It's 1°C on average. That means every molecule of air has AT LEAST 1°C extra thermal energy. And I'm not sure if anyone has noticed, there's a lot of air molecules. So while taking one cubic centimeter of air and increasing it by 1°C isn't a ton of energy. Do that for roughly all 109 tredecitillion molecules and you get about 2.2 zettajoules of energy. Annual US energy consumption is just 0.094 zettajoules. So one degree increase is equal to more energy than the US uses in 23½ years. The biggest nuclear bomb humans ever made, that pulls in at about 0.00021 zettajoules. So one degree is roughly 10,500 Tasr Bombas going off and then the resulting heat just never leaving.
All of that energy. It has to go somewhere. Sometimes it makes ice turn to water, sometimes it increases the speed at which some wind is moving, sometimes it increases the surface temperature of land, sometimes it evaporates water leaving an area very dry. But it has to go somewhere. And it cannot just radiate back out into space, it hits a CO₂ molecule, bounces off of it, and flies right back down to Earth. And the more CO₂ molecules we put out there, the more often that happens.