Here is the latest with regard to its impact on India:
Subject: CSE press release this week: On the heat wave
CSE Press Release… this week
Changing climate: what fanned the heat wave
In March-April this year, large swathes of India had been reeling under a searing heat wave. People were dropping dead, and rising temperatures were playing havoc with the air circulation patterns that control heat and cause rain
A frightening pattern has been emerging in all this -- there have been more heat waves and for a larger duration in this decade than in the previous two decades
A new report focuses on changing weather patterns and points out that the changes are happening much faster and outstripping all efforts to predict them
New Delhi, May 22, 2009: Disturbances in air patterns, different parts of the earth heating at different rates, and an early rise in temperatures were some of the reasons scientists in India held responsible for the bruising heat wave that had swept several states in India in March-April this year.
And what is even more disturbing is that these changes have been taking place “faster than scientists can predict” – says a latest report in Down To Earth, a fortnightly magazine that Centre for Science and Environment helps publish.
In March-April, over 70 people reportedly died in Orissa due to sunstroke, with mercury soaring to 46 degree centigrade in April in some cities. The state’s health machinery was caught napping. In West Bengal, the heat wave killed nine. ‘Abnormal’ dry spells and dust storms swamped Guwahati in Assam, while the entire Malwa region in Madhya Pradesh reeled from a severe water stress.
What is wrong with the weather, asks the report. According to the Indian Meteorological Department (IMD), disturbances in the air circulation pattern over India led to mercury soaring across the country. Circulation of air helps distribute heat over the earth. The cyclonic storm, Bijli, which formed in the Bay of Bengal in mid-April, cut off the cool easterly winds blowing in from the Bay of Bengal. To add to it, an anticyclone hovering around Rajasthan blew hot winds from north–west to central and western India.
Some scientists have attributed the heat wave to an exceedingly dry winter, while others have pointed to the unusual heating of the Tibetan Plateau – which was two degrees warmer than normal in February this year.
The IMD also puts the lack of winter cyclones that form in Bay of Bengal and provide rains to the north-east, as a reason. The Down To Earth report quotes A K Srivastava, a scientist at the department’s Pune centre: “Tropical cyclones in the peak cyclone months of May and November have increased, while those occurring in the rest of the year have decreased.”
Warming – earlier, more frequent and more intense
An IMD study has compared the number, duration and spread of heat waves from 1971 to 2000 recorded in 35 sub-divisions across the country. The study says that on an average, almost 23 sub-divisions were hit by heat waves between 1991 and 2000, while 10 sub-divisions were hit in 1981-1990 and only about 7 were hit in 1971-1980.
The study also says that 25 sub-divisions went through more than 15 spells of heat waves in 1991-2000, compared to only two in the previous two decades. Notably, the decade 1991-2000 has been the warmest in the last 140 years.
Meteorological data shows that March and April have been warming faster in the last 100 years. The average temperature for March has increased by 0.76 degree centigrade over the last century; that for April has increased by 0.58 degree centigrade.
While governments sleep over these very visible trends, more intense and longer heat waves are taking a higher toll. Is climate change more imminent than thought of?
For more on the subject, see the latest Down To Earth cover story at http://www.downtoearth.org.in/cover.asp?foldername=20090531&filename=news&sid=13&sec_id=9
For more details, or to speak with a climate change expert at CSE, please contact Shachi Chaturvedi at email@example.com or on 98187 50007.
You can also speak with Dr D R Pattanaik, scientist, IMD-Delhi on 98683 97243, or write to him at firstname.lastname@example.org; or with Dr M Rajeevan, scientist, National Atmospheric Research Laboratory, Tirupati on 08585-272016 or 272026, or write to him at email@example.com , firstname.lastname@example.org