TRUTHS Mission Scientist, at NPL. “A recent publication from the Committee on Earth Observation Satellites has highlighted the urgency for improved accuracy of observations from space, to help ensure our actions are having the desired impact.”

If everything goes as planned, the satellite could launch in 2029.

A new tropical storm, Peter, has formed in the Atlantic. Another, Rose, is likely to follow soon

A new tropical storm has been brewing in the Atlantic. Christened “Peter”, it marks the 16th named storm of this year’s hurricane season.

Forecasted path of tropical storm Peter. Image credits National Hurricane Center.

Tropical storm Peter formed east of the Caribbean on Sunday, centered some 400 miles off the Leeward Islands. According to the National Hurricane Center (NHC), the storm is expected to pass north of the Lesser Antilles and is likely to produce between one and three inches of rainfall around its edge. Puerto Rico, the Virgin Islands, and the Leeward Islands are liable to see “areas of urban and small stream flooding” up through Tuesday, the NHC adds. Top wind speeds are expected to fall below or around 45 mph (72.5 km/h).

Stormy again

Although it has barely been a week since Hurricane Nicholas slid across Texas and Louisiana, and just a little over three since Hurricane Ida battered the same shores, a new storm is brewing in the Atlantic.

Tropical storm Peter is the sixth hurricane to form this year. Along with these, three major hurricanes (meaning they were a category 3 or higher in intensity) have raged in 2021, making it quite the busy year. Naturally, more could be on the way. As far as Peter is concerned, the NHC notes that a strong cold mass of air is moving eastward across the U.S., which is likely to butt heads with the storm. This front of cold air should push Peter back out to the ocean and insulate the Eastern Seaboard, if not completely, then at least to a certain extent.

Despite the formation of this tropical storm, no coastal watches or warnings were in effect as of this Sunday in any of the areas highlighted by the NHC.

Forecasters are also keeping tabs on a tropical depression in the eastern Atlantic. This particular low-pressure system was picked up around 315 miles west-southwest of the Cabo Verde Islands (off the western coast of Africa). While not particularly intense right now, moving northwards at around 14 mph with sustained winds of around 35 mph (22.5 and 56.3 km/h respectively), there is still a high chance that it will morph into a new tropical storm — which will be named “Rose”. The two storms started coalescing pretty much at the same time, but Peter developed more rapidly in intensity.

If we consider Rose as well, this would be the third Atlantic hurricane season in recorded history to have 17 named storms by the 20th of September. The others were the 1966 season, the 2005 one, and 2020. The link between climate change and freak weather or events such as hurricanes has been highlighted in the past, and the high incidence of storms recorded this season certainly seems to follow that hypothesis.

Each hurricane in every year is given a name starting with the corresponding letter of the alphabet — A for the first, B for the second, and so on. Last year, in particular, had so many named storms that meteorologists exhausted the alphabet and had to assign Greek letters, only the second time in history that this has happened. It still holds the record for the highest number of storms in a single year, 30. The runner-up is still the 2005 hurricane season, with 28 recorded storms.

Hurricanes are primarily fed by expanses of open, warm water. As the planet’s climate heats up overall, so do the oceans, meaning we’re likely to see stronger and more frequent events of this kind in the future. They are also likely to become wetter — to carry more precipitation — due to higher overall levels of moisture in the atmosphere, as higher mean temperatures lead to higher levels of surface evaporation. As storms increase in intensity and sea levels rise, they are also liable to generate more storm surges, and thus become more dangerous over time.

A report by the United Nations released in August has also issued a warning to this extent. According to the document, unavoidable shifts in climate will lead to more intense and more frequent heatwaves and droughts over the next 30 years. Hurricanes have already been following this trend for the last 40 years, it adds.

The first climate change famine is here: Madagascar is desperate

Thousands of people in Madagascar are suffering “catastrophic” levels of hunger and food insecurity as the country is hit by the worst drought seen in four decades, devastating isolated farming communities in the south. The situation could even worsen soon as Madagascar enters the traditional “lean season” before the harvest. 

Experts believe this is the first famine to be driven entirely by climate change.

A farmer in Madagascar. Image credit: Flickr / US Mission to the UN.

“The hunger season is coming,” Issa Sanogo, the UN resident coordinator on the Indian Ocean Island nation said in a chilling statement. “People may be left without the means to eat, without money to pay for health services, or to send their children to school, to get clean water, and even to get seeds to plant for the next agricultural season.”

Low levels of rain in the past two years have cause the most severe drought since 1981, especially in the Grand Sud area of the country. People are taking desperate measures to survive, eating locusts, raw cactus fruits, or wild leaves to survive, explains ReliefWeb, an information service provided by the United Nations. 

The UN estimates that about 1.4 million people are in high levels of acute food insecurity, with 30,000 experiencing the highest internationally recognized level of food insecurity. This is driven by a “devastating drought” and the global health crisis of the Covid-19, which has steeply increased food prices due to low availability, the UN said.

The worst is yet to come. The situation is likely to deteriorate further in the very near future. Over 500,000 children under the age of five are expected to be acutely malnourished through April 2022, of which over 110,000 are likely severely malnourished and require urgent life-saving treatment. Such a severe crisis is unprecedented, said UN resident Sanogo. 

“The drought has gone on for longer than expected, and the funds received are insufficient to cover current and future needs. We must act now: annual crops are a problem that will probably become a new crisis in the next agricultural season. There is an urgent need to implement long-term solutions,” Sanogo said in a statement.

Non-governmental organization such as the World Food Program (WFP) are carrying out emergency programs that involve food assistance and distribution, prevention and treatment of acute malnutrition. They are also working with small-hold in the south of Madagascar, helping them procure land and make the right decisions on what to grow. However, given the scale of the crisis, this is unlikely to be enough.

The role of climate change

Madagascar is the world’s largest grower of vanilla, most of which is produced in the northeast of the world’s fourth-largest island. Citizens in the south rely on subsistence agriculture from small landholdings. Shelley Thakral, a spokeswoman for the WFP, told local media the south is “vulnerable” as it’s dry, while the north has plenty of tropical rainforests and is more shielded by the effects of climate.

While Madagascar frequently experiences droughts and is also affected by the change in weather patterns caused by El Niño, experts argue that climate change can be directly linked to the current crisis. In 2016, the El Nino effect caused a rainfall drop of 75% compared to past 20 years in the south. This caused harvest losses of up to 95%. 

The people have also been affected by sandstorms. Their croplands are now filled with sand and cannot produce anything.

The recent landmark report by the Intergovernmental Panel on Climate Change (IPCC) reported an increase in aridity in Madagascar, which is expected to increase if climate change continues, Rondrgo Barimalala, a Madagascar scientist told BBC. The current crisis should be a powerful argument for people “to change their ways,” he said.

