I have had a response to my FOI request regarding the Department of Energy and Climate Change and the Interacademies Council report on the IPCC.
Firstly, I asked how much funding DECC gave to the inquiry, and the answer is as follows:
The UK strongly supported the IAC review of the IPCC as an opportunity to make an excellent organisation even more effective. Alongside other IPCC Governments, the UK received a request from UNEP to provide financial support to enable a review of the IPCC to be carried out, and provided US$ 35,000 to support the review process.
Then I asked about whether DECC had put in a response to the inquiry. The answer is that they had, and I was referred to pages 654-8 of the recently published archive of the submissions. The relevant extract can be seen below. DECC think that, on the whole, the IPCC is fine and dandy, with just a bit of tightening up around the margins required.
Lastly I asked for any related correspondence, and they've said that I will have to be a bit more specific. I will give this some thought.