A sudden flip in weather conditions—from a long hot and dry period to a parade of storms, for example, or from abnormally mild winter temperatures to extreme cold—can cause major disruptions to human activities, energy supplies, agriculture, and ecosystems. These shifts, dubbed “weather whiplash” events, are challenging to measure and define because of a lack of consistent definition. A new study demonstrates an approach to measuring the frequency of these events based on rapid changes in continent-wide weather regimes.
The study indicates that, while the frequency of whiplash events in recent decades has not changed substantially, future model projections indicate increases will occur as the globe continues to warm under a thicker blanket of greenhouse gasses. In particular, the researchers find whiplash will increase most during times when the Arctic is abnormally warm, and decrease when the Arctic is in a cold regime—something that will occur less often as the planet warms.
Examples of weather whiplash during 2022 so far include a long, hot, drought in western U.S. states during early summer that was broken by record-breaking flash flooding; exceptionally wet and cool conditions during June in the Pacific Northwest replaced by a heat wave in July; a record-warm early winter for most south-central states followed by a cooler-than-average January and February; and a spell of 67 consecutive hot, dry days in Dallas, TX, broken by the heaviest rains in a century.
“The spring and summer of 2022 have been plagued by weather whiplash events,” said lead author, Dr. Jennifer Francis, Senior Scientist at the Woodwell Climate Research Center. “A warming planet increases the likelihood of longer, more intense droughts and heat waves, and we’re also seeing these spells broken suddenly by heavy bouts of precipitation, which are also fueled by the climate crisis. These sudden shifts are highly disruptive to all sorts of human activities and wildlife, and our study indicates they’ll occur more frequently as we continue to burn fossil fuels and clear-cut forests, causing greenhouse gas concentrations to rise further.”
Co-author Judah Cohen, Principal Scientist at Verisk AER noted that these phenomena are tightly linked to regional warming in the Arctic.
“We know the Arctic region is experiencing the most rapid changes in the global climate system. Evidence is growing that these profound changes are contributing to more extreme weather events outside the Arctic, and this influence will only increase in the future,” said Dr. Cohen.
What’s New?
The Cerrado is a tropical savanna located just southeast of the Amazon rainforest. This biome is a patchwork of forests, savannas, and grasslands, nearly as biodiversity rich as the Amazon yet suffering more due to lax environmental protections. Over 46% of its original land cover has already been cleared for crops or pastures. A recent study assessed the impacts of this conversion on the temperature and water cycling in the region.
The study found that clearing of natural ecosystems resulted in increased land surface temperatures and reduced evapotranspiration — water evaporated to the atmosphere both from soils and as a byproduct of plant growth. Across the biome, land use changes caused a 10% reduction in water being cycled into the atmosphere annually, and almost 1 degree C of warming. Where native savanna vegetation was cleared, temperatures increased by 1.9C and the water recycled to the atmosphere decreased by up to 27%. These changes don’t take into account the additional effects of atmospheric warming from greenhouse gas emissions.
The study also projects forward three potential future scenarios based on different levels of environmental protection. The worst-case scenario assumes an additional 64 million hectares of both legal and illegal deforestation, which would leave just 20% of native vegetation in the Cerrado by 2050. If illegal deforestation is prevented but legal deforestation still advances, an additional 28 million hectares of deforestation would continue to warm and dry out the region. Only in the most optimistic scenario, with enforced zero deforestation policies and restoration of over 5 million hectares of illegally cleared vegetation, would the impacts of past clearing begin to reverse.
“If we continue down this path of weakening environmental policies, we’re probably heading towards an uncontrolled increase in deforestation,” says Ariane Rodrigues, researcher at the University of Brasilia and lead author on the paper. “As a result, we could reach almost 1 C of temperature increase by 2050 from land use change alone. If we add the estimated temperature increase from global greenhouse gas emissions, we will have a critical situation for food production, biodiversity, water and wildfire risk, affecting areas located way beyond the biome’s limits.”
Understanding Land Use in the Cerrado
Incentives for large-scale commercial agriculture in the Cerrado date back to the 1970s. Despite its high biodiversity, only 11% of the Cerrado is protected and technological advancements provided favorable conditions for agriculture to expand rapidly.
