In their reports in the 29 February issue ("Land clearing and the biofuel carbon debt," J. Fargione et al., p. 1235, and "Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change," T. Searchinger et al., p. 1238), the authors do not provide adequate support for their claim that biofuels cause high emissions due to land-use change. The conclusions of both papers depend on the misleading premise that biofuel production causes forests and grasslands to be converted to agriculture. (Letters)

At a conference in France's noisy capital, European acoustical scientists admitted that they and most policymakers are not close to meeting an 18 July deadline to develop action plans to shush the European Union's (E.U's) largest cities. The action plan deadline stems from a 2002 E.U. antinoise directive.

Rice is the staff of life for 3 billion people, predominantly in Asia. But does the food that sustains half of humanity also increase the risk of cancer for some? That question arises from three sets of findings-including data now in press-that report elevated arsenic levels in rice and products such as rice bran and rice crackers.

Is Japan's research whaling, which claims about 1000 whales a year, scientific investigation or disguised commercial whaling? A new review process endorsed by the International Whaling Commission last week at its 60th annual meeting hopes to get closer to the answer.

Water stress is a major problem affecting the future of human societies around the world, particularly in the rural areas of the developing world. The Newsmakers article "Barrn to lush" (2 May, p. 593) highlighted an award for the invention of a new manual pump used for irrigation in rural Africa. We fully respect and admire the invention of efficient and affordable pumping systems to solve water shortage problems in rural areas. However, we are concerned about the intensive application of these new pumps to water-limited systems. (Letters)

Continuous Global Positioning System observations reveal rapid and large ice velocity fluctuations in the western ablation zone of the Greenland Ice Sheet. Within days, ice velocity reacts to increased meltwater production and increases by a factor of 4. Such a response is much stronger and much faster than previously reported. Over a longer period of 17 years, annual ice velocities have decreased slightly, which suggests that the englacial hydraulic system adjusts constantly to the variable meltwater input, which results in a more or less constant ice flux over the years.

Much of the scientific and public focus on anthropogenic carbon dioxide emissions have been on climate impacts. Emission targets have been suggested based primarily on arguments for preventing climate from shifting significantly from its preindustrial state. However, recent studies underline a second major impact of carbon emissions: ocean acidification. Over the past 200 years, the oceans have take up `40% of the anthropogenic CO2 emissions. This uptake shows the rise in atmospheric CO2 considerably, thus alleviating climate change caused by anthropogenic greenhouse gas emissions.

Measuring the costs and benefits of projects intended to offset the emission of greenhouse gases is one of many thorny issues that the state of California must tackle as it begins drafting a cap-and-trade system of carbon credits.

An $11 billion plan to restore the Everglades will likely get an overhaul after a major land deal last week by the state of Florida. The state's $1.75 billion purchase is intended to create wetlands that will speed up the delivery of water to the thirsty ecosystem.

Protected areas (PAs) have long been criticized as creations of and for an elite few, where associated costs, but few benefits, are borne by marginalized rural communities.