In the absence of any efforts to curtail our emissions, burning of conventional fossil fuels will cause CO₂ concentrations to be around 2,000ppm by the year 2250."
This statement makes unstated, and therefore undebateable, assumptions about the growth of population and use of fossil fuels. It also seems to ignore the very real potential that earth's natural systems adjust to higher atmospheric CO-2 and absorb it into the biosphere, hydrosphere and lithosphere.
As I said in earlier comment, one of the stupidest things Baby Martin has ever posted, and that's saying a lot.