2023: the warmest year on record globally
NEWS RELEASE
Globally 2023 was the warmest year in a series stretching back to 1850, according to figures released today by the Met Office and the University of East Anglia.
2023 is the tenth year in succession that has equalled or exceeded 1.0 °C above the pre-industrial period (1850-1900).
The global average temperature for 2023 was 1.46 °C above the pre-industrial baseline; 0.17 °C warmer than the value for 2016, the previous warmest year on record in the HadCRUT5 global temperature dataset which runs from 1850.
Dr Colin Morice is a Climate Monitoring and Research Scientist with the Met Office. He said:
“2023 is now confirmed as the warmest year on average over the globe in 174-years of observation. 2023 also set a series of monthly records, monthly global average temperatures having remained at record levels since June. Ocean surface temperatures have remained at record levels since April.
“Year-to-year variations sit on a background of around 1.25 °C warming in global average temperatures above pre-industrial levels. This warming is attributable to human-induced climate change through greenhouse gas emissions.”
On top of the long-term warming, a transition into El Niño conditions contributed to further elevated temperatures for the latter part of the year. El Niño is part of a pattern of climate variability in the tropical Pacific that imparts warmth to the global atmosphere, temporarily adding up to 0.2 °C to the temperature of an individual year. This stands in contrast to the reverse pattern of climate variability, La Niña, which suppressed global average temperatures in 2021 and 2022.
Outlook for 2024
Professor Adam Scaife is a Principal Fellow and Head of Monthly to Decadal Prediction at the Met Office. He said: “It is striking that the temperature record for 2023 has broken the previous record set in 2016 by so much because the main effect of the current El Niño will come in 2024. Consistent with this, the Met Office’s 2024 temperature forecast shows this year has strong potential to be another record-breaking year.”
The Met Office global temperature for 2024 is forecast to be between 1.34 °C and 1.58 °C (with a central estimate of 1.46 °C) above the average for the pre-industrial period (1850-1900): the 11th year in succession that temperatures will have reached at least 1.0 °C above pre-industrial levels.
HadCRUT5
The HadCRUT5 dataset is compiled by the Met Office and the University of East Anglia (UEA), with support from the National Centre for Atmospheric Science. It shows that when compared with the pre-industrial reference period, 2023 was 1.46 ± 0.1 °C above the 1850-1900 average. This aligns extremely well with figures published today by other international centres.
Professor Tim Osborn, of the University of East Anglia’s Climatic Research Unit, said: “Twenty-five years ago, 1998 was a record-breaking year for global average temperature. But last year’s global temperature was 0.5 °C warmer than 1998, providing further evidence that our planet is warming on average by 0.2 °C per decade.
“At the current rate of human-induced warming, 2023’s record-breaking values will in time be considered to be cool in comparison with what projections of our future climate suggest.”
Other data sets
The World Meteorological Organization uses six international data sets to provide an authoritative assessment of global temperature change. They report 2023 was around 1.45 ± 0.12°C warmer than the 1850-1900 baseline based on an average of the six data sets.
The long-term warming is clear. Since the 1980s, each decade has been warmer than the previous one.
Importance of global mean temperature
Global average temperature is the key measure of climate change, providing a headline metric that is expanded upon by the changing patterns of rainfall, drought, ice, temperature and extreme weather that are associated with a warming climate. You can see the impact on other key climate indicators on the Met Office global climate dashboard.
It is complex and challenging to track the average temperature of an entire planet, using around a billion temperature observations from the last 174 years.
The UK’s contribution to measuring this key indicator of climate change is led by scientists at the Met Office, UEA and NCAS. This ongoing work is crucial as the world moves still closer to the limits set out in the Paris Agreement
Prof Philip Jones, Professorial Fellow at UEA’s Climatic Research Unit, said: “I've been working with the global temperature series since the early 1980s. There has never been a year like 2023 where the warmest-ever June, warmest-ever July through to the warmest-ever December was recorded for seven months in a row, from June to December, 2023.”
Defining global temperature change relevant to the Paris Agreement
While the global average temperature in a particular year is well-known, this will not be suitable as an indicator of whether the “Paris 1.5” has been breached or not, because the Paris Agreement refers to long-term warming, not individual years. But no alternative has yet been formally agreed.
In a recent paper published in Nature, Met Office scientist Prof Richard Betts and coauthors proposed an indicator combining the last ten years of global temperature observations with an estimate of the projection or forecast for the next ten years. If adopted by the international community this could mean a universally agreed measure of global warming that could trigger immediate action to avoid further rises.
Using this suggested approach, the researchers found that the figure for the current global warming level, relevant to the Paris Agreement, is around 1.26 °C, with an uncertainty range of 1.13 °C to 1.43 °C.
This graphic shows the annual global temperature anomaly for 2023 compared to a 1961-1990 averaging period. The global average temperature for 2023 was 1.46 °C above the pre-industrial baseline according to the HadCRUT5 data set. This map uses HadCRUT5 data, compiled by the Met Office and the University of East Anglia, with support from the National Centre for Atmospheric Science.
