Is it possible to achieve net-zero emissions?
Based on Science
Available technologies could allow the United States to achieve net-zero emissions by 2050. This would require rapid and widespread changes in policy and investment across many sectors of society and participation and commitment by government, industry, and individuals.
Last update October 27, 2021
What does a goal of net-zero emissions by 2050 mean?
Greenhouse gas emissions from human activities are causing climate change, including global warming. To slow climate change requires reducing these emissions. Large reductions in greenhouse gas emissions in the United States over the next decade are technologically feasible, and achieving net-zero emissions in the United States and globally by 2050 would have a big impact on future climate change.
Achieving zero emissions means releasing no greenhouse gases to the atmosphere—that is, no carbon dioxide (CO2), no methane, no nitrous oxide or other greenhouse gases. Achieving net-zero emissions means that some greenhouse gases are still released, but these are offset by removing an equivalent amount of greenhouse gases from the atmosphere and storing it permanently in soil, plants, or materials. Because it would be prohibitively expensive or disruptive to eliminate some sources of emissions entirely, achieving net-zero emissions is considered more feasible than achieving zero emissions at a nationwide scale.
Many governments and businesses have set a goal of achieving net-zero emissions by 2050. The U.S. currently produces 6 Gigatons of greenhouse gas emissions each year. The amount of greenhouse gas emissions is measured in terms of CO2-equivalent, which is the amount of CO2 that would have an equivalent global warming impact as a different greenhouse gas (for example, methane or nitrous oxide). To achieve net-zero emissions across the entire United States would require reducing net emissions by an average of 0.2 Gigatons of CO2-equivalent per year over the next 30 years. If the United States were to achieve this goal, it would reduce global greenhouse gas emissions by about 10%.
What technologies are needed to achieve this goal?
Achieving net-zero emissions would require major changes in U.S. energy production and use and increased removal of greenhouse gases from the atmosphere. The most feasible pathways to net-zero emissions include four main strategies:
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.
Existing technologies can support all of these strategies, but they will need to be implemented rapidly at a very large scale to achieve net-zero emissions nationwide by 2050. This will require new policies and investments as well as careful attention to the social and economic trade-offs involved. It will also require participation and commitment by government, industry, and individuals. Additional innovation can further improve technology solutions and reduce the costs.
