Greenhouse effect
Etymology
Named by loose analogy to a garden greenhouse, whose glass lets sunlight in but slows heat’s escape — though the atmosphere works by a different physical route. Svante Arrhenius quantified the warming from carbon dioxide in the 1890s.
noun phrase · /GREEN-hows ih-FEKT/
The warming that occurs when gases in a planet’s atmosphere trap heat that would otherwise escape to space.
What it names
The mechanism that keeps Earth warm enough to live on — and, when human emissions strengthen it, the engine of climate change.
Example
Burning fossil fuels adds carbon dioxide that intensifies the greenhouse effect, nudging global temperatures upward.
Related idea
The greenhouse effect is a natural and necessary process within the atmosphere; global warming is what happens when human emissions overcharge it. The effect itself is not the problem — its recent amplification is.