The Global Annual to
Decadal Climate Update is issued annually by the World Meteorological Organization
(WMO). It provides a synthesis of the global annual to decadal predictions
produced by the WMO designated Global Producing Centres and other contributing
centres. In June 2024, WMO released the latest Global Annual to Decadal Climate
Update (Target years: 2024 and 2024-2028).
The stark message of the Report:
Global temperature is likely to exceed 1.5°C above
pre-industrial level temporarily in next 5 years.
Key messages
- 80% likelihood of at least one
year temporarily exceeding 1.5°C between 2024-2028 - Short-term (annual) warming
does not equate to a permanent breach of the lower 1.5°C Paris Agreement
goal - Likely that at least one of
next five years will be the warmest on record, beating 2023 - Arctic
warming over the next five extended winters (November to March), relative
to the average of the 1991-2020 period, is predicted to be more than three
times as large as the warming in global mean temperature. - Predictions
of sea-ice for March 2024-2028 suggest further reductions in sea-ice
concentration in the Barents Sea, Bering Sea, and Sea of Okhotsk. - Report highlights urgency of
climate action.
The
global mean near-surface temperature for each year between 2024 and 2028 is
predicted to be between 1.1°C and 1.9°C higher than the 1850-1900 baseline,
according to the WMO report. It says that it is likely (86%) that at least one
of these years will set a new temperature record, beating 2023 which is
currently the warmest year. The chance of the five-year mean for 2024-2028
being higher than the last five years (2019-2023) is also likely (90%).
This
is a stark warning that we are getting ever closer to the goals set in the
Paris Agreement on climate change, which refers to long-term temperature
increases over decades, not over one to five years.
There is a 47% likelihood that the global
temperature averaged over the entire five-year 2024-2028 period will exceed 1.5
°C above the pre-industrial era, says the WMO Global Annual to Decadal Update
– up from 32% from last year’s report for the 2023-2027 period.
The chance (80%) of at least one of the next
five years exceeding 1.5°C has risen steadily since 2015, when such a chance
was close to zero. For the years between 2017 and 2021, there was a 20% chance
of exceedance, and this increased to a 66% chance between 2023 and 2027.
Under the Paris Agreement, countries agreed to
keep long-term global average surface temperature well below 2°C above
pre-industrial levels and pursue efforts to limit it to 1.5°C by the end of
this century. The scientific community has repeatedly warned that warming of
more than 1.5°C risks unleashing far more severe climate change impacts and
extreme weather and every fraction of a degree of warming matters.
Even at current levels of global warming, there
are already devastating climate impacts. These include more extreme heatwaves,
extreme rainfall events and droughts; reductions in ice sheets, sea ice, and glaciers;
accelerating sea level rise and ocean heating.
The global average near-surface temperature in 2023
was 1.45 °Celsius (with a margin of uncertainty of ± 0.12 °C) above the
pre-industrial baseline, according to the WMO State of the Global Climate
2023. It was by far the warmest year on record fuelled by long-term climate
warming which combined with other factors, most notably a naturally occurring
El Niño event, which is now waning.
Last year’s global temperature was boosted by a strong
El Niño. The WMO Update predicts the development of a La Niña and a return to
cooler conditions in the tropical Pacific in the near-term, but the higher
global temperatures in the next five years reflect the continued warming from
greenhouse gases.
The WMO Report was released to coincide with
a major speech by the UN Secretary-General António Guterres calling for
much more ambitious climate action. “We are playing Russian roulette with our
planet,” said Mr Guterres. “We need an exit ramp off the highway to
climate hell. And the good news is that we have control of the
wheel. The battle to limit temperature rise to 1.5 degrees will be won or
lost in the 2020s – under the watch of leaders today.”
Mr Guterres also drew on supporting evidence
from the European Union-funded Copernicus Climate Change Service implemented by
the European Centre for Medium Range Weather Forecasts. This showed that each
of the past 12 months has set a new global temperature record for the time
of year.
Given these 12 monthly records, the global
average temperature for the last 12 months (June 2023 – May 2024) is also the
highest on record, at 1.63°C above the 1850–1900 pre-industrial average,
according to the Copernicus Climate Change ERA5 dataset.