In terms of climate mitigation, forests are like green gold—working overtime to cool the planet, while also supporting a wealth of biodiversity. But we have not been saving them as one would a precious asset. Despite pledges to end deforestation, old growth forests are being cut down at alarming rates. And planting new trees is widely prioritized and incentivized over protecting existing forests. Across the board, standing forests are vastly undervalued. This has to change if we are to stand a chance of limiting warming to internationally agreed targets.
According to a recent study from scientists at Woodwell and the University of Virginia, tropical forests alone are holding back approximately 1 degree Celsius of warming. About 75% of that cooling effect is due to carbon sequestration. Forests grow, trees lock away carbon in their trunks and roots and shunt it into the soil. The other 25% comes from the innate properties of forests that work to cool vast regions of the globe.
Through photosynthesis, plants release water vapor into the air in a process called evapotranspiration. The vapor contributes to cooling near the ground, as well as cloud formation higher in the atmosphere that reduces incoming solar radiation. The shape of the tree canopy also contributes. So-called canopy “roughness” 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, with the heat dispersed throughout the deep atmosphere.
Forests also naturally produce molecules called biogenic volatile organic compounds (BVOC), which 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 these chemicals is cooling.
The cumulative result of these properties is that when forests are removed, the land around them begins to heat up even faster, which can increase the frequency of extreme heat and drought events. Without forests, some regions will become a lot less resilient to sudden shocks. And the release of carbon contributes to global warming which further exacerbates hot, dry conditions.
“Forests act like air conditioners,” says Woodwell Assistant Scientist, Dr. Ludmila Rattis, who studies the impacts of deforestation on agriculture in Brazil. “Deforesting in the face of climate change is like getting rid of your air conditioners before an upcoming heatwave.”
Protecting forests, and maintaining the cooling services they provide, is vital to limiting warming. But, with forests covering 30% of the Earth’s land, prioritizing protection is a massive task. And when it comes to carbon storage, not all forests are equally valuable. Older, healthier forests tend to have a more secure hold on their carbon.
“Mature forests have higher biodiversity and create their own microclimate,” says Woodwell Associate Scientist, Brendan Rogers. “They’re more resistant to drought and other types of disturbance. And because of that, they tend to be more stable in the face of environmental perturbations over time.”
New research from Woodwell and Griffith University has developed a method of identifying high-value forests using satellite imagery. Estimating the metric of “forest stability” through satellite data on the light reflected by vegetation and a water stress index of the tree canopy, researchers were able to determine gradients of stability within forest patches in the Amazon and boreal forests.
Using a gradient of forest stability allows for a better prioritization of forest protection strategies based on their carbon value.
“The first priority is to protect stable forests from further human disturbance,” says paper co-author Dr. Brendan Mackey. “The second priority is to identify forest areas where restoration efforts will be most cost effective.”
But if the state of existing forests is any indication, forest protection continues to be deprioritized. Many wildfires are left to burn unless they threaten human settlements. Governments continue to incentivize deforestation for development or agricultural expansion. Indigenous and local communities are not compensated for their work stewarding their territories and keeping forests safe. And the warmer the planet gets, the more susceptible even protected forests become to drought, fire, and disease.
Research has shown that stewarding standing primary forests, and reviving degraded ones, represents the greatest opportunity for near-term carbon storage and removal. A study of global land-based carbon storage potential found that improved management of existing forests alone could store approximately 215 billion metric tons more than they currently do.
Protecting forests is cost effective, too. For example, in the United States, investing in fire fighting in Alaska’s boreal forests would require just $13 per ton of CO2 emissions avoided. That’s easily on par with other mitigation strategies like onshore wind or solar energy generation.
Effective strategies for protecting forests already exist, they’ve just been suffering from a lack of force—and often funding—behind their implementation. For example, forest carbon markets—where landowners and forest stewards are paid to protect standing forests that are otherwise vulnerable to deforestation—have the potential to keep forests safe while offsetting emissions from other sectors. But nascent carbon markets are inefficient, with weak standards for verifying the quality of credits being sold, and lacking the transparency needed to ensure credits are actually reducing overall emissions, rather than greenwashing carbon-intensive business practices.
Credits are also priced incorrectly for their relative climate value—the market currently values reforestation credits more highly, reducing incentive for landowners to conserve standing, old-growth forests when there is a better livelihood to be made in legally deforesting land for other uses. A truly effective carbon markets system would require large investments in science that can verify credit standards.
Forests are like our global carbon savings accounts—when we cut them down, we’re drawing out money and limiting our ability to collect interest and keep growing our funds. Successful mitigation can’t be accomplished without taking the full value of forests into account and strengthening policies to reflect that. If they aren’t, the planet will pay a far greater price for it as temperatures rise.
“We can’t afford to keep cutting forests. We need to reduce emissions now, and protecting forests is one of our best available solutions. Despite the obstacles, it’s worth the investment,” says Dr. Rogers.