Chris Funk, director of the Climate Hazards Center in California, told the BBC there’s a link with “warming in the atmosphere” and the current crisis in Madagascar and said the local government has to work to improve water management. They could forecast when there’s going to be above normal rains so farmers can use that information.

The situation in Madagascar, even taken on its own, is troubling. But given that we’ll be feeling the effects of climate change more and more, this is likely one of many such events to come. As families in Madagascar starve, we’ll have to contend with this thought

Biochar can help us keep climate change at bay and more food on the table, according to a new meta-study

Biochar — organic material baked in oxygen-starved environments — can help power up the agriculture industry while also fighting against climate change, according to a new paper.

Image via Wikipedia.

Coal is naturally produced underground, over millions of years, from ancient biomass. This organic matter that got buried in some way or another was then compressed and heated up through geological processes, which broke down its original structure and increased its carbon content. Biochar is produced in a very similar way, but instead of letting natural (and slow) geological processes cook it up, we make it ourselves.

This material can help fertilize soils and, thus, increase crop yields. At the same time, by preventing the carbon within it from being released back into the atmosphere, the use of biochar in agriculture can help fight climate change.

Very, very, very well done

“Biochar can draw down carbon from the atmosphere into the soil and store it for hundreds to thousands of years,” says Stephen Joseph, lead author of the paper, and a Visiting Professor in the School of Materials Science and Engineering at the University of New South Wales Science. “This study also found that biochar helps build organic carbon in soil by up to 20 percent (average 3.8 percent) and can reduce nitrous oxide emissions from the soil by 12 to 50 percent, which increases the climate change mitigation benefits of biochar.”

Biochar is a product usually made from aggregated organic waste — a mixture of waste biomass from agriculture, forestry, and household sources. For such an unassuming substance, it could lend a sizable hand towards fighting climate change and us having more food, according to a new paper. The findings are supported by the Intergovernmental Panel on Climate Change’s recent Special Report on Climate Change and Land, which estimated there was important climate change mitigation potential available through biochar. This report estimated that biochar use “could mitigate between 300 million and 660 million tons of carbon dioxide [globally] per year by 2050,” Prof. Joseph explains.

“Compare that to Australia’s emissions last year—an estimated 499 million tons of carbon dioxide—and you can see that biochar can absorb a lot of emissions. We just need a will to develop and use it.”

The meta-study reviewed 300 papers on the topic, including 33 meta-analyses that together reviewed around 14,000 biochar studies that have been published over the last 20 years. According to its result, the use of biochar, when mixed-in with crop soils, can boost yields by 10% to 42%, reduce the levels of heavy metals in plant tissues by between 17% and 39%, and increases the bioavailability of phosphorus, a critical nutrient that often acts as a bottleneck for the development of plants.

All in all, its use helps plants grow faster and larger, while also helping them better resist environmental stresses such as toxic metals, diseases, organic stressors such as herbicides and pesticides, and water stress.

The paper also explains how biochar acts on the roots of plants, boosting them. In the first three weeks of a plant’s life, it explains, biochar particles react with soils and stimulate germination (i.e. it helps seeds ‘catch’) and the development of the fledgling plant. Over the next six months or so, biochar particles in the soil form reactive surfaces which help draw nutrients towards the roots. As these particles start to age, something that happens around three to six weeks after being mixed into the soil (depending on environmental conditions), they break down and form microaggregates with other chemicals. This, in turn, helps protect roots and prevents the decomposition of organic matter.

Biochar yielded the best effects when used in acidic or sandy soils together with fertilizers, the authors explain.

“We found the positive effects of biochar were dose-dependent and also dependent on matching the properties of the biochar to soil constraints and plant nutrient requirements,” Prof. Joseph says.”Plants, particularly in low-nutrient, acidic soils common in the tropics and humid subtropics, such as the north coast of NSW and Queensland, could significantly benefit from biochar.”

“Sandy soils in Western Australia, Victoria and South Australia, particularly in dryland regions increasingly affected by drought under climate change, would also greatly benefit.”

Prof. Joseph has been studying the use of biochar ever since he was introduced to the practice by Indigenous Australians in the seventies. He explains that these people, alongside indigenous groups in Australia, Latin America (especially in the Amazon basin), and Africa, have been using biochar to maintain soil health and improve crops for centuries. Despite this, it hasn’t really been adopted as a commercial product, and most countries only produce a small amount of biochar every year.

To really make an impact, he explains, biochar needs to be integrated with farming operations on a wide scale. The first step towards that, he feels, is to tell farmers that biochar is an alternative they can opt for, and establish demonstrations so farmers can see that the benefits are real, not just words.

“This is in part due to the small number of large-scale demonstration programs that have been funded, as well as farmers’ and government advisors’ lack of knowledge about biochar, regulatory hurdles, and lack of venture capital and young entrepreneurs to fund and build biochar businesses,” he explains. “We’ve done the science, what we don’t have is enough resources to educate and train people, to establish demonstrations so farmers can see the benefits of using biochar, to develop this new industry”.

The paper “How biochar works, and when it doesn’t: A review of mechanisms controlling soil and plant responses to biochar” has been published in the journal GCB Bioenergy.

The new climate normal: The US is already one degree hotter

Every 10 years, the National Oceanic and Atmospheric Administration (NOAA) releases an analysis of the weather in the US over the past three decades. To absolutely no one’s surprise, the past decade has been hotter and wetter than any other in recorded history — by a mile.

Most of the country has warmed, except for the north-central US. Image credit: NOAA

In its report, NOAA looked at the weather from 1991 to 2020 and calculated average values for temperature, rainfall, and other conditions, using information from 9,000 daily reporting stations. NOAA refers to these averages as the “climate normal” and well, this normal isn’t looking normal at all.

The US has warmed 1.7 degrees (1 degree Celsius) since 1901-1930, the first period for which climate normal were calculated. That’s in line with the global rate of warming over that period. Still, the US was behind the world’s average until recently. The country has seen its biggest jump in temperatures during the last two 30-year periods.

“We’re really seeing the fingerprints of climate change in the new normals,” Michael Palecki, manager of NOAA’s effort to update the climate normals, said at an April news conference, in anticipation of the new report. “We’re not trying to hide that. We’re in fact reflecting that.”

Over the entire country, the yearly normal temperature is now 53.3 degrees (11.8 degrees Celsius). Twenty years ago, it was 52.3 degrees (11.3 degrees Celsius) based on data from 1971 to 2000. The new normal annual U.S. temperature is 1.7 degrees (0.9 Celsius) hotter than the first normal calculated for 1901 to 1930.

Some regions have warmed more than others and, over short time periods, some smaller areas haven’t warmed at all. Image credit: NOAA

Temperatures dropped slightly for 1991-2020 compared with 1981-2010 across a part of the north-central United States. Still, more than 90% of the U.S. has warmer normal temperatures now than 10 years ago. The US map is getting redder and redder.

