Nigel Calder reports on a new paper that purports to rebut Svensmark's cloud hypothesis.
During recent years, so the story goes, the Sun has been weak, cosmic rays have been relatively intense, and yet the expected increase in low clouds has not occurred. On the contrary, we’re told, low cloud cover has remained relatively sparse. That’s according the International Satellite Cloud Climatology Project, ISCCP, which pools data from the satellites of several nations.
However, the ISCCP data are apparently problematic:
The conspicuous downward trend in the ISCCP cloud data is almost certainly unreal. An expert view is that it results from changes in the operational status of the satellites from which the data are pooled.
In other words, the jury is still out.
Calder is very critical of the authors of the new paper - Agee et al - suggesting that they have cherrypicked the ISCCP figures rather than mentioning any of the other data sources, which tell a different story. He calls the paper "shoddy".