July 2023 was the hottest month on Earth since at least 1880 'by a longshot,' NASA says

a map showing regions of heat across the globe. Almost all areas are highlighted in red, showing that temperatures are rising way quicker than they should be.
This map shows global temperature anomalies for July 2023 according to the GISTEMP analysis by scientists at NASA’s Goddard Institute for Space Studies. Temperature anomalies reflect how July 2023 compared to the average July temperature from 1951-1980. (Image credit: NASA’s Goddard Institute for Space Studies)

In the wake of Hawaii's tragic wildfires, responsible for the deaths of more than 90 people and counting, NASA experts gathered Monday (Aug. 14) to discuss the state of our planet's climate emergency. The discussion was quite jarring. 

Not only did the panelists confirm that July of this year was the hottest month on a record dating back to the late 1800s, but also that the last five hottest Julys in this database occurred within the past five years. The agency further projects that next year will be hotter still

More specifically, a statement put out soon after the conference states that July was 0.43 degrees Fahrenheit (0.24 degrees Celsius) warmer than any other July in NASA’s record, which goes back to 1880, and 2.1 degrees Fahrenheit (1.18 degrees Celsius) warmer than the average July temperature between 1951 and 1980. 

"It was the warmest July by a longshot," Sarah Kapnick, chief scientist at the National Oceanic and Atmospheric Administration, said during the conference.

And a major takeaway from today's conversation was that it's humankind who holds the reins to this unfortunate truth. 

"Long-term trends we've been seeing since the 19th century, particularly since the 1970s, are all due to anthropogenic effects," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies.

The term "anthropogenic" in this case simply refers to human-driven activity such as burning coal for power, cutting down trees to build infrastructure and fostering air pollution.

Related: NASA searches for climate solutions as global temperatures reach record highs

Schmidt explained that NASA's data clearly shows other climate change factors such as El Niño events, which are natural weather patterns that lead to warming ocean surfaces, and volcanic activity create "very, very small" impacts on global warming when compared to these anthropogenic components. 

El Niño, for instance, can lead to a temporary temperature increase of about 0.1 degrees Celsius, according to agency data, yet global warming observed so far exceeds that quantity by quite a bit. "Without those human contributions to the drivers of climate change, we would not be seeing anything like the temperatures that we're seeing right now," Schmidt said.

The team's long-term observations come from statistical models filled with information about Earth's temperature evolution as it correlates with different processes occurring across the globe, natural as well as not. 

"Temperatures we are now experiencing, you can only get those temperatures if you include those greenhouse gas emissions into the atmosphere and the land-use change that we have created on Earth," Kapnick said. 

Such rising temperatures are worth worrying about because they help create the perfect conditions for severe natural disasters such as drought, cyclones and wildfires including Hawaii's crisis that's been taking place over the past few days.

"Just look around you and you'll see what's happened," NASA administrator Bill Nelson said during the conference. "We have record flooding in Vermont. We have record heat in Phoenix and in Miami. We have major parts of the country that have been blanketed by wildfire smoke and, of course, what we are watching in real-time is the disaster that has occurred in Hawaii with wildfires."

On that note, while he admits there are local situations on the Hawaiian island of Maui that contribute to the risk of wildfires, such as abandoned sugar plantations and non-native grasses, Schmidt explained that global warming definitely plays a part. To name just one example, climate change has forced storms to move north, leading to less rainfall over the island and creating drier conditions

"In general," Schmidt said, "climate change is a kind of threat-multiplier for wildfires."

Going forward, NASA intends to better understand exactly how much climate change is contributing to these Hawaiian wildfires as a specific, primary cause is yet to be formally announced.

Monday's discussion also touched upon the effects climate change is having on marine health. "The oceans are experiencing about 90% of global warming," Carlos Del Castillo, Ocean Ecology Laboratory chief at NASA's Goddard Space Flight Center, said during the conference. "As the oceans heat, the water expands. When you combine that with the melting of ice overland, that contributes to increases in sea level rise."

Consequences of such sea level rise — which is accelerating as the years go by — include coastal flooding and even coastal erosion. Castillo pointed to the example of Florida's Miami Beach. "They have been experiencing more frequent coastal flooding," he said, "five times more than what they experienced 50 years ago."

Castillo also brought attention to the fact that Louisiana's marshes are disappearing, and emphasized why we should be alarmed that coral reefs and sea grasses are dying off. 

"Unfortunately, coral reefs cannot grow legs and move away. So they have to stay put and experience the brunt of global warming," he said. "25% of marine species have something to do with corals. They contribute to medicine. They contribute to the livelihoods of millions of people. They protect the coastline from tidal surges and storms."

Shining a glimmer of hope on the situation is NASA's upcoming PACE mission, which stands for Plankton, Aerosol, Cloud, Ocean Ecosystem. 

One of many climate solutions the agency is working on – in addition to self-flying aircraft that'll tend to wildfires and open-source Earth data websites for scientists to glean information from — PACE is slated to launch in 2024 and intended to detect changes in things like ocean color changes.

"A year like this gives us a glimpse at how rising temperatures and heavier rains can impact our society and stress critical infrastructure over the next decade," Kapnick said. "These years will be cool by comparison, by the middle of the century, if we continue to warm our planet."

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Monisha Ravisetti
Astronomy Channel Editor

Monisha Ravisetti is Space.com's Astronomy Editor. She covers black holes, star explosions, gravitational waves, exoplanet discoveries and other enigmas hidden across the fabric of space and time. Previously, she was a science writer at CNET, and before that, reported for The Academic Times. Prior to becoming a writer, she was an immunology researcher at Weill Cornell Medical Center in New York. She graduated from New York University in 2018 with a B.A. in philosophy, physics and chemistry. She spends too much time playing online chess. Her favorite planet is Earth.

