In the peak of summer, with heat waves sweeping several parts of India, seven-phase general elections are underway in the world’s biggest democracy. The weather department and the government agencies have been regularly issuing alerts and warnings, to ensure the safety of citizens who step out to cast their votes, amid fear of heat strokes and heat-related illnesses as temperatures rise and heat waves turn deadlier.
But heat waves are rising not just on land. Globally, marine heat waves are registering a growing trend. A recent study titled Future Projections for the Tropical Indian Ocean has found that the Indian Ocean is warming rapidly and moving towards a state of near-permanent marine heat waves, with 220-250 days of heat waves projected in a year until 2050.
The findings of this new research, led by Roxy Mathew Koll, scientist with Climate Research Lab, Indian Institute of Tropical Meteorology (IITM), Pune, are published in a recent book, The Indian Ocean and its Role in the Global Climate System, released on April 26.
“In the present-day climate scenario, where we are experiencing 1.2-degree Celsius warming, marine heat waves have already emerged in the Indian Ocean and are rising; at present, they range up to 20 days a year,” said Koll, talking to Mongabay India about the implications of prolonged marine heatwaves in the Indian Ocean. “But, by 2050, we are expected to breach the two-degree Celsius mark, and these heatwaves are likely to increase to 220-250 days, which is two-thirds of a year. We are calling it a permanent heatwave state for the Indian Ocean,” he said.
“These prolonged marine heatwaves will not only intensify cyclones but also affect fish migration, coral reefs, phytoplanktons and marine biodiversity,” warned Koll, who is also the lead author of the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate.
The projected heat waves in the Indian Ocean are of concern as nearly 250 million people live within 50 km of the Indian coastline (3.5% of the world’s population). The 8,118-km long coastline is also home to more than seven million people who depend on fishing for their livelihood.