A new study published in Proceedings of the Royal Society A, confirms that neither variations in solar output, nor variations in the flux of cosmic rays, are capable of explaining the rise in global temperatures since 1980. The flip-side to this coin, however, is that the pattern of greenhouse gas emissions is equally incapable of explaining the temperature profile of the twentieth century up to 1970. Global temperatures increased up until 1940, despite a negligible increase in greenhouse gas emissions, and temperatures then decreased until about 1970. The pattern of solar activity explains the global temperature pattern very nicely up until 1970.
The obvious conclusion to an independent analyst is that both solar activity and anthropogenic emissions of greenhouse gases contribute to global temperature patterns. And yet the people on both sides of this debate seem congenitally incapable of acknowledging that both anthropogenic and non-anthropogenic factors have contributed to the rise in global temperature over the twentieth century.