Heatwaves in India warn of climate threats

The month of March this year was the hottest in 122 years since the India Meteorological Department (Met Department or IMD) started maintaining records, as reported by Mongabay-India. The report adds that it comes after the extreme heat in March last year, which was the third warmest on record.

One of the reasons the short-lived spring season has metamorphosed into summer is the accumulation of greenhouse gases in the atmosphere, besides local weather conditions, scientists have said.

At an average maximum nationwide temperature of 33.10 degrees Celsius, March heralded the early onset of summer, a trend that is becoming the norm. To be sure, the weather office attributed the high temperatures due to the scanty rainfall seen in the month.

The rainfall deficiency was as high as 72% over India, rising to as much as 89% over the northwest parts of the country. Summer temperatures have been rising across India in the past few decades. This is visible in the number of heatwave days the country experiences in the summer months between April and June.

The policymakers’ summary of the latest report by the Intergovernmental Panel on Climate Change (IPCC) reveals that total net anthropogenic GHG emissions have continued to rise during the period 2010 — 2019, as have cumulative net CO2 emissions since 1850. Average annual GHG emissions during 2010-2019 were higher than in any previous decade, but the rate of growth between 2010 and 2019 was lower than that between 2000 and 2009.

Net anthropogenic GHG emissions have increased since 2010 across all major sectors globally. An increasing share of emissions can be attributed to urban areas.

Emissions reductions in CO2 from fossil fuels and industrial processes, due to improvements in energy intensity of GDP and carbon intensity of energy, have been less than emissions increases from rising global activity levels in industry, energy supply, transport, agriculture and buildings.

The report warns that the global greenhouse emissions should peak by 2025 “at the latest” and need to be reduced by 43% by 2030, to limit global warming to around 1.5 degree Celsius above pre-industrial levels.

The Mongabay-India report adds that the number of heatwave days in India is increasing at a rapid pace every 10 years, an ongoing study by the Met Department showed. From 413 in 1981-90 to 575 in 2001-10 and 600 in 2011-20, the number of days that see extremely hot days is persistently increasing at 103 weather stations, mostly in inland areas, the study showed.

The latest numbers, which are yet to be published, are an update of an earlier research at the same weather stations till 2010. The ongoing study also showed most of the 103 weather stations have recorded a significantly increasing trend in heatwave frequency between April and June during the 1961-2020 period, according to the researchers.

Summer temperatures have been rising across India in the past few decades. This is visible in the number of heatwave days the country experiences in the summer months between April and June.

The high heat in March did not even spare the Himalayan states of Himachal Pradesh and Uttarakhand, which typically experience cooler temperatures during this time, indicating an overall rise in temperatures across the country. The IMD study found that the number of cold wave days over the mountainous region has been decreasing over the past three decades.

The IPCC report ‘Climate Change 2022: Mitigation of Climate Change’ by ‘Working Group III’ is the third and concluding installment of the IPCC’s Sixth Assessment Report (AR6).

It examines current trends of emissions, projected levels of future warming, and how to transition to a low carbon economy in order to limit global warming to 1.5 degree Celsius by 2100, in line with the 2015 Paris Agreement targets.

It stresses that international cooperation is a critical enabler for achieving ambitious climate change mitigation goals. The UNFCCC, Kyoto Protocol, and Paris Agreement are supporting rising levels of national ambition and encouraging development and implementation of climate policies, although gaps remain.

Partnerships, agreements, institutions and initiatives operating at the sub-global and sectoral levels and engaging multiple actors are emerging, with mixed levels of effectiveness. In all countries, mitigation efforts embedded within the wider development context can increase the pace, depth and breadth of emissions reductions.

Policies that shift development pathways towards sustainability can broaden the portfolio of available mitigation responses, and enable the pursuit of synergies with development objectives. Actions can be taken now to shift development pathways and accelerate mitigation and transitions across systems.