Putting This Summer’s Record Global Heat Into Context

This summer saw global average temperatures that were unprecedented. June set a record for the hottest June. July set a record not just for the hottest July — but the hottest month ever since modern record keeping began in the 19th century. August came in second for the all-time record. The results: deadly heat waves, overheated ocean waters, massive wildfires.

To help put these phenomena into context, here are some of State of the Planet‘s most-read articles on extreme heat over the past few years, along with media reports about this year’s baking temperatures that quote Columbia Climate School experts.

Potentially Fatal Combinations of Humidity and Heat Are Emerging Across the Globe

by Kevin Krajick | May 8, 2020

Global map showing wet bulb temperatures

Map by Jeremy Hinsdale; adapted from Raymond et al., Science Advances, 2020. Interactive map

According to a new study, dangerous combinations of heat and humidity are already appearing across the globe. The study identifies thousands of previously rare or unprecedented bouts of extreme heat and humidity in Asia, Africa, Australia, South America and North America, including in the U.S. Gulf Coast region. Along the Persian Gulf, researchers spotted more than a dozen recent brief outbreaks surpassing the theoretical limit of human survival. The outbreaks have so far been confined to localized areas and lasted just hours, but they are increasing in frequency and intensity, say the authors.

Summer Heat Waves Caused Several Glaciers to Collapse

by Jaden Hill | September 13, 2022

During the summer heat waves of 2022, glaciers in the Italian Dolomites, Kyrgyzstan and central Switzerland experienced collapses due to the extreme heat. “This summer’s heat wave serves as a dramatic lesson, prompting multiple unexpected changes all at once,” author Jaden Hill writes.

You Asked: How Exactly Does Carbon Dioxide Cause Global Warming?

by Sarah Fecht | February 25, 2021

Over the past few years, we have received many questions about carbon dioxide — how it traps heat, how it can have such a big effect if it only makes up a tiny percentage of the atmosphere, and more. With the help of Jason Smerdon, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory, we answer.

Afternoon heat mapping measurements in South Bronx

Study Maps Urban Heat Islands With Focus on Environmental Justice

by Jeremy Hinsdale | August 26, 2021

Buildings, roads and infrastructure all absorb and re-emit more of the sun’s heat than natural landscapes do. Combine a densely built environment with heat generated by human activities and you soon begin to see urban heat islands—inner-city zones where temperatures can be as much as 20 degrees F warmer than surrounding, vegetated areas. In summer 2021, researchers collaborated with citizen scientists to map the heat in parts of upper Manhattan and the Bronx at the street level for the first time.

Photo: Grant Harley/University of Idaho

1,000-Plus Years of Tree Rings Confirm Historic Extremity of 2021 Western North America Heat Wave

by Kevin Krajick | March 27, 2023

A tree ring study in Western North America indicated that the region’s summer 2021 heat wave was almost certainly the worst in at least the past millennium. “The unprecedented nature of summer 2021 temperatures across [the study area] suggests that no region is impervious to the economic and biological impacts of increasing summer temperatures,” wrote lead author Karen Heeter and colleagues.

The Fire This Time: Facing the Reality of Climate Change

by Steve Cohen | June 12, 2023

“Last week for a few terrifying days, we saw additional evidence of our interconnected biosphere. Fires burning about 400 miles from New York City turned the air orange and drove New Yorkers from their streets,” wrote author Steve Cohen. “People in other parts of America and other parts of the world are familiar with this phenomenon—New Yorkers were not. Now we are.”

Exposure to Deadly Urban Heat Worldwide Has Tripled in Recent Decades, Says Study

by Kevin Krajick | October 4, 2021

A new study of more than 13,000 cities worldwide has found that the number of person-days in which inhabitants are exposed to extreme combinations of heat and humidity has tripled since the 1980s. The authors say the trend, which now affects nearly a quarter of the world’s population, is the combined result of both rising temperatures and booming urban population growth. “This has broad effects,” said the study’s lead author, Cascade Tuholske. “It increases morbidity and mortality. It impacts people’s ability to work, and results in lower economic output. It exacerbates pre-existing health conditions.”

