The year 2024 marked a critical point in the unfolding global climate crisis, according to the latest findings from the World Meteorological Organization (WMO). The newly released State of the Global Climate report has documented a cascade of worsening indicators, confirming that many impacts of human-induced climate change are not only intensifying but are also irreversible on timescales ranging from centuries to millennia. The WMO’s comprehensive assessment underscores the urgent need for decisive global action, noting that 2024 was likely the first full calendar year where global average temperatures exceeded 1.5°C above pre-industrial levels.
The report reveals that global mean near-surface temperatures reached 1.55°C ± 0.13°C above the 1850-1900 baseline, making 2024 the hottest year in the 175-year instrumental record. This milestone is significant not only for the record-breaking heat but also for its implications on the Paris Agreement’s goal of limiting long-term warming to below 1.5°C. While a single year breaching this threshold does not mean the target is permanently unattainable, WMO Secretary-General Celeste Saulo emphasized that such trends heighten the risks to human health, ecosystems, economies, and global stability. She warned that the window for limiting long-term temperature rise is narrowing rapidly, urging swift action.
A key factor contributing to the extraordinary warmth of 2024 was the ongoing accumulation of greenhouse gases, particularly carbon dioxide, which remains in the atmosphere for generations and continues to trap heat. CO₂ concentrations in 2023 reached 420.0 parts per million, 151% of pre-industrial levels, and increased further in 2024. These levels represent the highest atmospheric concentrations of carbon dioxide, methane, and nitrous oxide in at least 800,000 years. Combined with a strong El Niño event, reduced cooling aerosols, and possibly a shift in solar cycles, these greenhouse gas levels drove an unprecedented surge in global temperatures.
The oceans, which absorb approximately 90% of the excess heat caused by greenhouse gas emissions, also experienced record-breaking conditions. Ocean heat content in 2024 reached the highest level in the 65-year observational record, with each of the past eight years setting new records. This ocean warming is not only degrading marine biodiversity and coral reefs but also contributing to stronger tropical storms and accelerating sea level rise. The report states that ocean warming and acidification are effectively irreversible on centennial to millennial scales, and projections show that these trends will persist throughout the 21st century.
Sea level rise, another critical indicator, continued at an alarming rate. Global mean sea level in 2024 was the highest recorded since satellite measurements began in 1993, with the rate of increase doubling from 2.1 mm per year in the 1990s to 4.0 mm per year in the past decade. This trend, driven by melting glaciers and polar ice sheets, particularly in Antarctica, underscores the vulnerability of coastal regions worldwide.
Extreme weather events further illustrated the human and economic toll of the climate crisis. Tropical cyclones, floods, droughts, and heatwaves in 2024 resulted in the highest number of displacements in 16 years, exacerbating food insecurity and causing significant economic damage. These disasters highlight the critical role of early warning systems, yet only half of all countries currently have adequate systems in place. The WMO is calling for increased investment in weather, water, and climate services to enhance resilience and protect communities from future shocks.
The WMO’s report, compiled with input from a global network of meteorological services, scientific institutions, and UN partners, serves as a stark reminder of the stakes involved in the climate battle. As world leaders prepare to submit new national climate plans, the urgency of scaling up clean energy solutions and reducing emissions has never been clearer. António Guterres, Secretary-General of the United Nations, summed it up succinctly: “Our planet is issuing more distress signals but this report shows that limiting long-term global temperature rise to 1.5°C is still possible. Leaders must step up to make it happen.”
