It is getting alarmingly hot – from the early onset of summer in India to the heat wave in Europe and the US with a red alert in Japan. Nature’s moods are becoming increasingly unpredictable. Madhavan Rajeevan, former secretary, Ministry of Earth Sciences, says the human-induced climate change is now disruptively discernible. Excerpts from an interview with Richa Sharma:
What does the rise in temperatures across the world signify?
It signifies the impact of climate change. The change may manifest in terms of increase in heat waves, increase in heavy rains and flash floods, melting of ice and glaciers, rise in sea levels and coastal erosion, among many other things.
Climate change can occur due to natural variability as well as human-induced (anthropogenic) variability. However, what human-induced climate change does is to increase its frequency and intensity worldwide.
Extreme weather events are not limited to tropical countries. What is the way forward?
Extreme events can occur anywhere. Therefore, actions to limit extreme events should be global. Limiting the greenhouse emissions coupled with checking the rise in global temperatures to 1.5 degree C should be aimed at.
All countries, especially big polluters such as the US, EU, China, Russia and Australia, also have to act as per the Paris climate change agreement. If we restrict the global temperature rise to 1.5 degree C, we can expect to restrict extreme weather events.
Will extreme heat expedite action from developed countries to take immediate measures?
The big polluters will have to lead the initiative and agree to limit global temperature rise to 1.5 degree C. Allowing the temperatures to rise to, say 2 deg C, will have catastrophic impact on life.
What is the role of anthropogenic activities in expediting the climate change-induced disaster in India and globally?
Anthropogenic activities are largely responsible for climate change-induced disasters in India and globally, even though it is difficult to attribute each disaster event to human activities unless we do an in-depth analysis.
Nowadays, there is a growing science of evidence on attribution. For example, the European heat wave of 2003 and this year’s Indo-Pakistan heat wave are attributed to human-induced climate change.
How do we deal with heat waves?
Heat waves can affect our health, agriculture, water resources, power management and air quality. Suitable adaptation policies should be used to cope with the impact of heat waves.
The most effective way to reduce the impacts of a heat wave is to develop a comprehensive response plan that combines individual strategies into an integrated approach, including cultural, institutional, technological and ecosystem-based adaptations.
We need to develop strategies for raising education and awareness among the public, improving energy efficiency to reduce stress on electrical systems to avoid power outages and reducing heat island effects, constructing cool shaded and shelters and developing evidence-based forewarning systems to reduce crop damage.
Thanks to reliable forecasting systems developed at the Ministry of Earth Sciences, we now have the capability of forewarning heat waves at least 4-5 days in advance.
Based on these warnings, some state governments have come up with state action plans.
Marine heat waves are a major cause for concern. How is it going to affect our monsoon system?
From 1925 to 2016, global average marine heatwave frequency and duration increased by 34% and 17% respectively, resulting in a 54% increase in annual Marine Heat Waves (MHWs) days globally.
A recent study over the Indian Ocean suggested that the MHWs in the western Indian Ocean and the north Bay of Bengal has led to a reduction in monsoon rainfall over the central Indian subcontinent.
What simple steps can people take to deal with extreme weather events?
We should create more awareness about the heat waves. Adequate outreach can ensure the health and safety of city dwellers during the heat waves, especially vulnerable groups such as the elderly, children, those who work outside and low-income communities.
Farmers and those who travel long distances during the daytime by bus or trains also are vulnerable.
Simple measures like avoiding working long hours outside during daytime, drinking plenty of fluids and taking care of the elderly will help to reduce mortality due to heat waves.
Our forewarning system should further improve to increase its accuracy and so should the warning lead time to about 7-8 days.
Similarly, our healthcare system, especially in villages, should be adequately equipped to deal with heat wave events.