Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), which provides the scientific basis for international and government policies to halt or mitigate global warming, spoke to AFP by telephone from New Delhi.

Question: Does the current heatwave have anything to do with the increase in greenhouse gases in the atmosphere and climate change?

Answer: That seems to be the growing evidence from all the models that have been carried out because these temperatures are clearly not being caused by natural factors, according to all scientific work that has been done.

The evidence seems to point to human factors, that's basically concentration of greenhouse gases. The danger is that these extreme events will increase in the future. So this is a warning of sorts of what we're likely to get in the future.

You are aware of the very severe summer in Europe and it's still going on. But in India we had an extreme severe summer, our hottest season is in May and June. This year in Andra Pradesh we had 1,664 recorded deaths (in two months) and in other parts of India, including very severe temperatures. We never had this extent of hot weather in the past.

Q: Are we suffering from the greenhouse gases we are currently emitting into the atmosphere or from those we emitted a century ago or more?

A: This is really the result of cumulative emissions over a period of time. ...The concentration of greenhouse gas in the atmosphere... is now close to 380 parts per million (ppm). This is the result of what has been happening over the last 150 years.

The largest amount is coming from the last 50 years. We're suffering from that already. And that leads to another conclusion: even if we make drastic reductions today, climate change is going to continue for a number of decades. That makes it more urgent that we do something about it today.

Q: In 2001, the IPCC forecast an increase of 1.4 degree Celsius of the global mean surface temperature by 2100, compared to 1990. This was based on a greenhouse gas concentration of some 550 ppm compared to the current 380 ppm.

At these modest increases of temperature and greenhouse gas concentration, will extreme weather events such as the current heatwave become more frequent?

A: This 1.4 (percent increase) is the lower end of the scale in our projections. It is actually a very high rate of increase. The important thing is that it is an increase in the global average temperature.

Which means that in some parts (of the world), it may be three or four degrees and in other parts a little less. The projections are that in the northern hemisphere, the tropics and the sub-tropics will be the worst affected. Cooling will be towards the polar region of the northern hemisphere.

So what we're dealing with is a wide range of impacts as far as temperatures are concerned. And we're also dealing with much greater variations in temperatures... and an increased frequency of extreme weather events, including changes in precipitation.

That means, you will get floods, droughts on a much more severe scale than in the past.

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