Global Warming due to CO2 Levels

When I moved from from the US to the UK I was immediately struck by the greater attention paid to environmental issues, most notably global warming.  Starting over in a new country provides one with the unique opportunity to attempt to correct life style imbalances.  One of these for me had been a stressful and time wasting commute to work.

I have thus taken to cycling the 11 km to work most days.  I've benefited from the "brain time" this provides as well as the increased fitness but fundamental to these commutes has been a smugness engendered by knowing to I was doing nothing to add to CO2 emissions and other pollutants each day and consequently helping the environment.

It is often a struggle on days when it is dreary and cold outside and it is all to easy to choose to instead commute by car especially given a substantial hill between home and work.  So it was with some irritation a few days ago when work colleagues were discussing a documentary, on Channel 4 I think, which disputed the link between CO2 levels and global warming.  The theory goes, as heard second hand, that while global warming is "fact" it is unrelated to CO2 levels and instead related to solar activity.

The implications of this, if true, are somewhat staggering:

1. There is no need to limit or cut back on CO2 emissions.
2. There is a failure on the part of the worldwide scientific community.
3. Global warming is irreversible unless solar activity returns to previous levels

Confronted with this challenge I am trying to review the science behind global warming.

There seems to be no doubt that it is indeed getting warmer  see Levels since 1960

Most (all) models are based on greenhouse gases as being the major contributor to warming since 1970 but the are worth seeing on the same graph.  Some warming models plotted together on the same graph

I'm still reading and trying to understand the various conflicting view points, many  scientists seem to argue that solar activity has contributed less than 20% to global warming, but will follow up in future entries.