There may be more to global warming than we thought. On top of the effect of human-made carbon emissions, natural changes in the warm ocean currents travelling to the icy north may be helping to heat up the entire northern hemisphere.

The sea-ice cover in the polar regions is one of the most expansive and seasonal geophysical parameters on the earth's surface. The presence or absence of sea-ice affects the atmosphere and the ocean, and therefore the climate in many ways. In this study we have used the Multi-frequency Scanning Microwave Radiometer (MSMR) brightness temperature data over the Antarctic/Southern Ocean region to calculate the weekly sea-ice extents, during the melting phase from August 1999 to March 2000 to quantitatively estimate the melting rates of sea-ice on a hemispheric scale.

Atmospheric measurements show that the carbon dioxide (CO2) concentration in the atmosphere is currently '385 parts per million (ppm) and rising fast. But this value is a global average that tells us nothing about the regional distribution of greenhouse gas emissions. As the world embraces myriad mitigation strategies, it must gauge which strategies work and which do not. Gaining such understanding will require a greenhouse gas monitoring system with enough accuracy and precision to quantify objectively the progress in reducing emissions.

The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming the Arctic, and fluctuations of regional fresh water inflow into the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence.

Sikkim Government is gearing up to send a high-level glaciologists' team to study the meltdown of the glaciers in Sikkim due to global warming and to find out remedies. The team led by Professor S I Hasnain and accompanied by officials and members of various project teams, would visit west Sikkim to study the state of East Rathong glacier during their nine-day expedition starting from April 24, an official said. Chief Minister Pawan Kumar Chamling had set up a commission under Hasnain to study the state of glaciers late last year, the official said.

The mountain pine beetle (Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytinae) is a native insect of the pine forests of western North America, and its populations periodically erupt into large-scale outbreaks. During outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees.

One of the most dramatic perturbations to the Earth system during the past 100 million years was the rapid onset of Antarctic glaciation near the Eocene/Oligocene epoch boundary (34 million years ago). This climate transition was accompanied3 by a deepening of the calcite compensation depth

The international team of climate change scientists that produced an influential series of reports last year will be doing things a little differently in the future. Government delegates to the Intergovernmental Panel on Climate Change (IPCC), meeting in Budapest, Hungary, approved a plan for the 20-year, 100-nation enterprise that would generate more precise and relevant information on climate change-without taking any longer than the current 6-year gap between reports.

Past atmospheric methane concentrations show strong fluctuations in parallel to rapid glacial climate changes in the Northern Hemisphere, superimposed on a glacial

When people talk about catastrophic climate change, there's a fair chance that Greenland is on their mind. If they use the term 'tipping point', then it is pretty much a sure thing. One-twentieth of the world's ice is locked up atop that island, and if it were to melt completely, global sea levels would rise by seven metres. The collapse of the Greenland ice sheet is in the front rank of potential climate catastrophes.