Expect a warming of 0.2 C in the next two decades: Ajit Tyagi, DG Metereology
Gayatri Ramanthan
Are there major changes in temperature and rainfall patterns as recorded by the IMD over the last 100 years?
Yes. There are variations in both rainfall and temperature recorded by IMD’s observational network. Essentially all the rainfall and temperature records – not only in India but all over the world – show variations in different time scales. The monsoon rainfall in India does not show any trend but there are some regional patterns that indicate that the intensity and frequency of heavy to very heavy rainfall is showing an increasing trend during the last 50 years, in parts of Orissa, Andhra Pradesh Chattisgarh and Madhya Pradesh.
Mean annual temperatures show a significant warming of about 0.5 degrees C / 100 year in the last century and recent data indicates a substantial acceleration of this warming after the 1990s. This is comparable to global warming trends. Spatial distribution of warming trends indicate a significant warming along the west coast, central India and interior peninsula and over northeast India. However, a cooling trend has been observed in northwest and some parts of southern India.
Can these changes be attributed solely to global warming and climate change?
It is not clear if these trends can be attributed only to global warming or not. More analyses is being undertaken to examine aspects of these changes. Most of the rainfall variations we have observed are within natural variations but temperature change trends can be attributed in part to human induced changes.
What are IMD’s projections for the next few decades?
Projections for future climate are made using global and regional climate models and they have inherent uncertainties mainly arising from patterns of future emissions that are linked to the ways we consume energy. For the next two decades a warming of 0.2 degrees C per decade is projected. Even if we stop all emissions now, a further warming of about 0.1 degree C per decade would be expected.
If global temperature rise is not capped at 2 degrees C then what consequences can be expected for India?
Vulnerability to climate is a location specific issue that is dependent on many physical economic and social factors. There could be communities and areas, like sensitive eco-systems that could be very badly impacted even with small increases in temperature are rainfall regime changes. According to IPCC assessments and our own assessments impacts on agriculture, water sector, health sector and disasters due to extreme weather events like droughts and floods would be the future challenges. As we have to take precautions to protect these sectors even in the present context it will be prudent to start taking climate information into consideration to adjust to future changes.
If global temperature rise is capped at 1.5 or 2 degrees C, then what would be the consequences for India? Which regions are most likely to be affected?
It is difficult to single out specific locations as impacts will depend on the vulnerability of each sector and the resilience of the affected communities. Generally speaking the impacts will be felt more keenly in areas that are already drought prone, coastal regions that are exposed to extreme weather events like cyclonic storms and sensitive mountain eco systems.
Can these changes be reversed?
To a large extent these changes cannot be reversed, but there is considerable scope for adaptation in each sector. By adaptation I mean actions to mitigate the effects of adverse weather and climate. Like we may grow crops that are suited to tolerate water and temperature stress or grow crops in months when the temperatures and rainfall are more suitable for them.
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