Taxonomy term

Wetlands are prolific sinks for atmospheric carbon. They pull carbon dioxide out of the air and sequester the carbon in plants, soils and sediments. But there’s a catch: Wetlands also emit methane, an even more potent, albeit far less abundant, greenhouse gas than carbon dioxide. Two new studies, one measuring methane emissions from a rehabilitated freshwater peatland in California and the other looking at emissions from tropical mangrove forests in Australia, are revealing that these so-called “blue carbon” sinks may emit much more methane than previously thought.

Two upcoming missions will provide the first systematic approach to searching the atmospheres of exoplanets for signs of life — and they could find it in the next several decades.

Oxidants in the troposphere, such as ozone and hydroxyl radicals, influence the life spans of other atmospheric components, including pollutants and greenhouse gases like carbon monoxide and methane. But how the abundance of tropospheric oxidants varies as climate changes is poorly understood. Part of the challenge is that these oxidants are too reactive to be preserved in paleo-records, such as ice cores.

Geologists are fond of the saying, “The past is key to the future.” Unfortunately, the past has been a poor guide when it comes to understanding modern climate change. Now, however, a new study suggests that one episode — a spike in global temperatures that occurred about 55 million years ago — may be a better analog than previously thought, and could yield insights into the planet’s future.