Investing in less CO2 intensive building technologies. (The carbon dioxide emissions from the production of concrete are so high that if concrete were a country, it would be the third-largest emitter of CO2 behind China and the United States.)The central ingredient in concrete is cement, which is made by crushing limestone and clay and adding iron ore or ash. The mixture is heated in a kiln to more than 2,600 degrees Fahrenheit, a process that consumes vast quantities of fossil fuel.

When heated, the calcium carbonate in limestone breaks into calcium oxide and carbon dioxide, which is released into the air. The calcium oxide is ground with limestone and gypsum to make cement.

Half of the CO2 emissions in the production of concrete come from the reaction that breaks up the calcium carbonate and the other half from the fossil fuels required to heat the kilns and transport the materials.

Things we should also consider. Getting rid of cars. Investment in mass International and intranational public transit.

Meat alternatives that require less physical space. reining in massive fishing fleets (half the oxygen and half the carbon captured comes from the ecological systems in the ocean which we ravage) Invest in renewable energy, like tidal, solar, geothermal, etc

Even if we were to go 100% nuclear tomorrow (which just isn't possible, we'd (the entirety of earth) would run out of nuclear fuel in 90 years), that would account for about 1/4 the carbon emissions of the planet per year.

Climate change is more than just the amount of CO2 in the atmosphere, it's about how we as a species, integrate with the rest of the species on this planet.