2024 was another year of record-breaking temperatures, driving the global water cycle to new climate extremes and contributing to ferocious floods and crippling droughts, a new report led by The Australian National University (ANU) shows. 

The 2024 Global Water Monitor Report, involving an international team of researchers and led by ANU Professor Albert van Dijk, found rising temperatures are changing the way water moves around the planet, “wreaking havoc” on the water cycle. 

Early online research in AMS journals discuss earlier snowmelt's correlation with Alaska wildfires, which hurricanes are more likely to intensify rapidly, and whether irrigation will impact rain on the Arabian peninsula.

Climate change is driving more intense wildfires in Canada, according to a new modeling study, with fuel aridity and rising temperatures amplifying burn severity, particularly over the last several decades. The findings underscore the growing impact of climate change on wildfire behavior, with the most severe effects concentrated in Canada’s northern forests. Fueled by ongoing climate change, Canada – one of the most forested and fire-prone regions in the Northern Hemisphere – is grappling with increasingly severe and prolonged wildfire seasons. 2023 marked a record-breaking fire season. Over seven times the historic average area burned that year. Burn (or fire) severity is a crucial metric used to measure the ecological impacts of wildfires and can inform ecosystem responses, landscape resilience, and fire management strategies. However, comprehensive national-scale modeling of burn severity and its key drivers remains limited, challenging scientists’ ability to generate long-term, high-temporal-resolution (e.g., daily) estimates. Addressing these gaps is crucial for understanding how climate change shapes wildfire dynamics across Canada’s vast and remote forests. Weiwei Wang and colleagues combined 40 years of spatiotemporal wildfire data to build a multinomial logistic regression (MLR) model to investigate the factors influencing burn severity across 10 Canadian ecozones. Wang et al. found that fuel aridity – the amount and moisture of flammable vegetation – was the most significant driver of forest fire burn severity and that summer months were more prone to severe burning. The most severe fire conditions have occurred over the last 2 decades. The analysis also revealed variation in the effect of individual drivers across different regions in Canada. Northern Canada experienced a marked increase in burn severity driven primarily by changing climate, whereas fuel aridity and vegetation type played a more critical role in southern Canada. “From an ecological perspective, the increase in fire activity in boreal forests, especially in the northern regions of the world, has raised grave concerns about the health and function of biomes that act as important carbon sinks,” writes Jianbang Gan in a related Perspective. “Cooperation between the US, Canada, and Russia, which share 93% of the global boreal forest, is needed to effectively manage fire while preserving this valuable ecosystem of the northern hemisphere.”

 

For reporters interested in trends, in an October 2024 Science study (www.science.org/doi/10.1126/science.adl5889), Jones et al. show how vegetation dynamics coupled to weather were the primary drivers of forest fire carbon emissions from 2001 to 2023 in the nontropical regions of the world. In another October 2024 Science study (www.science.org/doi/10.1126/science.adk5737), Balch et al. found that the growth rate and intensity of wildfires across the U.S. has substantially increased between 2001 and 2020.

A species of migrating bat “surfs” the warm winds of incoming storm fronts to conserve energy, according to a study that used tags to track the tiny animals on their long journeys across central Europe. The findings offer new insights into how weather, physiology, and environmental factors shape bats’ seasonal migration patterns. While bird migration is well-documented and studied, this is not the case for seasonal migration of bats – particularly the few long-distance, migratory species. These nocturnal travelers face substantial challenges, including high energy demands, anthropogenic threats, declining insect populations, and climate change. Emerging evidence also shows shifts and reductions in migratory bat ranges. Migration decisions appear tied to local weather, especially favorable winds, which aid both foraging and migration. However, due to technological constraints, full bat migration patterns remain untracked, limiting insights into this increasingly vulnerable phenomenon. To address these challenges, Edward Hurme and colleagues developed a new biotelemetry technology using 1.2-gram “Internet of Things” (IoT) tags, which were used to track 71 female common noctule bats (Nyctalus noctule) during their annual spring migration across central Europe. These IoT tags, connected to a 0G wireless network, collect data on location, activity, and environmental temperature and transmit it daily without requiring the bats to be recaptured. Hurme et al. found that the bats traversed up to 1,116 km over 46 days, including single-night flights reaching 383 km – distances much farther than previously recorded. Many bats preferred to align journeys to their maternity roosts with warm nights and incoming storm fronts, surfing the tailwinds to reduce energy demands. Yet these bats also exhibited unexpected flexibility in migration timing, demonstrating their ability to migrate across a range of conditions if required. However, females migrating toward the end of the season faced greater energy costs due to increasing maternity weight and less favorable winds and weather. “Studies that leverage new technologies or approaches can reveal previously unknown aspects of these understudied animals,” writes Liam McGuire in a related Perspective. “But if action is not taken to address threats facing bat populations, they may not be around much longer to study.”

University of Maryland researcher Stephanie Lansing received a Phase 1 $7.8 million award from Defense Advanced Research Projects Agency (DARPA) to develop and test a biologically fueled energy source to power research and sensing devices throughout the world’s oceans. There is a vast array of ocean sensing devices that provide critical information for understanding marine environments, monitoring climate change and maintaining national security. Many of these sensors are currently powered by long underwater cables or lithium-ion batteries.  \Lansing is leading a large, collaborative effort that will overcome the need for batteries and ship-based or shore-based power cables by using microorganisms in ocean water and specialized bacteria to create a marine-based microbial fuel cell that can produce outputs of up to 10 Watts (0.01 kW) consistently for a year or more.

A collaborative study led by Piao Shilong’s team and Zhang Yao’s team from the Institute of Carbon Neutrality at Peking University reveals the distinct mechanisms by which plants and animals respond to climate change in their life-cycle phenology. This research provides comprehensive global-scale evidence on the asynchronous phenological changes between plants and animals.