Charlottesville, Virginia, saw the biggest jump in normal temperatures among 739 major weather stations. Other large changes were in California, Texas, Virginia, Indiana, Arizona, Oregon, Arkansas, Maryland, Florida, North Carolina, and Alaska. In Chicago, the new yearly normal temperature rose 1.5 degrees (0.8 Celcius) in the last decade.

Not just warmer — also wetter

The new normal shows not just in higher temperatures, but also in more precipitation. NOAA’s data estimated a national precipitation average of 31.31 inches for 1991-2020. This is 0.34 inches higher compared to the 1981-2010 value of 30.97 inches. The 20th-century average was 29.94 inches.

Speaking with the Washington Post, Palecky said most of the US has been turning into a “much wetter environment”, quoting NOAA’s data. Still, precipitation trends vary by region more than temperature. Between 1981-2010 and 1991-2020, it turned wetter across much of the eastern two-thirds of the nation but drier across most of the southwest.

It’s probably not a coincidence that the last four maps in the series — the 1961-1990, 1971-2000, 1981-2010 and 1991-2020 Normals — are nationally the four wettest maps in the collection.

At least some of that wetness relative to the 20th-century average is linked to the overall climate warming, NOAA explained.

Image credit: NOAA

Large parts of the US are expected to get even wetter over time, especially the northern states, because of climate change. However, rainfall and snowfall appear to be trending toward clusters of intensified precipitation, separated in some cases by longer dry periods. Plus, there are signs of a megadrought over the southwest United States.

“What we’re trying to do with climate normals is to put today’s weather in a proper context so we understand whether we’re above normal or below normal and also we’re trying to understand today’s climate so people know what to expect,” Palecki told the Washington Post.

Once published, NOAA’s reports come in handy for many across the country, enabling policymakers to prepare mitigation measures (should they so desire). Weathercasters also call on the values to tell how a day’s temperatures compare to the norm for that calendar date, state regulators use climate averages when setting rates for the electricity and natural gas and farmers can plan what to plant and when.

Still, climate change is hard to quantify. Increases in greenhouse gas emissions might mean that the 30-year average doesn’t capture the true likelihood of a given temperature right now, and this small difference can have a big effect on the interests of utilities, where temperature increments can translate into big costs. Simply put, some days (or weeks) can still be abnormally cold or dry, even as the country as a whole is getting hotter and wetter.

That’s why NOAA is looking at new ways to report climate normal that might reflect more accurately what to expect in the 2020s. Researchers have suggested using climatological periods shorter than 30 years, for example. Following the advice, NOAA’s climate normal included a supplemental set of 15-year data for the period 2006-2020.

Satellite data shows that the Earth’s glaciers are melting faster than ever before

The rate at which glaciers are melting has been steadily picking up according to a new study, based on satellite data. They’re now losing 31% more mass every year than they were just 15 years ago. The cause is anthropogenic climate change, the authors explain.

Mountain glacier in Argentina. Image credits Adam Derewecki.

The study is based on 20 years’ worth of declassified three-dimensional satellite data. Based on these measurements, the authors estimated that mountain glaciers worldwide have been losing in excess of 328 billion tons (298 billion metric tons) of snow and ice per year every year since 2015. This is 78 billion tons (71 billion metric tons) a year more than the average between 2000 and 2004.

Half of the world’s glacial loss today is coming from the United States and Canada, the paper adds.

De-icing

In addition to more ice being lost per year, global glacial thinning rates (another important indicator of glacier health) have also doubled in the last 20 years.

Virtually all of the world’s glaciers are affected, the team explains, even ones that were traditionally considered stable, such as those in Tibet. The precious few exceptions to this rule include a couple of glaciers in Iceland and Scandinavia, kept stable by increased levels of precipitation. But overall, global melt rates have been and still are accelerating. Alaska has the single highest overall melt rate seen in the study.

Melting rates are increasing quite uniformly across the world, a process that “mirrors the global increase in temperature” says Romain Hugonnet, a glaciologist at ETH Zurich and the University of Toulouse in France, who led the study. The cause, ultimately, is our growing use of fossil fuels such as coal, oil, and gas, which release greenhouse gases in the atmosphere.

The study’s findings are particularly worrying as this is the first paper to use 3D satellite imagery to examine all of Earth’s glaciers, not just those that are part of the Greenland or Antarctic ice sheets.

Not only are such results a chilling account of how deeply climate change is impacting glaciers and the world as a whole, but it also points to massive problems-to-be. Glaciers supply millions of people with their daily water needs, and them shrinking so quickly means that a lot of people will soon be in need to secure new sources of water. On the other end of the spectrum, rapid glacier shrinking increases the risk of events such as outburst floods from glacial lakes.

And, ultimately, all these glaciers melting around us have to flow somewhere — which is the ocean. Sea level rise is a very real problem that’s poised to cause us some massive issues in the future. Sea levels are already rising today, partially because of melting in glaciers and ice sheets, partially because higher mean temperatures make water expand in volume. Even so, today, glacier melt is responsible for an estimated 21% of the overall sea-level change we’ve recorded. Although the ice sheets hold overall more water and are thus the greater long-term threat, mountain glaciers hold a respectable amount of water and should not be overlooked in this regard.

Shrinking glaciers are a problem for millions of people who rely on seasonal glacial melt for daily water and rapid melting can cause deadly outbursts from glacial lakes in places like India, Hugonnet said.

But the largest threat is sea level rise. The world’s oceans are already rising because warm water expands and because of melting ice sheets in Greenland and Antarctica, but glaciers are responsible for 21% of sea level rise, more than the ice sheets, the study said. The ice sheets are larger longer term threats for sea level rise.

“It’s becoming increasingly clear that sea level rise is going to be a bigger and bigger problem as we move through the 21st century,” said National Snow and Ice Data Center Director Mark Serreze.

The paper “Accelerated global glacier mass loss in the early twenty-first century” has been published in the journal Nature.

Can geoengineering stop climate change? A new paper says it can help, but it’s no magic bullet

The climate keeps getting hotter, and officials around the world are failing to rise to the task of tackling emissions to ensure a future for our kids and grandkids. Amid this backdrop, an international team of experts suggests reflecting sunlight back into space could help keep the warming under control.

Image via Pixabay.

The team focused on exploring the potential benefits and shortcomings of using various technological means of reflecting sunlight away from our planet — which should help cool it down. This approach, known as solar radiation modification (SRM), should be much cheaper and more cost-effective than our other current alternatives. Together with reductions in greenhouse gas emissions, an SRM-type program could help mitigate or even counter the warming trend that started in the Industrial Revolution.

Mirror our problems away

“There is a dearth of knowledge about the effects of climate intervention on ecology,” said Phoebe Zarnetske, community ecologist and associate professor in Michigan State University’s Department of Integrative Biology and the Ecology, Evolution, and Behavior program, co-lead researcher of the team.

