Thousands of ancient Native American sites to lose protections.

Emissions of CO₂ from the continents and underlying mantle are emerging as potentially important drivers of past climate fluctuations.

Progress in the post-combustion treatment of diesel vehicle exhaust has led to shifting proportions of the constituents of nitrogen oxides. Observations from 61 European cities suggest that the outlook on attaining NO₂ standards is more optimistic than expected.

Stable layering in the ocean limits the rate that human-derived carbon dioxide can acidify the deep ocean. Now observations show that ocean warming, however, can enhance deep-ocean acidification through increased organic matter decomposition.