The commitment made by our Prime Minister at COP26 in Glasgow demands a rapid increase in renewable power and early retirement of coal power plants. Karnataka can be a leader in the growth of renewable energy technology in India as it is already a leader in the area of information technology.
There are many sites favourable for solar power plants in north Karnataka and locations favourable for wind power plants in the western Ghats and Bellary. Wind power is available mainly during the monsoon but it compensates for the poor yield from solar power plants during that season.
There will be a need for large energy storage facilities to tide over the periods during which neither wind or solar energy is available. The large hydropower plants in Karnataka can be used for energy storage through ‘pumped storage’ systems. These systems will pump water from downstream of the dam to the lake located upstream during mid-day when there is more solar power generation.
The cost of storing electrical energy in batteries is coming down rapidly. This will make renewable energy and its storage less expensive than power generated from new coal power plants in Karnataka. To enable India to attain the goal of reducing net emissions of greenhouse gases to zero by 2070, there will be a need to retire old and inefficient coal power plants.
Climate change occurs on a variety of temporal and spatial scales. On a global scale we know that emission of greenhouse gases such as carbon dioxide and methane lead to global warming. On a city scale, many other factors play a role. The maximum temperature in Bengaluru has increased by around 2 degrees in March during the past 100 years while the global mean temperature has gone up by around 1 degree during the same period. One cannot attribute all the warming in Bengaluru to carbon dioxide. A part of the warming is on account of the increase in built-up area, higher road traffic and destruction of greenery in Bengaluru.
Global warming has increased the number of high rainfall events in India This has led to flooding in urban areas and landslides in hilly regions. Flooding in urban areas is partly a consequence of uncontrolled development that has not allowed the rain water to flow freely. To reduce flooding there is a need to promote construction of porous pavements and roads. In addition, we need enough green areas to soak up excess rainfall. While constructing roads in hilly regions, we must ensure that there is sufficient provision for the free flow of rainwater.
When more of the rain falls as heavy downpour there is less rain during the rest of the monsoon season and this leads to droughts. This can be avoided if Karnataka becomes a ‘Kerenataka’ (a land of lakes) once more. In order to prevent landslides and floods in western Ghats, it will be necessary to prohibit mining and other development activities in this region.
Greener plan for city
The future climate of Bengaluru will depend primarily upon how we develop urban areas. There will be a need for more lakes and mini-forests and the city must become more friendly to pedestrians and cyclists. We have to make sure that all rooftops have solar panels or solar water heaters. We should promote the use of electric vehicles and buses. They will reduce vehicular emissions and air pollution.
During the 19th and early 20th century, the kingdom of Mysore was known for its far-sighted novel initiatives for the development of the State. In the 21st century, Karnataka can become a leader for the sustainable development of India.
Prof. J Srinivasan is a Distinguished Scientist at Divecha Centre for Climate Change and Honorary Professor, Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science
(This is a part of a series on the impact of climate change on Karnataka and the way forward)