“As scientists, we need to understand and predict the positive and negative effects it could have on the natural world, identify key knowledge gaps, and begin to predict what impacts it may have on terrestrial, marine, and freshwater species and ecosystems if it were adopted in the future.”

The Climate Intervention Biology Working Group has been holding monthly meetings since September 2019 to discuss how SRM could be used to help fight climate change and its potential consequences. They distilled their conclusions into the paper we’re discussing now. As Zarnetske says, this is meant to give us a rough guideline as to how such technology could be used in the future, identify which areas we still need to work on, as well as potential consequences for various types of ecosystems and the species they support should SRM be adopted in the future.

Cost-wise, it seems to be quite attractive: SRM would be cheaper to implement than atmospheric carbon dioxide (CO2) capture for example, the authors note. However, before we implement such an approach, we need to know exactly what to expect from it.

“While climate models have become quite advanced in predicting climate outcomes of various geoengineering scenarios, we have very little understanding of what the possible risks of these scenarios might be for species and natural systems,” explains Jessica Gurevitch, distinguished professor in the Department of Ecology and Evolution at Stony Brook University, the other co-leader of the research group.

“Are the risks for extinction, species community change, and the need for organisms to migrate to survive under SRM greater than those of climate change, or does SRM reduce the risks caused by climate change?”

One approach the team studied and made the focus of their paper is stratospheric aerosol intervention (SAI). This involves blocking part of the sunlight incoming towards our planet by using aerosol substances — very similar to what happens after a volcanic eruption. In theory, at least, it is a very promising idea: we should be able to maintain aerosol clouds of certain thickness over different areas, allowing us to achieve a target temperature at ground level.

However, one issue they’ve been able to foresee is that we simply don’t understand how the use of SRI methods on a large scale would interact with ecosystems. Cooling provided by such approaches may be “unevenly distributed”, the team explains, which could have a major impact on the functioning of today’s ecological communities. The use of SAI would lead to changes in rainfall and surface ultraviolet levels, “would increase acid rain, and would not mitigate ocean acidification,” according to Zarnetske.

The team’s conclusion is that SRM methods are not a magic bullet against climate change, and there are still several big unknowns regarding their use. The paper reveals the under-researched complexity of cascading relationships between ecosystem function and climate under different SAI scenarios. In fact, they argue, climate change mitigation must continue regardless of whether SRM is adopted, and the question remains whether some or any SRM can be beneficial in addition to decarbonization efforts.

“We hope that this paper will spark a lot more attention to this issue and greater cooperation between scientists in the fields of climate science and ecology,” added Gurevitch.

But studying geoengineering solutions isn’t exactly easy. Last Wednesday, the Swedish Space Corporation had to postpone a test flight designed to test such methods — the Stratospheric Controlled Perturbation Experiment, or SCoPEx — after pushback from a local Indigenous peoples’ group. Many people are understandably anxious to delve into geoengineering applications, given the damage they could cause if we aren’t careful. Whether such methods will be adopted in the future or not, we can’t yet say. But it’s definitely going to be considered, and spark a very interesting debate.

The paper “Potential ecological impacts of climate intervention by reflecting sunlight to cool Earth,” has been published in the journal PNAS.

Climate change brings season change: by 2100, half the world will see 6-month-long summers

A toned beach body will become a matter of life and death in the Northern Hemisphere by the end of the century, judging by a new study; but likely, so will a good air conditioning unit. According to the authors, a business as usual scenario will mean that, by 2100, half of the Earth will experience summers spanning almost six months every year.

Image credits Lee Seonghak.

Longer summers definitely hold some promise for fun, but the changes predicted in this study are quite worrying. The disruptions to natural systems caused by longer summers would have a significant impact on human health, agriculture and the environment, according to the team.

Times are a-changin’

“Summers are getting longer and hotter while winters shorter and warmer due to global warming,” said Yuping Guan, a physical oceanographer at South China Sea Institute of Oceanology, Chinese Academy of Sciences, the lead author of the study.

We’re used to a world with four seasons, each arriving at roughly the same time every year, in a known order. That, however, is likely going to be a bit of interesting historical trivia by the end of the century in the Northern Hemisphere. the driver, unsurprisingly, is climate change.

Under a business-as-usual scenario, the authors note, both the start dates and length of individual seasons are going to see significant, and irregular, changes by the end of the century. Overall, however, past recordings show that summers have become longer and warmer while winters got shorter over the last 50 to 70 years, suggesting this trend will keep going (or ramp up) in the future.

The authors say their study was spurred by observed changes in the cycle of the seasons, pointing to unseasonable weather reports “for example false spring, or May snow, and the like,” Guan said.

They used daily weather recordings from 1952 to 2011 in the Northern Hemisphere to chart how each season varied in length and onset in this area. Summer was defined as the time with the top 25% hottest temperatures of each year, while winter was defined as the time where temperatures hit the year’s 25% coldest days.

On average, between 1952 and 2011, summer grew from 78 to 95 days (an extra 17 days overall) and winter shrank from 76 to 73 days. Spring and autumn went from 124 to 115 days and 87 to 82 days respectively. Spring and summer also saw a shift to earlier onset, while autumn and winter started later. The greatest overall changes to seasonal cycles seen in this study were concentrated in the Mediterranean and Tibetan Plateau regions.

Armed with these historic trends, the researchers used climate change models to chart how seasons will shift in the future. If measures are not taken to slow down or reverse climate change, by 2100, the models show, spring and autumn will keep shrinking, and winters will last for under two months.

These findings are particularly troubling from an environmental point of view. Humans can adapt more easily to changes in seasonal cycles, but natural ecosystems are deeply tied to them. Changes such as the ones predicted in this paper would have enormous implications for phenomena such as bird migration patterns or the timing of plant emergence and flowering periods. Essentially, changes in seasons can mean that animals may become disconnected from their environment, particularly their food sources. The same instincts that kept wildlife fed and alive all this time will become liabilities, as they won’t match with the world around them any longer.

On our end, agriculture is likely the area where seasonal changes will impact us the most. False springs or late snows can destroy whole crops even today, and these events are only going to become more common. Longer summers also mean longer growing seasons, and if you have a pollen allergy, or if you simply hate mosquitoes, you aren’t going to have a good time at all.

Lastly, freak weather events, including wildfires, heatwaves, or cold surges like the recent one in Texas, will also become more common and more intense. Hurricanes and typhoons will also become more violent, as their energy is directly tied to how hot the oceans are, and they’re hotter in summer.

All in all, this is the extent of the threat that we can see right now — as things progress, new elements may start factoring into making the eventual situation even worse. Ideally, we’ll never get to find out. For that to happen, however, meaningful change and action is needed — and it’s needed now.

