Water vapor is a stronger greenhouse gas than carbon dioxide. So why do we focus on CO2?

Before I answer that question, I need to get into the difference between  water vapor and the other greenhouse gases. These other gases include carbon dioxide, methane and nitrous gases. These are non-condensable gases at normal atmosphere temperatures and pressures.  Water vapor, however, readily condenses. It also has distinctive thermal properties in vapor, liquid, and solid phases. So, a fair question to ask.

One answer from the establishment is that we have little if any control over water vapor. I think that's a short-minded view but I'll get back to that.

A more fundamental answer comes from understanding the action of non-condensable gases. Basically, you put them up, they stay up. Put more water vapor up and it can easily precipitate back down. Carbon or nitrous gases have to be absorbed or somehow broken down, they don't precipitate and fall out of the sky.

As for the establishment answer, well actually there are some people who argue if we adopted sustainable agriculture and land management we would have an impact on climate by changing the water vapor flow. Desertification has an impact and certainly not a good one and that is something we do.

So I think carbon is a good place to start, but definitely we need to stop the completely unsustainable and very destructive agricultural practices as well.