[An animated monthly version of this graphic is available here]
Globally 2023 was the warmest year in a series stretching back to 1850, according to figures released today by the Met Office and the University of East Anglia.
2023 is the tenth year in succession that has equalled or exceeded 1.0 °C above the pre-industrial period (1850-1900).
The global average temperature for 2023 was 1.46 °C above the pre-industrial baseline; 0.17 °C warmer than the value for 2016, the previous warmest year on record in the HadCRUT5 global temperature dataset which runs from 1850.
Dr Colin Morice is a Climate Monitoring and Research Scientist with the Met Office. He said:
“2023 is now confirmed as the warmest year on average over the globe in 174-years of observation. 2023 also set a series of monthly records, monthly global average temperatures having remained at record levels since June. Ocean surface temperatures have remained at record levels since April.
“Year-to-year variations sit on a background of around 1.25 °C warming in global average temperatures above pre-industrial levels. This warming is attributable to human-induced climate change through greenhouse gas emissions.”
On top of the long-term warming, a transition into El Niño conditions contributed to further elevated temperatures for the latter part of the year. El Niño is part of a pattern of climate variability in the tropical Pacific that imparts warmth to the global atmosphere, temporarily adding up to 0.2 °C to the temperature of an individual year. This stands in contrast to the reverse pattern of climate variability, La Niña, which suppressed global average temperatures in 2021 and 2022.
Outlook for 2024
Professor Adam Scaife is a Principal Fellow and Head of Monthly to Decadal Prediction at the Met Office. He said: “It is striking that the temperature record for 2023 has broken the previous record set in 2016 by so much because the main effect of the current El Niño will come in 2024. Consistent with this, the Met Office’s 2024 temperature forecast shows this year has strong potential to be another record-breaking year.”
The Met Office global temperature for 2024 is forecast to be between 1.34 °C and 1.58 °C (with a central estimate of 1.46 °C) above the average for the pre-industrial period (1850-1900): the 11th year in succession that temperatures will have reached at least 1.0 °C above pre-industrial levels.
HadCRUT5
The HadCRUT5 dataset is compiled by the Met Office and the University of East Anglia (UEA), with support from the National Centre for Atmospheric Science. It shows that when compared with the pre-industrial reference period, 2023 was 1.46 ± 0.1 °C above the 1850-1900 average. This aligns extremely well with figures published today by other international centres.
Professor Tim Osborn, of the University of East Anglia’s Climatic Research Unit, said: “Twenty-five years ago, 1998 was a record-breaking year for global average temperature. But last year’s global temperature was 0.5 °C warmer than 1998, providing further evidence that our planet is warming on average by 0.2 °C per decade.
“At the current rate of human-induced warming, 2023’s record-breaking values will in time be considered to be cool in comparison with what projections of our future climate suggest.”
Other data sets
The World Meteorological Organization uses six international data sets to provide an authoritative assessment of global temperature change. They report 2023 was around 1.45 ± 0.12°C warmer than the 1850-1900 baseline based on an average of the six data sets.
The long-term warming is clear. Since the 1980s, each decade has been warmer than the previous one.
Importance of global mean temperature
Global average temperature is the key measure of climate change, providing a headline metric that is expanded upon by the changing patterns of rainfall, drought, ice, temperature and extreme weather that are associated with a warming climate. You can see the impact on other key climate indicators on the Met Office global climate dashboard.
It is complex and challenging to track the average temperature of an entire planet, using around a billion temperature observations from the last 174 years.
The UK’s contribution to measuring this key indicator of climate change is led by scientists at the Met Office, UEA and NCAS. This ongoing work is crucial as the world moves still closer to the limits set out in the Paris Agreement
Prof Philip Jones, Professorial Fellow at UEA’s Climatic Research Unit, said: “I've been working with the global temperature series since the early 1980s. There has never been a year like 2023 where the warmest-ever June, warmest-ever July through to the warmest-ever December was recorded for seven months in a row, from June to December, 2023.”
Defining global temperature change relevant to the Paris Agreement
While the global average temperature in a particular year is well-known, this will not be suitable as an indicator of whether the “Paris 1.5” has been breached or not, because the Paris Agreement refers to long-term warming, not individual years. But no alternative has yet been formally agreed.
In a recent paper published in Nature, Met Office scientist Prof Richard Betts and coauthors proposed an indicator combining the last ten years of global temperature observations with an estimate of the projection or forecast for the next ten years. If adopted by the international community this could mean a universally agreed measure of global warming that could trigger immediate action to avoid further rises.
Using this suggested approach, the researchers found that the figure for the current global warming level, relevant to the Paris Agreement, is around 1.26 °C, with an uncertainty range of 1.13 °C to 1.43 °C.
This graphic shows the annual global temperature anomaly for 2023 compared to a 1961-1990 averaging period. The global average temperature for 2023 was 1.46 °C above the pre-industrial baseline according to the HadCRUT5 data set. This map uses HadCRUT5 data, compiled by the Met Office and the University of East Anglia, with support from the National Centre for Atmospheric Science.
