Global Climate Change Conclusion

Bolin (1999) emphasized that though IPCC 1995 contains a statement that global climate changes in the 20th century were partly determined by human activity, this conclusion was formulated rather cautiously. In this context, evaluation of the probable contribution of random climatic variations independent of human influence is critical. Results of recent studies have substantially elucidated this problem, showing that random variations in global mean SAT on time scales from decades... 

The observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikel that global climate change of the past fifty years can be explained without external forcing, and very likely that it is not due to known natural causes alone . 

The most important (and controversial) conclusion by Jacobson (2002a, b) concerning the anthropogenic nature of present-day climate change is based on analysis of the SAT and SST combined data (i.e., on the secular trend of mean average annual global surface temperature, GST). In this connection, two questions arise ... 

---