Once the gravity and severity of Climate Change is realized, a “warlike” global effort would solve Climate Change as in we all face a common enemy. Some steps will be required: Convincing irrefutable Scientific data that urgent action is required (ever increasing methane increase from tundra thawing). The realization that defense and other budgets will need to be redirected towards solutions, achievable by a truce agreement to stop weapon development and warfare in general, and a broad set of agreements:
Becoming as close to Zero Carbon Emissions ASAP
End deforestation, repair damaged climate systems, reforesting, and planting as much vegetation as possible.
Water purity, conservation, and availability
Negative population growth, something like, say, WOW1, Women of the World one child max and free contraception. What is a truly sustainable human population and how to get there?