The half of the biome that remains unconverted is considered prime agricultural land. The Cerrado alone is responsible for 12% of global soybean production and 10% of global beef exports. Growing demand for these agricultural products is pushing farmers and ranchers to expand into the Matopiba region in the Northeast Cerrado — one of the largest remaining areas of undisturbed native vegetation.
Hotspots of reduced evapotranspiration and increased temperatures can already be seen in areas of Matopiba with intensifying agricultural activity. This means that farms will rely even more heavily on irrigation to combat drought, a strategy made less viable by the warming and drying caused by agriculture itself.
“That is the driest portion of the Cerrado, where there’s the most climate risk already,” says paper co-author and Woodwell Water program director, Dr. Marcia Macedo. “You can see that in the data — it’s getting hotter, and there’s less evapotranspiration, so we are really intensifying conflicts in areas that are already on the edge.”
What this Means for Protecting the Cerrado
The results of the paper highlight the urgent need for a paradigm shift that values the additional services the Cerrado provides beyond just crop production. Not only does it house unique ecosystems, but it plays a pivotal role in modulating the climate of the region. In the best-case scenario evaluated by the paper, zero-deforestation and restoration policies could avoid extensive warming and drying and begin compensating for the past transformation of Cerrado landscapes. Continued conversion of natural vegetation will jeopardize both biodiversity and agricultural stability in the Cerrado, as crops struggle to be productive under hotter and drier conditions.
Already, conflicts over water usage and irrigation are occurring in western Bahía state. As the region warms and dries, competition for a scarce resource will become more common and large-scale agriculture will become much less viable.
“We’re making some risky decisions in terms of land use,” says Dr. Macedo, “We’re losing a lot for short term gains in crop production, often in areas that will struggle to sustain large-scale agriculture as climate changes.”
Woodwell Team Awarded Commendation in Climate Creatives Challenge
A team of Woodwell researchers and Communications staff received a commendation in the inaugural Climate Creatives Challenge (CCC). The CCC is a series of design challenges created to encourage new ways of communicating the impacts of climate change and the benefits of adaptation. The first challenge engaged creators working across different media—from film to photography, sculpture, and graphic design— on the topic of extreme flooding.
The challenge asked: “How can we communicate the impacts of flooding (past, present or future) and the benefits of adaptation and resilience?”
The Woodwell team used the Center’s flood risk analyses to create an animated infographic demonstrating how extreme flooding could disrupt essential daily tasks for residents of Lawrence, MA. It compares two different neighborhoods to highlight that risk exposure can vary significantly within the same city, and that poorer residents often suffer the first and worst impacts.
Finding out-of-the-box ways to communicate the impacts of climate change is important, as solving the climate crisis will require us to engage audiences from diverse backgrounds and spur them to action.
“The beauty of climate communication is finding ways to overcome the challenge of informing people in a way that elicits empathy and inspires action, rather than overwhelming them into passivity,” says challenge participant and Woodwell Arctic communications specialist, Jessica Howard. “The Climate Creatives Challenge seemed like the perfect opportunity to not only take a more imaginative approach to communicating the impact of the climate crisis but to also further reveal how race and financial privilege make a difference in who bears the brunt of it.”
Contest judges awarded the graphic a commendation, stating that it was, “visually engaging” and “a clever depiction of disruption and inequality.” The final piece was featured in the compendium for Challenge One alongside other winners. Winners will also be displayed at Flood Expo in Birmingham, UK, September 14 and 15.
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Recent study shows widespread patterns of loss, upending scientists’ previous projections
The Arctic is no stranger to loss. As the region warms nearly four times faster than the rest of the world, glaciers collapse, wildlife suffers and habitats continue to disappear at a record pace.
Now, a new threat has become apparent: Arctic lakes are drying up, according to new research published in the journal Nature Climate Change. The study, led by University of Florida postdoctoral researcher Dr. Elizabeth Webb in collaboration with Woodwell Associate scientist, Dr. Anna Liljedahl, flashes a new warning light on the global climate dashboard.
Research reveals that over the past 20 years, Arctic lakes have shrunk or dried completely across the pan-Arctic, a region spanning the northern parts of Canada, Russia, Greenland, Scandinavia and Alaska. The findings offer clues about why the mass drying is happening and how the loss can be slowed.
