Global warming is not a uniform process. Mongolia, particularly at the high altitudes around Lake Hovsgol, has been warming more than twice as fast as the global average. Unique ecosystems are feeling the heat. Here at the transition between the steppe grassland and taiga, plants and animals are confronted with a changing environment-and the outlook is not good for the herders who are crowding up from the south.

In their policy forum ("The limits of consensus," 14 September 2007, P. 1505), M. Oppenheimer et al, make several misleading statements. They suggest that a premature drive for consensus led Working Group I to understate the risk of large future sea-level rise in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (WGI-AR4). (Letters)

The Turonian (93.5 to 89.3 million years ago) was one of the warmest periods of the Phanerozoic eon. It has been argued that there may have been several stages of continental ice growth during the period, reflected in both erosional surfaces and geochemical records associated with possible glaciation-induced sea-level falls.

An outstanding climate anomaly 8200 years before the present (B.P.) in the North Atlantic is commonly postulated to be the result of weakened overturning circulation triggered by a freshwater outburst. New stable isotopic and sedimentological records from a northwest Atlantic sediment core reveal that the most prominent Holocene anomaly in bottom water chemistry and flow speed in the deep limb of the Atlantic overturning circulation begins at '8.38 thousand years B.P., coeval with the catastrophic drainage of Lake Agassiz.

Survival questions
Are glaciers in the Himalayas melting faster than the natural rate? What will be the impact on hydrology

The two most important hydrological extremes are floods and droughts. These events pose serious hazards to human populations in many parts of the world. These water related disasters are caused because of large diversity in climate and topography of the country. Climate change in future is expected to have severe implications on river flows in South Asia including India. Global climate change is likely to result in severe droughts and floods in India, with major impacts on human health and food supplies.

The contemporary trend of global warming is aptly highlighted in the IPCC report 2007. There is a strong consensus amongst scientists and planners today that the earth's climate is entering a warm episode, nudged primarily by human activities of fossil fuel burning and land use changes that inject steadily increasing amounts of CO2 into the atmosphere. It is also quite possible that the increased concentrations of atmospheric CO2 will also have a direct influence on productive systems of plant species in view of increasing rates of photosynthesis and improved water use efficiency.

The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health. In this investigation, glacial retreat was estimated for 466 glaciers in Chenab, Parbati and Baspa basins from 1962.