They seem to say so in their intro video on this page: https://extinctionrebellion.uk/the-truth/the-emergency/. OK they say due to climate and ecological destruction, but it doesn't really matter for this. The point is just that disagreeing with experts doesn't generally seem to prevent an organisation from becoming "successful". (Plenty of examples outside climate too.)

It seems to be a big part in the UK cf Extinction Rebellion, Just Stop Oil.

One of the advantages of the climate protest movements is that they have a wealth of scientific work to point to for credibility.

Scientific work doesn't give particular support for the idea that climate change will create a substantial extinction risk though, and that doesn't stop the activists there. I'm not saying you're wrong or the OP's approach is justified, but public perceptions of activist groups' reasonableness seems only loosely linked to expert views (I've not seen much evidence of the "then they can go on to check what experts think" bit happening much).

The Humane League is what comes to mind - searching for them in the forum may bring up recent estimates of their cost effectiveness - I don't know offhand.

But I thought I'd also say sorry you weren't offered a meal respecting your ethical choice - it seems like an extraordinary thing to happen today (depending on where you are in the world).

I thought I'd follow up on how I wrote a will leaving money to EA charities, following my previous question about it here. I ended up drafting a will myself and haven't yet had it checked by a solicitor. I've gone down this route as I'm still youngish and so having some probability of the will failing does not seem like something worth spending hundreds of pounds to avoid at present - if I were 20 years older, I may have considered that worth it. For context I'm resident in England, and these steps are not necessarily good to follow in other countries - I can't say.

My process was to firstly get a free draft will from www.freewills.co.uk . I copied the text to a document I could edit and set out the clauses specifying the distribution of the estate, using wording from https://www.givewell.org/legacy-giving and https://www.givingwhatwecan.org/get-involved/bequests, and including some extra wording about cause areas to allocate the bequests to, which I checked with GiveWell and GWWC beforehand. I also added sub-clauses about what to do if these charities no longer exist (just general instructions to say my Trustees should use their judgement and about how they could identify charities in line with my wishes, with a couple of examples - if GiveWell or GWWC did cease existing, I intend to update my will, so these clauses should only matter for a fairly narrow window of time and so super high-quality wording doesn't seem needed).

Following this previous Forum post, I added the following clause after the clauses setting out the bequests as an extra failsafe:

But if the trusts hereinbefore declared shall fail or determine then and in that event my Trustees shall stand possessed of the said residue of my estate UPON TRUST to transfer pay or apply the same to or for such exclusively charitable institution or purpose or exclusively charitable institutions or purposes and if more than one in such proportions as my Trustees may in their absolute discretion select.

Then I got it signed and witnessed. See https://www.gov.uk/make-will/make-sure-your-will-is-legal .

Keywords to aide searching, as searching for "will" brings up lots of other things!: testament, writing will, leave money to charity

Are there any good research articles that do a decent job of isolating the role of reducing mortality rates? Review articles would be particularly useful.

Here's a link to the GiveWell-commissioned research that I have: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3635855 .

There was some Givewell-commissioned research that did find that saving lives likely leads to future population increases. I imagine there's a fair amount of uncertainty, but it seemed to be the best information available at the time I was looking into this a few years ago. I could dig it up if it's of interest and difficult to find.

Even if the current population isn't consuming much factory-farmed meat, if it's children's lives being saved, the amount they consume over the next half century or so may be substantial as the countries develop and adopt more industrialised food production. Also, saving lives today seems likely to increase population in future (I recall a GiveWell-commissioned study on this), so potentially leading to greater factory-farmed meat consumption.

I came across this account of working as an IPCC author and drafting the SPM by a philosopher who was involved in the 5th IPCC report, which provides some insight: link to pdf - see from p.7. @jackva   

Yeah I think that it's just that, to me at least, "politicized" has strong connotations of a process being captured by a particular non-broad political constituency or where the outcomes are closely related to alignment with certain political groups or similar. The term "political", as in "the IPCC SPMs are political documents", seems not to give such an impression. "Value-laden" is perhaps another possibility. The article you link to also seems to use "political" to refer to IPCC processes rather than "politicized" - it's a subtle difference but there you go. (Edit - though I do notice I said not to use "political" in my previous comment. I don't know, maybe it depends on how it's written too. It doesn't seem like an unreasonable word to use to me now.)

Re point 1 - I guess we can't know the intentions of the authors re the decision to not discuss climate adaptation there.

Re 2 - I'm not aware of the IPCC concluding that "we also have now expectations of much lower warming". So a plausible reason for it not being in the SPM is that it's not in the main report. As I understand it, there's not a consensus that we can place likelihoods on future emissions scenarios and hence on future warming, and then there's not a way to have consensus about future expectations about that. One line of thought seems to be that it's emission scenario designers' and the IPCC's job to say what is required to meet certain scenarios and what the implications of doing so are, and then the likelihood of the emissions scenarios are determined by governments' choices. Then, a plausible reason why the IPCC did not report on changes in expectations of warming is that it's largely about reporting consensus positions, and there isn't one here. The choice to report consensus positions and not to put likelihoods on emissions scenarios is political in a sense, but not in a way that a priori seems to favour arguments for action over those against. (Though the IPCC did go as far as to say we are likely to exceed 1.5C warming, but didn't comment further as far as I'm aware.)

So I don't think we could be very confident that it is politicized/political in the way you say, in that there seem to be other plausible explanations.

Furthermore, if the IPCC wanted to motivate action better, it could make clear the full range of risks and not just focus so much on "likely" ranges etc.! So if it's aiming to present evidence in a way to motivate more action, it doesn't seem that competent at it! (Though I do agree that in a lot of other places in the SYR SPM, the presentational choices do seem to be encouraging of taking greater action.)