Can someone provide an official MP explanation? Here's my take on it:
p1 - Earth is getting warmer, evidence emerging supporting "controversial" link between greenhouse gases
p2- Early data was a little off, causing doubt in global warming theories. Sulfates were found to be the missing piece of puzzle that reconciled predictions and actual temp data.
p3- People ( skeptics?) also tried to tie other activity to rising/changing global temps. Solar flares weren't enough to account the entire warming/increase in temps even though solar fluctuations matched general changes in temps. Reasonable to say global warming is happening due to greenhouse gases.
The scale seems pretty simple, one side being GG - > GW and the other being there are other things/reasons to blame for GW or that its not happening at all. The author is on the former side.
Clear authors opinion at end of paragraph 3. " In light of ..... that shift."