The probability that summers between 2061 and 2080 will be warmer than the hottest on record stands at 80 per cent across the world's land areas, excluding Antarctica, which was not studied, according to scientists at the US National Centre for Atmospheric Research (NCAR).
If greenhouse gas emissions are reduced, however, that probability drops to 41 per cent.
"Extremely hot summers always pose a challenge to society," said NCAR scientist Flavio Lehner, lead author of the study.
The researchers used two existing sets of model simulations to study what future summers might look like.
They created both by running the NCAR-based Community Earth System Model 15 times, with one simulation assuming that greenhouse gas emissions remain unabated and the other assuming that society reduces emissions.
By using simulations created by running the same model multiple times, with only tiny differences in the initial starting conditions, the scientists could examine the range of expected summertime temperatures for future scenarios.
The researchers compared results to summertime temperatures recorded between 1920 and 2014 and to 15 sets of simulated summertime temperatures for the same period.
The results show that between 2061 and 2080, summers in large parts of North and South America, central Europe, Asia, and Africa have over 90 per cent chance of being warmer than any summer recorded if emissions continue unabated.
Reducing emissions would lower the global probability of future summers that are hotter than any in the past, but would not result in uniformly spread benefits.
In some regions, including the US East Coast and large parts of the tropics, the probability would remain above 90 per cent, even if emissions were reduced.
The study appears in the journal Climatic Change.
You’ve reached your limit of 5 free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Access to Exclusive Premium Stories
Over 30 subscriber-only stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app