The Guardian: Thermal dome burns through climate models | Opinion

The recent incredibly high temperatures in the northwestern United States and Canada were – and are – very frightening. The heat and the fires it caused killed hundreds of people and are believed to have killed a billion sea creatures.

Daily temperature records have been broken by more than 9 degrees Fahrenheit in some places. In Lytton, British Columbia, the heat reached 121 degrees. The forest fires that consumed the city produced their own thunderstorms, as well as thousands of lightning strikes.

An early study shows that human activity has made this thermal dome – in which a high pressure ridge acts as a cover preventing hot air from escaping – at least 150 times more likely. The World Weather Attribution Group of scientists, which uses computer climate models to assess global heating trends and extreme weather conditions, has warned that the heat of two weeks ago exceeded even their worst-case scenarios.

While it has long been recognized that the climate system has thresholds or tipping points beyond which humans risk losing control of what happens, scientists have not hidden their concern that ‘a generally cold part of the Pacific Northwest had been turned into a furnace. A climatologist said that the prospect opened by the thermal dome “takes my breath away.”

The worrying signs of climate change are not limited to North America. Pakistan and Siberia have also seen record temperatures in recent weeks, as have Moscow, Helsinki and Estonia. In Madagascar, the worst drought in 40 years has left one million people facing food shortages. Climate author David Wallace-Wells suggested that current conditions should be seen as harbingers of a “permanent emergency.”

As policymakers struggle to absorb the very serious implications for human societies of current models, it is frankly difficult to accept the suggestion that these models may underestimate the threat. The prospect of the jet stream blocking and weather systems such as tropical storms stop moving in the way we’re used to, carries nightmarish possibilities. And California still has most of its wildfire season ahead.

If there is anything positive to be learned from this new information and reports on the suffering and destruction caused by the heat, perhaps it is that it intensifies the pressure on policymakers to act. On July 7, the Swiss-based Financial Stability Board issued a warning ahead of the G20 meeting in Venice this weekend. He urged finance ministers and central banks to take greater account of far-reaching climate impacts.

The magnitude of these impacts will depend on decisions taken by governments over the coming months and years. So far, the binding commitments to cut carbon emissions needed to avoid temperature rises above 2 degrees Celsius are notable for their absence. With each worrying news about the climate, the stakes ahead of the November Cop26 conference keep growing.

Environmentalists used to shake their heads when very unusual weather conditions were reported in terms that ignored the contribution of climate change. Now, thanks to the science of attribution, the connection is firmly established. To avoid future thermal domes, countries like the United States and Canada must stop pumping so much energy into the climate system.

The Guardian newspaper, London

The Guardian newspaper, London


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North American heatwave broke records

Climatologists have been shocked by recent deadly heat waves in western Canada and the northwestern United States, which have exceeded all global heating forecasts

Climate scientists have warned that the world is already experiencing episodes of extreme heat that are only expected to occur on a much hotter planet.

The extraordinary heat that engulfed northwestern Canada and the United States last week broke temperature records by several degrees, with temperatures exceeding 40 ° C for days and reaching 49.6 ° C in the village of Lytton, Canada.

Soon after, Lytton was destroyed in forest fires. In Western Canada, nearly 500 people are estimated to have died and experts expect the death toll to rise.

Without the influence of man-made climate change, the heat wave would have been “virtually impossible,” according to a rapid attribution analysis by an international team of 27 leading climatologists who have worked tirelessly to publish the study.

Climate change, they found, has made the heat wave at least 150 times more likely to occur – such extreme heat not occurring according to current statistical analyzes.

Ocean fire reveals weak regulation of Mexico’s oil and gas sector

The results have prompted scientists to question their understanding of the impact of climate change on heat waves, which could lead to the revision of some climate models.

Friederike Otto, from the Environmental Change Institute at the University of Oxford, one of the study’s authors, said climate science has been “a little complacent” about how it understands sea waves. heat.

The intensity of heat waves is increasing in orders of magnitude not seen for other extreme events, she said. “Heat waves are how climate change is killing us. This is how climate change manifests itself more strongly.

Using computer observations and stimulation, the scientists compared the past climate in the region covering Portland, Seattle and Vancouver with current trends after global warming of around 1.2 ° C since the end of the 19th century.e century.

They found that the temperatures during last week’s event were so extreme that it was difficult to estimate with certainty how rare the event was, but suggested that it amounted to a single event in a thousand. years in the current climate.

