May 2024 set a new record as the warmest May ever, marking the 12th straight month of record-breaking global temperatures, as reported by the Copernicus Climate Change Service (C3S). This data, highlighted by the UN Secretary-General, underscores the urgent need for climate action.
In May 2024, the global average temperature was 0.65°C above the 1991–2020 average and 1.52°C higher than the pre-industrial average (1850–1900). This marked the 11th month in a row, starting from July 2023, where global temperatures exceeded 1.5°C above pre-industrial levels. Over the past year, from June 2023 to May 2024, the average global temperature has also hit a record high, being 0.75°C above the 1991–2020 average and 1.63°C above the pre-industrial average.
Monthly global surface air temperature anomalies (°C) relative to 1850–1900 from January 1940 to May 2024 are plotted as a time series for all 12-month periods spanning June to May of the following year. The most recent 12 months (June 2023 – May 2024) are highlighted with a thick red line, while all other years are represented by thin lines, shaded by decade from blue (1940s) to brick red (2020s). Data source: ERA5. Credit: C3S/ECMWF. Graph source: https://climate.copernicus.eu/hottest-may-record-spurs-call-climate-action
“It is shocking but not surprising that we have reached this 12-month streak. While this sequence of record-breaking months will eventually be interrupted, the overall signature of climate change remains, and there is no sign in sight of a change in such a trend,” said C3S Director Carlo Buontempo.
These findings align with the latest Global Annual to Decadal Climate Update from the World Meteorological Organization (WMO). The WMO report warns that we are nearing the temperature thresholds outlined in the Paris Agreement. It predicts that from 2024 to 2028, the global mean near-surface temperature will be 1.1°C to 1.9°C higher than the 1850-1900 baseline. The WMO report, released alongside a call for more ambitious climate action by UN Secretary-General António Guterres, indicates an 80% chance that at least one year between 2024 and 2028 will exceed the 1.5°C threshold, with a 47% likelihood that the average temperature over this period will surpass 1.5°C above pre-industrial levels.
“For the past year, every turn of the calendar has turned up the heat. Our planet is trying to tell us something. But we don’t seem to be listening. We’re shattering global temperature records and reaping the whirlwind. It’s climate crunch time. Now is the time to mobilize, act and deliver,” said Guterres.
Twelve-month running mean anomalies of the global average surface air temperature relative to the 1850–1900 pre-industrial reference period average, based on monthly data from January 1940 to May 2024. Data source: ERA5. Credit: C3S/ECMWF. Graph source: https://climate.copernicus.eu/hottest-may-record-spurs-call-climate-action
C3S staff also contributed to the Indicators of Global Climate Change report, noting that human-induced global warming is now increasing at 0.26°C per decade, the highest rate on record. The report reveals that human-induced warming has reached 1.19°C over the past decade (2014-2023), up from 1.14°C in the previous report. The remaining carbon budget, or the amount of carbon dioxide that can be emitted before exceeding 1.5°C of global warming, is around 200 gigatonnes, equivalent to five years of emissions at the current rate.
“We are living in unprecedented times, but we also have unprecedented skill in monitoring the climate, which can help inform our actions. This string of hottest months will be remembered as comparatively cold if we manage to stabilize greenhouse gas concentrations in the atmosphere soon,” Buontempo said.
The C3S Climate Bulletin for May, published on June 6th, provides a comprehensive overview of last month’s global temperatures and their historical context, as well as data on other key climate variables, such as sea ice extent and precipitation.
/Dorota