For the last 50 years or so
Multiply that by 3 and you're nearly correct. The first "quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide" was published in 1896 by Svante Arrhenius, building on research from John Tyndall as far back as 1859. Source: Wikipedia, but with appropriate citations to the works in question.
I've seen a lot of people carrying all that in their phone case, where they can conveniently lose every single scrap of personal information at once.