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Geert Jan van Oldenborgh of the Royal Netherlands Meteorological, another of the authors, told reporters that the heat wave had shattered previous temperature records of up to 5 ° C – “an extraordinary event”.

“For comparison, here in the Netherlands we were really shocked when the previous record was broken by 1.8 ° C and it’s more than double. “

The heat wave, said Van Oldenborgh, is “both a major disaster and weather event, but also a major scientific challenge to understand what happened.”

He said the state of climate science in 2020 would have shown that the heat wave was “fundamentally impossible” and that more research was needed to understand how it happened and whether such an event could occur in other parts of the world.

“It’s rather shaking that our theoretical picture of heat wave behavior has been shattered so brutally,” he said. “We are much less certain of how the climate [change] affects heat waves than we were two weeks ago.

South Africa Climate advisers call for faster shift away from fossil fuels

The authors of the article identified two possible explanations for the extreme jump in maximum temperatures observed in North America.

The first is ‘really bad luck’ and that, although exaggerated by climate change, it remains a very low probability event. However, in a future world characterized by global warming of 2 ° C, such an extreme heat wave could occur once every 5 to 10 years, according to the study.

Another explanation is that the climate system in this region has crossed a threshold that has increased the likelihood of such extreme heat well beyond the gradual rise in temperature peaks that have been observed so far.

In this scenario, record-breaking heat waves like last week’s event are already more likely to occur than climate models predict – which the team of scientists says needs further investigation.

“This is such an exceptional event that we cannot rule out the possibility that we are facing extreme heat today that we only expected to reach higher levels of global warming,” said Otto.

If this second scenario turns out to be correct, it could lead to the revision of climate models.

If an essential climate process is missing from current climate models, these will “definitely need to be improved,” Van Oldenborgh said.


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Canadian hell: northern heat surpasses worst climate models | Climate crisis

If you had made a list of possible locations for Hell on Earth before this week, the tiny mountain village of Lytton in Canada probably wouldn’t have occurred to you.

Few people outside of British Columbia had heard of this community of 250 people. Those who had it were more likely to view it as bucolic. Nestled at the confluence of rivers in the forested foothills of the Lillooet and Botania mountain ranges, the municipal website boasts: “Lytton is the perfect place for nature lovers to connect with incredible natural beauty and the freedom of the countryside. ‘fresh air.”

Over the past seven days, however, the village has been making headlines around the world for an incredibly prolonged and intense temperature spike that has turned the romance into hell.

US President Joe Biden and Canadian Prime Minister Justin Trudeau have warned worried populations to prepare for more. Shocked climatologists wonder how even the worst-case scenarios failed to predict such furnace conditions so far north.

Johan Rockström, director of the Potsdam Institute for Climate Impact Research, said recent extreme weather anomalies were not represented in global computer models used to project how the world might change with more emissions . The fear is that weather systems will be blocked more frequently due to human emissions. “This is a risk – of a severe regional climate impact triggered by global warming – that we have underestimated so far,” he said.

In Lytton, it was as if time itself had stagnated. Trapped in a vast dome of heat that enveloped western Canada and the northwestern United States, temperatures had no choice but to rise.

In Lytton, the Canadian national heat record was broken Monday, shattered Tuesday, then erased Wednesday when the local monitoring station recorded 49.6 ° C (121 ° F).

After the unbearable heat came the suffocating fire. First the forest burned down, then parts of the city. On Wednesday evening, Mayor Jan Polderman issued the evacuation order. ” It’s horrible. The whole town is on fire, “he said on television.” It took about 15 minutes from the first sign of smoke and, suddenly, fire everywhere. “On Thursday, satellite images showed a fires erupt around the village and a cloud of smoke widening in the area.

Heatwave in Canada: Resident films escape wildfire as flames engulf Lytton village - video
Heatwave in Canada: Resident films escape wildfire as flames engulf Lytton village – video

Police stations and hospitals have reported an increase in the number of heat-related deaths – 486 in British Columbia and dozens more south of the border. The roads twisted as the asphalt spread. At least one city has suffered power cuts.

The psychological, political and economic impacts are harder to quantify, but for many the horror has been accompanied by a sense of astonishment that these northern territories are hotter than the Middle East. David Phillips, the Canadian government’s senior climatologist, summed it up in an interview with CTV. “I mean, it’s just not something that looks Canadian.”

