NASA describes climate change as a long term change in the average weather patterns preexisting in local, regional and global climate. Most of the changes observed in Earth’s climate since the early 20th century are primarily driven by human activities, particularly fossil fuel burning which releases greenhouse gasses like methane, nitrogen dioxide and most importantly, carbon dioxide (CO2). These gasses are heat trapping in nature and are raising the Earth’s average surface temperature. The temperature increased caused by man-made activities is referred to as global warming.
Global warming is causing extreme weather events like floods, cyclones, draughts, forest fires, heat waves, and hurricanes and melting polar ice caps of the planet. India being a tropical country faces floods every year. We also have huge coastline spanning 7,500-odd km and runs past nine states which are very vulnerable to flooding. The rapid melting of polar ice caps because of Global warming has accelerated the rise of sea levels as observed by study conducted by an IPCC panel. This is going to impact people living near the coastal areas and in islands. Mumbai, one of the largest cities in the world, with a population of 20 million is projected to be completely submerged by rising sea levels. Glaciers are also melting in the Himalayas, which is projected to increase flow rates in the Ganges and Brahmaputra Rivers. In 2013, heavy rain followed by a glacial lake outburst caused devastating floods in the state of Uttarakhand. The floods 4,000 people, destroyed and caused damages of 3.8 billion dollars.
Monsoon in 2019 witnessed 560 extreme rainfall events, a 74% jump from 324 events recorded in the year 2018. The heavy rainfall caused floods that led to a death toll of 1685 lives, spread across 14 states of the country, with Maharashtra accounting for the maximum deaths. According to Home Ministry officials heavy rains and floods fully damaged 1.09 lakh houses, partially damaged 2.05 lakh houses and destroyed 14.14 lakh hectares of crops. Responding to floods in different areas at the same time as happened last year strains emergency response efforts. NDRF, Army and the Air Force were deployed to rescue people across six states in northern and western India. An estimated 1.2 million people were living in government relief camps.
According to IPCC panel, the frequency of freak weather events like floods would drastically reduce if the rise in temperature was limited to 1.5 degree Celsius, however it is highly unlikely that we are able to achieve that target. In a study conducted by IIT Gandhinagar, it was found that short bursts of heavy rainfall, lasting only hours, are likely to increase by 20 percent if the global mean temperature rises above 1.5 degree Celsius. Such extreme events will be responsible for most cases of urban flooding.