Fact brief – Is global warming actually happening?

Posted on 2 September 2025 by Sue Bin Park

Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.

Is global warming actually happening?

Multiple indicators show Earth is warming rapidly.

Global surface temperatures are now about 1.47°C (2.65°F) above the 19th century average, with the past ten years the warmest on record. Surface temperatures are measured by thousands of land weather stations and weather balloons, along with ships, ocean buoys, and satellite measurements. Oceans, which absorb over 90% of excess heat, hit record highs in 2024, making the last decade the warmest since the 1800s.

Sea levels are rising at the fastest rate in 2,500 years, driven by melting ice sheets and the thermal expansion of seawater. Polar regions are losing ice, while heatwaves and droughts are becoming more intense and frequent.

Atmospheric CO2 reached 428 ppm in July 2025, or 50% higher than preindustrial levels, before large-scale fossil fuel use. Evidence from air, land, oceans, and ice all point to global warming, with human activity as the primary cause.

Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact

This fact brief is responsive to quotes such as this one.

Sources

NASA Carbon Dioxide

NASA Global Temperature

NASA How do scientists measure global temperature?

NASA Ocean Warming

NASA Sea Level

World Meteorological Organization Climate change and heatwaves

CarbonBrief ‘Multi-year’ droughts have become more frequent, drier and hotter over past 40 years

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About fact briefs published on Gigafact

Fact briefs are short, credibly sourced summaries that offer “yes/no” answers in response to claims found online. They rely on publicly available, often primary source data and documents. Fact briefs are created by contributors to Gigafact — a nonprofit project looking to expand participation in fact-checking and protect the democratic process. See all of our published fact briefs here.