WMO Update: 50:50 chance that global temperature will temporarily reach the 1.5°C threshold over the next five years

There is a 50:50 chance that the average annual global temperature will temporarily reach 1.5°C above pre-industrial level for at least one of the next five years, and the probability increases over time, according to a new climate update issued by the World Meteorological Organization (WMO).

There is a 93% chance that at least one year between 2022 and 2026 will become the warmest on record and displace 2016 from the highest ranking. The probability that the five-year average for 2022-2026 will be higher than the last five years (2017-2021) is also 93%, according to the Global Annual to Decadal Climate Update, produced by the MET Office of the United Kingdom, leader of the WMO. center of such predictions.

The annual update leverages the expertise of internationally renowned climate scientists and best-in-class prediction systems from major climate centers around the world to produce actionable information for decision makers.

The possibility of temporarily exceeding 1.5°C has steadily increased since 2015, when it was close to zero. For the years between 2017 and 2021, there was a 10% chance of overcoming. That probability has risen to nearly 50% for the 2022-2026 period.

“This study shows, with a high level of scientific skill, that we are getting considerably closer to temporarily reaching the lowest target of the Paris Agreement on Climate Change. The figure of 1.5 °C is not a random statistic. It is rather an indicator of the point at which climate impacts will become increasingly harmful to people and, indeed, to the entire planet,” said WMO Secretary-General Prof. Petteri Taalas.

“As long as we continue to emit greenhouse gases, temperatures will continue to rise. And alongside that, our oceans will continue to warm and become more acidic, sea ice and glaciers will continue to melt, sea levels will continue to rise, and our climate will become more extreme. Arctic warming is disproportionately high and what happens in the Arctic affects us all,” said Professor Taalas.

The Paris Agreement sets long-term goals to guide all nations to substantially reduce global greenhouse gas emissions to limit global temperature rise this century to 2°C while making efforts to limit the increase further to 1.5°C.

The Intergovernmental Panel on Climate Change says climate-related risks to natural and human systems are greater for global warming of 1.5°C than at present, but less than at 2°C.

Dr. Leon Hermanson of the Met Office led the report. He said: “Our latest climate predictions show that the continued rise in global temperature will continue, with a uniform probability that one of the years between 2022 and 2026 will exceed 1.5°C above pre-industrial levels. A single year of exceeding 1.5°C does not mean that we have exceeded the iconic threshold of the Paris Agreement, but it does reveal that we are getting closer and closer to a situation where we could exceed 1.5°C over an extended period.”

In 2021, the global average temperature was 1.1°C above the pre-industrial baseline, according to the WMO interim report on the State of the Global Climate. The final report on the state of the global climate for 2021 will be published on May 18.

Back-to-back La Niña events in early and late 2021 had a cooling effect on global temperatures, but this is only temporary and does not reverse the long-term global warming trend. Any development of an El Niño event would immediately increase temperatures, as happened in 2016, which so far is the warmest year on record.

Findings from the annual update include:

• The global average annual near-surface temperature for each year between 2022 and 2026 is projected to be between 1.1 °C and 1.7 °C higher than pre-industrial levels (the average for the years 1850-1900).

• The possibility of global near-surface temperature exceeding 1.5°C above pre-industrial levels for at least one year between 2022 and 2026 is almost as likely as it is not (48%). There is only a small chance (10%) that the five-year average will exceed this threshold.

• The probability that at least one year between 2022 and 2026 will surpass the warmest year on record, 2016, is 93%. The probability that the five-year average for 2022-2026 will be higher than that of the last five years (2017-2021) is also 93%.

• The Arctic temperature anomaly, compared to the 1991-2020 average, is projected to be more than three times greater than the global average anomaly when averaged over the next five prolonged Northern Hemisphere winters.

• There is no signal of El Niño Southern Oscillation for December-February 2022/23, but the Southern Oscillation index is forecast to be positive in 2022.

• Precipitation patterns forecast for 2022 compared to the 1991-2020 average suggest a higher likelihood of drier conditions in southwestern Europe and southwestern North America, and wetter conditions in northern Europe, the Sahel, northeastern Brazil, and Australia.

• Precipitation patterns forecast for the average may to September 2022-2026, compared to the 1991-2020 average, suggest a higher likelihood of wetter conditions in the Sahel, northern Europe, Alaska and northern Siberia, and drier conditions in the Amazon.

• Precipitation patterns forecast for the average from November to March 2022/23-2026/27, compared to the 1991-2020 average, suggest an increase in precipitation in the tropics and a reduction in precipitation in the subtropics, in line with expected patterns of climate warming.

Notes to Editors:

With the UK Met Office acting as the main hub, climate prediction groups from Spain, Germany, Canada, China, usa, Japan, Australia, Sweden, Norway and Denmark contributed new predictions this year. The combination of forecasts from climate prediction centers around the world makes it possible to obtain a higher quality product than can be obtained from a single source.

The development of short-term prediction capacity was driven by the WMO-co-sponsored Global Climate Research Programme, which stated that one of its Major Overarching Challenges is to support research and development to improve multi-year to multi-year climate predictions and their usefulness for decision makers. .

Comprehensive assessment reports on the state of scientific, technical and socio-economic knowledge about climate change, its future impacts and risks, and options for reducing the rate at which climate change is occurring are the responsibility of the Intergovernmental Panel on Climate Change (IPCC). ), which also issued a Special Report on Global Warming of 1.5°C.

The World Meteorological Organization is the authoritative voice of the United Nations system on weather, climate and water

Source: WMO