Evidence of Long-term Climate Change at Major Cities of India during the Twentieth Century

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Cities in the developing countries have urbanized rapidly in the recent decades, therefore, necessitating investigations of urbanization effects on climate, particularly in these regions. The present study analyzes climatic trends at 56 major cities of India, of which 31 have populations exceeding one million. The main goal of the study is to answer the question – Has urbanization led to significant climate change? The answer will help us prepare for the future.
Standard statistical methods are used to find trends in maximum, minimum and mean temperature, diurnal temperature range, rainfall, mid-day and mid-night cloud cover. Taking population as an index of urbanization two periods, Less Urbanized Period (LUP) and More Urbanized Period (MUP) have been identified. Statistical comparisons of average temperatures of these two periods revealed that, temperatures were significantly higher during MUP as compared to LUP. A majority of the cities show warming tendencies with 33 cities indicating significant increases in annual temperatures. The minimum temperatures have increased indicating the role of urbanization. But, unlike other studies the maximum temperatures are increasing faster than minimum temperatures. This increase corresponds with decrease in mid-day cloud amounts.
Thus, answer to the above question is – Yes, urbanization has led to significant climate change with majority of the cities depicting significant rising trends. The result is significant with regards to future demands, particularly related to energy. The cities are going to grow faster and more people will come from outside to settle. Some states in India are already facing power crisis, further increase in day-time temperature will lead to increasing demand for power from the cities. Increase in the maximum temperature will intensify heat wave conditions which would be detrimental to city’s population.
Therefore, considering the importance of cities for a nation the above results would certainly help to plan for a better future and for the well-being of the society.

Stream: Human Impacts

Paper: Evidence of Long-term Climate Change at Major Cities of India during the Twentieth Century

My field of specialization is Climatology. I have done my masters and Ph.D. from the Department of Geography, University of Pune. I am interested in working on investigation of climatic trends, agroclimatology and human impacts on the environment. My doctoral research was on 'Long-term trends of selected weather parameters at major cities of India'. My work is based on instrumental records, but I would also like to investigate climate change using proxies. My other fields of interests include use of Geographical Information Systems to understand climatic trends in a better way. I also work on extraction of land surface temperature using remotely sensed data. I have remote sensing data to find spatio-temporal variations in urban heat island. Since 2001, I have been working as a lecturer in the Department of Geography, University of Pune.

I am a Geomorphologist and work in field of Coastal Geomorphology. I have done my masters and my doctoral research from Department of Geography, University of Pune. My interest area in research is basically in coastal geomorphology along with urban hydrology and applications of remote sensing and GIS techniques. I have completed one major research project on extraction of land surface temperature for pune city using remotely sensed data.