R-410A bromine or chlorine, R-410A (which contains only fluorine) does not contribute to ozone depletion, and is therefore becoming more widely used, as ozone-depleting refrigerants like R-22 are phased out. However, it has a high global warming potential (1700 times the effect of carbon dioxide), similar to that of R-22. Since R-410A allows for higher SEER ratings than an R-22 system, by reducing power consumption, the overall impact on global warming of R-410A systems will be substantially lower than that of R-22 systems due to reduced greenhouse gas emissions from power plants. R-410A R-410A, sold under the trademarked names AZ-20, EcoFluor
Global cooling other scientists doubted these conclusions. In 1972, George Kukla and Robert Matthews, in a Science write-up of a conference, asked when and how the current interglacial would end; concluding that "Global cooling and related rapid changes of environment, substantially exceeding the fluctuations experienced by man in historical times, must be expected within the next few millennia or even centuries." The 1970 Study of Critical Environmental Problems reported the possibility of warming from increased carbon dioxide, but no concerns about cooling, setting a lower bound on the beginning of interest in "global cooling". By 1971, studies indicated that human caused air