Photo: Radhika Iyengar

Are You Feeling the Heat Yet?

by Radhika Iyengar | May 3, 2022

A personal report on some of the ways climate change is impacting India, now the world’s most populous country. “My family members there report that hot air is burning their noses and their shoes are sticking to the road tar as it melts in the heat when they walk. It has become unbearable to live in many parts of India. And of course, people who are economically deprived will bear the brunt of this dangerous heat.”

Greener Ways to Keep Cool During a Heat Wave

by Renee Cho | August 3, 2018

“It is really important for people to try to stay cool during the summer heat and especially during heat waves, because heat can kill people and it can make people sick, and that includes even healthy young folks and athletes,” said Kim Knowlton of Columbia University’s Mailman School of Public Health. If you don’t have access to air conditioning, or opt not to use it, here are some greener strategies to keep cool. Hopefully they’ll also save you money on your electricity bill.

Columbia Climate School In The Media

  • New Research Shows Direct Link Between Greenhouse Gas Emissions and Polar Bear Decline

    Inside Climate News | Sept. 3, 2023
    A 2021 report from the Sabin Center for Climate Law summarizes the scientific findings about the impacts of climate change on endangered species. Global warming is an overarching threat to nearly all species, and if biodiversity collapses, some of the planet’s best natural mechanisms to remove CO2 from the atmosphere and slow atmospheric heating will fail.

  • Extreme heat may speed up cognitive decline for certain people

    The Independent | Aug. 23, 2023
    According to scientists at NASA’s Goddard Institute for Space Studies, July 2023 was hotter than any other month in the global temperature record. With harsher summers and global temperatures on the rise, it can be quite hard for the body to adjust.

  • Wildfires, hurricanes and heat: The U.S. is getting hit by extreme weather from all sides

    NBC News | Tuesday, Aug. 22, 2023
    The myriad disasters should be a wake-up call about society’s vulnerabilities to climate-aggravated hazards and the need to mitigate and adapt to the realities of a warming world said Andrew Kruczkiewicz, a senior staff research associate at the Columbia Climate School.

  • Mediterranean Sea warming to ‘unprecedented’ levels amid global heat wave

    United Press International| Aug. 18, 2023
    A global heat wave is pushing temperatures in the Mediterranean to new highs. The Goddard Institute for Space Studies at the U.S. space agency NASA said this July was 0.43 degrees warmer than any July on record. “The science is clear—this isn’t normal,” said Gavin Schmidt, the director at GISS.

  • Americans Flock to Areas With Harshest Climate Change Effects

    Nerd Wallet | Aug. 8, 2023
    “Extreme heat and humidity is going to be a reality pretty much no matter where you move,” says Alex De Sherbinin, senior research scientist at the Columbia Climate School. “But life-threatening damages from those kinds of things are going to be more restricted to some locales than others.”

  • Swaths of the US are living through a brutal summer. It’s a climate wake-up call for many

    Associated Press | Aug. 7, 2023
    Radley Horton, a scientist who studies ocean and climate physics at Columbia University, said there are a few additional ingredients that can converge to create a heat wave. Drier conditions, for example, mean more of the sun’s energy can go toward heating the air rather than evaporating water from plants and the soil. The time of year can also play a role: At latitudes farther from the equator, the Earth’s tilt can lead to summer days with 15 hours or more of sunlight — a long time for heat to build up.

  • July’s heat waves, high ocean temperatures show extreme weather to come

    The Washington Post | July 31, 2023
    Gavin Schmidt, director of the NASA Goddard Institute for Space Studies, largely agrees. Conditions during what was Earth’s hottest ever observed month were shocking, but not surprising,” he said. As the sweltering summer of 2023 marches into August, with another round of triple-digit heat advisories, scientists and environmental advocates are hoping the recent extremes somehow spur the kind of global, collective action that has been largely absent.

  • Antarctica has a winter sea ice shortfall four times the size of Texas

    Axios | July 31, 2023
    Scientists don’t know what is driving the shortfall, but they are deeply concerned about its consequences, as sea ice influences the planet’s climate, global ocean currents and marine ecosystems. Lettie Roach, an associate research scientist at Columbia University, said she finds it especially concerning to see the sea ice shortfall occurring at the same time as scorching heat is breaking global temperature records.