- Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
- It is affecting rainfall patterns. In high latitudes, rainfall is likely to increase, while it is projected to decrease over large parts of the subtropics.
- Changes to monsoon rain are expected, which will vary by region.
- Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion.
- Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
- Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets.
- Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence.
- These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
- For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.
“About 50% of the sea level rise is due to thermal expansion. Also, the Indian Ocean region is warming at a higher rate that means the relative sea level can also increase over the regions. Hence, the coastal regions will see sea level rise through the 21st century, and it will contribute to more frequent and severe coastal flooding in low level areas and coastal erosion. Along with this, extreme sea level events that were previously seen once in a hundred years, could also happen every year by the end of the century,” said Swapna Panickal, IPCC author and climate scientist from Indian Institute of Tropical Meteorology.
“2°C global warming has serious implications due to possible increases in extreme weather events like heat waves, heavy precipitation, intensification of tropical cyclones etc. Also, the variability of climate will increase suggesting more drought episodes where drying is happening and floods where wetting is happening. Dry becomes drier and wet becomes wetter. Another worrying fact is that we should expect compounding extreme weather events. For example, drought followed by heat waves. A flood followed by another flood. We have not documented this aspect very well. I have reviewed a few research papers recently for some leading journals on this emerging area,” said M Rajeevan, former secretary, ministry of earth sciences.