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The document examines how rising temperatures increase the speed and frequency of thunderstorm straight-line winds, particularly in the central U.S., and projects an increase in the occurrence of large-scale derecho events.

Climate change is increasing the intensity of extreme precipitation across the U.S., with the Northeast and Midwest seeing the largest increases since 1958. Under 2°C of global warming, 85% of U.S. counties are projected to experience a 10% or higher increase in precipitation on the heaviest 1% of days. This intensification contributes to flash flooding and landslides, disproportionately affecting racial minorities and those in mobile homes, particularly in the South and rural areas. Between 1988 and 2021, warming-induced rainfall intensification caused an estimated $84 billion in inland flood damages.

The report concludes that the prolonged regional heat in Siberia from January to June 2020 was effectively impossible without human influence, with a best estimate probability ratio of 99,000 compared to a 1900 climate. Such events would have been at least 2°C cooler without anthropogenic influence. For the specific record of 38°C at Verkhoyansk, the study found a confident anthropogenic shift in intensity of 1.5°C, although the probability ratio for this specific station event is of lower confidence. By 2050, the regional heat is expected to be further intensified, with a synthesis change in intensity of 4.85°C compared to 1900.

Hourly rainfall intensity in 126 U.S. cities has increased by an average of 15% since 1970, with the heaviest 1% of downpours intensifying most in the Northeast (+60%) and Midwest (+45%) between 1958 and 2021. Future warming of 2°C is projected to increase precipitation during the heaviest events by an average of 17% across U.S. counties. The document highlights that flood risks disproportionately affect people of color, those in mobile homes, and Black communities along the Atlantic and Gulf coasts, noting that rainfall changes between 1988 and 2017 caused approximately $73 billion in flood damages.

The report finds that over 60% of global coral reefs are threatened by local human activities, rising to 75% when heat stress is included. In the Coral Triangle, this figure exceeds 85%. The document highlights that while 28% of global reefs are in marine protected areas (MPAs), only 6% are effectively managed. It predicts that by 2050, nearly all reefs in the Coral Triangle will be threatened, with over 90% facing high to critical risks due to the combined effects of local pressures, ocean warming, and acidification.