Guwahati (PTI): The earth is clearly facing a catastrophe of substantial dimension and lack of climate stability can have an impact on agriculture and food security, Chairman of the Intergovernmental Panel on Climate Change (IPCC), Dr R K Pachauri, said on Tuesday.

"Climate change is not smooth and linear. The factors of a fairly balanced climate have been disturbed quite systematically leading to increase in precipitation -- rain and snow -- in the upper latitudes and decline in the lower latitudes", Noble Peace awardee said.

Climate changes included large quantities of rain and snow in a short period of time --as were the rains in Mumbai two years ago-- meltdown of glaciers eventually reducing flow of water through rivers, which in turn would reduce ground water and its subsequent recharge, he pointed out.

"Meltdown of glaciers effect agriculture as well and food security is compromised. By 2020 there will be a 50 per cent reduction of agriculture in Africa effecting their people's survival", Pachauri said.

Since use of fossil fuel was a part of industrialisation, its use has imposed a major burden on the resources of the world, he said at a felicitation programme by the state government.

Pachauri said data for the last couple of centuries showed the thermal expansion of ocean and melting of ice caused sea level to increase which were causing damages in Bangladesh and the Sundarbans.

It was the moral requirement for the global community to provide resources for constructing protective infrastructure in the underdeveloped countries where the sea level rise was posing a major challenge, he said.