Carbon dioxide warming and other possible global climate changes

Abstract

Climate can be thought of as the circulation-00 global climate into 'external' and 'internal' statistics obtained by averaging weather con- ditions over a long period of time, usually at least several years. Since the circulation varies on a wide range of time-scales, clima- tological averages over successive periods will frequently be different. In trying to understand long-term changes, climate modellers separate the various factors influencing ones. The main external influences considered are variations in solar radiation with orbital changes, increasing concentration of carbon dioxide and other greenhouse gases, and aero- sol emission by volcanoes. More recently, attention has also been paid to the effects of acid rain, fluorocarbons (on ozone chemis- try), and nuclear war-generated smoke and dust. The internal influences result from day-to-day weather variability and can also produce persistent anomalies in the atmosphere and ocean circulation through atmosphere- surface feedbacks. The El Niño/Southern Oscillation phenomenon is probably the best- known example of this type.