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
Effects of global warming warming of around 0.6 °C during the 20th century. In a study carried out by David R. Easterling et al., trends were observed over a period of time. “It is clear from the observed record that there has been an increase in the global mean temperature of about 0.6℃ since the start of the 20th century and that this increase is associated with a stronger warming in daily minimum temperatures than in maximums leading to a reduction in the diurnal temperature range.” The future level of global warming is uncertain, but a wide range of estimates (projections) have been made.