The lake decline comes as a surprise. Scientists had predicted that climate change would initially expand lakes across the tundra, due to land surface changes resulting from melting ground ice, with eventual drying in the mid-21st or 22nd century. Instead, it appears that thawing permafrost, the frozen soil that blankets the Arctic, may drain lakes and outweigh this expansion effect, says Dr. Webb. The team theorized that thawing permafrost may decrease lake area by creating drainage channels and increasing soil erosion into the lakes.
These lakes are cornerstones of the Arctic ecosystem. They provide a critical source of fresh water for local Indigenous communities and industries. Threatened and endangered species, including migratory birds and aquatic creatures, also rely on the lake habitats for survival.
“Our findings suggest that permafrost thaw is occurring even faster than we as a community had anticipated,” Dr. Webb said. “It also indicates that the region is likely on a trajectory toward more landscape-scale drainage in the future.”
If accelerated permafrost thaw is to blame, that’s unwelcome news. The Arctic permafrost is a natural warehouse of preserved organic matter and planet-warming gasses.
“Permafrost soils store nearly two times as much carbon as the atmosphere,” Dr. Webb said. “There’s a lot of ongoing research suggesting that as permafrost thaws, this carbon is vulnerable to being released to the atmosphere in the form of methane and carbon dioxide.”
According to Dr. Liljedahl, this study shifts the perspective on prior research—there is still more to learn when it comes to how climate change is altering the Arctic landscape.
“This work shows that we are “living the future” already,” said Dr. Liljedahl. “Or if you look at it from the other perspective, the current models used to project future surface water coverage and permafrost thaw across the Arctic are “off”. They are not capturing key processes. We have already seen reduced lake coverage happening over the previous two decades.”
There is a silver lining in the researcher’s findings. Previous models of lake dynamics predicted lake expansion, which thaws the surrounding permafrost. But because lakes are drying, near-lake permafrost is likely not thawing as fast.
“It’s not immediately clear exactly what the trade-offs are, but we do know that lake expansion causes carbon losses orders of magnitude higher than occurs in surrounding regions,” Dr. Webb said. “So it should mean that we won’t see quite as much carbon emitted as previously thought, because lakes are drying and not wetting.”
The research team used a machine-learning approach to examine the climate change mechanisms responsible for lake area change. By harnessing large ensembles of satellite images to assess patterns of surface water loss, they were able to analyze decades of data across the Arctic. The data is available on the Permafrost Discovery Gateway (PDG), a project that Dr. Liljedahl leads, the goal of which is to make permafrost data broadly accessible to encourage Arctic change research.
“We made the pan-Arctic dataset, including both long-term trend analysis and individual years, accessible on the PDG so that anyone with internet access can interact with the dataset. We are still building the PDG visualization and analysis tools so more options to enable discovery will become available in the coming two years,” said Dr. Liljedahl
The best way to curtail the lakes’ demise and protect permafrost is to
cut fossil fuel emissions and limit global temperature rise.
“The snowball is already rolling,” Webb said, stating that we need to act now to slow these changes. “It’s not going to work to keep on doing what we’re doing.”
It was supposed to be a quiet season, but only two months into summer and Alaska is already on track for another record-setting wildfire season. With 3 million acres already scorched and over 260 active fires, 2022 is settling in behind 2015 and 2004 so far as one of the state’s worst fire seasons on record. Here’s what to know about Alaska’s summer fires:
2. Historic fires are Burning in Yukon-Kuskokwim Delta and Bristol Bay
Southwestern Alaska, in particular, has been suffering. The season kicked off with an unseasonably early fire near Kwethluk that started in April. Currently, the East Fork Fire, which is burning near the Yup’ik village of St. Mary’s, AK, is among the biggest tundra fires in Alaska’s history. Just above Bristol Bay, the Lime Complex— consisting of 18 individual fires— has burned through nearly 865,000 acres. One of the longest lasting fires in the Lime Complex, the Upper Talarik fire, is burning close to the site of the controversial open-pit Pebble Mine.
2. Seasonal predictions showed a low-fire season
For Dr. Brendan Rogers, who was in Fairbanks, AK for a research trip in May, the explosive start of the fire season contrasts strongly to conditions he saw in late spring.