  • Classical Motion
    Are we really measuring the planet's temperature, or are we measuring science's thermometer density?

    How much time does a thermometer spend above average and below average? How many are in cold regions and how many in hot?

    What is the error, the play, in the calculation of the average temp? Is it so find as to determine factions of degree of change? Can you really discern increases from a decrease? With a precision that find? That sure?

    With the bias location and biased environment of the samples? And only a sheet coverage. 2D coverage with rarefied altitude changes. Just to confuse it further.

    One would need an atmospheric wide 3D array to measure it. And also a ocean temp gradient. Ocean wide buoy array.

    Watching all the regions yo-yo might clue us in. Right now.....we can only guess at the yo-yos. We don't even know all the yo-yos.
  • Spif
    Your worries are misplaced. Physics and math has had this worked out for a long time. With less effort than you spent composing that, you could have searched up the details, if you were really concerned.
    NASA has info: https://climate.nasa.gov/explore/ask-nasa-climate/3071/the-raw-truth-on-global-temperature-records/#:~:text=Since%201950%2C%20however%2C%20adjustments%20to,less%20than%200.2%20degrees%20Fahrenheit).
    So does NOAA: https://www.climate.gov/maps-data/climate-data-primer/how-do-weather-observations-become-climate-dataOr a non-US gov site, for those types of criticism: https://berkeleyearth.org/methodology/And look - at least 1 World-wide buoy array! - https://viz.pmel.noaa.gov/osmc/?color_by=platform_type
  • Phillip Huggan
    Thermometer density. Probably 3 things more important than temperature are disease increase caused by temperature, biodiversity, and geopolitical stability. All along the WW2 winners are comfortable with AGW to a point. Maybe the 2008 Obama China meeting has the specs. Diseases still seem to be more affected by our incroachment and getting healthy people @ bio infrastructures. Biodiversity is interesting:
    we gain for another degree or two. This intergalcial is the 1st with big berries surviving droughts. Now the sabre-tooth can't shred vines. Other plants self-reinforce oasis and isolated aquifers. Asians found N.A. 100k after we left Africa just died. The polar bear evolves to tie the saber-tooth tiger (we tie Cheetah in space only). The tiger evolves to chunk out the mammoth not worried about scratching or chomping humans. And a continent learns from the balance of power that Rome and Greece always seem to lead Europe to springing out of the Coptic Church and longevity.
    That was a positive biodiversity gain. We can afforest nature environments for the next few decades just like berries gave the north a toehold from aeolian landscapes. I imagine we give up coal and tar for CVD CNTs and diamond. 3d printed calcite works for coral reefs and wave power structural bulk. China is tops on sapphire and Al stir-casting but you can use finer resolution heating so the oxide doesn't diffuse into the bulk Al when you heat it. 4 decades of spare AGW capacity, then 1st ranked among the 3 above priorities.
  • Classical Motion
    So you are saying and you believe that our physics and math can predict a 3D array of thermometers in our atmosphere and a 3D thermometer array in our oceans? Do you have that much faith? And that you believe that our physics and math explains what dynamics we have observed for our temperature?

    What is the response time of our atmosphere? And what does it mean if the response is advanced....or lagging? How much of the unknown affects of life have on our atmosphere and it's temperature? Can the living inputs and the living outputs affect/effect the physics and math?

    We will all see. For burning coal emissions are going way up shorty. They predict more in 10 years, than all previous years. That's a big, quick dose.

    Good luck.
  • Phillip Huggan
    We'll have better arrays. This is Alpha Centauri trigger with the big time machine (like a hi-res headphone station to me): No faith, science and math. We made a time machine to know the state-space down to Planck.
    6 yrs. The lag is not there we time machine it normal. None. See (my) reponse below. No they are not, China is dead-headed; after 2026 they will go down. The AI predictors were killed (by me since 2010) replaced with loyal to trigger automatons.
    We have 3 arch. or geological artifacts that are only explained by an act of god. It is to prevent easy immortality, but too obvious and futurism turns into find the magician. Our Canadian permafrost is magically an intact block of fuscum, not mixed with wetter riparium or tobacco or skulls or seeds or animals. This 1/2 kills the ice age and the real garbage history since 18000BC was removed in 1930 or Native ego-based religions evolve. The Nile had a barrier at 1km. The biggest mammoths did not extinct the other animals last ice age and dinosaurs were equally water retaining...say goodbye only to the blue whale.
    You win the thermometer argument on an act of lazy AI time machining. The lizards who made AI had part of our history: Nebra to the Giza builder. That was their 2M BC to 500k BC. Plesisaurus already killed their diversity including mammal echidna. They had birds. They ate them. The Giza builder knew we needed paper to learn immortality and their kind was not able to even risk plant breeding.
    IDK what our sensors will read around the Hudson's Bay lowlands, I thought I did.
  • Classical Motion
    That's all I was trying to say all along.
  • Phillip Huggan
    After watching CFL I've learned why "deadheading" was brought up. There are 8 levels of awareness and an individual good enough to be lasered may result in someone erased. When Dharma happened to many people w/ bad epigenetics they attacked me during Covid and got wiped out in the past. People have been prevented from reaching the top two levels for 600 more yrs to prevent bio events. After then diamond nanorods or Arcturus may be easy enough. People also have been degraded after choosing TV in 1982 for a reset that includes taste, desire for activity, and ethics: needed for Rigel (Sagan + Chretein + Spielberg correct). There are 600M people in the past not likely to have spent their lives in the bottom two rungs. I imagine TV came with waiting for other actors to work out Rigel.