period is used to byproducts lite warming
heat_production is not emitting. greenhouse_effect is not heating_air. global_warming is heating. global_warming is heating_air. heat_production is emitting. global_warming is not heating. sunlight has effect_of_heating_earth greenhouse_effect is heating_air. sunlight has not effect_of_heating_earth partially_blocking_sunlight has effect_of_cooling_earth