“It was a relatively average spring in interior Alaska, with higher-than-normal snowpack. Walking around the forest was challenging because of remaining snow, slush, and flooded trails,” said Dr. Rogers.
Early predictions showed a 2022 season low in fire due to heavy winter snow. But the weather shifted in the last ten days of May and early June. June temperatures in Anchorage were the second highest ever recorded. High heat and low humidity rapidly dried out vegetation and groundcover, creating a tinderbox of available fuel. This sudden flip from wet to dry unfolded similarly to conditions in 2004, which resulted in the state’s worst fire season on record.
3. Climate Change is accelerating fire feedback loops
The conditions for this wildfire season were facilitated by climate change, and the emissions that result from them will fuel further warming. The hot temperatures responsible for drying out the Alaskan landscape were brought on by a persistent high pressure system that prevents the formation of clouds— a weather pattern linked to warming-related fluctuations in the jet stream.
“With climate change, we tend to get more of these persistent ridges and troughs in the jet stream,” says Dr. Rogers. “This will cause a high pressure system like this one to just sit over an area. There is no rain; it dries everything out, warms everything up.”
The compounding effects of earlier snowmelt and declining precipitation have also made it easier for ground cover to dry out rapidly under a spell of hot weather. More frequent fires also burn through ground cover protecting permafrost, accelerating thaw that releases more carbon. According to the Alaska Center for Climate Assessment and Policy, the frequency of big fire seasons like this one are only increasing— a trend expected to continue apace with further climate change.
Additionally, this summer has been high in lightning strikes, which were linked to the ignition of most of the fires currently burning in Alaska. Higher temperatures result in more energy in the atmosphere, which increases the likelihood of lightning strikes. On just one day in July over 7,180 lightning strikes were reported in Alaska and neighboring portions of Canada.
4. Communities are Being Affected Hundreds of Miles Away
The destruction from these wildfires has forced rural and city residents alike to evacuate and escape the path of burning. Some residents of St. Mary’s, AK have elected to stay long enough to help combat the fires, clearing brush around structures and cutting trees that could spread fire to town buildings if they alight.
But the impact of the fires is also being felt in towns not in the direct path of the flames. Smoke particulates at levels high enough to cause dangerously unhealthy air quality were carried as far north as Nome, AK on the Seward Peninsula.
“Even though a lot of these fires are remote, that doesn’t preclude direct human harm,” says Woodwell senior science policy advisor Dr. Peter Frumhoff.
Recent research has shown that combatting boreal forest fires, even remote ones, can be a cost effective way to prevent both these immediate health risks, as well as the dangers of ground subsidence, erosion, and loss of traditional ways of life posed by climate change in the region.
5. The season is not over yet
Mid-July rains have begun to slow the progression of active fires but, according to Dr. Frumhoff, despite the lull, it is important to keep in mind that the season is not over yet.
“The uncertainty of those early predictions also applies to the remainder of the fire season — we don’t know how much more fire we’ll see in Alaska over the next several weeks.”
It’s a windy morning in May and the Valdez ranch in Delta County, Colorado is alive with the sounds of lowing cattle, chattering sparrows, and the whirrs and clanks of scientific equipment. This particular field is not being grazed at the moment, so Woodwell’s soil carbon team has free rein over the rows of alfalfa and sweetgrass.
In collaboration with Dr. Megan Machmuller at Colorado State University, Assistant scientist Dr. Jennifer Watts and senior scientist Dr. Jon Sanderman have brought their teams here to collect field observations that will help inform a comprehensive model of carbon storage on rangelands across the United States. Grazing lands have the potential to be a valuable carbon sink, provided the livestock on them are being sustainably managed, but the true magnitude of that value is not yet well understood. Developing a regional model of the way carbon moves through rangelands will deepen our understanding of the role they play as a natural climate solution.
Ensuring the model’s accuracy requires the team to collect an array of field data from different ranch types—from irrigated and planted pasture, to the natural vegetation of high mountain and desert grazing lands. Here’s how climate scientists study carbon in the field:
Carbon flux: What’s moving in and out of the atmosphere?