With the Arctic warming 3 to 4 times faster than the rest of the world, permafrost thaw has become a significant climate threat. Scientists estimate that permafrost contains 1.4 trillion tonnes of carbon, an amount more than double what is currently in the Earth’s atmosphere. That carbon sink is stable as long as it stays frozen, but with recent and projected thaw, the organic matter in permafrost is breaking down and releasing carbon dioxide and methane into the atmosphere, increasing the rate of climate change.
Addressing this issue requires extensive data collection on permafrost emissions, as well as equitable strategies for adaptation by Arctic communities. To tackle this issue, Woodwell has partnered with the Arctic Initiative at Harvard Kennedy School, the Alaska Institute for Justice, and the Alaska Native Science Commission to connect experts in climate science, human rights, and public policy with frontline communities and high-level decision makers. The partnership is pioneering a six-year research program called Permafrost Pathways that will develop action plans to address the compounding impacts of permafrost thaw.
With the understanding that this needs to be a sustainable process with long-term impact, Permafrost Pathways’ scientists are expanding and coordinating a pan-Arctic carbon monitoring network to improve the accuracy of permafrost thaw emissions estimates. More precise measurements will fill critical data gaps and reduce uncertainties, so that permafrost emissions can be factored into global carbon budgets, climate models, targets, and measures for mitigation and adaptation. That, combined with high-resolution satellite and aircraft-based observations and advanced computer modeling, will allow for tracking the changing landscape in near real-time and more accurately projecting future emissions.
Permafrost Pathways is also collaborating with local communities to co-create Indigenous-led adaptation strategies. For many, relocation or infrastructure upgrades are needed urgently, but there is currently no process or resources to enable communities to move forward. With Arctic residents already feeling the brunt of climate change, the involvement of frontline communities is crucial in developing successful adaptation plans and effective policies.
Despite its big strides, Permafrost Pathways is still in its infancy and there is a long road ahead when it comes to tackling the complexity of permafrost thaw. Today, at least 192 countries, plus the European Union, have signed on to the Paris Agreement’s promise of reducing emissions to keep warming below 2 degrees C. But many emissions reduction goals do not include carbon released by permafrost thaw. The international community needs to take strong action to change this or else permafrost thaw could undermine climate goals.
In the Intergovernmental Panel on Climate Change’s 2021 report, permafrost thaw was named as an issue that should be included in carbon budgets and global reduction schedules, but often isn’t because there is not enough data on its climate impact. Continued support of data gathering programs like Permafrost Pathways will provide the international community, top country-level climate negotiators, and environmental ministers the knowledge needed to fix that oversight and start filling gaps.
In Arctic communities, permafrost thaw is already causing disasters like flooding, coastal erosion, and infrastructure damage. To combat this, national and international policy makers need to act now to integrate permafrost thaw into disaster policies and community-led adaptation frameworks. This will create clear planning and response procedures for future permafrost-related issues.
Permafrost thaw is an issue that affects everyone. Understanding the local and global implications and sharing that information within immediate social circles as well as on social media platforms can help start conversations that spur action. The public also has the power to influence the development of climate policies by pressuring elected officials to tackle this serious issue.>
For more information about the issues surrounding permafrost thaw, read part one and part two in our Permafrost series. To stay informed and get involved, visit the Permafrost Pathways site.
A 2022 Intergovernmental Panel on Climate Change (IPCC) report confirms that the Earth is on track to warm 1.5 degrees celsius by 2040. Warming beyond this will cause global issues like struggling coral reefs, catastrophic storms, and extreme heat waves. The international community has developed a global carbon budget that tracks how much carbon can be added to the atmosphere by human-caused emissions before we push warming past 1.5 and even 2 degrees. It functions much like a household budget— where spending more than you earn can jeopardize your stability and comfort.
With the carbon budget, that means balancing how much carbon is released into the atmosphere with how much is being stored by natural sinks. According to the IPCC, the world needs to wean itself off of “spending” down that budget as we rapidly approach 2 degrees of warming.
But IPCC’s budget calculations aren’t factoring in a major source of emissions—permafrost thaw. Massive amounts of carbon are stored in frozen Arctic soils known as permafrost. As permafrost thaws, that carbon is released into the atmosphere in the form of carbon dioxide and methane. Scientists estimate that emissions from permafrost thaw will range from 30 to 150 billion tons this century.
Despite being on par with top-emitting countries like India or the United States, permafrost thaw is not included in the global carbon budget. It has historically been excluded because of gaps in data that make existing estimates of emissions less precise. Dr. Max Holmes, President of Woodwell Climate Research Center, says it’s “especially alarming… that permafrost carbon is largely ignored in current climate change models.” That’s because permafrost thaw emissions could take up 25-40% of our remaining emissions budgeted to cap warming at 2°C. Imagine leaving the cost of rent out of your household budget. It doesn’t mean you don’t have to pay it, it just means you won’t be prepared when that bill arrives.
