As parts of India continue to suffer from a severe heatwave in June, following on from last month, NASA scientists have revealed that May 2024 was the hottest May on record. This marks an unprecedented full year of record-high monthly temperatures globally.
Unprecedented Streak of Record Highs
According to researchers from NASA’s Goddard Institute for Space Studies (GISS), average global temperatures for the past 12 months have hit new highs for each respective month – an unparalleled streak in recorded history.
“It’s clear we are facing a climate crisis,” stated NASA Administrator Bill Nelson. “Communities across America — like Arizona, California, Nevada — and communities across the globe are feeling first-hand extreme heat in unprecedented numbers. NASA and the Biden-Harris Administration recognize the urgency of protecting our home planet. We are providing critical climate data to better lives and livelihoods, and benefit all humanity.”
Long-term Warming Trend
This sequence of record temperatures aligns with a long-term warming trend driven primarily by human-caused greenhouse gas emissions. This trend has become increasingly evident over the past four decades, with the last 10 consecutive years being the warmest since record-keeping began in the late 19th century. Prior to this 12-month streak, the previous longest streak of record monthly temperatures lasted seven months between 2015 and 2016.
“We’re experiencing more hot days, more hot months, more hot years,” said Kate Calvin, NASA’s chief scientist and senior climate advisor. “We know that these increases in temperature are driven by our greenhouse gas emissions and are impacting people and ecosystems around the world.”
Analyzing the Data
In NASA‘s analysis, a temperature baseline is defined by several decades or more, typically 30 years. The average global temperature over the past 12 months was 2.34 degrees Fahrenheit (1.30 degrees Celsius) above the 20th century baseline (1951 to 1980). This is slightly over the 2.69 degree Fahrenheit (1.5 degree Celsius) level with respect to the late 19th century average.
NASA scientists gather data from tens of thousands of meteorological stations on land and instruments on ships and buoys to calculate Earth’s global temperature. This raw data is analyzed using methods that account for factors like the varied spacing of temperature stations and urban heating effects.
Impact of Natural Phenomena
Natural phenomena like El Niño and La Niña, which warm and cool the tropical Pacific Ocean, can contribute to year-to-year variability in global temperatures. The strong El Niño that began in spring 2023 helped fuel last year’s extreme summer and fall heat.
As of May 2024, NOAA projected a 49% chance of La Niña developing between June and August, and a 69% chance between July and September. A La Niña event could partially suppress average global temperatures this year by cooling the tropical Pacific.
What’s Happening in India?
A sluggish southwest monsoon on Wednesday covered large parts of Maharashtra, awaiting a fresh pulse to march across central and northern India, which continued to reel under intense heat conditions.
Heatwave conditions were observed on Wednesday in most parts of Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, and Jharkhand; in many parts of north Rajasthan; in some parts of Himachal Pradesh, south Bihar, north Odisha; and in isolated pockets of Gangetic West Bengal. Severe heatwave conditions were also observed in isolated pockets of Uttarakhand, Himachal Pradesh, Punjab, Jharkhand, and Gangetic West Bengal. The maximum temperatures ranged from 45-47 degrees Celsius in some parts of west Jharkhand, south Uttar Pradesh, Haryana-Chandigarh-Delhi, Punjab, and north Rajasthan.
The prolonged and intense heat is a stark reminder of the climate crisis, emphasizing the need for urgent global action to mitigate the impacts of climate change.