That's the sum of climate change. "GDP growth of 3% instead of 5%."

Severe enough to be noticeable, but not severe enough to warrant radical climate action. Not an extinction threat. A "slow trickle of economic damage, some amount of otherwise preventable death and suffering, diffused across the entire world, applied unevenly, and spread thin across many decades" threat.

And stopping the GHG emissions demands radical, coordinated global action. Major emitters would have to pay local costs now - for the sake of global benefits many decades down the line. And those emitters are not the countries that face the worst climate risks. Global superpowers can tolerate climate change - it's countries that already struggle as it is, that don't have the resources to adapt or mitigate damage, that can face a significant uptick in death and suffering rather than damage in the realm of economics.

That makes climate action a very hard sell for the politicians. Thus the tepid response.

By now, I'm convinced that the only viable approaches to climate change lie in the realm of geoengineering. Which does not require multilateral coordinated action against a "tragedy of commons" scenario, and is cheaper than forcing local GHG emissions into negatives.

Even non-permanent geoengineering solutions offset impacts here and now - thus buying time for fossil fuel energy to succumb to the economic advantage of renewables. And geoengineering measures can be enacted unilaterally by many powers - as long as the political will is there to absorb a few strongly worded condemnation letters.