Prof. M Raghu of IIT Mumbai said that natural disasters become worse because of climate change. He said that proper early warning mechanisms and disaster management measures can help in handling the situation. Excerpts from an interview to Prof. Raghu follow:
1. What are the causes of extreme heat?
Extreme heat can be a natural seasonal phenomenon. In India, the five months from March to July are warmer followed by cooler temperatures during the monsoons. However, a below normal rainfall or delayed rains can lead to warmer conditions. This can be due to air masses coming from elsewhere like the deserts or the Middle East. There can also be local factors like depression caused by low atmospheric pressure. With climate changes, the chance of extreme weather conditions increase. Thus, an extreme weather condition that happens once in 10 years may happen every three years.
2. Why does climate change cause more heat waves?
Climatic change leads to greenhouse effect in which, Earth's surface acts like a glass, trapping the sun's heat and stopping it from escaping into space. Thus, it causes global warming. For example, the Middle East is warming up and causing winds over the Arabian Sea to get warmer. As a result of which, some parts of India become hotter. The intensity and frequency of heatwaves tend to increase based on the location. The increasing urbanisation and deforestation enhances the conditions to become hotter.
3. Why be concerned about a degree or two change in the average global temperature? What is the impact regionally?
One has to be cautious about the rate of warming in the global context. For example, most of India had cooler weather conditions during 2023 due to local air circulations but one can still experience heatwaves that are conditions happening at the background of the cooling trend. So the local manifestations of global temperature changes have to be understood and predicted on day-to-week timescales. We call these as early warning systems that are provided by the IMD. But the scales at which such warnings are given are too large and it is difficult to assess it at the city or village let alone neighbourhood scale. So, these scales have to be improved though these are already getting better.
4. Is heat wave a natural disaster? What should we do about disaster management?
Of course it's natural disaster but becomes worse in some places due to climate changes. All conditions are now as per a warmer world so everything is affected by climate change. Disaster management has improved a lot but people have to pay attention to the warnings and alerts. Infants, elderly people and those working in the open areas have to be more careful. Also, exposing elderly people to the hotter weather conditions in the name of ceremonies and functions have to be done with caution. There is a need to set up hydration and cooling centres and make hospital accessibility easier.
5. Who is the most at risk from the impact of climate change? Are there any impact studies in India?
All states are not equally vulnerable and both the young and the old are at risk. Farmers, construction workers, street vendors and slum dwellers are more exposed to the extreme weather conditions. Many studies have been done for assessing the socio-economic vulnerability towards natural hazards but all are at the tehsil level. The data required for identifying those who are vulnerable is not available right now and the census data too is not specific. We need to improve these. But the good news is that the overall vulnerability has reduced with reduction of poverty and better education, employment and housing facilities. The National Disaster Management Agency is definitely doing much better compared to a decade ago.
6. How can people reduce the risks of climate change?
First thing is to be aware of the seasonal arrival of heatwaves and to watch out for warnings and alerts. One has to be aware of nearby facilities namely hospitals and shelters. It has to be ensured that kids and elders do not step out of their homes when there are warnings. We need to protect our greenery and plant more trees as a strategy to combat extreme weather conditions. Ensuring hydration is also an important factor.
7. What is the El Niño impact?
El Niño tends to increase temperatures over most parts of India and the Indian Ocean surface warms up as well. So heatwaves tend to get worse during an El Niño. These will be included in the early warnings so we must still focus on receiving and paying attention to early warnings. The panchayats and governments must communicate the early warnings on time to schools, hospitals and others.
8. India is facing extreme floods and high temperatures. What is the reason?
Monsoon has become erratic because of temperature anomalies on land and ocean surface as well as impacts of the warming of Arctic and the Southern Ocean. So floods and droughts happen at the same time in different parts of the country. Duration, intensity and frequency of active and break periods in the monsoon season are affected so heavy rains and intense dry periods are combined. But early warnings are again the salvation.
9. What is the climate change impact on southern region particularly Telugu states?
Climate change is increasing temperatures over the peninsular India and heatwaves and extreme rain are always a likelihood. A systematic survey of climate hazards in each season are needed to manage water, agriculture, energy, health, buildings, and so on. Andhra Pradesh and Telangana have done well in agriculture related information and they can work together with IMD and NDMA to manage everything in a better manner. A seamless line of communication is needed down to the neighbourhood level to protect lives, property and crops.
10. What is the impact of agriculture production and livelihoods due to climate change?
Erratic and heavy rains, dry spells or warmer conditions cause crop damages and is always stressful for plants. Some good news is that during Kharif season, rain can help even when it is erratic. Cultivation during Rabi season has now gone up and this has to be taken as a strategy in terms of saving water for production during the non-rainy season. Northeast monsoon rainfall can be combined effectively to manage the annual production. But, attention has to be paid on making proper crop selections and in minimising groundwater depletion.
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