Impact Timeline
How key climate indicators have changed over decades
Decadal Temperature Change
1850–1900
Baseline
Pre-industrial
1970s
+0.0°C
Relative to baseline
1980s
+0.2°C
Rapid warming begins
1990s
+0.5°C
Warmest decade to date
2000s
+0.7°C
Accelerating trend
2010s
+1.0°C
Paris Agreement era
2020–2025
+1.3°C
Near 1.5°C threshold
2025 Monthly Global Temperature Anomalies (°C above 1991–2020)
Record warm January 2025 was the warmest January on record globally.
2nd warmest March, April, and May each ranked second warmest.
21 months Consecutive months above 1.5°C from July 2023 through 2025.
2025 Temperature Anomaly by Region
10 Warmest Years on Record
| Rank | Year | Anomaly (°C) | Dataset |
|---|---|---|---|
| 1 | 2024 | +1.60 | ERA5 |
| 2 | 2023 | +1.48 | ERA5 |
| 3 | 2025 | +1.47 | ERA5 |
| 4 | 2016 | +1.31 | ERA5 |
| 5 | 2020 | +1.27 | ERA5 |
| 6 | 2019 | +1.23 | ERA5 |
| 7 | 2015 | +1.22 | ERA5 |
| 8 | 2017 | +1.18 | ERA5 |
| 9 | 2022 | +1.16 | ERA5 |
| 10 | 2021 | +1.15 | ERA5 |
All 10 warmest years have occurred since 2015.
Antarctic Sea Ice Extent (Annual Avg, M km²)
Antarctic sea ice hit its 3rd lowest annual average in 2025. The four lowest minima on record have occurred in the past four years.
Greenhouse Gas Concentrations (2024, latest consolidated)
CO₂
423.9 ppm
152% of pre-industrial
Methane (CH₄)
1,942 ppb
266% of pre-industrial
Nitrous Oxide (N₂O)
338.0 ppb
125% of pre-industrial
All three major greenhouse gases reached record high concentrations in 2024. Preliminary data show continued increases in 2025. The annual CO₂ increase of 3.5 ppm in 2024 was the largest single-year increase since modern measurements began in 1957.
Earth's Energy Imbalance
EEI Change Since 1976–1995
+2×
More than doubled
Ocean Heat Absorbed
~18×
Annual human energy use, each year
Ocean CO₂ Uptake (past decade)
29%
Of total anthropogenic emissions
Marine Heatwave Days
3×
Tripled since 1991
The Earth's energy imbalance (EEI) has more than doubled since the 1976–1995 period, providing a crucial integrative measure of the pace of climate change. The ocean has been absorbing the equivalent of about eighteen times the annual human energy use each year for the past two decades, while also taking up 29% of anthropogenic CO₂ emissions — causing ongoing ocean acidification.
Warming Rate Acceleration (°C/decade)
1979–2008 (mid-point)
0.18°C
2016–2025 (recent)
0.27°C
End of 2025 (evolving climate)
0.25°C
Human-induced warming (2025)
1.37°C
2026 Forecast & Projections
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2026 forecast: Expected to be the 4th warmest year, slightly cooler than 2025 due to ongoing La Niña, with a possible return to El Niño later in the year.
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80% chance that at least one year in 2025–2029 will replace 2024 as the warmest year on record.
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70% chance the 5-year average (2025–2029) will exceed 1.5°C above pre-industrial levels.
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1.5°C breach likely by 2029 based on the current rate of warming — over a decade earlier than IPCC AR6 central estimate.