Humans put out 40 billion tons of CO2 every year. Offsetting all of this would require 1 trillion gallons of water which sounds like a lot but is only 1 cubic mile of water. It doesn't say how fresh the water needs to be but if salt water is possible to use, then these injection systems could be setup all over the world in places where access to ocean water and basalt bedrock is plentiful. That energy company says they plan to setup facilities to inject 10000 tons of CO2 every year. It would still take 4 million more of these facilities to offset all carbon emissions.