Greenhouse Effect
Greenhouse gases let sunlight in but stop some of the heat radiating back to space. A natural greenhouse effect keeps Earth habitable; human emissions have intensified it and driven modern warming.
Scientific detail
Greenhouse gases absorb and re-emit longwave radiation, reducing outgoing longwave flux at the top of the atmosphere and raising equilibrium surface temperature. Anthropogenic CO₂, CH₄ and N₂O have added roughly +3 W m⁻² of radiative forcing since 1750 (IPCC AR6), driving observed global warming. Passive radiative cooling partially bypasses this effect by emitting through the 8–13 μm atmospheric window directly to space.
Related terms
Effective Radiative Forcing
The net change in Earth's energy balance caused by a given intervention or driver.
Atmospheric Window
A range of infrared wavelengths (roughly 8–13 μm) where the atmosphere absorbs relatively little of Earth's outgoing thermal radiation.
Decarbonization
Reducing CO₂ emissions across energy, transport, industry and agriculture.
Thermal Lag
The delay between emitting greenhouse gases and feeling the full warming they cause.
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