Vital signs of the planet

The summer of 2023 was the hottest on Earth since global records began in 1880, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.

The months of June, July, and August combined were 0.41 °F (0.23 °C) warmer than any other summer in NASA’s record, and 2.1 °F (1.2 °C) warmer than the average summer between 1951 and 1980. August alone was 2.2°F (1.2°C) warmer than average. June through August is meteorological summer in the Northern Hemisphere.

This new record comes as exceptional temperatures have swept across much of the world, exacerbating deadly wildfires in Canada and Hawaii, and intense heatwaves in South America, Japan, Europe and the United States, while likely contributing to heavy rains in Italy and Greece. And Italy. Central Europe.

“The record-breaking summer temperatures of 2023 aren’t just a bunch of numbers — they’re having serious real-world consequences. From extreme temperatures in Arizona and across the country, to wildfires across Canada, we’re going to have a huge impact on our lives,” said NASA Administrator Bill Nelson. “And severe flooding in Europe and Asia. Extreme weather threatens lives and livelihoods around the world.” “The impacts of climate change pose a threat to our planet and future generations, threats that NASA and the Biden-Harris administration are addressing head-on.”

NASA compiles its temperature record, known as GISTEMP, from surface air temperature data acquired by tens of thousands of weather stations, as well as sea surface temperature data from ship- and buoy-based instruments. This raw data is analyzed using methods that take into account the varying distances between temperature stations around the world and the effects of urban heating that can skew calculations.

The analysis calculates temperature anomalies rather than absolute temperature. The temperature anomaly shows how much the temperature deviates from the baseline mean for the period 1951 to 1980.

“Exceptionally high sea surface temperatures, fueled in part by the return of El Niño, were largely responsible for the record summer warmth,” said Josh Willis, a climate scientist and oceanographer at NASA’s Jet Propulsion Laboratory in Southern California.

El Niño is a natural climate phenomenon characterized by warmer than normal sea surface temperatures (and higher sea levels) in the central and eastern tropical Pacific Ocean.

The record-setting summer of 2023 continues a long-term warming trend. Scientific observations and analyzes conducted by NASA, the National Oceanic and Atmospheric Administration (NOAA) and other international institutions over decades have shown that this warming has been driven primarily by human-caused greenhouse gas emissions. Meanwhile, natural El Niño events in the Pacific pump more warmth into the global atmosphere and are often associated with the hottest years on record.

“With rising temperatures and marine heat waves creeping up on us for decades, El Niño has us setting all kinds of records,” Willis said. “The heatwaves we are seeing now are longer, hotter and more extreme. The atmosphere can also hold more water now, and when it is hot and humid, it becomes more difficult for the human body to regulate its temperature.

Willis and other scientists expect to see the greatest effects of El Niño in February, March and April 2024. El Niño is associated with weakening easterly trade winds and the movement of warm water from the western Pacific Ocean toward the west coast of the Americas. . This phenomenon can have widespread impacts, often leading to cooler and wetter conditions in the southwestern United States and drought in Western Pacific countries, such as Indonesia and Australia.

“Unfortunately, climate change is happening. The things we said would happen will happen,” said Gavin Schmidt, a climate scientist and director of the Geographic Information System (GISS). “And it will get worse if we continue to release carbon dioxide and other greenhouse gases into our atmosphere.”

NASA’s complete temperature data set and the complete methodology used to calculate the temperature and its uncertainties are available online.

GISS is a NASA laboratory operated by the Earth Sciences Division at the agency’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with the Earth Institute of Columbia University and the New York School of Engineering and Applied Sciences.

For more numbers and maps related to this announcement, visit:

https://svs.gsfc.nasa.gov/14407

News media communications

Karen Fox/Aries Kick
Headquarters, Washington
202-358-1100
karen.fox@nasa.gov/aries.keck@nasa.gov

Jacob Richmond
Goddard Space Flight Center
301-286-6255
jacob.a.richmond@nasa.gov