Soil carbon storage begins where plants interact with the air. As they grow, plants draw carbon out of the atmosphere through photosynthesis. When they decay, microbes in the soil digest plant matter and breathe carbon dioxide and methane back out. Measuring the difference between these two processes gives us “net ecosystem flux”—a measure of whether a patch of land is sequestering or emitting carbon overall.
Measuring carbon flux requires a specially made chamber. Dr. Watts and Seasonal Field Technician Jonas Noomah employed a plexiglass contraption that Noomah constructed himself. The chamber is placed over a patch of ground, connected by clear tubes to a machine that can analyze the volume of CO2 within the cube. A handheld fan dangles inside the box to keep the air circulating. The transparent plexiglass allows photosynthesis to continue unhindered. After a few minutes, the box is covered to block out the light and the analysis is run again to capture emissions without the photosynthesis component. The numbers can be compared to assess the rate and overall carbon sink or source status of flux within the ecosystem.
Plant productivity: What’s growing under-hoof?
While plants are growing, they lock away carbon as part of their leaves, stems, and roots, so another important metric in the carbon model is plant productivity—more productive plants with established root systems are more likely to store more carbon belowground.
Productivity can be estimated with satellite imagery, but needs to be validated with on-the-ground measurements. Postdoctoral researcher Dr. Yushu Xia and research assistant Haydée Hernández-Yañez walked transects of pasture to collect data on a variety of indicators that could influence aboveground (and belowground) biomass, including height of vegetation, soil moisture, and temperature. Then the scissors come out and all the plants in a plot are cut and put into a labeled paper bag to be weighed and analyzed later in a lab to determine the total mass of plant matter.
Rangelands managed for better carbon storage also come with a host of co-benefits, including higher levels of plant diversity. Different plants cycle carbon and other nutrients at different rates, so Hernández-Yañez sifts through the vegetation before it’s snipped, identifying and recording the species to provide more detail in productivity estimates.
Soil carbon: What’s locked deep in the ground?
Over time, carbon passes out of the cycle of growth and decay, becoming locked underground as soil organic carbon. Accessing and analyzing soil organic carbon requires coring deep into the earth and pulling out a stratified cylinder of dirt. Dr. Machmuller led the team’s soil coring effort along with Dr. Sanderman and research assistant Colleen Smith.
With a hydraulic soil coring machine attached to the back of a pickup truck, the team rambled through muddy pasture and over sharp bushes to collect 50 centimeter cores. When the terrain was too steep, they pulled out a handheld corer that had to be driven into the soil with a sledgehammer.
The soil cores are separated into three sections and crumbled up. Smith then uses a handheld scanner that employs the same technology used by astronomers to determine the chemical makeup of distant star systems to read the carbon content of each section. The scanner bounces light off the soil particles and the pattern of reflection gives clues to what molecules are present at different depths. Abundance of carbon is sometimes obvious to the naked eye in the cores, showing up as darker, wet sticky soil.
Putting data in the hands of land managers
Drs. Watts and Sanderman and their team are in the process of creating a rangeland carbon management tool that will make the soil carbon data model accessible directly to ranch managers. The website, developed by Dr. Xia, will generate data on carbon and plant productivity, for any geographic area down to the size of a single pasture. The hope is that the tool could be integrated into land managers long-term decision making, and show the results of adapting to more holistic, sustainable management practices over time.
“In the western US on our rangelands, just like in our croplands, we can change how we manage in a way that potentially could become a natural climate solution,” says Dr. Watts. “One where we’re bringing in more carbon than we’re emitting and we’re creating ecosystems that not only are beneficial for carbon sequestration, but also have more biodiversity, offer more habitat for wildlife, and more water conservation.”
Demonstrating the co-benefits of managing rangelands for carbon will also help expand conversations about whether ranching can be done sustainably, from the ground up.
“It allows for transfer of climate solutions into the hands of practitioners who may not otherwise think about climate change. It opens the conversation.” says Dr. Watts.
Ultimately, having that data could be useful for rangeland managers taking part in carbon credit markets, which could help them get paid for sustainable management.
“Rangelands haven’t been included in voluntary carbon credit markets like cropping systems have,” says Dr. Sanderman. “Their monitoring is a big problem because there’s so much land. How do you keep track of all that? That’s what our tool will be able to offer.”
