Seasonal variation in tropical sea surface temperatures doubled during an abrupt warming event 11,700 years ago. This shows that seasonal changes must be considered when inferring past climatic events, and predicting those to come.

Abnormal protein aggregates are a hallmark of Alzheimer’s disease. It emerges that these plaques cause swellings in neuronal projections called axons that prevent proper circuit function.

The response of cumulus clouds in trade-wind regions to warming is a large uncertainty in climate projections. Observations now indicate that the mechanism leading to the strongest cloud reductions in models does not occur in nature, suggesting that extreme sensitivity of Earth’s temperatures to climate change is less likely than previously thought.

A 67-million-year-old fossil bird found in Europe provides evidence suggesting that scientists should reconsider centuries-old ideas about the nature of the ancestral avian beak.