Tag Archives: Change

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.

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.

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.

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.

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.

Climate change is decoupling bee lifecycles from that of flowers

We know climate change is threatening the pollinators and crops that feed us, but a new study shines light on yet another of its unwanted effects.

Image via Pixabay.

Plants and pollinators are progressively decoupling their life cycles, the authors find, which can lead to massive issues for flowering plants. This decoupling stems from climate change, as average temperatures and snowmelt impacts when plants and beers emerge.

Timing troubles

“We analyzed time-series abundance data collected at 18 sites around the Rocky Mountain Biological Laboratory (RMBL) in the Elk Mountains of western Colorado during a nine-year, National Science Foundation-funded bee monitoring project,” says lead author Michael Stemkovski, a doctoral student at the Utah State University Department of Biology.

“We find bee emergence timing is advancing with snowmelt timing, but bee phenology — timing of emergence, peak abundance, and senescence — is less sensitive than flower phenology,” adds Rebecca Irwin, a professor of applied ecology at of North Carolina State University and senior author of the paper.

The team assessed 67 bee species in the Colorado Rockies using data collected over a 9-year period, finding a “phenological mismatch” between their life cycles and those of flowering plants, driven mostly by changes in temperature patterns. This has the potential to disrupt the relationship formed between pollinators and flowering plants, who have come to depend on one another.

Previous research has looked into the effect of temperature on this relationship, as did the current study. However, the team also looked at how topography and the different traits of various bee species mix into the issue, as well. While species characteristics definitely did play an important part in shaping this relationship, as did elevation, snowmelt timing remained “the most important factor”, they argue.

The issue here is that the lifecycles of bees seem to shift more slowly than those of the plants they pollinate and feed off of. In time, this mismatch could lead to very serious disruptions, as flowers mature before bees are ready to ‘wake up’ from overwintering.

It shouldn’t be that big of an issue by itself, the team argues, because species can shift and adapt to new conditions relatively well. The potential problem here is that, unless we address the root cause of climate change — greenhouse gas emissions — we’ll be placing too much strain on this relationship too fast. Eventually, it can break down altogether.

“In the short-term, we expect mutualist species to suffer fitness losses,” Stemkovski says. “In the long-term, bees and plants may be able to adapt and reestablish some synchrony, unless climate change outpaces the rate of adaptation.”

Pollinators have received a lot of attention lately, because they are vital for our lives as we know them — but they’re also struggling really hard due to human activity. This paper comes as the latest in a long line of warning calls that, unless we change our ways quickly, they will be changed for us, and we won’t like the outcome.

“Given global concerns about pollinator declines, the research provides important insight into the potential for reduced synchrony between flowers and their pollinators under climate change,” Irwin concludes.

The paper “Bee phenology is predicted by climatic variation and functional traits” has been published in the journal Ecology Letters.

Climate change is destabilizing marine food webs

Climate change could starve out the oceans, finds a new study from the University of Adelaide.

Image credits Susanne Pälmer.

Man-made climate change is a threat to all life on the planet whether it flies, walks, swims, or crawls. That being said, individual types of ecosystems will feel the heat at different times, and in different ways.

Sadly for us, marine ecosystems will be among the first. The oceans have always had a special connection to life — this is where it spawned. Even today, ocean ecosystems are the linchpin of life, supplying food, oxygen, and recycling essential nutrients for us landlubbers.

Marine ecosystems, the new paper reports, are in for a rough time. Increased average temperatures and higher CO2 atmospheric content threaten to push the food webs maintaining marine ecosystems beyond their breaking point.

Storms a-brewing

“Healthy food webs are critical for ecosystems so that the world’s oceans can continue to provide an important source of food for humans,” says lead author Professor Ivan Nagelkerken, from the University of Adelaide’s Environment Institute.

“Greenhouse gas emissions are affecting the health and persistence of many marine species because of increasing seawater temperatures and CO2 levels. Our research shows that ocean warming reshuffles species communities; the abundance of weedy plant species increases but the abundance of other species, especially invertebrates, collapses.”

