If all we're disagreeing on is the severity of the impact, which neither of us have defined, then possibly we're more aligned that we think. Or not.

I will be clear. I think that over the next three or so decades, we're going to see massive migration, crop failures, resource wars, and unprecedented weather disasters. Far less complex civilizations have collapsed from lesser stressors.

Scientists in general and the IPCC in particular, skew towards conservatism in public pronouncements, in part because they get castigated as alarmists. But there are many serious, competent, climate scientists experiencing considerable panic over the current state of affairs. A Google search can find dozens of examples.

Climate change is also a subset of the problem that we're overusing and destroying planetary resources to a disastrous degree. Have a look at the updated Club of Rome report - the original work was done in the 1970s and has proven remarkably accurate. The most recent update predicts a massive collapse in the human population somewhere around 2040.