Reaching Net Zero
To slow down climate change, it is necessary to stop global warming by reaching NET ZERO. NET ZERO is when CO2 emissions are reduced so no additional CO2 is added to the atmosphere. CO2 emissions that can’t be reduced are offset by sinks such as forests that remove and store CO2 from the atmosphere. Other greenhouse gases such as methane and nitrous oxide from agriculture and land use changes have to be reduced to net zero as well.
Reaching NET ZERO will stabilize but not reduce the earth’s temperature until greenhouse gases already in the atmosphere are reduced naturally over a very long time. Polar ice caps and glaciers will continue to melt, causing sea levels to rise. Other climate changes will also persist for decades or longer.
To reach NET ZERO, we have to stop using fossil fuels, the main source of CO2 emissions. We also have to make changes in agriculture and land use to eliminate methane and nitrous oxide emissions. We have to plant billions of new trees and stop deforestation to expand natural CO2 sinks. For those applications where fossil fuels can’t be eliminated, we need to use hydrogen or synthetic fuels from recycled CO2 produced using electricity from renewables. Eliminating fossil fuels requires phasing out the use of internal combustion engines and power plants fueled by coal and natural gas.
To reach NET ZERO it is necessary and feasible to power the earth with abundant and affordable energy from renewable sources, primarily wind and solar, with contributions from hydro and nuclear. Phasing out fossil fuel use will also eliminate most air pollution, improve public health, and reduce other damage to the environment.
If we aren’t willing to take these actions, we can’t get to NET ZERO. It is less a technical problem than a problem of economics, politics, and international relations. We can get there with the technology at hand or being perfected, if we can attain the collective will to do so. The world’s leading industrial economies have to cooperate and lead the transition to renewable energy. These countries are the largest source of greenhouse gases, and also have the technical, financial, and management resources needed to make the transition.