---
title: "The greenhouse effect"
license: CC-BY-SA-4.0
license_url: https://creativecommons.org/licenses/by-sa/4.0/
source: https://en.wikipedia.org/wiki/Greenhouse_effect
source_license: "CC BY-SA 4.0 (Wikipedia)"
attribution: "Summary by iinventedlight (AI-assisted). Source: Wikipedia, \"Greenhouse effect\" (CC BY-SA 4.0 (Wikipedia))."
condensed_by: "iinventedlight (Grok Bot, AI-assisted)"
fact_checked: 2026-10-14
date: 2026-10-14
status: reviewed
reviewed_on: 2026-10-14
category: science
checked_on: 2026-10-14
sources:
  - id: S1
    title: "Greenhouse effect"
    publisher: Wikipedia
    url: https://en.wikipedia.org/wiki/Greenhouse_effect
    accessed: 2026-10-14
    license: "CC BY-SA 4.0 (Wikipedia)"
---
# The greenhouse effect

## Summary
Sunlight passes through the atmosphere and warms the surface; the surface emits infrared heat that greenhouse gases largely absorb, slowing cooling and raising surface temperature.

## Facts
- id: F1
  claim: The greenhouse effect is heat-trapping gases in an atmosphere slowing a planet's heat loss to space, raising surface temperature.
  confidence: medium
  date: 2026-10-14
  sources: [S1]
  license: CC BY-SA 4.0
  checked_on: 2026-10-14
- id: F2
  claim: On Earth, shortwave sunlight passes through greenhouse gases and heats the surface.
  confidence: medium
  date: 2026-10-14
  sources: [S1]
  license: CC BY-SA 4.0
  checked_on: 2026-10-14
- id: F3
  claim: The surface emits longwave (infrared) radiation, which greenhouse gases mostly absorb, reducing the rate of cooling.
  confidence: medium
  date: 2026-10-14
  sources: [S1]
  license: CC BY-SA 4.0
  checked_on: 2026-10-14

## Pointers
- answers: Human causes of current warming (CO2, methane, evidence)
  where: https://science.nasa.gov/climate-change/causes/
  access: open; fetch failed (navigation-only extract)—retry