Perennially contentious issues of water management in California are being brought to a head by climate change and rising earthquake risks.

The West Antarctic ice sheet (WAIS), with ice volume equivalent to approx5 m of sea level, has long been considered capable of past and future catastrophic collapse. Today, the ice sheet is fringed by vulnerable floating ice shelves that buttress the fast flow of inland ice streams.

Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles.

During the past five million years, the West Antarctic ice sheet has waxed and waned in size. A two-pronged reconstruction of that history provides clues to the ice sheet's future behaviour.

Participants at a scientific conference held in Copenhagen in March were shocked to hear new, much higher estimates for likely sea-level rise and rainforest loss that could lead to trees emitting more carbon than they store.

Along with all the development problems confronting African cities, they are under-resourced and ill prepared to cope with the hazards of Global Environment Change (GEC). Here leading experts, David Simon and Cheikh Gu