Global greenhouse gas (GHG) emissions hit record levels in 2024, accelerating climate change and pushing the Earth’s climate system into increasingly dangerous territory. These findings come from the third edition of the Indicators of Global Climate Change (IGCC) report, published in Earth System Science Data. The IGCC serves as an annual update to track critical climate indicators between major reports by the Intergovernmental Panel on Climate Change (IPCC).
Human Activity Driving Unprecedented Warming
The IGCC report, compiled by over 60 international scientists, including former IPCC authors, confirms that nearly all the observed warming over the past decade is human-induced. In 2024, global average surface temperatures likely exceeded the 1.5°C mark above pre-industrial levels, with human activity responsible for around 1.36°C of this rise. Natural variability accounted for the remainder.
This temperature spike is consistent with predictions following the recent El Niño event and record North Atlantic Ocean warmth. Scientists warn that such temperatures, while alarming, may now become the new normal.
“The heat level we observed in 2024 is no longer extraordinary it signals a future where such temperatures become more frequent unless decisive action is taken,” the report notes.
Carbon Budget Shrinking Rapidly
Perhaps the most worrying revelation is the rapid depletion of the planet’s remaining carbon budget the total amount of CO₂ that can still be emitted to limit global warming to 1.5°C. The report estimates this budget at only 130 billion tonnes of CO₂ as of January 2025, down nearly 75% since 2020. At current emission rates, this budget would be exhausted in just over three years.
This shrinking window underscores the failure of global emissions to peak by 2025 a key requirement to meet the Paris Agreement goals.
Emissions at Historic Highs
Despite international pledges, GHG emissions remain at all-time highs. Over the past decade, human activities have emitted an average of 53 billion tonnes of CO₂-equivalent gases annually. Fossil fuel use, industrial processes, and international aviation now back to pre-pandemic levels remain the largest contributors.
Emissions from forest loss, particularly due to tropical wildfires intensified by El Niño-driven droughts, also surged. Methane and nitrous oxide concentrations climbed 3.1% and 1.7%, respectively, since 2019.
Meanwhile, cuts in aerosol pollution tiny particles that have a cooling effect have paradoxically made the warming effect of GHGs more pronounced.
Rising Oceans, Growing Risks
For the first time, the IGCC included detailed sea level rise estimates. Between 2019 and 2024, global sea levels rose by 26mm twice the long-term average. This reflects both melting polar ice and thermal expansion of warming ocean waters.
Higher sea levels are already worsening storm surges and erosion risks, threatening over a billion people in low-lying coastal areas by 2050.
Oceans have absorbed 91% of excess heat trapped by GHGs, preventing even greater surface warming but fueling marine heatwaves and disrupting ecosystems.
Energy Imbalance Deepens
The Earth’s energy imbalance—the difference between solar energy absorbed and heat radiated back into space—has doubled since the 1970s. It now averages 1W/m², driving further warming locked into the system. Even if emissions stopped today, warming would continue due to this built-in energy load.
Paris Agreement Goals in Jeopardy
The report warns that breaching the 1.5°C limit is now inevitable without “drastic and immediate” action. Nationally Determined Contributions (NDCs) remain insufficient to bend the curve downward, raising the risk of hitting 2°C or more of warming within decades.
Call for Sustained Scientific Monitoring
Finally, the IGCC highlights the importance of maintaining long-term global climate datasets from institutions like NASA and NOAA. As the climate system changes faster than ever recorded, these data sources are essential for tracking the Earth’s vital signs. Any disruption could undermine our ability to respond to climate risks.
Outlook: A Closing Window of Opportunity
“Every fraction of a degree matters,” the authors emphasize. “With each year of delay, the world moves closer to dangerous tipping points.” The findings reinforce urgent calls for global cooperation on emission cuts, clean energy transitions, and climate adaptation.
Without transformative changes, the path to a stable climate future may soon close.