A woman and her cat rest inside a tent at the Oregon Convention Center cooling station in Portland, United States. Photograph: Kathryn Elsesser / AFP / Getty Images

More and more people in more countries feel that their climate belongs to another part of the world. Across the border in Washington state, the maximum heat measured at Olympia and Quillayute was 6 ° C above the previous all-time record, according to the Weather Prediction Center. In Oregon, the city of Salem hit 47C, shattering the previous record of 9C. Several parts of California and Idaho also recorded new highs.

The week before, Northern Europe and Russia also suffocated in an unprecedented heat bubble. June records were broken in Moscow (34.8C), Helsinki (31.7C), Belarus (35.7C) and Estonia (34.6C).

Further east, Siberia experienced an early heat wave that helped reduce the amount of sea ice in the Laptev Sea to an all-time high for the time of year. The city of Oymyakon, Russia, widely considered the coldest inhabited place on earth, was warmer (31.6 ° C) than it ever was in June. This follows an incredibly prolonged heat wave in Siberia last year that lasted for several months.

Carlo Buontempo, director of the Copernicus Climate Change Service, said there was a clear human imprint on this “very abnormal” event. Without emissions from cars, farms and industry, he said, record temperatures in western North America would only be expected once every tens of thousands of years, but the probability increases with the levels of greenhouse gases. “In today’s climate, having an extremely hot June is common and likely to happen twice in three decades. However, an analysis of numerous computer models suggests that by the end of the century, these extreme temperatures are more likely than not. It is estimated that human influence increased the likelihood of a new record several thousand times. “

Dome

The rise in temperatures is visible all over the world. Even in the Middle East, temperatures over 50 ° C were once outliers, but parts of Pakistan, India, Australia, the United States and Canada are now regularly approaching or exceeding this mark. .

But the intensity of the heat in the northwestern Americas this year and in Siberia last year took many scientists by surprise and suggested that additional factors could be involved in the northern latitudes.

One theory is that the recent spike in temperature may have been caused not only by global warming, but by the slowing of weather systems that remain stuck in one place for an extended period of time, giving them time to escalate and recede. cause more damage. This was a major factor in the devastation in Texas caused by Hurricane Harvey in 2018, which remained over Houston for several days rather than blowing inland and weakening. The stranded high pressure fronts were also blamed for the scorching heat wave in Europe in 2019.

Experts at the Potsdam Institute and elsewhere believe that the rapid warming of the Arctic and the decline of sea ice are causing the jet stream to move in large meanders, called Rossby resonance waves, trapping weather systems at high and low pressure in one place. for longer.

This theory remains disputed, but Michael Mann, director of the Earth System Science Center at Pennsylvania State University, said this week’s surprisingly fierce heat in Lytton and elsewhere should prompt climatologists to consider additional impacts of the weather. ‘human activity.

“We should take this event very seriously,” he wrote in an email. “You’re warming the planet, you’re going to see an increase in the incidence of extreme heat. Climate models capture this effect very well and predict large increases in heat extremes. But something else is happening with this heat wave, and indeed, with many of the very persistent extreme weather conditions we’ve seen in recent years in the United States, Europe, Asia and elsewhere, where models don’t capture not quite the impact of climate change. “

Whatever interactions to blame, scientists agree that the easiest way to reduce the risk of further temperature shocks is to cut fossil fuel emissions and stop deforestation.

“It seems that this heat wave is still a rare phenomenon in the current climate, but that it remains dependent on our decisions,” he added. Friederike Ottosaid the associate director of the Environmental Change Institute at the University of Oxford. “If the world does not quickly eliminate the use of fossil fuels and other sources of greenhouse gas emissions like deforestation, global temperatures will continue to rise and such deadly heat waves will become even more severe. current. “



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Climate variability leads to more intense thunderstorms • Earth.com

Climate variability leads to more intense thunderstorms In a new study by Texas A&M University, experts report that large thunderstorms in the southern Great Plains of the United States have increased in frequency and intensity. The researchers found that these changes are linked to climate variability.

“Thunderstorms in the southern Great Plains of United States are among the strongest on Earth and have increased in intensity and frequency in recent years, ”the researchers explained.

“Assessing changes in storm characteristics under different climate scenarios, however, remains very uncertain due to the limitations of the physics of climate models. “

The current study focused on isotopes from stalactites in Texas caves dating back between 30,000 and 50,000 years. The researchers analyzed the oxygen isotopes contained in the stalactites to identify trends from past thunderstorms.

“Storm regimes shift from weakly to strongly organized over millennial time scales and coincide with well-known abrupt climate changes during the last ice age,” the study’s authors found.

“Modern synoptic analysis suggests that the organization of thunderstorms in the southern Great Plains is strongly related to changes in large-scale wind and humidity patterns.”

