The repercussions of global temperature rise for India

• From an early onset of heat waves across northern states to one of the worst floods in recent years in Assam and other northeastern states, India has experienced several record-breaking weather events so far this year.
• An assessment by the Union Ministry of Earth Sciences in June 2020 states that since the middle of the twentieth century, India has witnessed a rise in extreme temperature and rainfall events, droughts, and sea levels and an increase in the intensity of severe cyclones, alongside other changes in the monsoon system.
• According to the UN Intergovernmental Panel on Climate Change’s (IPCC) Assessment Report 6 of Working Group I, the world is on track to breach the temperature guardrail of 1.5oC in the next 18 years.
• As per analysis, India could become 1.2oC warmer and receive almost 10% more rainfall every year and Ladakh is likely to be the worst hit at 2.23oC warmer than pre-industrial levels.
• Annual mean temperatures may rise in five other Himalayan states which are Jammu and Kashmir (1.76oC), Himachal Pradesh (1.73oC), Uttarakhand (1.62oC), Sikkim (1.55oC) and Arunachal Pradesh (1.47oC). The temperature rise is most likely to trigger the rapid melting of glaciers and precipitation change.
• The northern and western parts of India will likely be more vulnerable than the eastern part, in terms of temperature rise. The arid states of Rajasthan and Gujarat will likely see 1.43oC and 1.33oC increase in annual average temperatures.

• Kerala (1.31oC), Punjab (1.27oC) and Chandigarh (1.26oC) may also experience a substantial temperature rise. In contrast, Jharkhand, Bihar, West Bengal and Odisha could record less than 1oC increase in their annual average temperature, when the world crosses the 1.5oC threshold.
• The warmer temperatures may translate into an increase in the number of days of heatwaves. Rajasthan could record 13 additional days with temperatures beyond 40oC, followed by Delhi, Gujarat (12 additional days each), Telangana (10 additional days) and Andhra Pradesh (8 additional days).

• The India Meteorological Department considers a non-hilly region for the declaration of a heatwave when the temperature crosses 40oC.

• While most of India is expected to see an increase in rainfall, the distribution of this increase is likely to be uneven. The maximum increase in rainfall is expected in northwestern India. Eg: Rajasthan could receive up to 22.87% more rain than the 1850-1900 average, followed by Gujarat with 22.16% and Punjab with 20.54%.
• Arunachal Pradesh, Sikkim and Andaman and Nicobar are the only three states and UTs where rainfall levels are most likely to go down.
• The repercussions of a 1.5oC global temperature rise would be catastrophic for India.

More than Weather 

• As per analysis, Northwest India shows both enhanced warming and a significant increase in rainfall. Eg: Kerala, Tamil Nadu, and northeast India show enhanced warming, but only a nominal increase in rainfall or even a decrease in rainfall. The eastern states of Odisha, West Bengal, Jharkhand and Chhattisgarh show nominal warming and a nominal increase in rainfall.

• The low-level jet stream winds, responsible for the monsoon rains, have been moving northwards over the past three decades. This is the reason rainfall levels in Kerala have decreased over time.
• The northward or poleward shift of the low-level jet stream has been identified as major impacts of global warming on large scale atmospheric dynamics as consistent movement in the jet stream has led to “a drying trend in the southern part of the Western coast of India and a wetter monsoon season in the upper parts of the Western coast in the last three decades.

• It is also possible that in the northwest, western disturbances have decreased rainfall in the pre monsoon season. South India and northeast India generally get rains during other seasons too, so the rainfall-temperature links might be more visible in the annual averages too.
• It would be difficult to delineate the potential relationship between warming and change in precipitation patterns without an in-depth study involving both models and observations. Scientists suggest taking a look at the seasonal changes to understand the overall trend as annual values mask the seasonal links.

Conclusion

• The findings are alarming. It underscores the need to get serious about the climate crisis and at the same time gives insights into what awaits each state or UT kown as “climate adaptability”.