A recent study published in the journal Nature Climate Change has revealed that Chennai and Kolkata, along with several other Asian cities, are at high risk if sea levels rise. The study warned that these cities may face significant consequences by the year 2100 if high levels of greenhouse gas emissions are not controlled.
The effects of natural sea level fluctuations on projected sea level rise due to global warming and climate change were studied. The World Meteorological Organisation has stated that sea level rise is a major threat to India and other countries with large coastal populations.
Global warming is a major cause of sea level rise as warming water expands and melting ice sheets release more water into the oceans. Internal climate variability, which is a naturally occurring process of sea level fluctuations caused by El Nino or changes in the water cycle, was found to significantly impact sea level rise. The report predicted an exponential rise in flooding events, with coastal flooding events expected to occur 18 times more often by 2100 than in 2006 based on climate change in Manila. However, they could occur 96 times more often based on a combination of climate change and internal climate variability.
Co-author of the research, Aixue Hu, stressed the importance of society being aware of the potential for extreme sea level rise in order to develop effective adaptation strategies. The study drew on a set of simulations conducted with the NCAR-based Community Earth System Model that assumed society would emit greenhouse gases at a high rate in this century