Understanding these changes will not only help reconstruct past storm patterns, experts say, but will also help predict mid-latitude patterns that will emerge in decades to come.

“Proxy recordings are available in the southern great plains in caves,” study co-author Christopher Maupin said. “There are probably thousands of caves in the southern Great Plains and southern Texas. Why has there not been more research in these areas? Cave deposits are so promising as a proxy.

Study co-author Courtney Schumacher said scientists understand modern precipitation models. “However, we don’t know what will happen in the future, and this work will help predict storm trends in the future,” Schumacher said. Climate variability leads to more intense thunderstorms

“If we can run a climate model for the past that is consistent with the cave records, and run that same model in the future, we can have more confidence in its findings if it matches the cave records than if they were. are not. On two models, if one really matches the isotopes of the cave, you can trust that one to understand the distribution of storms in the future. “

“There are some really important questions about what has happened in the past regarding the large weather events we experience through mesoscale convective systems (large storms) versus non-mesoscale things (small storms).”

“We get so much precipitation from really big storms, and the model grids can’t capture big weather events because the grids themselves are so big. Paleoclimatology helps organize past events to develop an indirect record of how they react to average climate. “

Schumacher noted that large storms that cover hundreds of miles provide about 50 to 80 percent of rainfall in Texas.

“These thunderstorms are so big that even though most of the rain occurs in Oklahoma, the rain in Texas will still carry the isotopic signature of these huge storms,” said Maupin.

“You take fingerprints from these systems wherever they are, and they don’t need to be super-localized to be recognized. Large storms cause depleted isotope signatures. You cannot explain the variability of stalactites by temperature changes alone.

The study is published in the journal Geosciences of nature.

Through Chrissy sexton, Terre.com Editor-in-chief


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More intense and frequent thunderstorms linked to global climate variability – sciencedaily

Heavy thunderstorms in the southern Great Plains of the United States are among the strongest on Earth. In recent years, these storms have increased in frequency and intensity, and new research shows that these changes are linked to climate variability.

Co-authored by Christopher Maupin, Courtney Schumacher and Brendan Roark, all scientists from Texas A&M University’s College of Geosciences, along with other researchers, the results were recently published in Natural geosciences.

In the study, the researchers analyzed the oxygen isotopes of 30,000-50,000-year-old stalactites from Texas caves to understand the trends of past thunderstorms and their durations, using a radar calibration for the isotopes of the storms. precipitation in the region. They found that when storm regimes shift from weakly to strongly organized over millennial time scales, they coincide with well-known global abrupt climate changes during the last ice age, which occurred about 120,000 ago. at 11,500 years.

Through modern synoptic analysis, researchers have learned that thunderstorms in the southern Great Plains are strongly related to changes in wind and humidity regimes occurring on a much larger scale. Understanding these changes and various correlations will not only help reconstruct past thunderstorm occurrences, but will also help predict future mid-latitude thunderstorm patterns.

“Proxy recordings are available on the southern great plains in the caves,” Maupin said. “There are probably thousands of caves in the southern Great Plains and southern Texas. Why hasn’t there been more research in these areas? Cave deposits hold so much promise as a proxy. “

Schumacher said scientists understand modern precipitation patterns and that large storms can deplete isotopes.

“However, we don’t know what will happen in the future, and this work will help predict storm trends in the future,” she said. “If we can run a climate model for the past that is consistent with the cave records, and run that same model in the future, we can have more confidence in its conclusions if it matches the cave records than if they do not. On two models, if one really matches the isotopes of the cave, you can trust that one to understand the distribution of storms in the future. “

Caves hold little-known climatic records

Maupin, a paleoclimatologist, described the limitations that exist in capturing the true distribution of weather events over time.

“There are some really important questions about what has happened in the past regarding the large weather events we experience through mesoscale convective systems (large storms) versus non-mesoscale things (small storms),” he said. declared Maupin. “We get so much precipitation from really big storms, and the model grids can’t capture big weather events because the grids themselves are so big. Paleoclimatology helps organize past events to develop an indirect record of how they react to average climate. “

Maupin collaborated with National Taiwan University to do a uranium and thorium dating and found that the stalactites and stalagmites actually dated from the Ice Age.

Interdisciplinary collaboration

Schumacher’s expertise was needed to make connections with various rainy events that occurred over time. She had experience with radar data and global rainfall measurements.