The researchers modeled a coastal ecosystem consisting of three habitats that are predominant in the Gulf St. Vincent, Adelaide, where the South Australian Research and Development Institute (SARDI) maintains a site. They then observed how higher temperatures and ocean acidification would impact these areas.

All in all, the ‘trophic pyramid’, which is a schematic of who eats who in an ecosystem, would grow at the base and the top, but contract in its middle layers. This “unusual profile” most likely describes a “transitory state” before a collapse, Nagelkerken explains. After this collapse, marine food webs will be “shortened, bottom-heavy”, meaning they will house much fewer species, and most of them will be plants or plant-eaters. In marine food webs, fish are generally the top predators (and, as such, the highest on the pyramid).

Trophic pyramids show how energy and nutrients flow in an ecosystem; to be sustainable, they need to be triangular in shape, with many species at the bottom (thereby concentrating energy on this level). As each species feeds on the level below, this energy is moved up the pyramid. If the lower levels aren’t abundant enough, everything above them falls apart (goes extinct, or close to).

“Where food web architecture lacks adjustability, ecosystems lack the capacity to adapt to global change and ecosystem degradation is likely,” says collaborator and co-author Professor Sean Connell from the University of Adelaide’s Environment Institute.

“Marine food webs that are not able to adapt to global change show all the signs of being transformed into a food web dominated by weedy algae. Even though there were more plants at the bottom of the food web, this increased energy does not flow upwards towards the top of the food web.”

While things don’t look encouraging now, the team says that future emissions of carbon dioxide are only going to make the problem worse.

Unless some species quickly adapt to the new conditions, ocean ecosystems are likely to become much less abundant in the future. The species we most rely on economically and for food are exactly the ones that are at risk of collapse.

“An ecological tipping point may be passed beyond which the top of the food web can no longer be supported, with an ensuing collapse into shorter, bottom-heavy trophic pyramids,” says Professor Nagelkerken.

“This will weaken the health and sustainability of ocean ecosystems unless species are capable of genetic adaptation to climate stressors in the near future.”

The paper “Trophic pyramids reorganize when food web architecture fails to adjust to ocean change” has been published in the journal Science.

These Canadian ice caps were estimated to melt by 2022 — they’re already gone

A paper published back in 2017 estimated that the St. Patrick Bay ice caps in Canada would disappear in 5 years due to climate change. We’re barely halfway through that time, and they’ve already melted.

Satellite images show the location where the St. Patrick Bay ice caps used to exist on the Hazen Plateau of northeastern Ellesmere Island in Nunavut, Canada.
Image credits NSIDC.

NASA imagery shows that the ice caps have melted far faster than scientists predicted — 3 years instead of 5. That initial estimation was made by scientists from the National Snow and Ice Data Centre (NSIDC) at the University of Colorado Boulder in 2017.

The melting of these caps should be a very clear warning that climate warming is picking up around the world, and shows the dangers of officials choosing to ignore or confound science consensus.

Melt rate — fast

The ice sheets spread over more than 10 square kilometers (around 4 sq miles) in total back in 1950. Mark Serreze, a geographer, NSIDC director, and lead author of the 2017 paper, remembers the striking view when he visited the area in 1982.

“When I first visited those ice caps, they seemed like such a permanent fixture of the landscape,” says geographer and NSIDC director Mark Serreze. “To watch them die in less than 40 years just blows me away.”

By the time Serreze started writing the paper, these ice sheets were only 5% of the size they were in 1959. Today, satellite images from NASA’s Terra satellite shows that no trace of this ice remains — and with the way things are progressing, it won’t be back in the foreseeable future.

The ice caps are part of a larger body of ice sheets in the Hazen Plateau on Ellesmere Island. This land stretches well into the Arctic and is one of the most northerly points in all of Canada. Two other glaciers that would often link with the now-melted pair, the Murray and Simmons ice caps, are faring better due to their high altitude. However, researchers think these two will also collapse soon, as their size was at 39% and 25%, respectively, of what they were in 1959.

