Feature Article

The consequences of global climate change are profound, and the scientific community has an obligation to assess the ramifications of policy options for reducing greenhouse gas emissions and enhancing CO2 sinks in reservoirs other than the atmosphere. Ocean iron fertilization (OIF), one of several ocean methods proposed for mitigating rising atmospheric CO2, involves stimulating net phytoplankton growth by releasing iron to certain parts of the surface ocean.

A major attempt to streamline-or, critics claim, politicize-the revision of important air-quality standards has run into trouble. One year ago, the U.S. Environmental Protection Agency (EPA) overhauled its lengthy process of updating the National Ambient Air Quality Standards (NAAQS), which have far-reaching impacts on many regulations. Some critics feared the move would allow politics to trump science by giving agency appointees more say and sidelining external scientific review.

In a research by paleoceanographer Andre Bornemann of Leipzig University in Germany and his colleagues analyzed apparently unaltered Foraminifera picked from sediment core drilled from Demerara Rise beneath the western equatorial Atlantic. Following a classic technique, the researchers measured oxygen isotopes in the forams' shells. They found a sharp shift toward the heavier oxygen-18 isotope in both surface and bottom dwelling forams from 91.2 million years ago.

Last year, climate change scientists thought they had driven a silver stake through the idea that fluctuations in solar activity were behind global warming in the last century. Now, a high-profile team led by geophysicist Vincent Courtillot, director of the Institut de Physique du Globe in Paris, has sought to raise the dead in a paper linking changes in Earth's magnetic field to temperature variations in recent millennia.

some winter crops (wheat, mustard, barley and chickpea) in northwest India was evaluated on the basis of historic records and through a dynamic crop growth model, WTGROWS. The optimal date of sowing was also evaluated in view of the increase in seasonal temperature. The yield of these crops, especially wheat, already showing signs of stagnation in most places of northwest India, is most likely to be affected by temperature

Concentration of greenhouse gases play major role in raising the earth

Farming contributes more to global warming than all the world's cars, trains, ships and planes put together. And the single biggest problem with farming is not carbon but nitrogen. From the maize fields of Kansas to the emerald rice paddies of China, today's bountiful harvests depend on generous applications of nitrogen fertiliser. Although only a tiny proportion escapes into the atmosphere as nitrous oxide, it is an extremely potent greenhouse gas. It's a vexing problem, but Eric Rey believes he has some of the answers, in the form of crops genetically modified to require less fertiliser.

When the first comprehensive report in years to examine energy use by computer servers was published in February 2007, it was greeted with surprise by industry insiders. Jonathan Koomey, a staff scientist at Lawrence Berkeley National Laboratory in California, found that worldwide power consumption by servers had doubled between 2000 and 2005. "Everyone thought CO2 emissions were a problem for transportation and big energy," says Bill St Arnaud of Canarie, Canada's internet development organisation in Ottawa, Ontario.

While cutting down rainforests to grow palm oil for biofuels may constitute "madness" (1 December 2007, p 50), burning other vegetable oils is no more sane, nor less damaging to Indonesia's rainforests. Indonesia is expected to increase its palm oil production by more than half over the next 10 years. This is driven, in part, by China, which used to buy rapeseed oil from Europe for food and for industrial uses, but is switching to Indonesian palm oil because Europe's cars and trucks now burn the rapeseed oil as a biofuel.

One way to cut greenhouse gas levels in the atmosphere may be to exploit a particular talent some plants have of locking away carbon. All we need to do is choose the right strains of crops to grow, and they will sequester carbon for us for millennia. That's the idea of two agricultural scientists in Australia, who say the trick is to grow grasses such as wheat and sorghum, which lock up large amounts of carbon in so-called plantstones, also known as phytoliths.