“Large storms that cover hundreds of miles provide about 50 to 80 percent of rain in Texas,” Schumacher said. “These storms today have different isotopic signatures. “

Maupin’s research pushes back on outdated paleo-world principles, as you need to study how storms grow bigger and what influences them, he said.

“These thunderstorms are so big that even though most of the rain occurs in Oklahoma, the rain in Texas will still carry the isotopic signature of these huge storms,” said Maupin. “You fingerprint these systems no matter where they occur, and they don’t need to be super localized to be recognized. Big storms cause depleted isotope signatures. You can’t explain the variability of stalactites. with the only temperature changes. “

Research Experience for Aggie Undergraduates

Celia Lorraine McChesney ’16 and Audrey Housson ’16 were two undergraduate researchers involved in this publication, and both learned a lot through fieldwork, collaboration and the high impact learning experience.

“The cave samples have been used as a high-impact learning tool to understand the paleoclimate of Texas,” said Maupin. “One of the undergraduates started micro-milling the stalactites. I was very fortunate to have access to the resources of the College of Geosciences and to work with these talented undergraduates on groundbreaking research. “

McChesney said his experience working on his graduation thesis at the lab was “invaluable” and the research has allowed him to travel and go into the field.

“As an undergraduate research student at Texas A&M, I was proud to be part of one of the first teams to correlate climate change and weather links in a paleoclimatic dossier,” said Housson. “All this experience allowed me to discover the academic world and made me more confident as a scientist. Now, as a geologist and civil engineer, I work on heavy civil infrastructure projects like tunnels and dams related to water resources. I love how my career ties into my undergraduate research where knowing the correlation between climate change and weather helps plan water resources in the future. “

Funding for this research was provided in part by a High Impact Undergraduate Research Grant from Texas A&M University.


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Predictions of climate variability and effects on agriculture – BC Local News

As I sit down to write this, it is with the heaviness of the news that a family friend has been found deceased. This leaves those closest to you wondering what more they could have done to reach out.

Oliver Rujanschi, we will miss you and the warmth you were. Sorry friend!

And we are all moved by the tragic depth of the discovery of so many innocent children buried at Kamloops Residential School.

***

A few years ago, many of us interested in the impacts of climate change got together with the Government of British Columbia’s Climate Action Unit of the Ministry of Agriculture, to define a strategy for cope with the expected impacts.

The temperature projections for 30 years (2050) were 2.1 to 4.1 degrees Celsius in annual mean temperatures. This comes with an additional 35-64 frost-free days.

On the precipitation front, one would expect an increase of 5.1% per year and a decrease of 27% falling as snow. In all likelihood, summers will be drier.

Extremes can involve and increase the frequency and magnitude of extreme precipitation events. The average number of days above 30C will increase each year.

With this information in hand, producers and stakeholders identified the top five climate issues.

First, there has been the increased risk of forest fires. The region then experienced significant forest fire seasons in 2009, 2010 and 2012. Subsequently, 2017 and 2018 saw record fires, burning 1.1 million hectares (over two million acres ).

Second, changing hydrology affects us in the following ways: Hotter, drier summers have reduced water supplies while increasing water requirements for crops and livestock. The summers of 2019 and 2020 saw a number of farms and ranches hit hard by the flooding.

Third, increased variability was of great concern to growers, in particular: unpredictable storms, temperature / precipitation fluctuations and extremes, and freeze-thaw cycles.

Fourth, changes in pests, diseases and invasive species are upon us. Although we know the impacts of the mountain pine beetle, we do know that fire ants, cutworms and gray moth are increasingly important. This is in part due to the warmer winters.

Fifth, there will be changes in wildlife and ecological systems: the ecological communities and water resources of the Cariboo rangelands change, which alters forage productivity.

On all these fronts, producers and the government have made progress on projects.

There is much more to report and I direct interested readers to Climate Action Agriculture at www.climateagriculturebc.ca/regional-adaptation/cariboo/.

Many projects are showcased there.

Producer leaders have worked hard with governments to oversee studies and trials designed to benefit food production in our home region.

When we have the certainty of a tragedy to come, or even mere suspicion, we owe it to our fellow human beings to act. The same is true of the past and future human, personal and societal tragedies to which I alluded in my opening lines.

Soil is the skin of the Earth organism. Human health and the health of the Earth are one.

David Zirnhelt is a breeder and member of the Cariboo Cattlemen’s Association. He is also chairman of the advisory committee for the sustainable breeding program applied to TRU.

