Notes

Life on a warming planet. Canada is now battling multiple wildfires across the provinces of British Columbia, Alberta, and Manitoba—with one fire covering some 13,000 acres and forcing the evacuation of thousands of people near Fort Nelson, B.C. Smoke from the fires has meanwhile triggered air-quality alerts in five U.S. states—Wisconsin, Minnesota, North Dakota, South Dakota, and Montana—as officials there asked residents to limit their time outdoors. Wildfires like these have been fueled by an ongoing, extreme drought over the past few years. And just this week, the journal Nature published a study that finds the summer of 2023 to have been the Northern Hemisphere’s hottest in about 2,000 years.

Last September, Rachel Cleetus explored the heat waves, wildfires, and other extreme weather events of the passing summer—parsing out their relationship to human-caused climate change and assessing the state of play in efforts to mitigate it. “Some sectors are harder to decarbonize than others,” Cleetus says. “In transportation, global demand for electric vehicles has been accelerating for individual people and families, and for mass transit, but air travel and maritime transportation are much harder to move. The production of iron, steel, and cement is also hard to decarbonize.” As she explains, despite the growing adoption of renewable-energy technologies, humanity has already locked in significant climate impacts, such as rising sea levels and disappearing ice sheets—and could yet cause irreversible changes to other natural systems.