Past eight years confirmed to be the eight warmest on record

The past eight years were the warmest on record globally, fuelled by ever-rising greenhouse gas concentrations and accumulated heat, according to six leading international temperature datasets consolidated by the World Meteorological Organization (WMO).

The average global temperature in 2022 was about 1.15 [1.02 to 1.27] °C above the pre-industrial (1850-1900) levels. 2022 is the 8th consecutive year (2015-2022) that annual global temperatures have reached at least 1°C above pre-industrial levels, according to all datasets compiled by WMO. 2015 to 2022 are the eight warmest years on record. The likelihood of – temporarily – breaching the 1.5°C limit of the Paris Agreement is increasing with time.

The persistence of a cooling La Niña event, now in its third year, means that 2022 was not the warmest year on record, but is “only” the fifth or sixth warmest. But this cooling impact will be short-lived and will not reverse the long-term warming trend caused by record levels of heat-trapping greenhouse gases in our atmosphere. The WMO El Niño/La Niña Update indicates about a 60% chance that La Niña will persist during January-March 2023, and should be followed by ENSO-neutral conditions (neither El Niño or La Niña).

The 10-year average temperature for the period 2013-2022 is 1.14 [1.02 to 1.27] °C above the 1850-1900 pre-industrial baseline. This compares with 1.09°C from 2011 to 2020, as estimated by the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment report, and indicates that long-term warming continues.

Dramatic weather disasters

“In 2022, we faced several dramatic weather disasters which claimed far too many lives and livelihoods and undermined health, food, energy and water security and infrastructure. Large areas of Pakistan were flooded, with major economic losses and human casualties. Record breaking heatwaves have been observed in China, Europe, North and South America. The long-lasting drought in the Horn of Africa threatens a humanitarian catastrophe,” said WMO Secretary-General Prof. Petteri Taalas.

Global warming and other long-term climate change trends are expected to continue because of record levels of heat-trapping greenhouse gases in the atmosphere. Extreme heatwaves, drought and devastating flooding have affected millions and cost billions this year, according to the World Meteorological Organization’s provisional State of the Global Climate in 2022 report. Late December, severe storms affected large areas of North America. High winds, heavy snow and low temperatures led to widespread disruption in the east. Heavy rain, mountain snow, and flooding affected areas in the west.

“There is a need to enhance preparedness for such extreme events and to ensure that we meet the UN target of Early Warnings for All in the next five years,” said Prof. Taalas. “Today only half of 193 Members have proper early warning services, which leads to much higher economic and human losses. There are also big gaps in basic weather observations in Africa and island states, which has a major negative impact on the quality of weather forecasts.”

Understanding the figures

WMO uses six international datasets to provide an authoritative temperature assessment. The same data are used in its annual State of the Climate reports which inform the international community on global climate indicators.

The rankings of individual years should be considered in the long-term context, especially since the differences between individual years are sometimes marginal. Since the 1980s, each decade has been warmer than the previous one. This is expected to continue.

The warmest eight years have all been since 2015, with 2016, 2019 and 2020 constituting the top three. An exceptionally strong El Niño event occurred in 2016, which contributed to record global temperatures.

WMO uses datasets (based on climatological data from observing sites and ships and buoys in global marine networks) developed and maintained by the United States National Oceanic and Atmospheric Administration (NOAA), NASA’s Goddard Institute for Space Studies (NASA GISS), the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit (HadCRUT), and the Berkeley Earth group.

WMO also uses reanalysis datasets from the European Centre for Medium Range Weather Forecasts and its Copernicus Climate Change Service, and the Japan Meteorological Agency (JMA). Reanalysis combines millions of meteorological and marine observations, including from satellites, using a weather model to produce a complete reanalysis of the atmosphere. The combination of observations with modelled values makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions.

2022 was nominally ranked as the 5th warmest year in the Berkeley Earth data set, and the ERA5 and JRA-55 reanalysis. It was ranked as the 6th warmest year in the HadCRUT5, NOAAGlobalTemp and NASAGISTEMP data sets. However, it is worth noting that the differences in temperature between the 4th and 8th warmest year are relatively small.

The small differences among these datasets indicate the margin of error for calculating the average global temperature.

The temperature figures will be incorporated into the final WMO report on the State of the Climate in 2022 which will be issued in April 2023. This includes information on all key climate indicators and selected climate impacts, and updates a provisional report issued in November 2022 at the occasion of COP27.

The Paris Agreement seeks to hold the increase in the global average temperature to well below 2°C above pre-industrial levels while pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.  At 1.14 [1.02 to 1.27] °C above the pre-industrial (1850-1900) levels, the global average temperature for the ten-year period 2013-2022 is already approaching the lower limit of temperature increase the Paris Agreement seeks to avert.

La Niña refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation. It usually has the opposite impacts on weather and climate as El Niño. La Niña has a temporary global cooling effect.

The final report with more updates on the State of the Global Climate in 2022 will be released and launched in April at the occasion of Earth Day.

The World Meteorological Organization is the United Nations System’s authoritative voice on Weather, Climate and Water.