Quesnel Cariboo Observer


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Scientists study how regional climate variability affects animals in arid North America: UNM Newsroom

As visual evidence of climate change continues to shed light on a huge problem in the world, scientists studying at several National Science Foundation (NSF) Long-Term Ecological Research (LTER) sites are partly addressing the problem. problem by examining changes in the diversity and abundance of small mammals to understand their vulnerabilities to climate change.

Long-term regional monitoring can improve detection of biodiversity declines associated with climate change by combining information from both temporal and spatial dimensions. In the drylands of North America, future climate predictions include a nearly 100 percent chance of a decadal drought, the impacts of which will be magnified by ongoing global warming. Drylands are regions constrained by water scarcity and are essential for understanding how climate change affects biodiversity, as they cover 45 percent of the earth’s surface.

Ord’s kangaroo rat (Dipodomys ordii) is a grassland species present in all long-term study areas of the arid zones of our study. Like many rodent species we studied, D. ordii’s responses to drought conditions varied among sites and ecosystem types. Photo credit: Nicole Kaplan

In a study published today in Global Change Biology titled “Decline in rodent abundance and diversity follows regional climate variability in the drylands of North America“, a group of scientists are trying to understand long-term changes in the diversity and abundance of small mammals and identify species that may be most sensitive to our drier, less predictable climate.

“Over the past 100 years in the southwestern United States, our climate has become drier and more variable, with increasing differences in drought index from year to year.” said Jennifer Rudgers, professor of biology at the University of New Mexico, senior author. and director and principal investigator of the Sevilleta Long Term Ecological Research (SEV LTER) Program in New Mexico. “Increasing climate variability is an aspect of climate change that has not been studied as extensively as changes in average temperature such as the climate becoming, on average, warmer or drier. Yet most climate predictions for the future include the prediction of increasing variability. ”

As part of the study, scientists analyzed abundance data from 22 rodent species in grassland, scrub, ecotone, and forest ecosystems in the southwestern United States as part of a time series (1995-2006 and 2004-2013) representing the Pacific phases. Decadal oscillation (PDO). PDO influences drought in southwestern North America, where rodents are diverse and important consumers.

The study, which took place at LTER sites from the northern Chihuahuan Desert to the southern Great Plains of western North America, combined 12 datasets on eight ecosystem types to examine the models. temporal diversity, composition and abundance of rodent species at the regional scale.

Data gathering

Sevilleta National Wildlife Refuge Branch Fellows Ariel Elliott is recording data on a kangaroo rat. Photo credit: Kathy Granillo

“Long-term observations that occur during periods with varying climates have allowed us to look for non-linear relationships between mammalian abundance and climatic variables,” Rudgers explained. “Non-linearities give signals about the sensitivity of species to climate variability. Because our climate is quite variable, we could capitalize on this inherent variability to detect past patterns that can predict the future. “

A key element that impacted the study was the Pacific Decadal Oscillation (PDO) and the role it plays in climate change. PDO is a climatic phenomenon that occurs when the sea surface waters in the northern Pacific Ocean fluctuate in temperature. This is an often decades-long oscillation that affects precipitation in the southwestern desert. When the surface temperatures of the Pacific Ocean along the west coast of North America are warm, the southwestern United States is generally in a phase of drought. When surface waters are cool, they tend to be wetter in the southwest.

“Because we had long-term small mammal abundance datasets (almost 20 years of data), we were able to separate our dataset into two time periods that each covered a phase of AOP: one wetter and earlier period in the mid-1990s-early 2000s and a drier, later period (2004-2013), ”said Rudgers. “This allowed us to explore how the climatic sensitivities of small mammals have changed over time, in concert with different phases of AOP.”

Using a climate sensitivity function approach developed by the team, scientists were able to comb through long-term observations that occurred during periods with varying climates to look for non-linear relationships between the abundance of mammals and climatic variables.

WER1 stamp

UNM is the only R1 in New Mexico: doctoral university with very high research activity as classified by the Carnegie Commission on Higher Education.

“We detected regional trends in our New Mexico, Colorado, and Arizona data sets,” Rudgers said. “Regionally, the diversity of rodent species has declined by 20 to 35 percent, with greater losses in the subsequent period. The abundance has also declined regionally, but only recently, with losses of 5 percent of the animals we have captured and released.

However, Rudgers noted that these declines in diversity varied across ecosystem types and locations. “The greatest declines in diversity have occurred in three types of ecosystems: the juniper pine forests and creosote shrub areas of the Sevilleta National Wildlife Refuge in New Mexico and the mixed shrub areas of salt bush on the Shortgrass Steppe LTER site in Colorado.

