Wildfire disasters worldwide are growing notably in frequency and cost, according to a new study, with nearly half of the most damaging events over the last 44 years occurring in just the past decade, driven largely by increasingly extreme fire weather in vulnerable, densely populated regions. The findings, informed by an analysis of global reinsurance data and international disaster reports, reveal a concerning trend and highlight the need to adapt for a more fire-prone world. Humans have coexisted with wildfires for millennia, but climate change, land mismanagement, and expansion into flammable landscapes have intensified risks. However, despite widespread concerns, the authors of this new study say there has been little systematic global evidence on whether societally disastrous wildfires – events with major social and economic consequences – are becoming more frequent or costly. This may be due, in part, to the lack of long-term, global data on the socioeconomic effects of wildfires, with many governments worldwide keeping such information inaccessible to the public. To address this gap, Calum Cunningham and colleagues compiled and harmonized two global disaster databases – Munich Re’s NatCatSERVICE, one of the most comprehensive proprietary reinsurance datasets, and the publicly available Emergency Events Database (EM-DAT) – to examine wildfire disasters from 1980 to 2023. These integrated datasets allowed the authors to evaluate, at a global scale, both societal impacts and financial losses from major wildfire disasters (i.e., those that caused 10 or more fatalities or were among the 200 largest wildfire-related economic losses relative to national GDP).

 

Cunningham et al. found that wildfire disasters have become markedly more burdensome worldwide over the last 40 years, with a pronounced acceleration beginning around 2015. Major economic disasters from wildfires have increased more than fourfold since 1980, with 43% of the 200 most damaging events occurring in just the past decade. Wildfire fatality events have also risen significantly, tripling in frequency since 1980. According to the findings, this escalation is driven by a combination of intensifying climate conditions that promote extreme fire weather and human factors such as expansion of the wildland–urban interface, land-use shifts, and long-term fire suppression policies. Although fire-prone biomes such as Mediterranean, temperate conifer, and boreal forests bear a disproportionate share of disasters, significant impacts are now also emerging in diverse regions, particularly along the margins of affluent urban areas where financial consequences are especially pronounced.

Astronomers using the James Webb Space Telescope have detected the molecule phosphine beyond our Solar System, according to a new study, finding it in the atmosphere of the cold brown dwarf Wolf 1130C. The presence of the phosphorus-containing molecule phosphine (PH₃) is well established in the atmospheres of Jupiter and Saturn, as well as in some giant stars. Although models predict that PH₃ should be similarly common in gas giant exoplanets and brown dwarfs, searches for the molecule in the atmospheres of those objects have shown it to be in very low abundance, if not totally absent. Using the JWST NIRSpec instrument, Adam Burgasser and colleagues obtained high-resolution spectra of the cold, metal-poor brown dwarf Wolf 1130C. Within these observations, Burgasser et al. identified multiple absorption lines of PH₃, indicating an abundance of 0.100 ± 0.009 parts per million – an amount comparable to Jupiter and Saturn and far higher than previous limits for other exoplanets or brown dwarfs. Comparison with atmospheric models shows the properties can be reproduced if there is strong vertical mixing of an atmosphere with low abundances of elements heavier than helium. “The inability of models to consistently explain all these sources indicates an incomplete understanding of phosphorus chemistry in low-temperature atmospheres,” write the authors. “We therefore caution against the use of phosphine as a biosignature until these discrepancies are resolved.”