The paper “Changing Lengths of the Four Seasons by Global Warming” has been published in the journal Geophysical Research Letters.

More evidence that 2020 was an unusually hot year

The ECMWF’s Copernicus reanalysis had already stated the year of 2020 as the warmest on the record. Now, other five independent analyses surveyed by World Meteorological Organization (WMO) show that it was at least one of the three warmest years. The teams are: United States National Oceanic and Atmospheric Administration (NOAA), NASA’s Goddard Institute for Space Studies (NASA GISS), and the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit (HadCRUT) and another reanalysis from Japan Meteorological Agency (JMA).

WMO has shown five of its data sets indicating that 2020 was a hot year, with a global average temperature of 14.9°C. This is 1.2°C above the average temperature before industrial activity.

Comparison of global warming trend from six different datasets. Credits: Berkeley Earth.

The centers that analyzed the data consider all sorts of instrumental data, buoys in the sea, stations, aircraft, and satellites. This is usually similar to all approaches, what differs is the way they interpolate the data.

Interpolation means a way of estimating data for a place that did not have a real measurement. Just like superhero movies, when the hero wants to find the source of a villainous activity. Researchers sometimes use the word “triangulate”, which is a form of interpolation. This explains why some researchers report slightly different results. For instance, NASA interpolates data considering the poles, NOAA doesn’t and other centers also vary their methodology, so the average temperature will differ.

NASA agrees with ECMWF in that 2020 is tied with 2016 for ignoble honor of the warmest year on record. NOAA and HadCRUT say it’s the second warmest and JMA says it’s the third warmest. What matters is that it was a very warm year despite the formation La Niña, which tends to reduce the average. The 2016 had the help of El Niño to increase the temperature, which means 2020 was far too warm.

The sixth dataset is from Berkeley Earth, an independent, non-governmental group that gathers data to study climate change. The founder, Richard A. Muller, started the project because he believed some skeptics pointed problems in the way the traditional centers, such as NASA, delivered their results. Spoiler alert: after the first analysis they concluded the data didn’t differ so much from everyone else.

Berkeley Earth concluded that 2020 was the second warmest year since 1850, differing only by 0.022°C. For 45 countries, 2020 was the warmest year ever, especially for European countries. This is because land warms faster than the ocean and the Northern Hemisphere has more land cover. Russia warmed the most, by a staggering 4°C above the pre-industrial era.

2020 temperature difference relative from 1951-1980. Creditis: Berkley Earth.

The year 2021 may not be as hot as 2020 due to the continuation of the La Niña event. Scientists estimate that it could come in fifth place in the heat race. It is important to note that Berkeley Earth’s estimate is just a minor perturbation in the trend. This doesn’t mean an end to global warming.

Unfortunately, Berkeley showed the trending of the temperature curve and it looks terrible. If we continue with the pace we are now, by 2037 the world could be 1.5°C above the 1850-1900 trend. Paris Agreement established the 2°C or less threshold in order to avoid an even worse climate crisis.

Climate change is turning the Eastern Mediterranean into a completely new ecosystem

As global warming intensifies, the Mediterranean are feeling the heat. Some mollusk populations in the eastern areas of the sea are buckling the waters they call home have become too hot to survive in, new research shows.

Image via Pixabay.

The waters around the coast of Israel are some of the hottest in the whole Mediterranean. But they’re rapidly becoming even hotter, as average temperatures have risen here by 3° Celsius over the last four decades. Today, water temperatures here regularly exceed 30°C (86°F) which, alongside invasive species coming through the Suez Canal from the Red Sea, are putting local mollusk populations under a lot of pressure.

Wipe-out

“My expectation was to find a Mediterranean ecosystem with these ‘newcomers’,” said Paolo Albano from the University of Vienna’s Department of Paleontology, lead author of the paper, for the AFP.

“However, after the first dive, I immediately realised that the problem was another one: the lack of the native Mediterranean species, even the most common ones that you would find everywhere in the Mediterranean.”

Albano initially set out to study the differences between native and non-native populations along the Israeli shelf in the eastern Mediterranean but was stuck by the dearth of local species in the area.

The team gathered over 100 samples from the seafloor, using these to gauge the characteristics of local mollusc populations, such as which species were present, their numbers, and so forth. These were then compared to historical data on the same topic. Only around 12% of the shallow-sediment molluscs noted in the historical records were still present today, the paper reports. In rocky reef environments, that figure dropped as low as 5%.

Furthermore, the researchers estimate that 60% of the remaining local mollusc populations are below their reproductive size, meaning they’re shrinking over time.

Albano says that there are many factors contributing to this collapse, most notably pollution and the pressures from invasive species. But warming waters are playing the main part in driving local mollusk populations into the ground.

“Tolerance to temperature is what really matters here and most of the native Mediterranean species are in the easternmost Mediterranean Sea at the limits of their tolerance to temperature,” said Albano.

Populations of invasive species, however, are thriving in the area. In effect, these changes are setting the stage for a “novel ecosystem“, the team explains, as species moving in from the Red Sea stand poised to effectively replace local ones. Albano says the Eastern Mediterranean is “paradigmatic of what is happening in marine ecosystems due to global warming: species respond to warming by shifting their ranges and in some areas, this means local eradication of species.”

The paper “Native biodiversity collapse in the eastern Mediterranean” has been published in the journal Proceedings of the Royal Society B.

New projections warn that Greenland’s ice sheet will see 60% more melt than we’ve estimated

New research warns that the Greenland ice sheet is likely to melt even more than previously estimated — a solid 60% more.

Bad news keeps piling up for the Greenland ice sheet. A study earlier this month reported that in around 600 years or so, it will melt enough that it won’t ever be able to recover (the ice sheet creates its own microclimate, meaning it is making itself possible right now). Despite this, new research suggests that we’ve underestimated how large the problem truly is.

Melt a-plenty

The team, headed by researchers from the Universities of Liège and Oslo, used multiple climate models with the latest observations, finding that we’re likely to see a 60% greater melting of the Greenland ice sheet by 2100 than previously predicted. That melt will, obviously, contribute to a rising sea level.

“The MAR model (one of the models used for the paper) was the first to demonstrate that the Greenland ice sheet would melt further with a warming of the Arctic in summer. While our MAR model suggested that in 2100 the surface melting of the Greenland ice sheet would contribute to a rise in the oceans of around ten centimeters in the worst-case scenario (i.e. if we do not change our habits),” explains Stefan Hofer, a post-doc researcher at the University of Oslo.

“Our new projections now suggest a rise of 18 cm.”

The results of this paper will be integrated into the next Intergovernmental Panel on Climate Change (IPCC) report, AR6, the team adds. As they will be based on our most up-to-date models, the findings outlined by the paper should be more reliable than anything we’ve had previously.

