Features in 2012

Questions about the sensitivity of Earth's climate to greenhouse gas forcing challenge our understanding of climate change. Matthew Huber looks at what we can learn from past greenhouse periods.

People have changed the world irrevocably. Jan Zalasiewicz discusses whether formalization of the Anthropocene as an epoch in geological time will help us understand our place in Earth history.

The current assessment of climate change is nearing completion. It is now time to consider how best to provide increasingly complex climate information to policymakers, suggests Thomas F. Stocker.

Numerous earthquakes have occurred at subduction zones in the past 5 years, and some were devastating. Kelin Wang describes what we have learned about the seismicity of the shallow zone.

Readily available O₂ is vital to life as we know it. James Kasting looks at how and when the first whiffs of oxygen began to reach the Earth's atmosphere.

Ocean acidification, caused by the uptake of anthropogenic carbon dioxide, is a significant stressor to marine life. Ulf Riebesell charts the rapid rise in ocean acidification research, from the discovery of its adverse effects to its entry into the political consciousness.

The last five years have seen a boom in exploration of the Solar System. Barbara Cohen explains that the biggest gains have been right here on Earth.

A surprising fraction of Earth's element cycling takes place in inland waters. Jonathan Cole suggests that interactions between these water bodies and the terrestrial biosphere are more extensive and interesting than previously thought.

Record minima in Arctic summer sea ice have been trumping each other. Marika Holland reflects on the likely fate of the northern sea ice cap.

The Late Ordovician period, ending 444 million years ago, was marked by the onset of glaciations. The expansion of non-vascular land plants accelerated chemical weathering and may have drawn down enough atmospheric carbon dioxide to trigger the growth of ice sheets.