Climate change: Extreme events are getting more frequent, intense

The one issue that has continued to dominate global headlines in the recent weeks, apart from Covid-19, is the series of extreme weather events, such as extreme heat, forest fires, floods, storms and drought events in different parts of the world. Scientists have been warning of the increasing frequency and intensity of extreme weather events due to climate change, but perhaps even they never expected that records would be broken so soon.

In fact, the World Meteorological Organisation (WMO) has concluded that there’s about a 40% chance of the annual average global temperature temporarily reaching the dangerous threshold of 1.5 deg C above the pre-industrial level in at least one of the next five years – and these odds are increasing with time. The Paris Agreement has set a target of stabilising global mean warming below the dangerous threshold of 1.5-2 deg C. The global mean warming level has already touched 1.2 deg C, compared to a century ago.

First, extreme flooding events have occurred in 2021 in different parts of Karnataka, Kerala, Maharashtra, Assam, etc., in India; in China, where recently a whole city of 10 million was completely under water; in Germany, Belgium, France, etc., in western Europe; in Colorado, New Mexico, etc., in the US, where record rainfall occurred over short periods.

According to the WMO, monsoon rains led to massive flooding, dam collapses, landslides, and displacement of millions of people in Bangladesh, China, India, Japan, Pakistan, Nepal, South Korea, Turkey and Vietnam in 2020. In India, in 2019, nearly 2,000 died and 1.8 million were displaced by floods.

In Karnataka, the flood-causing events have become a regular feature in recent years: 2018, 2019 and 2020. In Karnataka, during 2019, crop damage occurred in 9.7 lakh ha, with an estimated loss of Rs 15,230 crore. Similarly, in 2020, over four lakh ha of crops were damaged, with a loss of Rs 5,000 crore. According to climate change projections made at the Indian Institute of Science, a majority of districts in Karnataka and across India are projected to experience increased rainfall (10-25%) and, more importantly, increased frequency of high intensity rainfall events leading to floods, even by the mid-2030s. But the extreme events which scientists expected in the later decades of the century are already occurring.

Second, according to the WMO, the global mean temperature in 2020 was the second warmest on record. The past six years, including 2020, are likely to have been the six warmest years on record. Heat stress has already been recorded in many parts of the world, even in unexpected regions such as Canada, the north-western parts of the US, Siberia and Europe. In the Death Valley of California, the temperature reached 55 deg C. Lytton, a town in Canada, touched 49.6 deg C, compared to a July average of 28 deg C, and the whole town was engulfed in fires. Hundreds have died in rich countries and in India this year already. In Siberia, known as the frozen land, during mid-2020, the temperature was 18 deg C higher than normal. This year also, the temperatures in the Russian Arctic hit an unprecedented 48 deg С.

According to International Labour Organisation estimates, the economic losses due to heat stress at work are projected to be over $2.4 trillion by 2030, being most pronounced in lower and middle-income countries. According to a study by Rutgers University, some 1.2 billion people could be impacted by heat stress at 3 deg C global warming, particularly in the poorer countries.

Third, forest fires are raging already this year. In the US, over four million hectares of forests have been burned annually in three out of the last five years. Siberia, known as one of the coldest regions in the world, has been experiencing extreme high temperatures, leading to the burning of 1.5 million ha of forests. In Australia, in 2019, over 11 million ha of forests were burnt, leading to death or displacement of nearly three billion animals, including 143 million mammals, 2.46 billion reptiles, 180 million birds and 51 million frogs, according to a study by the WWF. This is one of the worst wildlife disasters, driven by high temperatures and drought caused by climate change. Every country from Canada to western Europe to Siberia to Australia has experienced regular extreme forest fires in the past 5-10 years, leading to loss of human life, property, wildlife and biodiversity.

Fourth, storms, cyclones and hurricanes have all occurred across the world. With increasing frequency of hurricanes, the WMO concluded that the hurricane season exhausted the regular list of names for each one of them. The North Atlantic hurricane season had its largest number of named storms — 30 — on record in 2020, with a record number making landfall in the US. India also had its share of storms and cyclones, such as cyclones Amphan, Nisarga, Nivar, Gati and Burevi, with Amphan turning out to be a ‘super cyclonic storm’. In 2019, India had eight cyclones of which six turned were ‘severe cyclones.’

One can add many other climate-related extremes: droughts, sea-level rise, locust swarms, ocean warming, Arctic and Greenland ice-sheet loss, Himalayan glacial ice melt (a quarter of ice lost in 40 years), landslides, crop pest incidence, etc. All have accelerated in recent years and are projected to be more severe in the coming decades due to climate change.

According to Germanwatch, which ranked countries on Climate Risk Index-2021, India ranked seventh in the world. The top 6 included small countries such as the Bahamas, Malawi, Zimbabwe and Afghanistan. Thus, India is one of the most vulnerable major countries to climate-related risks and extremes. The adverse impacts of climate change-related extremes are already being felt by billions around the world. These will only increase in the coming years and decades, unless all governments make fundamental or transformational changes to achieve the Paris Agreement goal of limiting global warming to 1.5 deg C, which seems highly unlikely.

(The writer is a former professor, IISC, Bengaluru, and a climate change expert)