The Amazon rainforest is one of the planet’s best natural climate solutions. Roughly 123 billion tons of carbon are estimated to be stored in the trees and soils of the Amazon and, if protected, it has the power to continue sequestering billions of tons of carbon each year.
But that irreplaceable carbon sink is under steady threat from a cycle of deforestation, fire, and drought that is both exacerbated by and contributing to climate change. Preliminary analysis from Woodwell of last year’s data has outlined that the most vulnerable regions of the Amazon are where drought and deforestation overlap.
2021 data shows deforestation drives fire in the Amazon
Unlike temperate or boreal forest ecosystems—or even neighboring biomes in Brazil— fires in the Amazon are almost entirely human caused. Fire is an intrinsic part of the deforestation process, usually set to clear the forest for use as pasture or cropland. Because of this, data on deforestation can provide a good indicator of where ignitions are likely to happen. Drought fans those flames, producing the right conditions for more intense fires that last longer and spread farther. Examining the intersection between drought and deforestation in 2021, Woodwell identified areas of the Amazon most vulnerable to burning.
Areas of deforestation combined with exceptionally dry weather to create high fire risk in northwestern Mato Grosso, eastern Acre, and Rondonia. Although drought conditions shifted across the region throughout the course of the year, deforestation caused fuel to accumulate along the boundaries of protected and agricultural land.
These areas of concentrated fuel showed the most overlap with fires in 2021, indicating that without the ignition source that deforestation provides, fires would be unable to occur, even during times of drought.
In June of 2021, we identified a dangerous and flammable combination of cut, unburned wood and high drought in the municipality of Lábrea, that put it at extreme risk of burning. Data at the end of December of 2021 confirmed this prediction. The observed fire count numbers from NASA showed that last year, Lábrea experienced its worst fire season since 2012.
Fires and climate change form a dangerous feedback loop
As a result of deforestation in 2021, at least 75 million tons of carbon were committed to being released from the Amazon. When that cut forest is also burned, most of the carbon enters the atmosphere in a matter of days or weeks, rather than the longer release that comes from decay.
This fuels warming, which feeds back into the cycle of fire by creating hotter, drier, conditions in a forest accustomed to moisture. Drought conditions weaken unburned forests, especially around the edges of deforestation, which makes them more susceptible to burning and releasing even more carbon to the atmosphere to further fuel warming.
Fire prevention strategies enacted by the current administration over the past 3 years have been insufficient to curb burning in the Amazon, because the underlying cause of deforestation remains unaddressed. Firefighting crews are not sufficiently supported to continue their work in regions like Lábrea that are actively hostile to combating deforestation and fire. If deforestation has occurred, fire will follow. To ensure the safety of both the people and the forests in these high-risk municipalities, the root causes of deforestation must be addressed with stronger and more strategic policies and enforcement.
Forests are one of our best natural climate solutions for combating increasing global temperatures. A recent study from researchers at the University of Virginia and Woodwell Climate Research Center found that avoiding tropical deforestation could prevent more than 1 degree Celsius of atmospheric warming.
About 75% of that temperature change comes from the release of carbon stored in the large old growth forests. But there is another 25% that comes from changes in biophysical properties, of forests.
One important biophysical property is evapotranspiration. Through photosynthesis, plants release water vapor into the air that contributes to cooling near the ground, and cloud formation higher in the atmosphere, that reduces incoming solar radiation.
A second biophysical property is the roughness of the tree canopy, which disrupts air flow above the forest. The more uneven the canopy, the more turbulent the air, which disperses heat away from the surface. In the tropics, evapotranspiration and canopy roughness are high, which means that surface temperatures remain relatively low and dispersed throughout a deep atmosphere.
The picture gets more complicated when you factor in compounds called biogenic volatile organic compounds (BVOC) that forests naturally produce. These compounds can either contribute to cooling by encouraging the formation of clouds, or to warming by creating ozone and methane. In the tropics, the net effect of BVOCs is cooling.
Outside of the tropics, different biophysical effects dominate. In the Arctic, the ability of different surfaces to reflect energy plays a large role in regional cooling. Features like snow cover can dramatically impact the amount of reflection.
The study shows that protecting forests is vital to combating climate change. Forests are not only key to storing and sequestering carbon, but also to regional adaptation as temperatures rise. Their innate properties keep us cool.