If we save our own nation by protecting our borders and doing our utmost to feed and protect our own citizens then we will have to watch the suffering of the billions dying elsewhere. If we make this choice we will have to be steadfast about it and there will doubtless be many Britons who will rebel against acting so selfishly. But we probably could survive.
If we take the unselfish route and try to save everyone the outcome is likely to be horrific conflict in the fight over resources, and continuing devastation of the planet until most, or all, of humanity is dead.
If we decide to put the planet first, then we ourselves are the pathogen. So we should let as many people die as possible, so that other species may live, and accept the destruction of civilisation and of everything we have achieved.
Finally, we might decide that civilisation itself is worth preserving. In that case we have to work out what to save and which people would be needed in a drastically reduced population - weighing the value of scientists and musicians against that of politicians, for example - a prospect that does not look at all easy from here.
Indeed none of these choices looks easy, but if we fail to make any decisions then I believe the most likely outcome is that we in the rich west will go on trying to salve our consciences by giving aid to the poorer parts of the world until we realise, far too late, that Gaia is going to chuck us all off whatever we do, and nothing can be saved at all.
