Explore these 15 maps by award-winning Woodwell Climate cartographers Greg Fiske and Christina Shintani. Created in 2024, each tells a story about the immense beauty of the high north, the dramatic changes unfolding as the Arctic continues to warm three to four times faster than the rest of the world, and the equitable solutions being developed to address climate impacts in the region

Climate Impacts on Boreal Fire

In order for a fire to start, you need three things— favorable climatic conditions, a fuel source, and an ignition source. These elements, referred to as the triangle of fire, are all being exacerbated as boreal forests warm, resulting in a fire regime with much larger and more frequent fires than the forests evolved with.

Climate conditions

Forest fires only ignite in the right conditions, when high temperatures combine with dryness in the summer months. As northern latitudes warm at a rate three to four times faster than the rest of the globe, fire seasons in the boreal have lengthened, and the number of fire-risk days have increased.

In some areas of high-latitude forest, climate change has changed the dynamics of snowfall and snow cover disappearance. The rate of spring snowmelt is often an important factor in water availability on a landscape throughout the summer. A recent paper, led by Dr. Thomas Hessilt of Vrije University in collaboration with Woodwell Associate Scientist, Dr. Brendan Rogers, found that earlier snow cover disappearance resulted in increased fire ignitions. Early snow disappearance was also associated with earlier-season fires, which were more likely to grow larger— on average 77% larger than historical fires.

Fuel

The second requirement for fires to start is available “fuel”. In a forest, that’s vegetation (both living and dead) as well as carbon-rich soils that have built up over centuries. Here, the warming climate plays a role in priming vegetation to burn. A paper co-authored by Rogers has demonstrated temperatures above approximately 71 F in the forest canopy can be a useful indicator for the ignition and spread of “mega-fires,” which spread massive distances through the upper branches of trees. The findings suggest that heat-stressed vegetation plays a big role in triggering these large fires.

Warming has also triggered a feedback loop around fuel in boreal systems. In North America, the historically dominant black spruce is struggling to regenerate between frequent, intense fires. In some places, it is being replaced by competitor species like white spruce or aspen, which don’t support the same shaded, mossy environment that insulates frozen, carbon-rich soils called permafrost, making the ground more vulnerable to deep-burning fires. When permafrost soils thaw and burn, they release carbon that has been stored—sometimes for thousands of years—contributing to the acceleration of warming.

Ignition

Finally, fires need an ignition source. In the boreal, natural ignitions from lightning are the most frequent culprit, although human-caused ignitions have become more common as development expands into northern forests.

Because of lightning’s ephemeral nature, it has been difficult to quantify the impacts of climate change on lightning strikes, but recent research has shown lightning ignitions have been increasing since 1975, and that record numbers of lightning ignitions correlated with years of record large fires. Some models indicate summer lightning rates will continue to increase as global temperatures rise.

There is also evidence showing that a certain type of lightning— one more likely to result in ignition— has been increasing. This “hot lightning” is a type of lightning strike that channels an electrical charge for an extended period of time and tends to correlate more frequently with ignitions. Analysis of satellite data suggests that with every one degree celsius of the Earth’s warming, there might be a 10% increase in the frequency of these hot lightning strikes. That, coupled with increasingly dry conditions, sets the stage for more frequent fire ignitions.

Fire Management as a Climate Solution

So climate change is intensifying every side of the triangle of fire, and the combined effects are resulting in more frequent, larger, more intense blazes that contribute more carbon to the atmosphere. While the permanent solution to bring fires back to their natural regimes lies in curbing global emissions, research from Woodwell Climate suggests that firefighting in boreal forests can be a successful emissions mitigation strategy. And a cost effective one too— perhaps as little as $13 per metric ton of carbon dioxide avoided, which puts it on par with other carbon mitigation solutions like onshore wind or utility-scale solar. It also has the added benefit of protecting communities from the health risk of wildfire smoke.

Rogers, along with Senior Science Policy Advisor, Dr. Peter Frumhoff, and Postdoctoral researcher Dr. Kayla Mathes have begun work in collaboration with the Yukon Flats National Wildlife Refuge in Alaska to pilot this solution as part of the Permafrost Pathways project. Yukon Flats is underlain by large tracts of particularly carbon-rich permafrost soils, making it a good candidate for fire suppression tactics to protect stored carbon.

The project will be the first of its kind— working with communities in and around the Refuge as well as US agencies to develop and test best practices around fighting boreal fires specifically to protect carbon. Broadening deployment of fire management could be one strategy to mitigate the worst effects of intensifying boreal fires, buying time we need to get global emissions in check.

What are ice wedges, and why are they important to climate change?

“I think ice wedges are what make permafrost interesting,” says Dr. Anna Liljedahl.

Liljedahl works on Woodwell Climate’s Arctic team as an Associate Scientist. She aims to understand how climate change is affecting water storage and movement. Much of her recent work focuses on ice wedges and how they are reacting to warming Arctic summers. But just what are ice wedges anyway?

