Plant another 10 billion trees.
The best way to remove CO2 from our atmosphere in the long term is to simply plant a tree. Trees turn CO2 into cellulose and continue to do so for at least a century, sometimes far longer. It costs a few dollars per tree and about 20 minutes of labor to plant a sapling.
Put solar on as many rooftops possible.
All the sunny rooftops within 2500 miles north and south of the equator are a good bet for solar. Every human in modern society will use electricity every day of their lives, and the traditional utility primarily burns fossil fuels to generate this electricity. Solar on every roof raises the inherent value of every home and business as well.
Electrify all ground transportation.
We still need fossil fuels for jet planes…. but not for trains, buses and automobiles. With solar on the roof and electric cars in every driveway it becomes far cheaper to fuel up our vehicles. I drive a plug-in electric car that charges off the solar on my roof. This system works, and my costs for the additional equipment is LESS in the long term.
These three steps are all practical and possible.