environment

Updated: Jan 21, 2019 09:34 IST

Pointing towards a rise in catastrophic weather events in India — including last year’s Kerala floods and the freak dust storms in northern India — the India Meteorological Department (IMD) has said that the year 2000 was a “tipping point” for the impact of climate change-led warming in the country, and scientists predict a cataclysmic fallout by 2040 if emissions are not contained.

In a report released last week, IMD documented a gradual, significant rise in the annual mean temperature from 2000 onwards. Since meteorological record keeping began in India in 1901, the report said that there has been a perceptible spike in the past 19 years. IMD’s “Statement on Climate of India during 2018” linked this trend to climate change because India’s warming trends are very similar to the pattern of global warming.

Global surface temperature has increased by about 1.1 degrees Celsius over the pre-industrial era (1850-1900), and the rise in global temperature has been the highest since 2000 with the 20 warmest recorded years all occurring in the past 22 years, according to World Meteorological Organization’s (WMO) “The State of the Global Climate in 2018”.

In India, 11 out of 15 warmest years occurred during the past 15 years (2004-2018). The past decade (2009-2018) was also the warmest decade on record in India.

Scientists from across government and independent agencies say India is projected to experience a temperature rise of 1.5 degrees by 2040 if measures are not taken to curb greenhouse gas (GHG) emissions. This could impact agriculture, coastal communities, and cost several animal species their natural habitat.

These findings are in sync with last year’s critical Intergovernmental Panel on Climate Change’s (IPCC) “Global Warming of 1.5 degrees” report, whose co-author Joyashree Roy said: “India may face serious consequences including severe heat stress in big cities, high air pollution levels, salt-water intrusion in coastal areas triggered by rise in sea levels, and increased vulnerability to disasters in high mountain ecosystems.”

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India and other countries will have to make “unprecedented transitions in all sectors” to avoid this, the report said.

Scientists say that even with the current rate of warming in India, a lot of changes have taken place in forests and other fragile ecosystems which haven’t been documented yet.

“India is warming rapidly — cities are warming faster than other parts of the states. The Himalayan states are recording a higher warming trend compared to southern states. This will have a massive impact on agriculture and economy. About 30 to 40% of the forest ecosystems are expected to undergo significant changes with the current warming trends,” said NH Ravindranath, scientist at the Indian Institute of Science (IISc) and co-author of several IPCC reports.

IMD’s 2018 climate report — which also documented deaths due to extreme weather events — showed an increasing trend of 0.6 degree over a period of 100 years with a significant increase in maximum temperature of about 1 degree in 100 years. “Our warming rate is lower than the global average but we can’t be complacent because our baseline is already high. The average maximum summer temperatures recorded in India are far higher than the global averages, so we are affected by heat waves more frequently. To stop the acceleration of warming in India, we have the National Action Plan on Climate Change (NAPCC). With focus on increasing forest cover and shift to renewable energy, reduction of carbon dioxide emissions from thermal plants , we are hoping that warming trends can be arrested,” said KJ Ramesh, director general of meteorology, IMD.

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“The temperature data is a clear signal that we are seeing the impacts of global warming. Both daytime and nighttime temperatures have gone up in the last two decades. It’s worrying because both the frequency and intensity of heat waves are increasing in India. The pattern is very similar to the global trends in temperature rise. We see it as a demonstration of global climate change,” said M Rajeevan, secretary, ministry of earth sciences (MoES).

The 2018 annual rainfall over the country as a whole was 85% of Long Period Average (LPA) value for the period 1951-2000. Rainfall data also indicates that 2000 onwards, in most years, average rainfall has been lower than the average for the past 50 years but this may not be “statistically significant”, Ramesh said. IMD earlier reported that rainfall data for 1951 to 2016 shows that rainfall events of more than 10cm to 15cm per day are increasing while those of less than 5cm per day are gradually decreasing.