The Te = 255K is a mathematical abstraction

Let's say it is a correct assertion the Tmean - Te = 288K -255K = 33°C, (which is of course not, because there is not such a thing as Te, because it is a pure theoretical abstraction)...

But let's say it is correct, and there is a 33°C atmospheric greenhouse effect on Earth's surface.

And the 420 ppm - 280 ppm = 140 ppm of CO2 had risen the average surface temperature by 1,5°C since predindustrial 1850 average surface temperature.
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But the assertion doesn't align with the numbers.

Let's explain:

If the 140 ppm caused a 1,5°C rise in Global temperature, then the predindustrial 280 ppm of CO2 had to be a cause of 3°C from the Te = 255K, so there should be by now the average surface temperature of our planet Earth

   255K + 3°C + 1,5°C = 260K...

But it is 288K. And 288K - 260K = 28°C. The 28°C difference where to be attributed then?
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But there is another greenhouse gas with average 3% content in atmosphere, which is 30000 ppm.

Ok, 30000 ppm /28°C = 1071 ppm/°C for water vapor.
And, for comparison,

140 ppm /1,5°C = 93 ppm/°C for CO2.
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Something is very wrong here. I think there is not any 33°C atmospheric greenhouse effect, because the Te = 255K is a mathematical abstraction.

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