Global warming causing carbon dioxide (CO2) levels are now the highest that they have been in the last 8,00,000 years, according to the State of Climate 2024 report published by World Meteorological Organization (WMO) on March 19, 2025. WMO measured the CO2 levels at 420 parts per million in 2023.
Along with the record CO2 levels, other greenhouse gases (GHGs) such as methane (CH4) and nitrous oxide (N2O) were also at their highest levels in the past 8,00,000 years.
The record levels of GHGs have resulted in record breaking temperatures in 2024 along with natural variations such as El Nino in the early part of 2024. The global mean near surface temperature was 1.55°C above pre-industrial average, according to an analysis by WMO using six international datasets with 2024 being the first year to cross the 1.5°C Paris Agreement threshold annually.
“While a single year above 1.5°C of warming does not indicate that the long-term temperature goals of the Paris Agreement are out of reach, it is a wake-up call that we are increasing the risks to our lives, economies and to the planet,” said Celeste Saulo, secretary general of the WMO.
The report stated that the long-term warming was between 1.34°C and 1.41°C as compared to the average in the period 1850-1900 (pre-industrial period). The WMO used multiple methods to arrive at this conclusion even though “it noted the uncertainty ranges in global temperature statistics”.
Recent research papers have also indicated that the world may already be in the early period of crossing the long-term threshold of 1.5°C with a recent analysis by the European Union’s Copernicus Climate Change Service (C3S) stating that the threshold is likely to be crossed by September 2029, if the current temperature trend continues.
The current temperature trend is dangerous one. The report states that each of the last 10 years is among the 10 warmest years on record since 1850. “This has happened for the first time since temperature records began and is one of the most surprising findings of the WMO report,” said Chris Hewitt, director of Climate Services branch of the WMO, during a press briefing on March 18.
The last eight years have also set the records for the highest ocean heat content, according to the report. Ninety per cent of the global heat being trapped by the GHGs is absorbed by the oceans.
“Data for 2024 show that our oceans continued to warm, and sea levels continued to rise. The frozen parts of Earth’s surface, known as the cryosphere, are melting at an alarming rate: glaciers continue to retreat, and Antarctic sea ice reached its second-lowest extent ever recorded. Meanwhile, extreme weather continues to have devastating consequences around the world,” said Saulo. Seven of the last 10 years have had the highest negative mass balance of glaciers.
“We also observe that the ocean warming has accelerated in recent decades and the record sea ice extents in the Arctic and Antarctica are also major concern coming out of the WMO report. We expected the ocean warming to slow down towards the end of 2024, which did not happen. This needs to be studied further,” said Karina von Shuckmann, an ocean expert with the WMO.
The rate of sea level rise has also doubled since satellite measurements began, according to the WMO report. The warming and sea level rise has also compounded extreme weather events such as tropical cyclones, extreme rainfall, floods and droughts around the world. These events caused the greatest number of displacements in 2024 since 2008, as per the report.