Greenland’s ice sheet is the second-largest in the world after the Antarctic one, covering some 1.7 million square kilometers. A complete melt of this sheet would cause a rise in ocean levels by up to 7 meters, which is immense. Although the estimations in this paper are nowhere near that figure, they’re still higher than previous estimates, which is cause for concern.

The current paper reports that we’re looking at an 18cm (~7 in) increase in sea levels by 2100, which is 8cm higher than the previous estimation used by the IPCC. The researchers also used their MAR model to ‘downscale’ on previous IPCC scenarios. Keeping the same emission estimates that these used, the current model shows 60% more surface melting of the Greenland ice cap until the end of the century. Downscaling basically means turning a model with coarse resolution (i.e. low detail) into one with a higher resolution (more, finer detail).

“It would now be interesting”, says Xavier Fettweis, researcher and director of the Laboratory,” to analyze how these future projections are sensitive to the MAR model that we are developing by downscaling these scenarios with other models than MAR as we have done on the present climate.”

This was the first attempt to downscale the future scenarios regarding Greenland that the IPCC uses, the team notes. Future efforts to refine our climate models will receive support from various international projects such as the EU’s Horizon 2020, which should help the team gain access to even more cutting-edge data. Since melting processes are influenced by a wide variety of factors, our ability to predict them hinges on having as much reliable data factored in as possible.

The paper “GrSMBMIP: intercomparison of the modelled 1980-2012 surface mass balance over the Greenland Ice Sheet” has been published in the journal The Cryosphere.

In 10 to 20 years, it will be so hot that tropical trees live shorter lives

It’s not the best time to be a tropical tree, as rising average temperatures risk impacting their lifespan.

Image credits Roel Brienen.

A new study explains that the longevity of trees at the tropics is shortened by higher temperatures. The findings help further our understanding of how climate change will impact ecosystems in the area and its effects on the rest of the planet. The team argues this is the first direct evidence that tropical trees experience shorter lives in hotter environments, and that forests all around the world will be affected.

Over-temperatured

“Many regions in the tropics are heating up particularly rapidly and substantial areas will become warmer, on average, than approximately 25 °C,” says Professor Manuel Gloor at the University of Leeds, a co-author of the paper.

“Our findings – which are the first to demonstrate that there is a temperature threshold – suggests that for trees in these regions, their longevity is likely to be negatively affected.”

The temperature above which trees become affected is 25 °C, the paper explains. This result is based on four years’ worth of tree ring data recovered worldwide. Roughly 100,000 trees from 400 species in 3,000 sites across the planet formed the dataset. All in all, the team reports that although tropical trees grow twice as fast as those in cold areas, they also live shorter lives (186 years vs 322 years on average).

Average temperatures in tropical forests today sit between 21 °C and 30 °C depending on location. These averages will rise alongside the rest of the world to around 2.5 °C above pre-industrial levels over the next 10 to 20 years. The effect this will have on trees varies depending on exactly how much hotter it gets. Changes in precipitation patterns (another effect of climate change) are going to exacerbate this ever further.

Substantial areas of today’s rainforests will see significantly lower tree longevity. They only cover 7% of the Earth’s surface, but harbor around 50% of its species of plants and animals, and a corresponding 50% of the planet’s carbon stocks. Any change here will have strong, global echoes for habitats, air quality, and carbon scrubbing ability.

“These results are a warning sign that, along with deforestation, global warming adds extra stress on the Earth’s tropical forests,” says Dr Roel Brienen from Leeds, paper co-author.

“If tropical trees die earlier, this will affect how much carbon these forests can hold, raising concerns about the future potential of forests to offset CO2 emissions from fossil fuel burning. It could also cause changes in biodiversity and a decrease in the number of species on the planet.”

Tropical forests in South America are closest to this threshold, but they’re not the only ones at risk. Even the Congo Forest in west Africa, the world’s second largest but with lower average temperatures, will be affected.

The saddest finding here, in the words of co-author Marcos Buckeridge, Director of the Biosciences Institute of the University of São Paulo, is that it’s “unavoidable”. It’s too late to stop average temperatures from passing this threshold “even if we were to take drastic emissions reductions measures”.

The paper “Global tree-ring analysis reveals rapid decrease in tropical tree longevity with temperature” has been published in the journal Proceedings of the National Academy of Sciences.

Greenland’s ice sheet is poised to melt forever — we have 600 years to stop it

New research suggests that the Greenland Ice Sheet is inching in towards a dangerous threshold: in around 600 years, it will melt enough that the sheet won’t ever recover, no matter what we do, and sea levels remain permanently higher. This scenario assumes that current rates of melt remain constant.

The glaciers and landscape in northeast Greenland, captured in 2014. Here you can see refrozen meltwater ponds from last year’s summer cover with snow that has fallen during the winter months. Image credits Credits: NASA /Michael Studinger.

The team from the National Centre for Atmospheric Science and the University of Reading show that climate change is leading to an irreversible rise in the sea level alongside a declining Greenland ice sheet. Worse yet, this sheet is closing in on a point of no return, past which it will never fully regrow — leaving a permanent mark on the global sea level.

Big Ice, Big Loss

The Greenland ice sheet is roughly three times the size of Texas and stores an important quantity of Earth’s frozen water. Under current melting rates, it contributes around 1mm of sea level rise per year (around one-quarter, 25%, of the total increase). It’s estimated that it lost a total of three-and-a-half trillion tonnes of ice since 2003, even with seasonal growth periods factored in.

Needless to say, that’s a lot of water. Rising seas threaten all coastal areas around the world, and can affect potentially millions of people who live in low-lying areas.

If the current target of the Paris Agreement (keeping global warming from going above 2°C compared to pre-industrial temperatures) is not met, we should expect the sea level to rise by several meters and significant ice loss, the authors note. Both would last for tens of thousands of years, and the worse global warming gets, the more dramatic these shifts would be.

The current paper shows that even if temperatures are brought back under control at a later time, the Greenland ice sheet will never fully regrow after it passes its critical threshold. If that point is passed, the sea level would permanently rise by at least 2 meters (with other sources adding to that figure).

Being so large, the sheet has a significant cooling effect on its local climate. In essence, there’s so much ice in Greenland that it’s making Greenland colder and more icy — not a bad trick. But if the sheet declines, local temperatures would increase, which increases melting rates, and snowfall levels would drop dramatically, which would slow down the formation of ice. The team estimates that if the Greenland ice sheet retreats from the northern part of Greenland, that area would remain permanently ice-free. All in all, we have around 600 years before that threshold is passed, the team estimates based on data from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

The team simulated the effects of the Greenland ice sheet melting under a range of scenarios, from minimal warming to worst-case conditions. All scenarios led to a decline in size of the sheet and contributed to rising sea levels to one extent or another.

So what’s to be done? Well we need to stop and then reverse climate warming before that threshold is reached.

