GENEVA, Switzerland, May 17, 2023 (ENS) – Fueled by high levels of heat-trapping greenhouse gases and a naturally occurring El Niño event, global temperatures are likely to surge to record levels in the next five years, warns a new update by the World Meteorological Organization, WMO.
“There is a 98 percent likelihood that at least one of the next five years, and the five-year period as a whole, will be the warmest on record,” the update predicts.
In addition to increasing global temperatures, the rise in human-induced greenhouse gases in the atmosphere is leading to more ocean heating and acidification, sea ice and glacier melt, sea level rise and more extreme weather.
There is a 66 percent likelihood that the annual average near-surface global temperature between 2023 and 2027 will be more than 1.5°C above pre-industrial levels for at least one year, the WMO forecast states.
“This report does not mean that we will permanently exceed the 1.5°C level specified in the Paris Agreement which refers to long-term warming over many years. However, WMO is sounding the alarm that we will breach the 1.5°C level on a temporary basis with increasing frequency,” WMO Secretary-General Professor Petteri Taalas said.
“A warming El Niño is expected to develop in the coming months and this will combine with human-induced climate change to push global temperatures into uncharted territory. This will have far-reaching repercussions for health, food security, water management and the environment. We need to be prepared,” Taalas said.
There is a 32 percent chance that the five-year mean will exceed the 1.5°C threshold, according to the update, titled, “Global Annual to Decadal Climate Update” produced by the United Kingdom’s Met Office, a government body that is the WMO’s lead center for such predictions.
The chance of temporarily exceeding 1.5 °C has risen steadily since 2015, the year the Paris Agreement on climate was unanimously adopted by world governments. In 2015 that risk was close to zero.
For the years between 2017 and 2021, there was a 10 percent chance of exceeding 1.5 °C.
“Global mean temperatures are predicted to continue increasing, moving us away further and further away from the climate we are used to,” said Dr. Leon Hermanson, a Met Office expert scientist who led the report.
“These new highs will be fuelled almost completely by the rise of heat-trapping greenhouse gases in the atmosphere, but the anticipated development of the naturally-occurring El Nino event will also release heat from the tropical Pacific,” Dr. Hermanson said.
Today’s report, an annual publication, was released ahead of the World Meteorological Congress, scheduled for May 22 to June 2, where discussions will focus on how to strengthen weather and climate services to support climate change adaptation.
Priorities for discussion at Congress include the ongoing Early Warnings for All initiative to protect people from increasingly extreme weather and a new Greenhouse Gas Monitoring Infrastructure to inform climate mitigation.
Key Points of the 2023 Global Annual to Decadal Climate Update
The average global temperature in 2022 was about 1.15 °C above the 1850-1900 average. The cooling influence of La Niña conditions over much of the past three years temporarily reined in the longer-term warming trend. La Niña means the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific.
But La Niña ended in March 2023 and an El Niño is forecast to develop in the coming months. Typically, El Niño increases global temperatures in the year after it develops. In this case this would be 2024.
The annual mean global near-surface temperature for each year between 2023 and 2027 is predicted to be between 1.1 °C and 1.8 °C higher than the 1850-1900 average. This is used as a baseline because it was before the emission of greenhouse gases from human and industrial activities.
There is a 98 percent chance of at least one in the next five years beating the temperature record set in 2016, when there was an exceptionally strong El Niño.
The chance of the five-year mean for 2023-2027 being higher than the last five years is also 98 percent.
Arctic warming is extremely high. Compared to the 1991-2020 average, the temperature deviation is predicted to be more than three times as large as the global mean deviation when averaged over the next five Northern Hemisphere extended winters.
Predicted precipitation patterns for the May to September 2023-2027 average, compared to the 1991-2020 average, suggest increased rainfall in the Sahel, northern Europe, Alaska and northern Siberia, and reduced rainfall for this season over the Amazon and parts of Australia.
Warming Could Upend Paris Agreement Goals
The Paris Agreement sets long-term goals to guide all nations to reduce global greenhouse gas emissions to limit the global temperature increase in this century to 2 °C while pursuing efforts to limit the increase even further to 1.5 °C, to avoid or reduce adverse impacts and related losses and damages.
The Intergovernmental Panel on Climate Change says that climate-related risks for natural and human systems are higher for global warming of 1.5 °C than at present, but lower than at 2 °C.
The Global Annual to Decadal Update is one of a suite of WMO climate products, including the flagship State of the Global Climate, which seek to inform policy-makers. WMO will release its provisional statement on the State of the Global Climate in 2023 at the UN Climate Change Conference, COP28, in December.
The UK’s Met Office acts as the WMO Lead Centre for Annual to Decadal Climate Prediction. This year there are 145 ensemble members contributed by 11 different institutes to the predictions, which start at the end of 2022. Retrospective forecasts, or hindcasts, covering the period 1960-2018 are used to estimate forecast skill.
Confidence in forecasts of global mean temperature is high since hindcasts show very high skill in all measures.
The forecasts shown here are intended as guidance for Regional Climate Centres (RCCs), Regional Climate Outlook Forums (RCOFs) and National Meteorological and Hydrological Services (NMHSs). It does not constitute an official forecast for any region or nation, but RCCs, RCOFs and NMHSs are encouraged to appropriately interpret and develop value-added forecasts from this Climate Update.
The World Meteorological Organization is the United Nations System’s authoritative voice on Weather, Climate and Water.
Featured image: Polar bear tests Arctic ice for strength. Polar bears already face shorter ice seasons, limiting hunting and breeding opportunities. September 15, 2016 (Photo by Mario Hoppmann courtesy NASA Goddard Space Flight Center)