Unprecedented levels of ocean heat, ice melt and sea level rise are among the many key measures of climate change setting alarming records in recent years, according to the World Meteorological Organization鈥檚 (WMO) State of the Global Climate report for 2024.
鈥淲e saw record temperatures across wide areas,鈥� says at the WMO. Reversing some of the resulting changes would take hundreds or thousands of years, the report warns.
The report sets out a grim list of unwanted records. For instance, the rate of sea level rise has doubled since satellite measurements began, increasing from 2.1 millimetres per year between 1993 and 2000 to 4.7 millimetres per year between 2015 and 2024.
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Glaciers are losing ice faster than ever, with the largest loss of glacier mass in a three-year period occurring in the past three years. Losses were particularly big in Norway 鈥� including the northern archipelago of Svalbard 鈥� as well as in Sweden and the tropical Andes.
The 18 years with the lowest extent of summer sea ice in the Arctic Ocean were the past 18 years, and the three years with the lowest extent of sea ice around the Antarctic continent were the past three years.
鈥淲hat happens in the poles doesn鈥檛 necessarily stay in the poles,鈥� warns Kennedy, meaning changes in these areas can affect the climate around the whole planet.
A new record for ocean heat 鈥� a key measure of how much additional heat the planet is accumulating 鈥� has been set in every one of the past eight years. And the 10 warmest years on record were the past 10 years.
The report also notes that 2024 was probably the first calendar year to be 1.5掳C warmer than the pre-industrial era, with an average global near-surface temperature of 1.55掳C above the 1850 to 1900 average, plus or minus 0.13掳C. This uncertainty in the measurement means there is also a chance it wasn鈥檛 warmer than 1.5掳C.
A single year above this value doesn鈥檛 mean the 1.5掳C target set out in the Paris Agreement has been breached, says Kennedy. While not clearly defined, most climate scientists agree it refers to the average temperature over something like 20 years rather than a single year.
The report also outlines three methods that are being considered for defining when we have exceeded the Paris target. According to these, the global climate is now 1.34掳C, 1.37掳C or 1.41掳C warmer than the 1850 to 1900 average.
The error bars for these three methods, however, are all wide enough to exceed 1.5掳C, meaning there is a small chance we have already exceeded the 1.5掳C Paris target. 鈥淲e can鈥檛 rule out 1.5 by these methods,鈥� says Kennedy.