“The declines in abundance that we observed and the sensitivity of mammals to climatic variables were highly dependent on the ecosystem and location that we studied,” said Rudgers. “Thus, sensitivity to climate change was not at all consistent across a species’ range. In fact, the identities of winning and losing species differed between ecosystems for 70 percent of the taxa. This means that we need to take the local environment into consideration when making predictions about species vulnerabilities. “


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Climate models can predict decadal precipitation v

image: Ensemble mean forecast anomalies averaged over forecast years 2 to 9 for summer precipitation over the Inner Tibetan Plateau. Red line: retrospectives; Blue line: near real-time predictions; Black line: observations. Shadows represent uncertainty.
seen Following

Credit: HU Shuai

Summer precipitation on the Tibetan Plateau is highly predictable over multi-year timescales in large ensemble forecasts, according to a research team led by ZHOU Tianjun of the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences.

The study, published in Scientists progress June 9, shows that the predictable summer rainfall signal in the Tibetan Plateau hinterland is significantly underestimated in advanced decadal forecast models.

The predictable signal is so weak that it can be masked by unpredictable noise. “The predictable signal that is too weak comes from the low signal-to-noise ratios in the models compared to the real world,” said ZHOU, corresponding author of the study. “This phenomenon is kind of a deficiency in climate models, but it also prompts us to once again recognize the decadal predictability of prediction models.”

ZHOU is Principal Investigator at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics at IAP. He is also a professor at the University of the Chinese Academy of Sciences.

ZHOU and his team used large assemblies from the Sixth Coupled Model Intercomparison Project (CMIP6) of the Decadal Climate Prediction Project (DCPP), an archive of comprehensive decadal prediction experiments based on various climate models, to eliminate stochastic noise. unpredictable and extract the predictable signal. summer rainfall in the Tibetan plateau.

The researchers produced realistic predictions through a post-processing variance adjustment procedure, indicating that the Tibetan Plateau’s summer precipitation is highly predictable over ten-year time scales.

The Tibetan Plateau has the most glaciers outside of the Arctic and Antarctic. Melt water supplies more than 10 major rivers, including the Yangtze River, the Yellow River and the Ganges. “Our results mean a lot for the management of water resources for about 40% of the world’s population,” ZHOU said.

Based on real-time forecasts, the researchers revealed that the Tibetan Plateau hinterland will become wetter, with a 12.8% increase in rainfall for the period 2020-2027 compared to 1986-2005.

“The government and scientists have recognized the urgent need for effective short-term climate information (2021-2040), but there are large uncertainties in traditional short-term climate projections based on summer rainfall scenarios on the Tibetan Plateau. due to internal variability. in the climate system, ”ZHOU said. “Our results demonstrate that decadal climate prediction systems can be a valuable tool in overcoming the shortcoming of traditional projection uncertainties based on short-term climate change scenarios on the Tibetan Plateau.”

###


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of any press releases posted on EurekAlert! by contributing institutions or for the use of any information via the EurekAlert system.


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New Research Finds Climate Models Usually Do It Right

New climate research, conducted primarily in San Diego, reveals that a study of Earth’s temperatures during the last ice age confirms some widely held ideas about climate change.

Lead author Alan Seltzer, a paleoclimatologist at the Wood’s Hole Institute of Oceanography, studied ancient water as a way to better understand never-before-recorded planetary temperatures.

New Research Finds Climate Models Usually Do It Right

Hear this story from Erik Anderson.

New Research Finds Climate Models Usually Do It Right

Working in the oceanography laboratory of the Scripps Institution of Oceanography at Jeffery Severinghaus in La Jolla, Seltzer analyzed the composition of ancient groundwater in San Diego and other places around the world.

“A huge amount of our planet’s land surface, like about a third of our planet’s land surface, contains ancient water that has fallen as rain or entered the subsoil as runoff from the earth. rivers during the last ice age, ”said Seltzer.

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After chemically dating the water using radiocarbon techniques, the researchers measured the amount of rare gases dissolved in the water. They compiled data on all continents except Antarctica.

“Paleo noble gas temperature records are so powerful because they are based on a physical principle and are not influenced much by life – which always complicates everything – or by extreme short-term events,” said co-author Martin Stute, researcher in the Department of Environmental Sciences at Barnard College and Associate Principal Investigator at the Lamont-Doherty Earth Observatory.

This technique allowed researchers to extrapolate the temperature of the planet during the last ice age.

