Feature Article

China has more dams than any other country, and many of them are in Sichuan, an earthquake-prone, mountainous region. The majority of them produce hydroelectricity. The region is well-placed to supply power to large industrial cities down the Yangtze valley, and when the dams were built this must have appeared a logical strategy. Now it looks foolhardy. Hundreds of Sichuan's dams have been damaged by the earthquake and could collapse during the coming monsoon season. (Editorial)

In September 2006, Tara, a 36-metre schooner crewed by eight scientists and engineers, moored up on the Arctic sea ice and spent the next 15 months moving slowly with it across the top of the world. The expedition wasn't aiming for the pole: it was an ambitious attempt to record what is happening to the polar climate in unprecedented detail.

This is one biofuel that lives up to its green billing in more ways than one. It's an emerald-green crude oil, produced by photosynthesis in algae, which could fuel cars, trucks and aircraft - without consuming crops that can be used as food.

The lush tropical rainforests of Papua New Guinea are not the unspoilt haven that many believed till now. In fact, they are disappearing faster than those in the Amazon.

If you can't innovate, then reinvent the wheel. That seems to be the thinking behind the US Department of Energy's (DoE) plans for a nuclear fuel reprocessing programme - but this tactic may play into the hands of weapons-makers.

Environment impact assessment was supposed to be a critical tool in environmental decision-making. But it has been re-engineered to severely reduce its usefulness as an instrument for public participation in decision-making.

Long-period seismic sources associated with glacier motion have been recently discovered, and an increase in ice flow over the past decade has been suggested on the basis of secular changes in such measurements. Their significance, however, remains uncertain, as a relationship to ice flow has not been confirmed by direct observation. Here the authors combine long-period surface-wave observations with simultaneous Global Positioning System measurements of ice displacement to study the tidally modulated stick

A dispute about non-native algae has broken out in India between beverage giant PepsiCo and the Central Salt & Marine Chemicals Research Institute (CSMCRI), which is based in Bhavnagar, Gujarat. Institute researchers originally imported the alga Kappaphycus alvarezii for research; in 2001 PepsiCo began cultivating it for the food thickener carrageenan in the Gulf of Mannar marine bioreserve, along India's southeastern coast.

Ocean-fertilization advocates suffered another setback last week as 191 nations agreed to a moratorium on large-scale commercial schemes to mitigate climate change. The agreement, adopted on 30 May at a meeting of the United Nations Convention on Biological Diversity in Bonn, Germany, calls for a ban on major ocean fertilization projects until scientists better understand the potential risks and benefits of manipulating the oceanic food chain.