“Our experiments underline the importance of mitigating global temperature rise. To avoid partially irreversible loss of the ice sheet, climate change must be reversed — not just stabilised — before we reach the critical point where the ice sheet has declined too far,” says Professor Jonathan Gregory, climate scientist from the National Centre for Atmospheric Science and University of Reading, a co-author of the paper.

There were some scenarios the team found where the ice sheet could be stabilized before reaching its point of no return. All of them, however, hinged on steps being taken ahead of time to reverse global warming.

The paper “Large and irreversible future decline of the Greenland ice sheet” has been published in the journal The Cryosphere.

Even a localized nuclear war can alter the world’s climate

A nuclear exchange could lead to global climate instability for several years, a new paper reports. Surprisingly, however, the effects depend in no small measure on where bombs fall and what happens after detonation — not on the weapons themselves. Their severity could range from minimal to significant cooling of the climate.

Atmospheric black carbon (soot) levels one month (left), six months (middle), and 12 months after the nuclear exchange. Image credits Lawrence Livermore National Laboratory.

We don’t talk about nuclear weapons too much today. It’s pretty interesting when you consider that our weapons have only become stronger and faster since the Cold War, and back then, the threat of nukes was always looming. In order to understand what their use would mean for the planet, a research team from the Lawrence Livermore National Laboratory (LLNL) looked at the climate consequences of a regional nuclear weapon exchange. The scenario involved 100 15-kiloton nuclear weapons being launched between India and Pakistan.

The scenario was run through two high-fidelity models taking a wide range of factors into account, the team explains.

Bombing the climate

“One of the new aspects of our work is that we examined the dependence of the climate effects on different amounts of fuel available at the location of the detonation and subsequent fire,” said LLNL mechanical engineer Katie Lundquist, the leader of the study and a co-author of the team’s paper.

The team focused their analysis on the fires such weapons would ignite, They considered factors such as available fuel at the site of the fires and the characteristics of the plume such as smoke composition and aerosol properties. All these allowed the team to simulate the effect such fires would have on global climate through their emission products. If the fires started by these bombs are large enough, they can block incoming sunlight and thus influence global climate.

All in all, if smoke and soot from these fires remain in the lower troposphere they will be quickly degraded and have a negligible effect. If they can reach all the way to the upper troposphere or higher (due to the rising heat of particularly strong fires) they will push through to the stratosphere. Here, smoke can deflect much more of the incoming light, enough to cool the surface down.

“Our simulations show that the smoke from 100 simultaneous firestorms would block sunlight for about four years, instead of the eight to 15 years predicted in other models,” the Livermore researchers wrote.

In the example given above, they write, global surface temperatures would likely drop by 1 to 1.5 degrees Celsius.

However, if the weapons only start fires in suburban areas, there would be little to no climate effect. Fires in dense urban areas are the most problematic, they explain, as they contain a lot of varied types of fuel in a small area (high fuel density). All this material can produce enough heat and particles to influence the climate. Such fires could produce a cooling effect three times that of the 1991 eruption of the Mount Pinatubo volcano in the Philippines.

The study comes to show just how important local factors are in determining the climate impact of such an exchange. It also helps showcase the full extent a local nuclear war could have.

The paper “Examining the climate effects of a regional nuclear weapons exchange using a multiscale atmospheric modeling approach” has been published in the Journal of Geophysical Research: Atmospheres.

Lockdowns shut whole economies down, but greenhouse gas levels are still rising

Lockdowns imposed against the spread of the coronavirus fostered a noticeable decline in humanity’s greenhouse gas (GHG) emissions while they were in effect. Despite this, GHG levels in the atmosphere hit “record highs” in 2019 and continued to increase all throughout 2020, according to the World Meteorological Organization (WMO).

Image credits Marcin Jozwiak.

The results show that we’re still well on our way towards a much hotter climate in the future. Although the economic slowdown caused by the pandemic has helped in this regard, it wasn’t able to bring atmospheric GHG levels down. Furthermore, this illustrates why stabilizing the climate requires a focus on long-term, sustained reductions of such gas in order to be successful.

Less, but not little

“The lockdown-related fall in emissions is just a tiny blip on the long-term graph,” WMO chief Petteri Taalas said in a statement. “We need a sustained flattening of the curve.”

GHGs prevent heat from the surface of the Earth from radiating back out into space. In effect, this makes them act as a blanket that’s warming up the planet. This process is actually pretty beneficial for us, as it helps keep temperatures in a comfortable range and prevents massive fluctuations (like what takes place on Mars, for example). But too much greenhouse effect can make for scorching heat, higher sea levels (through the melting of the ice caps), and it can promote freak weather events.

According to preliminary estimates in the WMO’s annual Greenhouse Gas Bulletin, CO2 emissions may have dropped by 17% globally at the height of lockdowns and shutdowns. Averaged out over the whole year, however, this would mean a drop of between 4.2% and 7.5%, it added.

The bad news is that this decrease was “no bigger than the normal year to year fluctuations,” the WMO states, which means that this drop won’t have any meaningful effect on GHG concentrations in the atmosphere and thus on global warming. Atmospheric CO2 levels in the air will continue to rise, although at a slightly reduced pace — around 0.23 parts per million (ppm) slower than previously estimated. This is well below the 1.0 ppm threshold, which is the natural variability between different years. WMO’s Bulletin listed the atmospheric concentration of CO2 at 410 parts per million in 2019, from 407.8 ppm in 2018. The rising trend has continued into 2020, it adds.

“On the short-term, the impact of the COVID-19 confinements cannot be distinguished from natural variability,” the report explains.

Emissions are the main source of GHGs coming into the air. Atmospheric levels, or concentrations, are the part of these emissions left over after a series of interactions between the air and wider environment including plant activity, the lithosphere, cryosphere, and the oceans. In essence, they’re an excess of gas that can’t be scrubbed out.

Taalas underscores that we first crossed the 400 ppm global threshold in 2015, and “just four years later, we crossed 410 ppm. Such a rate of increase has never been seen in the history of our records.”

“Carbon dioxide remains in the atmosphere for centuries and in the ocean for even longer,” Taalas adds. “The last time the Earth experienced a comparable concentration of CO2 was three to five million years ago,” when global temperatures were two to three degrees Celsius warmer and sea levels were 10-20 metres higher than now. “But there weren’t 7.7 billion inhabitants”.

CO2 is the main GHG emitted by humanity, and has the greatest overall effect on the climate (around 60%) due to its quantity. The second-most prevalent such gas is methane, which accounts for around 16% of total warming. Nitrous oxide is the third major greenhouse gas. The WMO adds that the Earth has registered a 45% increase in radiative forcing (the warming effect of GHGs) since 1990.

We should expect long-term ice loss even if we stop climate change today, according to a new study

New research at the Monash University reports that historic ice loss in Antarctica has persisted for several centuries after it first started.

Stock image via Pixabay.