Excluding permafrost thaw also means that projections of the rate of warming will be off. The unaccounted carbon will speed up warming, reducing the amount of time we have to avoid the worst impacts of climate change.
Permafrost thaw is already negatively impacting Arctic residents, especially Indigenous communities. In 2019, a Yup’ik community that has lived in Newtok, Alaska for hundreds of years had to begin moving to higher, volcanic ground because the thawing permafrost under their town was causing disastrous floods and sinking infrastructure. Woodwell Arctic program director and senior scientist, Dr. Sue Natali, who studies permafrost thaw in Yup’ik territory, says “it’s a place where permafrost is on the brink of thawing, and will be thawed by the end of the century, if not much sooner.”
Since permafrost spans multiple countries, it has been difficult to determine who should take responsibility for it. Consequently, there is currently little government framework for adaptation. The Yup’ik people had to reach out to a variety of government agencies and lived without plumbing for decades before the federal government finally awarded them support for relocation. The community paid a heavy price for it, though. Without proper policy in place to manage climate relocation, they had to bargain for government assistance, and in the end, turned ownership of the land they were leaving over to the U.S. government.
It took sixteen years from when Congress agreed to assist the Yup’ik community to when their promises were put into action. While scientists, like the ones spearheading Woodwell’s Permafrost Pathways program, are monitoring and modeling thaw to better prepare people for the damage it can cause, vulnerable communities do not have sixteen years to wait for assistance and relocation.
If permafrost thaw continues to be overlooked by government agencies, then it will remain difficult to prevent the Earth from warming beyond 2ºC and to support frontline communities most affected by it. Tackling permafrost thaw for both Arctic communities and the planet will require a coordinated international effort.
Looking for some background on Permafrost? Read the first piece in our permafrost series: “What is Permafrost?” To learn about what must be done to combat this issue, read part three: “What can be done about permafrost thaw?”
Thinking about climate change usually brings to mind dramatically melting ice caps and rising sea levels, but there’s another threat that’s caught the attention of climate scientists for its potential to be equally as disastrous—thawing permafrost.
Located anywhere between a few centimeters to 4,900ft below the Earth’s surface, permafrost is soil composed of sand, gravel, organic matter, and ice that has been frozen for at least two consecutive years. Some has been frozen for centuries or even millenia, and it’s this ancient permafrost in the Arctic that holds the greatest significance for climate change.
Arctic permafrost stretches across Alaska, Scandinavia, Russia, Iceland, and Canada, and can be found beneath the Arctic Ocean, the Arctic tundra, alpine forests, and boreal forests. It covers 15% of the land in the Northern Hemisphere and 3.6 million people live atop it. Scientists estimate that Arctic permafrost contains 1.4 trillion tonnes of carbon, an amount more than double what is currently in the Earth’s atmosphere. That carbon sink is stable as long as it stays frozen, but when it thaws, soil microbes break down the organic matter in permafrost and release carbon dioxide and methane into the atmosphere, increasing the rate of climate change.
In many places, forests, plants, and peat act as protective insulation for Arctic permafrost. This insulation helps keep carbon-storing organic matter, like plants and animals, as well as bacteria and archaea, frozen in the permafrost. However, climate change is already causing the Arctic to warm three to four times faster than the rest of the planet.
In addition to rapid warming speeding decay, it also strips back permafrost’s protective layers with increasing fires and heavy summer rains that burn and erode away top soil layers, further accelerating thaw. In some places, permafrost thaws so abruptly that the ground can collapse. Developing infrastructure that requires deforestation and underground pipes further exposes permafrost to warming. Additionally, as sea ice melts, coastal Arctic permafrost is exposed to warmer waters. The combined result is extensive permafrost thaw across the region.
Researchers have been studying permafrost thaw to determine the size of the threat it poses. Methods such as placing soil moisture sensors in strategic locations and examining soil cores collected by drilling holes into the soil to document the different layers of permafrost help gauge the rate and extent of thaw.
In a recent TEDTalk, Dr. Sue Natali, Woodwell’s Arctic program director and senior scientist, cautioned that, “By the end of this century, greenhouse gas emissions from thawing permafrost may be on par with some of the world’s leading greenhouse-gas-emitting nations.”
There are already visible signs of vast permafrost thaw in the Arctic. Since ice is an essential part of the ground’s structural integrity, the soil becomes unstable when it thaws. This leads to dangerous situations like landslides, sinkholes, and destabilized infrastructure that threaten millions of people. Remote communities are particularly impacted, losing access to roads and sources of freshwater.
For both the carbon it threatens to release, and the destabilizing impacts it has on Arctic residents, permafrost thaw is a serious threat. One that, as the Arctic continues to warm, demands urgent attention and remediation.
Until now, that attention has been slow in coming. Read about why combatting permafrost thaw is such a complex issue in part two of our Permafrost series: “The critical missing expense in global climate budgets.”
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.
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.
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.