GPF are currently looking at developing an approach to ensuring that expeditions who minimise their carbon use are recognised for this effort when their applications for funding are considered. It will be focused on travel as that is where most emissions arise from in any expedition. Wookey did some initial research into this and found that equipment emissions are basically negligible. I largely agree that carbon offsetting is performative at best and harmful at worst. Most of the time the cost of the credits is so little that there's no way it can make a tangible difference.
There needs to be a change in approach from those going caving abroad. We should focus on exploring cave in destinations which can be reached easily without flying. We are fortunate, as European cavers, that you do not need to travel long distances to reach amazing unexplored caving areas. Austria, where I have found kilometres of new cave both with UK cavers and locals and which still has huge untapped potential, is a days travel from London by train (London - Salzburg in under 12 hours), and is a day or two to get to with a car or by bus. There is really no reasonable justification for flying. This also applies to northern Spain, which is reachable on a ferry from Portsmouth in 24 hours and by driving overland in a similar time. Many caving regions in southern France can be reached by train from London in under 8 hours, some in under 6.
In this spring's funding round, GPF only funded 2 expeditions to areas outside of Europe: the DEEP trip to Dara cave in Lebanon and the North Peru trip (I'm not counting Mulu, which has its own fund, or the Shepton Thailand trip, which actually happened in Jan - Feb 2023 but then needed funding later). Of these, DEEP was focussed on helping local Lebanese cavers to scientifically document a cave system which is threatened by industrial quarrying. All the caving hardware (I think) was going to be left in Lebanon after the expedition ended. This is the sort of trip which I think it is worth flying to do, and it also counters the sadly more common colonial attitude that expeditions to countries in the Global South frequently adopt (thankfully this is much less the case in caving than in climbing or mountaineering, but it is still prevalent). Mulu and Meghalaya are other expeditions which continue to develop links with local cavers, and thus enable them to explore their own regions, to differing degrees of success, and I think that Pete's trip to Peru hoped to do the same (hope they are successful).
As BabyHagrid says, better to facilitate local people who want to explore cave in destinations which can't be reached without flying than repeatedly making massive trips. Caving is just a hobby, and I personally don't want my hobby to prop up the aviation industry if it doesn't need to. I personally don't see that 'science' justifies these big flights either - lets be honest, cave science is really not that important in the grand scheme of things. This research can definitely wait until we've got emissions under control and have tech that allows us to travel there without such crazy emissions.
Of the European trips funded by GPF in that round, only the CUCC expo specifically aims to reduce carbon emissions by encouraging attendees not to fly. I would welcome other European expeditions doing the same, and as I say GPF may well soon adopt policies which encourage this as well.