Net-zero refers to the target of reducing the greenhouse gas emissions that cause global warming to zero by balancing the amount released into the atmosphere from sources with the amount removed and stored by carbon sinks. This is also described as ‘carbon neutrality’ and sometimes ‘climate neutrality’.
Significant reductions in greenhouse gas emissions across the economy are necessary to get net-zero. Large-scale innovation and investment are required to reduce emissions of greenhouse gases other than carbon dioxide (such as methane) from sectors like agriculture and to provide technologically and economically viable alternatives to fossil fuel-intensive technologies in sectors like heating and transportation.
Natural solutions, including planting trees and altering land use to enhance the amount of carbon trapped in soil, can help reduce greenhouse gas emissions. It will also be necessary to use negative emissions technologies like Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS). However, these technologies have not yet been tested on a large scale, they can be costly and energy-intensive, and they can also have unintended negative effects.
What technologies are needed to achieve this goal?
1. Generate electricity without emissions. Using sources such as wind, solar, nuclear, and water power combined with advances in electricity storage can provide much of the nation’s electricity with minimal CO2 emissions. Other low-carbon energy sources can be used alongside these power sources to make sure electricity is always available.
2. Use vehicles and equipment that are powered by electricity instead of fossil fuels. Many of the biggest sources of greenhouse gas emissions can be replaced with equipment powered by electricity. In particular, switching to electric cars and trucks and using electric heating for buildings would greatly reduce emissions.
3. Use energy more efficiently. More efficient technologies and processes that reduce energy use can also reduce emissions significantly. Switching to electric equipment often improves efficiency. Also, “smart” technologies, which sense when energy is needed and when it is not, can help to optimize how electricity is generated and used, helping minimize waste.
4. Remove carbon dioxide from the atmosphere. To offset emissions that are too costly or difficult to avoid, it is necessary to remove CO2 from the atmosphere and store it permanently. This can be done with technologies that directly capture CO2 from the air and trap it so it cannot re-enter the atmosphere. Plants and soils already remove CO2 from the atmosphere, and certain land management practices can increase their capacity to absorb and store carbon.
