Climate crisis link to India’s spring heatwave

NEW DELHI: A heatwave will sweep large swathes of India over the next four to five days, extending from the west and northwest India to the east, weather officials warned on Tuesday, as an unusual heat blast hitting the country since last month seems set to intensify.

Last month, India recorded its warmest March since records were maintained and one of the driest spring seasons, with dry warm winds plunging much of North India into summer temperatures sooner than usual.

Experts said the trends are yet another indicator of the effects of climate crisis, which now puts hundreds of millions of people at greater health risk and trigger productivity loss.

“India’s current heatwave has been made hotter by climate change that is the result of human activities. Until net greenhouse gas emissions end, heatwaves in India and elsewhere will continue to become hotter and more dangerous,” said Friederike Otto, senior lecturer in Climate Science at the Grantham Institute, Imperial College London, said in a statement to Climate Trends, a climate communications organisation. Otto leads the World Weather Attribution group.

This follows freak weather conditions recorded in other parts of the world this year. In March, both of Earth’s polar regions experienced unprecedented simultaneous heat waves — in Antarctica, the average temperature was 4.8°C warmer than average, while in the Arctic, the average was 3.3°C higher than normal, AP reported last month.

For India, experts point to a cyclical weather phenomenon in the Pacific Ocean, the La Nina, which has led to effects that are unusual from the typical influence it is known for.

La Nina, a condition when the sea surface temperature in eastern and central Pacific Ocean is lower than usual, alters a planetwide wind system and leads to a harsher winter, a somewhat more intense summer, and a rainier monsoon in India in the following period. But this year, it seems to have eaten into the spring season entirely, triggering summer-like conditions much sooner.

“In India, the phenomenon is associated with wet and cold winters. The current impact of La Niña on the spring and summer season in India is unexpected,” said Raghu Murtugudde, a climate scientist at the University of Maryland, according to a statement by the Centre for Science and Environment (CSE).

The early heat waves of 2022 started on March 11 and have impacted 15 Indian states and Union territories (as of April 24), according to data from IMD, which was analysed by CSE.

“It is extremely unusual…,” said M Rajeevan, former secretary, ministry of earth sciences. “These cannot be due to local meteorological features, but linked to large-scale atmospheric and oceanic conditions, which require analysis.”

In a silver lining, however, Rajeevan added that the monsoon may not be affected. “Thankfully, this year El Nino (which saps the monsoon) is unlikely to impact us. This year either La Nina or ENSO neutral conditions are likely to persist, which will help the monsoon.”

ENSO neutral conditions in the Pacific Ocean affect ambient temperatures and rainfall over South Asia. La Nina conditions are likely to persist till mid-monsoon, according to IMD. “La Nina continues in the tropical Pacific, with current forecast favouring continuation of La Nina through the summer, with a slightly lower chance into the fall,” the research wing of National Oceanic and Atmospheric Administration tweeted on Sunday.

A second reason why the unusual effect may be happening is that the La Nina-triggered wind patterns lead to clear skies and what is known as an anti-cyclone system. “This is causing incursion of dry, very hot winds from the western region,” said DS Pai, director at Kottayam-based Institute for Climate Change Studies.

Such weather is already stressing India in several ways. The country is grappling with a power crisis, with surging demand triggering a clamour for coal to feed thermal power plants. On Monday, India breached its all-time peak power demand of 201.066 GW, surpassing a past record that was set on July 7 last year.

The early hot spell has also hit wheat yield, one of the mainstay winter crops harvested in spring. Traders and analysts have in recent days said it is clear from procurement trends that the country will have a smaller crop this year than previously predicted.

This could further fuel food inflation, adding to a price rise pressure that has now persisted for several months.

The weather is also a risk to public health. More frequent hot days and intense heat-waves increase heat-related deaths in Asia, the Asia factsheet of Intergovernmental Panel on Climate Change’s “Climate Change 2022: Impacts, Adaptation and Vulnerability” report said in February.

But the larger picture is clear: the climate crisis has likely begun leading to effects that are unpredictable.

“Before human activities increased global temperatures, we would have seen the heat that hit India earlier this month around once in 50 years. But now it is a much more common event — we can expect such high temperatures once in four years,” said Mariam Zachariah, research associate at the Grantham Institute, Imperial College London, in a statement to Climate Trends, a climate communications organisation.