In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth’s surface while around 30% is reflected back to space and does not heat the surface. The Earth radiates energy at wavelengths much longer than the Sun because it is colder
https://wmo.int/suns-impact-earth#:~:text=In total approximately 70%25 of,Sun because it is colder.
No, the energy captured by solar panels wasn’t already going to turn into heat to be released and trapped by earth’s atmosphere.
One million seconds is 11.6 days
One billion seconds is 31.7 years