For climate doom, just check the UN's reports, including the IPCC

Jason Hickel is a leftist that talks about degrowth and his academic publications include big meta-studies that conclude we're headed towards well over 1.5C. He also explains how this can be avoided by policies that would essentially require socialism.

I don't have sources on China off the top of my head, but I do know that they're investing massively in clean energy and transit, which are major elements of tackling global warming. They're doing a ton unilaterally and I think might be the only industrialized nation meeting their international climate commitments.