Few scientific creations have had greater impact on public opinion and policy than computer models of Earth's climate. These models, which unanimously show a rising tide of red as temperatures climb worldwide, have been key over the past decade in forging the scientific and political consensus that global warming is a grave danger. (Editorial)

"Politicians seem to think that the science is a done deal," says Tim Palmer. "I don't want to undermine the IPCC, but the forecasts, especially for regional climate change, are immensely uncertain." Palmer is a leading climate modeller at the European Centre for Medium-Range Weather Forecasts in Reading, UK, and he does not doubt that the Intergovernmental Panel on Climate Change (IPCC) has done a good job alerting the world to the problem of global climate change.

A new paper shows that regional and even global temperatures are being temporarily held down by a natural jostling of the climate system, driven in large part by vacillating ocean currents.

The climate of the North Atlantic region exhibits fluctuations on decadal timescales that have large societal consequences. Prominent examples include hurricane activity in the Atlantic, and surface-temperature and rainfall variations over North America, Europe and northern Africa. Although these multidecadal variations are potentially predictable if the current state of the ocean is known, the lack of subsurface ocean observations that constrain this state has been a limiting factor for realizing the full skill potential of such predictions.

The effects of global warming over the coming decades will be modified by shorter-term climate variability. Finding ways to incorporate these variations will give us a better grip on what kind of climate change to expect.

Extreme rainfall events today pose a serious threat to many populated and urbanized areas worldwide. An accurate estimate of frequency and distribution of these events can significantly aid in policy planning and observation system design. We report here a highresolution (10 km) analysis of heavy rainfall episodes (defined as 24-h rainfall exceeding 250 mm) over the Indian region.