evidence: Many ozone-depleting substances are also greenhouse gases, some are thousands of times more powerful than carbon dioxide on a per-molecule basis over the short and medium term.[35] The increases in concentrations of these chemicals have produced 0.34 ± 0.03 W/m2 of radiative forcing, corresponding to about 14% of the total radiative forcing from increases in the concentrations of well-mixed greenhouse gases.[36] Because of their ozone depleting effects, production of CFCs and many other related substances have been banned globally by the 1987 Montreal Protocol and its subsequent revisions. By one model-based estimate, had these continued to be produced unabated global temperatures in 2100 would be 2.5°C greater than they would otherwise have been; 1.7°C from the direct greenhouse effect of the additional CFCs, and 0.8°C from increased CO2 due to UV vegetation damage.[37]