[photochemsyn]

As ocean surface temperatures increase the atmospheric water vapor over the oceans increases as well. Water vapor is itself a infrared-absorbing gas so this drives additional warming, but this effect is included in climate models and projections of long-term CO2 effects (and has been experimentally tested, e.g. the Pinatubo explosion threw enough dust into the atmosphere in the early 1990s to cool the ocean surface and there was a subsequent drying of the atmosphere that lasted ~7 years).

The main effect on human and economic activity is that increased water vapor means more extreme weather events, as warm wet air holds more energy that can be violently released if a warm wet system runs into a cold dry polar system, so we can expect more major flooding events as these trends steadily continue. Clear-air water vapor also contributes to major heat waves during the summer, so those should continue as well, along with dry conditions in some regions leading to high fire risk. For individuals, this means living in wildfire zones, flood zones etc. has a high risk factor (which is also why insurance companies are fleeing those markets right now).

Practically the rational governmental response would be to put more funds into robust infrastructure (high temps mean high AC demand so more strain on the grid), more funds into emergency response for fires and floods and heat waves, and of course take major actions to eliminate fossil fuels from the energy mix as soon as possible... which is going to be a few decades at best, so adapting to these new conditions is pretty critical.