Ice wedges are one of the three main features of the Arctic’s land surface. Permafrost, ground that remains below 0˚C for at least two consecutive summers, lies under a thinner layer of thawing and refreezing soil, called the active layer. When permafrost cracks during cold winter days, snowmelt and runoff water seep into the empty space. These eventually freeze and create a wedge-shaped spear of ice that extends vertically down into the permafrost.

Ice wedges actively re-shape the tundra. When they freeze, they grow and expand outward, pushing against the bordering permafrost and active layer. With nowhere else to go, permafrost and soil push upwards, and ridges form on the surface of the tundra. The ridges interlock and form distinct shapes, referred to as ice-wedge polygons.

The ridged borders of ice-wedge polygons form directly above expanding ice wedges below the surface, and are therefore more elevated. The lower internal portion of the polygon allows pools of water from runoff and snowmelt to form atop the active layer. These polygons are visible all the way from space.

Thanks to satellite imagery, scientists like Liljedahl are able to monitor ice-wedge polygons remotely. Satellite images date back to the mid-20th century and can be used to observe changes in the landscape overtime.

During unusually warm summers, the tops of ice wedges can melt, which removes underlying support of the ground surface, causing slumps along the borders of ice-wedge polygons. These leveling borders form channels that siphon the water from pools in the centers of neighboring polygons. The resulting runoff streams can drain small pools and even larger lakes that took thousands of years to form.

With the progression of climate change, these drainage systems have become more common. Liljedahl refers to them in the title of her manuscript, just published in the July issue of Nature Water, “The Capillaries of the Arctic Tundra.”

The increase in creation of new “capillaries” in the Arctic is impacting not only the topographical landscape of the region, but also the livelihoods of all beings that find their home there.

At first, the melt of these ice wedges can spark an uptick in the variation of vegetation due to moisture along the sides of the channel. This, however, is temporary. When the ice wedges stabilize again in the winter, this variation decreases once more.

Aquatic mosses— one of the most productive vegetal forms in the Arctic, equivalent in productivity to Arctic shrubs— inhabit pools formed alongside the edges of ice-wedge polygons. They lose their homes when bodies of water drain away. Major vegetation changes can alter carbon storage, availability, and emissions across the tundra.

Humans are also impacted. Homes become too dangerous to live in as the ground supporting vital infrastructure collapses. Roads connecting communities to important resources are destroyed by subsiding ground.

Despite their widespread impact, ice wedges are often overlooked in Arctic climate models. Historically, their inclusion “costs too much computer time,” Liljedahl says, to factor in. Many climate models take a holistic approach to the Arctic landscape, as opposed to focusing on smaller details.

To remedy this, Liljedahl suggests utilization of developing technology such as Artificial Intelligence (AI). Classifying the Arctic landscape by type, for example, into high-center polygons, low-center polygons, and capillary networks, would factor ice wedge change into climate models. As AI advances and becomes a more common research tool, it could help decrease the human computing time that Liljedahl identifies as a barrier.

Arctic research is likely to change drastically in the coming years. With new technologies, and as we learn more about the Arctic landscape, research models will likely become more inclusive of the varied features within it, and much more accurate.

“There are exciting years ahead,” Liljedahl says, “I think we’re going to see some cool stuff coming out [of tundra research] in the next five to ten years.”

We can all agree 2023 was a weird year for weather, right? The United States set a record for the number of billion dollar weather disasters. A major Amazon River tributary reached its lowest water levels in a century during extreme drought. Extreme rain in Libya caused two dams to break, destroying homes and killing over 4,000 people.

And then, of course, there was the heat. 2023 was the hottest year on record. Countries around the world saw heat records fall month after month. The Arctic was hot. The ocean was hot. And debates swirl on about whether we’ve already passed critical warming thresholds.

So how do we put 2023 in context of the greater trend of warming? Here’s what some of Woodwell Climate’s scientists have to say about last year’s record-breaking events.

Did the models predict this?

The dramatic scenes of heat and extreme weather last year prompted many to ask why temperatures had seemingly spiked way above the trend line. Was this unexpected? Was it out of the range of what scientists had modeled? Woodwell Senior Scientist, Dr. Jennifer Francis says not entirely.

“Almost exactly a year ago,” says Francis, “we had just come out of three years of La Niñas and we came close to breaking global temperature records then, even though La Niñas tend to be cooler than neutral or El Niño years. And then along came the strong El Niño of 2023.”

El Niño and La Niña are two extremes of a natural phenomenon that impacts weather patterns across the Pacific, and around the world. In an El Niño year, the prevailing trade winds that normally push warmer waters into the western tropical Pacific—allowing cooler water to well up along the western coast of the Americas—are reversed, resulting in hotter ocean surface temperatures in the eastern equatorial Pacific. When the ocean is hotter than the air above it, that heat is released into the atmosphere, often making El Niño years record breaking ones for global temperatures.

“Last year’s spike looks a lot like the last big El Niño event in 2015-2016. It’s just that now the whole system is warmer. So to me, it wasn’t at all a surprise that we smashed the global temperature record in 2023,” says Francis.

