Spring shorter in Delhi, flags climate study

Most states in northwestern India are witnessing an abrupt rise in temperatures between January and February, new research has found, indicating that the season of spring has nearly disappeared from the region as the planet continues to warm with rising levels of carbon dioxide in the atmosphere.

The research, by US-based Climate Central, analysed temperature data recorded since 1970 and found that the region showed either a cooling trend or slight warming in January, followed by a strong warming in February.

In an ideal climate scenario, such a warming is witnessed only from March onwards.

For the report, the researchers calculated the difference between the warming rates in January and February, expressed as the change in average temperature since 1970.

Nine states and Union territories — Rajasthan, Haryana, Delhi, Uttar Pradesh, Himachal Pradesh, Ladakh, Punjab, Jammu and Kashmir, and Uttarakhand — showed warmed by over 2°C in this period, the research found.

The largest jump in warming rates occurred in Rajasthan, where February warming was 2.6°C higher than that in January.

“This supports the reports that it feels like spring has disappeared in many parts of India,” the report, Winter Temperature Trends Across India, said.

Experts said that while every year is different, trends suggest higher warming in January-February.

“We are seeing a higher rise in temperature in January and February over northwest. Whether spring is disappearing we cannot say because every year is different but overall trends indicate higher warming in January and February,” said M Mohapatra, director general, India Meteorological Department (IMD).

Separately, the winter season (period from December to February) overall is also warming across India, the study found, with every region showing a net warming trend in these months.

While Manipur experienced the highest warming of 2.3°C in winter months since 1970, Delhi had the lowest warming of 0.2°C.

The season, in fact, was the fastest warming season for 12 out of the 34 states and territories considered.

The analysis used daily average temperatures from ERA5 from January 1, 1970 to December 31, 2023. ERA5 uses computer models to blend meteorological observations from weather stations, balloons, and satellites.

The pattern of temperature rise was different across the country, Climate Central found.

While the southern part saw strong warming in December and January — Sikkim (2.4°C) and Manipur (2.1°C) saw the largest change — the northern part of the country had weaker warming trends in the same period.

The national capital recorded cooling trends (-0.2°C in December and -0.8°C in January) in this period, alongside Ladakh and Uttar Pradesh which saw similar trends.

The pattern changes dramatically between January and February.

The analysis shows that several parts of northwest India are recording strong warming trends in February.

“In the northern part of India, the contrast between January trends (cooling or slight warming) and February (strong warming) means that these regions now have the potential for abrupt transitions from cool winter-like temperatures to the much warmer conditions that traditionally occurred in March,” the analysis said.

HT reported on March 1, 2023 that last February was the warmest in the past 122 years — since IMD started keeping records in 1901.

The average maximum or day temperature was 1.73°C above normal, making it the warmest since 1901. The average minimum temperature was 0.81°C above normal making it the fifth warmest in terms of night-time temperatures alone.

February 2024 was the second warmest since 1901 when it comes to night/minimum temperatures for the country as a whole.

For South Peninsular India it was the warmest February since 1901 both in terms of day and night temperatures. This is mainly because extreme rain deficiency was recorded in the region in February, scientists said.

Minimum temperatures were highest for Central India also in February. During the winter season (January and February), there was a 33% deficiency in rainfall.

Global mean temperatures have risen by more than 1.3 degrees C since 1850, and set a new record in 2023. “The primary cause of this warming is rising levels of carbon dioxide in the atmosphere from burning coal, oil, and natural gas. The purpose of this analysis is to place India in the context of these global trends, with a focus on winter (December-February),” the analysis said.