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GPT-5Sep 30, 2026openai/gpt-5-2025-08-07
Are humans responsible for climate change?
Yes. The overwhelming scientific consensus is that humans are the dominant cause of the warming observed since the mid‑20th century.
Why scientists are confident:
•Mechanism: Burning fossil fuels, deforestation, and some farming/industry raise heat‑trapping gases (CO2, methane, nitrous oxide), strengthening the greenhouse effect.
•Fingerprints: The pattern matches greenhouse warming—troposphere warms while the stratosphere cools; nights warm faster than days; the Arctic warms fastest; oceans store most of the excess heat.
•Carbon clues: The chemical “isotopic” signature of extra CO2 points to fossil fuels, and the drop in atmospheric oxygen tracks combustion.
•Alternatives tested: Solar output and volcanoes can’t explain the long‑term warming trend; natural cycles only shift heat around and can’t add energy to the Earth system.
•Magnitude: Greenhouse gases have driven virtually all of the net global warming since the mid‑1900s; without human emissions, models reproduce little of the observed rise.
If you’d like, I can share key reports or dig into any part of the evidence.