Indicators of Global Climate Change 2025: annual update of key indicators of the state of the climate system and human influence

This peer-reviewed scientific assessment provides an annual update of key indicators of global climate change, using methodologies consistent with the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report. Drawing on more than 40 global datasets, the researchers examine greenhouse gas emissions, human-induced warming, Earth's energy imbalance, ocean heating and other measures of climate system change.

The assessment estimates that human activities contributed approximately 1.24°C of the 1.26°C observed global warming averaged over 2016–2025, relative to pre-industrial levels. Human-induced warming reached 1.37°C in 2025, with the rate of warming remaining historically high. The report also identifies substantial increases in Earth's energy imbalance and marine heatwave occurrence.

The findings provide updated scientific evidence to inform climate policy, monitor progress in reducing emissions and support understanding of the continuing human influence on the global climate system.

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Citation: Forster PM, Walsh T, Smith C, Lamb WF, Lamboll R, Cassou C, et al. Indicators of Global Climate Change 2025: annual update of key indicators of the state of the climate system and human influence. Earth System Science Data. 2026;18:3889–3922. https://doi.org/10.5194/essd-18-3889-2026