Such findings underscore the inertia of processes affecting ice sheets and suggest that today’s polar ice will continue to shrink for quite a long time even if climate change is avoided.

Long-term melt

“Our study implies that ice loss unfolding in Antarctica today is likely to continue unabated for a long time—even if climate change is brought under control,” said lead study authors Dr. Richard Jones and Dr. Ross Whitmore, from the Monash University School of Earth, Atmosphere and Environment.

The study charts the extent of ice in the Mawson Glacier, which is adjacent to a region of the Ross Sea that saw a rapid retreat of sea ice after the Last Glacial Maximum.

According to the team, this area experienced at least 220 meters of abrupt ice thinning between 7,500 and 4,500 years ago, and more gradual thinning up until a thousand years ago. The same abrupt ice loss has occurred (at similar rates) in other glaciers formed on various bed topographies across multiple regions during the mid-Holocene, they explain. The Holocene is the current geological epoch.

Sea-level and ocean temperature data suggest that warmer oceans were the key drivers of this ice loss. Warmer waters most likely hastened glacier retreat (through ground-line melting, which makes glaciers slip more quickly into the oceans) which led to greater sheet instability and faster melting.

“We show that part of the Antarctic Ice Sheet experienced rapid ice loss in the recent geological past,” said Professor Andrew Mackintosh, head of the Monash School of Earth, Atmosphere, and Environment, and co-author of the paper.

“This ice loss occurred at a rate similar to that being observed in rapidly changing parts of Antarctica today, and it was caused by the same processes that are considered to cause current and probable future Antarctic ice mass loss—ocean warming, amplified by internal feedbacks.”

This retreat continued for several centuries after it first started, the authors note, which gives us cause to believe that the ice loss we’re seeing today will behave similarly. Such findings are particularly troubling in the context of climate change, which is driving glacier ice loss through higher atmospheric and ocean mean temperatures.

The results are supported by previous research which also found that glaciers are beyond the point of no return in regards to ice loss.

The paper “Regional-scale abrupt Mid-Holocene ice sheet thinning in the western Ross Sea, Antarctica” has been published in the journal Geology.

Climate change killed half the corals in the Great Barrier Reef — and it could get worse soon

Australia’s Great Barrier Reef has lost more than half of its coral population in the last three decades, according to a new study, with climate change being the main driver of this loss. The researchers found that all types of coral had suffered a decline here, in the world’s largest reef system.

Flickr American Rugbier

Coral reefs are some of the most vibrant marine ecosystems on the planet. They are called the rainforests of the sea, as between a quarter and one-third of all marine species rely on them at some point in their life cycle. Fishes and other organisms shelter, find food, and reproduce near them.

The Great Barrier Reef covers nearly 133,000 square miles and is home to more than 1,500 species of fish, 411 species of hard corals, and 4,000 types of mollusk. It also holds great scientific value as the habitat of species such as the dugong and the large green turtle, both threatened with extinction.

A group of researchers from the ARC Centre of Excellence for Coral Reef Studies in Australia assessed coral communities and their colony size along the length of the Great Barrier Reef between 1995 and 2017. The found depletion of virtually all coral populations.

“A vibrant coral population has millions of small, baby corals, as well as many large ones” said Andy Dietzel, co-author, in a statement. “Our results show the ability of the Great Barrier Reef to recover is compromised compared to the past, because there are fewer babies, and fewer large breeding adults.”

Population declines were seen in both shallow and deep-water coral species, the researchers found. Branching and tablet-shaped corals, which provide habitats for several types of fish, were the worst affected by mass bleaching events in 2016 and 2017 (caused by record-breaking temperatures).

Bleaching occurs when corals that are under thermal stress drive out the algae, known as zooxanthellae, that give them color. Corals can recover if normal conditions return, but that can take decades. A study from last year found that damaged coral colonies had struggled to regenerate because most of the adult corals had died.

“We used to think the Great Barrier Reef is protected by its sheer size — but our results show that even the world’s largest and relatively well-protected reef system is increasingly compromised and in decline,” Terry Hughes, co-author, said in a statement. “There’s no time to lose, we have to decrease greenhouse gas emissions.”

Global temperatures have already risen by about 1ºC since pre-industrial times. The Paris Agreement on climate change commits countries to limit global warming to 2ºC, or ideally 1.5º. If that threshold is exceeded, 90% of the world’s corals will be gone, according to a report by the Intergovernmental Panel on Climate Change (IPCC).

The study was published in the journal Proceedings of the Royal Society B.

Can popular proverbs teach us anything about climate change perception?

Proverbs are not reliable indicators of weather and climate — but perhaps, these old sayings can yet teach us something. If not about climate itself, then about how people perceive it.

Image credits: Ashim D’Silva.

The study has been carried out in the Sierra Nevada, in Southern Spain, which is an ideal spot for this type of study for several reasons. For starters, the area is culturally rich, and much of this culture (including linguistic culture) has been preserved throughout the centuries. Secondly, it’s a mountainous area, particularly vulnerable to climate change, so you’d expect people to notice these changes — especially as local people have traditionally had extensive knowledge about water management and agricultural production.

In other words, it’s exactly the type of place where you’d expect to have a lot of weather-related proverbs.

“I was particularly impressed by the numerous indicators (clouds, wind patterns, animal behaviour) that, still nowadays, people in the area use for weather forecasting,” says María Garteizgogeascoa who led the study

Here are some examples (translated in English):

  • Fleecy sky, in three days soaked;
  • When March feels like May, May feels like March;
  • Snowy year, bumper harvest year;
  • With the appearance of the Carduus flower, summer is over.

This type of traditional indicator is common in many cultures across the world, but they’re not exactly accurate — at least not now.

For instance, “Cuando vienen los vilanos es conclusion del verano” translates as “With the appearance of the Carduus flower, summer is over” encodes knowledge of the flowering period of the flower — end of August in cold years, beginning of September in warmer years. But with recent climate change, the flowering period of the flower has changed, and the proverb is no longer accurate.

Local people are aware of this change. “I no longer pay attention to water signals because they are no longer credible” or “In the past, cattle used to announce the rain but now they only know when it rains after they get wet, as rain now is unpredictable,” are some of the statements made by the inhabitants of Sierra Nevada who participated in this study, indicating a perception that the climate has changed.

It should be said that the study did not analyze whether these proverbs ever stood true in the first place. But what the researchers did argue is that these proverbs can be a good way to study people’s perception of climate change.

“Very few studies, and none in Spain, have ventured to study climate change at local scales through songs, stories or proverbs. However, this work shows that, despite some limitations, these traditional ways of encrypted local knowledge could be a useful source to do so and a window of opportunity to engage with local communities. During my work in the field, proverbs proved to be a useful tool to engage participants in discussions about climate change issues,” concludes María Garteizgogeascoa.

The study has been published in the journal Regional Environmental Change.