The climate situation may be even worse than you think. In the first of three features, Richard Monastersky looks at evidence that keeping carbon dioxide beneath dangerous levels is tougher than previously thought.

The state of California has adopted regulations to curb greenhouse-gas emissions from transportation fuels, codifying evidence that biofuels are significantly dirtier than they were once thought to be.

Without a solid commitment from the world

More radiation generally increases vegetation photosynthesis, but field studies show that a given amount of diffuse radiation leads to more fixed carbon than direct radiation.

This paper analyses the terrestrial carbon balance of China during the 1980s and 1990s using biomass and soil carbon inventories extrapolated by satellite greenness measurements, ecosystem models and atmospheric inversions.

In China, as in other nations that produce carbon dioxide from fossil fuels on a large scale, the terrestrial biosphere mops up a proportion of the emissions. Estimates of the amounts involved are now available.

Germany has outlawed the cultivation of Monsanto's genetically modified maize, Mon810 - the only GM crop approved in the European Union.

Australia's Prime Minister Kevin Rudd launched a government-funded initiative to coordinate and accelerate carbon capture and storage (CCS) projects worldwide.

Science features prominently in the manifestos of the main political parties contesting India's month-long general election, which began on 16 April.

The United States has finally acknowledged that global warming is a threat. It must now act on that. (Editorial)