The spike put global temperatures far above the average of climate model simulations, but that doesn’t mean the models didn’t account for it. Risk Program Associate Director, Dr. Zach Zobel, says that averages tend to smooth out natural year-to-year fluctuations, when in fact the upper and lower ranges of model predictions do encompass temperatures like the ones seen in 2023.

“It was well within the margin of error that you would expect for natural variations,” says Zobel.

How does ocean heat impact the climate?

One element of last year’s heat, one that wasn’t necessarily forecasted, was the simultaneous appearance of several ocean heat waves around the globe. The ocean absorbs the vast majority of heat trapped by greenhouse gasses, and that heat can be released under the right conditions. El Niño is one example, but in 2023 it coincided with other not-so-natural marine heat waves across the world.

“In pretty much every single ocean right now there are heat waves happening, which is something quite new,” says Francis.

A couple of dynamics could be driving this. One possibility is that, after three years of La Niñas, in which equatorial Pacific ocean temperatures were generally cooler than the air, the ocean simply absorbed a lot of heat, which was then primed to be released in an El Niño year. Another, Zobel suggests, could be recent shipping laws that required shipping vessels to eliminate sulfate emissions by 2023. Sulfates are a pollutant that may have been helping bounce back solar radiation, hiding the true extent of warming.

“Usually when there’s an El Niño, the eastern tropical Pacific is very warm, but it doesn’t actually drive up ocean temperatures everywhere,” says Zobel. “That was the biggest surprise to me: how warm the northern hemisphere of the Atlantic and Pacific were for most of last year and into 2024.”

Ocean heat waves are typically long-lived phenomena, lasting many months, and so can be a useful tool for meteorologists looking to predict 2024’s extreme weather events.

“The good news is that it provides some kind of long-term predictability about weather patterns in the upcoming year,” says Francis. “The bad news is that they tend to be unusual weather patterns, because those ocean heat waves aren’t usually there.”

Will next year be hotter?

So are we in for another, hotter year after this one? Risk Program Director Dr. Christopher Schwalm says it’s likely.

“Warming predictions for 2024 from leading scientists all forecast a higher level of warming this year than last year,” says Schwalm.

Already, March 2024, was the 10th month in a row to break temperature records. Zobel says it’s typical for the year following an El Niño peak to maintain high temperatures.

“Because the ocean spent a good amount of the year last year warmer than average, that energy is typically dispersed throughout the globe in the following year,” says Zobel. “So even though the tropical Pacific might return to normal, that energy is still in the system.”

However, atmospheric scientists are already seeing signs that El Niño is slowing down and flipping to its counterpart, La Niña, adding another layer of complexity to predictions for 2024.

“The 2024 hurricane season is a large concern,” says Zobel. “La Niña is a lot more conducive to tropical cyclone development. If we combine above average numbers with the amount of energy that storms have to feed on, it’ll be a shock to the system.”

What does this mean for 1.5?

In the discussions around 2023’s temperatures, one number dominates the conversation: 1.5 degrees C. This is the amount of warming countries around the world agreed to try to avoid surpassing, in accordance with the United Nations’ 2015 Paris Climate Agreement. Estimates from Berkeley Earth say that 2023 may have been the first year spent above that threshold.

This assertion may take several years to verify— one year spent physically above 1.5 degrees of warming does not indicate the UN threshold has been permanently passed. What scientists are looking for is a clear average trend line rising above 1.5 degrees C without coming back down, and for that you need several years of data. That, regrettably, creates a lag time between climate impacts and updating climate policy. But, for many, the debate around the arbitrary 1.5 degree goal has become a distraction. Schwalm says scientists and policy-makers should be focusing on urgently combating climate change whatever the numbers say.

“We are already living in a post-Paris Agreement reality,” says Schwalm. “The sooner we admit that and reimagine climate policy, the better.”

“Actual real world impacts are going to be there, whether we’re at 1.48 or 1.52,” says Zobel.

And Francis agrees. “There are so many indicators telling us that big changes are underfoot, that we are experiencing major climate change, but reaching 1.5 isn’t going to all of a sudden make those things worse. It’s just one more reminder we’re still on the wrong track and we’d better hurry up and do something.”

Freeze on Russian collaboration disrupts urgently needed permafrost data flow

two researchers hold a ladder steady for a third researcher who is working with equipment at the top of a mid-size tower in Alaska

Warming temperatures in the Arctic are accelerating the thaw of carbon-rich permafrost and threatening to add massive amounts of carbon dioxide and methane to an atmosphere already overheating from the buildup of anthropogenic greenhouse gas emissions.

More than half that permafrost lies beneath remote Russian soil, where scientists have long worked in an international research community that freely shared its field stations, climate sensors and data sets to better understand the rapidly changing polar region’s planetary impacts.

Researchers are especially eager to know when a dangerous tipping point may be reached that would trigger the release of vast amounts of greenhouse gases stored in frozen soils.

But then came the Russian invasion of Ukraine on Feb. 24, 2022, and all that cooperation came to a halt, part of the fallout of Western sanctions on Russia. Since then, international researchers outside Russia have applied creative workarounds in order to continue their research, but problems remain.