Climate Change Intensifies, Diminishing La Niña’s Cooling Efficacy

Scientists report that climate change is growing stronger, diminishing the cooling effects of La Niña amidst increasingly warmer conditions in India. The IMD forecasts an early summer with elevated temperatures and prolonged heatwaves, following a record warm February. Current research underscores the significance of changing weather patterns impacted by both human activity and natural climate phenomena.

Climate change is intensifying, rendering the cooling effects of La Niña less effective in a warming future, according to climate scientists who have recently evaluated temperature trends across India. The India Meteorological Department (IMD) has forecasted an early summer characterized by above-average temperatures and prolonged heatwaves. Notably, February 2024 marked the warmest February in India since 1901, with significantly low rainfall reported since 2001.

Human-induced climate change is establishing a ‘new normal’ evident through warmer winters and reduced spring seasons. Concurrently, scientists underscore the significance of ‘year-to-year variability’ in weather patterns. Arpita Mondal, an associate professor at the IIT Bombay Centre for Climate Studies, noted that this winter has been remarkably dry, questioning the implication of such conditions on temperature moderation.

Raghu Murtugudde, an earth system scientist at IIT Bombay, commented on the global fluctuations in temperature anomalies during December to February, directly linked to jet stream movements. These jet streams, which are powerful upper-atmosphere winds, can drastically affect weather when they shift. Mondal further stated that the northward movement of these winds during pre-monsoon periods directly correlates with the characteristics of heatwaves, particularly their intensity and duration.

The El Niño and La Niña phenomena, components of the El Niño-Southern Oscillation (ENSO), are also crucial in understanding current climatic trends. Vimal Mishra, a professor at IIT Gandhinagar, elaborated that El Niño conditions lead to warmer springs, while La Niña typically results in cooler days. The ENSO cycle alternates between these two states and generally lasts between two to seven years.

The World Meteorological Organization (WMO) recently indicated that the existing weak La Niña is projected to be short-lived, predicting a 60 percent chance of its emergence from July to September 2025, following previous ENSO-neutral conditions. Reports also indicate that global temperatures from March 2024 to February 2025 are 0.71 degrees Celsius above the average recorded from 1990 to 2020, with sea surface temperatures being unusually elevated in several ocean regions.

Murtugudde expressed skepticism about the current La Niña conditions, emphasizing the persistence of warm anomalies in critical areas of the eastern Pacific. As these irregular patterns emerge, they are likely tied to the unprecedented warming recorded in 2023. Furthermore, studies suggest that as the climate continues to warm, the frequency and severity of El Niño events may increase significantly.

This past summer, India reported an unprecedented 536 heatwave days, the highest in 14 years, with the northwestern region experiencing the warmest June since 1901. Mishra explained that the definitive impact of climate change remains evident, noting that even under ENSO-neutral scenarios this year, severe heatwaves must be anticipated due to already elevated March temperatures. The WMO anticipates a 60 percent likelihood of ENSO-neutral conditions from March to May 2025 and warns that changes under climatic conditions could render La Niña less effective in curbing extreme heat episodes.

In conclusion, climate change continues to assert itself, with increasing temperatures and reduced effectiveness of La Niña in moderating warm conditions. The IMD forecasts an early summer of intense heatwaves, further exacerbated by ongoing climate trends. The research highlights that natural climate phenomena like El Niño and La Niña contribute to weather variability but are now being overshadowed by the pressing impacts of anthropogenic climate change. As such, we anticipate severe weather patterns moving forward, emphasizing the need for urgent climate action.

Original Source: www.theweek.in