When William Nordhaus, who would later win a Nobel prize in economics, modelled the interplay between the financial system and the environment he represented the “harm operate”—an estimate of hurt executed by an additional unit of warming—as a wiggly line. So little was identified concerning the prices of local weather change that he known as it “terra incognita”, unknown land, in contrast with the “terra infirma”, shaky floor, of the prices of stopping it. Finally, a tough calculation gave him an estimate that 1-2% of worldwide GDP can be misplaced from a 3°C rise in temperature. This was not more than an “knowledgeable hunch”, he wrote in 1991.
