Yes. You’ve got the theory wrong in a few ways. Sunlight doesn’t pass through our atmosphere without interaction with it and only heat the earth. It heats every molecule that absorbs a photon. Solid, liquid, or gas, so it heats the atmosphere, the oceans, and the land. CO2 can absorb more photons that just 15um. There are two more transitions in the IR alone. But those are just vibrational modes. It also has electronic and rotational modes that allow it to absorb or emit energy from the sun or other sources. CO2 is a very good IR absorber and can transfer than energy in a lot of ways to other atoms/molecules. It has a ton of vibrational relaxation modes. Methane is an even bigger problem this way. A better way to think of it is not as a shield around the earth but like holding a black metal rod in your hand. The sun heats the rod and transfers the energy efficiently to your hand. It’s not totally preventing the energy from leaving your hand but it’s adding a lot to the system. That’s a rough analogy because I’m tired but you have a ton more energy getting pulled into the atmosphere/earth system and getting spread around and changed. So it’s not just 15um in vs 15um out. Molecules and atoms just don’t work that way. IR Spectra https://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Type=IR-SPEC&Index=1#IR-SPEC This may also interest you. https://aviris.jpl.nasa.gov/proceedings/workshops/01_docs/2001Green_co2_web.pdf