Paris Climate Summit to reduce US GDP by 7%, increase US unemployment by 5 Million

Everyone's talking about how the carbon reduction from these proposals (reduce emissions by 80% by 2050) will only result in a tenth of a degree less heating.  What's being ignored is what the cost will be to the US economy:

When I queried [Bjorn] Lomborg specifically about the U.S. numbers, he provided this comment:

Also, note that a reduction by 80% in 2050 will cost the US about $1.2 trillion annually in lost GDP if politicians pick all the smart solutions (carbon tax etc).  This is according to the Stanford Energy Modeling Forum 24, which ran 12 scenarios on 6 models to estimate the cost.  This is 3.8% of GDP in 2050, and experience tells us that if politicians don’t do the smart thing, the cost will at least double (so about $2.4 trillion annually or 7.6% of GDP).  Seems somewhat unlikely.

By point of reference, 7.6% is more than half of the world wide drop in GDP during the Great Depression.  During the Depression, GDP dropped by about 30% and unemployment went up 20% or so.  Assuming unemployment/GDP is about the same now as then, that would translate into an increase in the unemployment rate of 5%, on top of the fudged figure we already have.  And this will be permanent, unless the emission caps are removed (unlikely).

So a cursory reading of the proposed Climate agreement is that an extra 5 Million Americans will be thrown out of work permanently.  But hey: eggs, omlets, amirate?

Can someone please explain to me how environmentalists think they're nicer than you and me?