I think it is your view of capitalism that is a little too benign. Capitalism's history is one of violent dispossession across much of the global South. It depended largely on forcibly integrating colonised people into the capitalist labour system, usually causing widespread dislocation. Sure the global north has done incredibly well out of this arrangement, but it wasn't all that pleasant for those doing the work and still isn't. And actually the real accelerant in human 'progress' was fossil fuel. Our entire modern civilisation was built using cheap energy derived from it, and now it is driving us to extinction.
As to your other point. Capitalism is not the default. How could a system hellbent on destroying the thing keeping us alive be a default state? This notion that capitalism is immutable is just a myth we've bought into and most can't see past it now. Capitalism is an artificial construct just like all economic systems, and can be changed if we so choose. Trade has always been here, but we won't unless we decide which products are important to trade and which give no discernable benefit to humanity (bar giving value to shareholders).
Obviously we won't agree on any of this. So change of tack.
How do think climate change will affect you and when would think that might be?