[An animated monthly version of this graphic is available here]
METHOD OF RESEARCH
Data/statistical analysis
Data/statistical analysis
NASA analysis confirms 2023 as warmest year on record
Earth’s average surface temperature in 2023 was the warmest on record, according to an analysis by NASA. Global temperatures last year were around 2.1 degrees Fahrenheit (1.2 degrees Celsius) above the average for NASA’s baseline period (1951-1980), scientists from NASA’s Goddard Institute for Space Studies (GISS) in New York reported.
“NASA and NOAA’s global temperature report confirms what billions of people around the world experienced last year; we are facing a climate crisis,” said NASA Administrator Bill Nelson. “From extreme heat, to wildfires, to rising sea levels, we can see our Earth is changing. There’s still more work to be done, but President Biden and communities across America are taking more action than ever to reduce climate risks and help communities become more resilient – and NASA will continue to use our vantage point of space to bring critical climate data back down to Earth that is understandable and accessible for all people. NASA and the Biden-Harris Administration are working to protect our home planet and its people, for this generation – and the next.”
In 2023, hundreds of millions of people around the world experienced extreme heat, and each month from June through December set a global record for the respective month. July was the hottest month ever recorded. Overall, Earth was about 2.5 degrees Fahrenheit (or about 1.4 degrees Celsius) warmer in 2023 than the late 19th-century average, when modern record-keeping began.
“The exceptional warming that we’re experiencing is not something we’ve seen before in human history,” said Gavin Schmidt, director of GISS. “It’s driven primarily by our fossil fuel emissions, and we’re seeing the impacts in heat waves, intense rainfall, and coastal flooding.”
Though scientists have conclusive evidence that the planet’s long-term warming trend is driven by human activity, they still examine other phenomena that can affect yearly or multi-year changes in climate such as El Niño, aerosols and pollution, and volcanic eruptions.
Typically, the largest source of year-to-year variability is the El Niño – Southern Oscillation ocean climate pattern in the Pacific Ocean. The pattern has two phases – El Niño and La Niña – when sea surface temperatures along the equator switch between warmer, average, and cooler temperatures. From 2020-2022, the Pacific Ocean saw three consecutive La Niña events, which tend to cool global temperatures. In May 2023, the ocean transitioned from La Niña to El Niño, which often coincides with the hottest years on record.
However, the record temperatures in the second half of 2023 occurred before the peak of the current El Niño event. Scientists expect to see the biggest impacts of El Niño in February, March, and April.
Scientists have also investigated possible impacts from the January 2022 eruption of the Hunga Tonga-Hunga Ha’apai undersea volcano, which blasted water vapor and fine particles, or aerosols, into the stratosphere. A recent study found that the volcanic aerosols – by reflecting sunlight away from Earth’s surface – led to an overall slight cooling of less than 0.2 degrees Fahrenheit (or about 0.1 degrees Celsius) in the Southern Hemisphere following the eruption.
“Even with occasional cooling factors like volcanoes or aerosols, we will continue to break records as long as greenhouse gas emissions keep going up,” Schmidt said. “And, unfortunately, we just set a new record for greenhouse gas emissions again this past year.”
“The record-setting year of 2023 underscores the significance of urgent and continued actions to address climate change,” said NASA Deputy Administrator Pam Melroy. “Recent legislation has delivered the U.S. government’s largest-ever climate investment, including billions to strengthen America’s resilience to the increasing impacts of the climate crisis. As an agency focused on studying our changing climate, NASA’s fleet of Earth observing satellites will continue to provide critical data of our home planet at scale to help all people make informed decisions.”
Open Science in Action
NASA assembles its temperature record using surface air temperature data collected from tens of thousands of meteorological stations, as well as sea surface temperature data acquired by ship- and buoy-based instruments. This data is analyzed using methods that account for the varied spacing of temperature stations around the globe and for urban heating effects that could skew the calculations.
Independent analyses by NOAA and the Hadley Centre (part of the United Kingdom Met Office) concluded the global surface temperatures for 2023 were the highest since modern record-keeping began. These scientists use much of the same temperature data in their analyses but use different methodologies. Although rankings can differ slightly between the records, they are in broad agreement and show the same ongoing long-term warming in recent decades.
Building on a half century of research, observations, and models, the Biden-Harris Administration including NASA and several federal partners recently launched the U.S. Greenhouse Gas Center to make critical climate data readily available to decisionmakers and citizens. The center supports collaboration across U.S. government agencies and the non-profit and private sectors to make air-, ground-, and space-borne data and resources available online.
NASA’s full dataset of global surface temperatures through 2023, as well as details with code of how NASA scientists conducted the analysis, are publicly available from GISS. GISS is a NASA laboratory managed by the Earth Sciences Division of the agency’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with Columbia University’s Earth Institute and School of Engineering and Applied Science in New York.
