Mandated reductions in sulfate emissions from international shipping routes in 2020 are partly responsible for a surprising increase in global temperatures in 2023, according to researchers at Cornell University.

People who have limited access to air conditioning may be at higher risk of seeking emergency care for health problems following exposure to wildfire smoke, according to a new study led by Boston University School of Public Health (BUSPH). Published in the journal Environmental Research: Health, the study found that exposure to fine particle matter (PM2.5) from wildfire smoke in California is associated with higher rates of emergency department visits for all causes, non-accidental causes, and respiratory disease. This risk varied by age and race, but was especially high for individuals who lived in areas with lower availability of air conditioning.

Samuel Arman and colleagues’ close examination of tooth microwear among living and extinct kangaroo species suggests that most of the species living in Australia during the Late Pleistocene had a broad, generalist diet rather than being specialized grazers. This broad diet likely allowed them to survive the glacial-interglacial cycles that drove fluctuations in vegetation on the continent. The findings add more evidence to the idea that human hunting, rather than failure to adapt to climate changes, was behind the late megafaunal extinction in Australia. By 40,000 years ago, Australia had lost 90% of its large species, more than half of them kangaroos. To determine whether kangaroo species were able to adapt to climate-driven vegetation changes at the time, Arman et al. examined 2650 enamel scans from 937 individual specimens to characterize the diets of a diverse Pleistocene kangaroo fossil assemblage. Chewing food with different material properties leaves distinctive microscopic wear marks on tooth enamel that can then be associated with different diets. The researchers found no statistically significant differences in microwear among most species in the fossil assemblage, and the microwear itself suggested the species did not pursue specialized diets.

More than 14,000 physicists from around the world will convene to present groundbreaking research at the American Physical Society’s joint March Meeting and April Meeting, now called the Global Physics Summit. The conference will be held in person in Anaheim, California and online everywhere March 16-21.