The greenhouse effect is:
O When I paint my house green
O When I grow plants in a greenhouse
O When gases like CO2 and CH4 trap and hold heat in Earth's atmosphere, keeping it warm
O When gases like CO2 and CH4 release heat from Earth's atmosphere, letting it go to outer space
O When I paint my house green
O When I grow plants in a greenhouse
O When gases like CO2 and CH4 trap and hold heat in Earth's atmosphere, keeping it warm
O When gases like CO2 and CH4 release heat from Earth's atmosphere, letting it go to outer space