People are getting excited about links between the IPCC and Greenpeace. See Climate Audit, Mark Lynas, Bishop Hill, and NoFrakkingConsensus.
I have no problem with stakeholders being in the IPCC, as long as they are a minority and as long as they are from all walks of life.
I do have a problem with the IPCC claiming that every author is a leading expert. That is just nonsense.
I do have a problem with this line: "Close to 80 percent of the world‘s energy supply could be met by renewables by mid-century if backed by the right enabling public policies". Lots of things could be achieved with the right enabling public policies, including genocide and nuclear war. The fact that something can be done, does not mean it will be done or should be done.
The coal-fired power plants that are being build today will still be generating electricity in 2050. 80% renewables by 2050 would require premature scrapping, that is capital destruction. The underlying study says it excludes scrapping, but then it got its vintages wrong.
That study also assumes rapid technological progress in renewables and none in fossil fuels. That is a silly assumption. It seems to use learning rates that originate from single regression models, and would thus suffer from omitted variable bias.
The IPCC is supposed to reflect the full range of findings in the literature, but it is also meant to assess the literature. In my mind, that implies criticizing faulty studies in the report. Highlighting them in the first sentence of a press release is unwise.