He also confirmed the results that determine ocean temperatures during this period, giving scientists more confidence in models that predict climate change.

“This gives the models a little more confidence in a longer term climate perspective well beyond human observation,” said Seltzer.

Researchers can tell with more confidence what the temperature of the earth will be based on the amount of carbon in the air.

“The most important thing he tells us is that the models are actually on the right track and we can believe the models more than before so that we can believe them,” Severinghaus said.

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Previous work seriously underestimated the climate’s sensitivity to greenhouse gases, according to Severinghaus. Climate change could be more destabilizing than current forecasts predict, he said.

“The rather high climate sensitivity that our results suggest is not good news regarding future global warming, which could be stronger than expected using previous best estimates,” said co-author Werner Aeschbach, researcher at the Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany.

“In particular, our overall review strengthens the conclusion from several single rare gas case studies that the tropics were significantly colder during the last ice maximum than today. The unpleasant implication for the future is that the warmer regions of the world are not immune from further warming, ”he said.

The results are published in the current edition of the journal Nature.


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Scientists explain why climate models cannot r

image: Warming rate during the rapid warming period (1975 / 01-1997 / 12) (a) and warming gap period (1998 / 01-2013 / 12) (b) and the change in warming rate during the period of hiatus from the period of rapid warming (c). All warming rates are derived from 28 simulated global temperature time series (bars) and six observed (vertical lines).
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Credit: © Science China Press

A new study led by Dr Wei and Dr Qiao of the First Institute of Oceanography at the Department of Natural Resources provides an assessment of the performance of recently published CMIP6 models to simulate the slowdown in global warming observed in the early 2000s. This study reveals that the key to simulating and predicting short-term temperate change is to separate and properly simulate the two distinct signals i.e. the human-induced long-term warming trend and natural variabilities, in particular those at interannual, interdecadal and multidecadal scales. . This work was published online in SCIENCE CHINA Earth Sciences on April 15, 2021.

After the unprecedented warming during the last quarter of the 20th century, the growth of global surface temperature unexpectedly slowed between 1998 and 2013 despite the sharp increase in greenhouse gas emissions; this phenomenon is called hiatus or slowing down of global warming to be more precise. Slowing global warming challenges existing scientific understanding of the mechanisms of global temperature change, so has been one of the most worrying issues in recent climate research and even the public.

However, the sophisticated and advanced climate models of CMIP5 could not simulate this slowdown in warming. Over the period 1998-2013, the models mainly show a rapid warming surge that deviates considerably from the observed flat temperature time series. The models considerably overestimate the rate of warming observed over the recent period. IPCC AR5 said: “Almost all historical CMIP5 simulations do not reproduce the recent observed warming gap.” As a result, the ability to simulate and predict sophisticated climate models has been called into question.

Now, CMIP6 model data is gradually released since 2020. Newly developed models include a better understanding of the mechanisms of global temperature change, in particular more reasonable physical processes of natural variability. Successful simulations of the global warming slowdown are expected in next-generation models. As data from 28 new models becomes available, there is a need to timely review the ability of CMIP6 models to exhibit the recent slowing of warming.

Against six widely used global surface temperature datasets, the research team at the First Institute of Oceanography at the Department of Natural Resources are evaluating the performance of the 28 newly released CMIP6 models to simulate the recent slowdown in warming and find that the Most CMIP6 models still fail to reproduce. slowing warming, although they show encouraging improvements over the CMIP5 models (Figure 1).

In addition, they explored possible reasons for the difficulty of CMIP6 models in simulating the recent slowdown in warming. They reveal that it is associated with model shortcomings in simulating temperature change signals distinct from the long-term human-induced warming trend and / or the three crucial natural variabilities at interannual, interdecadal and multidecadal scales ( Figure 2).

This study reveals that the key to simulating and predicting short-term temperate change is to separate and properly simulate the two distinct signals, i.e. the human-induced long-term warming trend and variability. natural, in particular those at interannual, interdecadal and multidecadal scales. . This suggests that key-scale variabilities require more attention in models, given their vital roles in modulating the change in the rate of warming at decadal to multi-decadal scales. This result can provide important information for simulating and predicting short-term climate change.

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This research was funded by the National Natural Science Foundation of China (No. 41806043 and 41821004).

See the article: Wei M, Shu Q, Song Z, Song Y, Yang X, Guo Y, Li X, Qiao F. 2021. Could CMIP6 climate models reproduce the slowdown in global warming of the early 2000s? Science China Earth Sciences, 64, https://doi.org/10.1007/s11430-020-9740-3


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