Indicators of Global Climate Change

Key Messages

• Temperatures: For 2024 the observed global average temperature exceeds 1.5°C above pre-industrial level, although human-caused warming of 1.36°C remains below observations. The difference can be explained by El Niño and warmer-than-average North Atlantic waters.
• Paris Agreement: Reaching 1.5°C global warming on a long-term basis is now inevitable in around five years if we don't take the immediate, transformative action needed to reduce emissions from fossil fuels and deforestation to net zero.
• CO2 Emissions: Human activities resulted in 41.6 gigatonnes (billion tonnes) of CO₂ emissions—an all-time high in 2024. Data for other greenhouse gases in 2024 is expected later this year. In 2023, greenhouse gas emissions from human activities reached an all-time high of 54.6 gigatonnes (billion tonnes) of CO₂ equivalent.
• Carbon Budget: The remaining carbon budget for a 50% likelyihood to stay under 1.5 °C of global warming is only around 130 gigatonnes, around 3 years' worth of current emissions.
• Sea Level Rise: Since the start of the 20th century, global sea levels have risen by approximately 228 mm (22.8 cm). Between 2019 and 2024, the level rose by about 26 mm — an average rate of ~4.3 mm per year. This is more than double the long-term average rate of 1.8 mm/year recorded since 1901.
• Immediate Transformative Action Required: To achieve net zero and to stabilize temperatures, the pace and scale of climate action globally must match the rate and scale of the climate challenge.
• To stop warming around 1.5 °C we must yearly reduce CO₂ emissions by 6 Gigatonnes (or 8 Gigatonnes of CO₂ equivalent) and reach net zero in around 6 years — by 2031.
• To stop warming around 1.7 °C we will have to reduce emissions yearly by 1.6 Gigatonnes of CO₂ (or 2.1 Gigatonnes of CO₂ equivalent) and reach net zero in 24 years — by 2049.
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