Climate change is real
Earth is warming, and human activities are the main cause of the recent long-term rise. Burning coal, oil and gas adds heat-trapping gases to the air. Natural changes alone do not explain the pattern.
This page is about recent global warming. Earth’s climate also changed naturally long before people began burning fossil fuels.
On this page
Why heat-trapping gases matter
Carbon dioxide traps some of the heat that would otherwise leave Earth. Burning coal, oil and gas adds more of it to the air. Scientists test this explanation against temperature records and measurements of heat radiation, as well as explanations involving the Sun and volcanoes.
Temperature measurements show a lasting rise
Land and ocean measurements show a long-term warming trend. A global climate report puts 2025 at about 1.43°C warmer than the 1850–1900 average. A single year can be hotter or cooler than the years around it; it is not the same as a lasting change in the climate. One unusually hot day is weather; a lasting rise in average temperatures is a change in climate.
Testing the causes
Scientists compare the warming we measure with the effects expected from human and natural influences. Natural changes alone do not fit the full pattern. A recent update estimates that people account for almost all of the measured long-term warming over 2016–2025; the exact estimates and uncertainty are below.
Natural causes still matter
Sunlight, volcanoes and ocean cycles affect climate. Scientists test whether these causes fit the size, timing and pattern of recent warming. They do not explain the whole rise. Uncertainty about how much warming comes next does not mean human influence is absent.
One disaster needs its own investigation
Climate change can make some extreme weather more likely or more intense. The answer depends on the event and place. The damage also depends on where people live, how buildings are protected and other conditions. The warming finding does not mean every disaster is caused only by climate change.
The conclusion rests on temperature records, the physics of heat-trapping gases and tests of other explanations.
Keep in mind
- The global average does not mean every place warms at the same rate.
- Weather varies from day to day and year to year within the long-term trend.
- This evidence does not decide which climate policy is best.
How certain are the temperature estimates?
Different measurements and calculations leave a range of possible values around each estimate. The human-caused part is calculated from evidence about the causes, not read directly from a thermometer.
For 2016–2025, the recent update gives measured warming as 1.26°C, with a range of 1.13–1.36°C, and human-caused warming as 1.24°C, with a range of 1.0–1.5°C. The IPCC’s earlier 2010–2019 human-caused estimate was 1.07°C, with a likely range of 0.8–1.3°C; natural influences were estimated at −0.1 to +0.1°C for that comparison. Temperature datasets share some measurements, and updated reviews reuse earlier methods. Agreement does not make them wholly separate experiments. The radiation study used two sites in clear skies; it does not measure the entire planet’s heat balance. The study in Oklahoma and Alaska measured heat radiation during 2000–2010, under clear skies, and used calculations to separate carbon dioxide’s effect. That is a check on one part of the explanation, not a measurement of the whole planet.
Sources you can check
Publication links open in a new tab, so you can keep your place here.
GISS Surface Temperature Analysis, GISTEMP v4 (opens in a new tab)
NASA GISS
Land and ocean temperature records show the long-term trend. The estimate includes corrections for measurement changes and gaps.
Return to reading ↑State of the Global Climate 2025 (opens in a new tab)
WMO, March 2026
Combines temperature records and other climate measurements. Its 2025 figure is a single-year average, not a permanent threshold crossing.
Return to reading ↑AR6 Working Group I, Chapter 3: Human Influence on the Climate System (opens in a new tab)
IPCC, 2021
Tests human and natural explanations against observations and physical mechanisms. Short-term natural variation still matters.
Return to reading ↑Indicators of Global Climate Change 2025 (opens in a new tab)
Earth System Science Data, June 2026
Updates estimates of observed and human-caused warming. It builds on assessment methods rather than providing a wholly separate experiment.
Return to reading ↑Observational determination of surface radiative forcing by CO₂ from 2000 to 2010 (opens in a new tab)
Nature, 2015
Measures the effect of rising carbon dioxide on heat radiation at two sites. Those measurements test the mechanism, not the whole global budget.
Return to reading ↑AR6 Working Group I, Chapter 11: Weather and Climate Extreme Events in a Changing Climate (opens in a new tab)
IPCC, 2021
Examines extreme weather. The strength of attribution differs by event, place and measure.
Return to reading ↑
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