This outline of the St. Patrick Bay ice caps, taken from the 2017 The Cryosphere paper, is based on aerial photography from August 1959, GPS surveys conducted during August 2001, and for August of 2014 and 2015 from NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER).
Outline of St. Patrick Bay ice caps recorded over time.
Image credits NSIDC.

One thing I find particularly heartbreaking about this story is that Serreze and his team first started work in the Hazen Plateau around 1980 as they were trying to understand whether human activity was causing climate change. At the time, scientific consensus was not yet established on the issue, and some research suggested we were actually going through a period of global cooling (at least publicly — Shell knew).

So one of the sites that helped us prove once and for all that the way we do things is hurting the planet has been destroyed exactly because of that damage.

But it’s also a sobering wake-up call that the climate isn’t changing in the future — it’s changing right now.

“We’ve long known that as climate change takes hold, the effects would be especially pronounced in the Arctic,” says Serreze. “But the death of those two little caps that I once knew so well has made climate change very personal. All that’s left are some photographs and a lot of memories.”

One gene can turn mosquitoes from females to males, which don’t bite

Researchers at Virginia Tech have found that they can turn female Aedes aegypti mosquitoes into males by tweaking a single gene in their DNA.

Image via Pixabay.

The findings could help us reduce the spread of mosquito-borne diseases. Female mosquitoes need to bite mammals in order to absorb their blood — which is converted into nutrients for their eggs. Males, on the other hand, don’t. They spend their days sipping on nectar.

Mosquito bites create an ideal opportunity for diseases such as malaria, Zika, or Dengue to spread, as they involve a small amount of the insect’s saliva entering the victim’s tissues. Shifting the ratio towards males can thus nip such diseases in the bud.

Changing demographics

“The presence of a male-determining locus (M locus) establishes the male sex in Aedes aegypti and the M locus is only inherited by the male offspring, much like the human Y chromosome,” said Zhijian Tu, a professor in the Department of Biochemistry in the College of Agriculture and Life Sciences, lead author of the study describing the process.

“By inserting Nix, a previously discovered male-determining gene in the M locus of Aedes aegypti, into a chromosomal region that can be inherited by females, we showed that Nix alone was sufficient to convert females to fertile males. This may have implications for developing future mosquito control techniques.”

The team produced several such gene-modified mosquitoes that express an extra copy of the Nix gene that is activated by its own promoter.

This sex conversion was found to be highly effective and “stable over many generations in the laboratory”, the team explains, suggesting that it would be useful in wild populations without constant reintroduction of modified mosquitoes.

However, these converted males can’t fly naturally. In order to remedy this, the team found that a second gene (myo-sex) needs to be added to the M locus as well. The team inactivated the myo-sex gene in wild-type males to confirm its function — and these insects lost their ability to fly.

Flight is important for these sex-changed insects as mosquitoes rely exclusively on flight for feeding, mating, and escaping predators. In other words a flightless mosquito, no matter how well-engineered, won’t do us much good. This being said, however, the authors report that sex-changed males were still able to father sex-converted offspring if they were presented with an anesthetized wild female.

All in all, the Nix gene has great potential as a tool to reduce the population of biting mosquitoes, and thus, the spread of disease. However, there’s still a lot of work to be done in the lab before such insects can be released into the wild.

The paper “Nix alone is sufficient to convert female Aedes aegypti into fertile males and myo-sex is needed for male flight” has been published in the journal Proceedings of the National Academy of Sciences.

It could take decades after slashing emissions for the climate to cool down

Global warming is perhaps the ultimate hurdle humanity will have to overcome in our lifetime. Researchers from Norway are helping us get a better idea of what that process would entail.

Image via Pixabay.

According to their work, it could take decades after we reduce greenhouse emissions for the planet to start cooling down. While the idea that it takes time to alter climate patterns — known as ‘climate inertia’ — isn’t new, the study does offer a more in-depth estimation of how such a process would unfold.

