In the next few decades the biggest contributors to the issues you mentioned are going to be the billions of people in Africa and Asia who are rapidly developing themselves out of poverty. What do you think we should do about that?
a] we could be a positive example of a sustainable approach to earth stewardship, by switching to plant based diets instead of eating ourselves to extinction, what we do they copy, by switching to plant based we would save 75% of agricultural land (enabling reforestation and stopping biodiversity loss if done properly)
b] don't f*ck up the climate much more, so they won't have to migrate to save their bare existence, no walls will stop those hundreds of millions once they start moving (50+C temperatures near the equator, melting glaciers threatening water scarcity for hundreds of millions in asia, overfished seas etc.)
c] help them develop / educate their population instead of insisting on exploiting their natural resources, only education and abolishing idiocy and indiference can help us (by curbing population explosion and protecting the last remnants of the ecosystems we have)
d] help them save/reforest their local ecosystems so they'll be able to take care of themselves, without functioning ecosphere no functioning economy is possible
e] stop deforesting ... we could start making clothes, paper, furniture and houses from cannabis again for example, it grows much faster than trees do
f] stop behaving immorally, exporting bad laws and practicies to the world, just to protect national interests of a single country - e.g. instead of cannabis for textile production we have clothes from plastic materials (= microplastics in water everywhere), enabling production of forever chemicals and agricultural herbicides/pesticides even if we know how destructive it is, industrialized agriculture degrading soils all over the world, we could go on and on