The obvious - greenhouse gases CO₂ and H₂O are very rare in Earth's the actually very thin atmosphere of 1 bar at sea level.
The air density is some 1,23 kg/m³, and it is a very thin atmosphere... In Earth's very thin atmosphere there are on average 1% H₂O and 0,04% CO₂.
Those two are trace gases in Earth's very thin atmosphere. H₂O and CO₂ very tiny contents in earth's atmosphere are not capable to absorb the alleged huge "absorbed by atmosphere 70%-85% outgoing IR radiation" portion.
One may object, Earth's atmosphere is not thin, Earth's atmosphere is all right, since we live in it.
Yes, we live in Earth's atmosphere because it is very thin. Yes atmosphere is dense enough for us to breathe, and for birds to fly - but that's it. Earth's atmosphere is marginally dense. Only few kilometers in altitude there is not enough atmosphere to breathe, and there is not enough air for birds to fly.
So, this atmosphere - the our Earth's atmosphere is not capable to absorb 70%-85% of outgoing IR radiation portion.
The common sense claims the obvious: there is not any significant Greenhouse warming effect on Earth's surface!