Cooling takes time

The study was published by three researchers at the CICERO Center for International Climate Research in Oslo, Norway.

They worked with several climate models to determine how global climate would respond to different levels of reductions in greenhouse emissions, or to changes in the overall make-up of those emissions.

Slashes in carbon dioxide emissions were the only changes that had a noticeable effect on global warming, but even then, it would take a long time to see progress.

However, when emissions of other gases being emitted were reduced as well, this cooling trend would accelerate. If these other pollutants are not reduced, the planet will cool down very slowly.

According to the team’s best-case scenario (near-zero-emissions starting this year), we’ll see the planet starting to cool down somewhere in 2033. Under the RUCP2.6 scenario (an emission reduction scenario considered to be achievable by many researchers and politicians), the team saw no positive changes until 2047. Finally, if emissions are reduced by around 5% each year, we’ll start seeing an improvement by 2044.

The team’s effort isn’t a clear-cut image of the future, and they acknowledge this fact, but it is a very useful glimpse into where we’re headed, roughly, and what to expect.

One of the most important takeaways of this research is that time is extremely important in fixing our climate issues. The later we start, the later we’ll see results, or the more emissions we’ll have to slash (which translates to more severe economic effects). We have to balance those effects with the damage our emissions are causing to the planet’s ecosystems — economies don’t tend to fare well during periods of massive environmental upheaval.

But not all is lost. The quarantine showed that we can make a real, positive change in our emissions with surprising ease. Air quality improved dramatically over many of the world’s busiest cities during the lockdown. We can recreate that drop in emissions in the future — and it will be a very good place to start.

The paper “Delayed emergence of a global temperature response after emission mitigation” has been published in the journal Nature Communications.

Microalgae could protect coral reefs from climate change

Coral reefs are among the most biodiverse ecosystems of the planet but also among the most threatened, currently dying at record rates across the world due to climate change.

Credit Wikipedia Commons

Reducing carbon emissions is considered the main way to help them, which would prevent waters from getting too hot and acidic. But researchers in Australia are exploring other alternatives as well, such as training the microalgae that keep corals alive.

Higher average temperatures put stress on coral and can lead to them ejecting their symbiotic algae, a process known as coral bleaching. When that happens, it can be a death sentence for coral and the species that rely on healthy reefs. In an effort to help them, scientists created an exposure therapy experiment for the tiny algae that provide them with life.

“Coral reefs are in decline worldwide,” lead-author Patrick Buerger said in a statement. “Climate change has reduced coral cover, and surviving corals are under increasing pressure as water temperatures rise and the frequency and severity of coral bleaching events increase.”

The researchers exposed ten strains of algae to water heated to about 89 degrees Fahrenheit (or 31ºC) for four years, which is roughly the peak temperature the Great Barrier Reef reached in February. That threshold has been registered to trigger mass bleaching.

Then, the team compared those strains to other algae, which they’d exposed to roughly 81 degrees Fahrenheit (or 27ºC) over the same period. It turns out algae can develop higher heat tolerance. All ten of the strains exposed to higher temperatures evolved to withstand them.

The researchers then introduced those strains to coral larvae and exposed them to water warmed to 89-degree Fahrenheit (or 31ºC) to see if they could also help prevent the coral from bleaching. In three out of the ten cases, the coral didn’t eject the algae. This suggests that algae that have adapted to heat could help restore the world’s coral reefs and buffer them against future change.

“While evidence suggests that corals are slowly adapting to a warmer world, it appears they are struggling to keep pace with climate change,” the researchers said in a statement.

If more research confirms these results and labs are able to develop more heat-resistant algae, scientists could introduce them to coral reefs in the wild. The researchers think this could give reefs a big boost in resisting the effects of the climate crisis.

Despite covering less than 0.1% of the ocean floor, reefs host more than one-quarter of all marine fish species, in addition to many other marine animals. Additionally, reefs provide a wide variety of ecosystem services such as subsistence food, protection from flooding, and sustain the fishing and tourism industries.

The study was published in the journal Science Advances.