As wildfire smoke becomes a growing public-health story in the Northeast, a first-of-its-kind study in Environmental Health finds that Canadian wildfire smoke in the summer of 2023 worsened asthma symptoms in children across Vermont and upstate New York—even though the fires were burning hundreds of miles away.

Scientists from the Max Planck Institute for Marine Microbiology find that urea is a major energy source for ammonia-oxidizing archaea (AOA) in the open ocean, while coastal AOA prefer ammonium. The study, published in Nature Communications, suggests that organic nitrogen plays a far greater role in ocean productivity than previously recognized.

Reciprocity matters--people were more supportive of climate policies in their country if they believed other countries were making significant efforts themselves, per survey of 4,000 Chinese, Indian, Japanese and US citizens.

A UC Berkeley-led analysis of tree mortality after two recent Amazonian droughts shows that “hot drought” conditions, which are becoming more frequent, are leading to tree dieoffs and reducing the region’s ability to absorb anthropogenic carbon dioxide. Climate models show that the new, hotter, drier conditions, referred to as the “hypertropics,” are outside the parameters of normal biomes in the Amazon and more like some tropical biomes 10-40 million years ago.