Achieving net zero – and even negative – carbon emissions is surprisingly doable and affordable

New analysis provides a detailed plan for the United States to become carbon neutral by 2050.

To achieve net zero carbon dioxide emissions from energy and industry by 2050, it is possible to rebuild America’s energy infrastructure to run primarily on renewable energy, at a net cost. about $ 1 per person per day, according to a new study released by the Department of Energy. Lawrence Berkeley National Laboratory (Berkeley Lab), University of San Francisco (USF), and consulting firm Evolved Energy Research.

Researchers created a detailed model of the entire US energy and industrial system to produce the first comprehensive, peer-reviewed study of how to achieve carbon neutrality by 2050. According to the Group d intergovernmental experts on climate change (IPCC), world must reach zero net CO2 emissions by mid-century to limit global warming to 1.5 degrees Celsius and avoid the most dangerous impacts of climate change.

Researchers have developed multiple feasible technological pathways that differ significantly in remaining fossil fuel use, land use, consumer adoption, nuclear power, and biofuel use, but share a key set strategies. “By methodically increasing energy efficiency, switching to electric technologies, using clean electricity (especially wind and solar power) and deploying a small amount of carbon capture technology, the United States can achieve zero emissions ”, write the authors in“ Carbon Neutral Pathways for the United States ”, recently published in the scientific journal AGU Advances.

Transform infrastructure

“Decarbonizing America’s energy system is fundamentally a transformation of infrastructure,” said Margaret Torn, senior scientist at the Berkeley Lab, one of the study’s lead authors. “This means that by 2050, we need to build many gigawatts of wind and solar power plants, new transmission lines, a fleet of electric cars and light trucks, millions of heat pumps to replace furnaces and heaters. water, and more energy efficient buildings – while continuing to research and innovate new technologies. “

In this transition, very little infrastructure would need “early retirement” or replacement before the end of its economic life. “No one is asking consumers to replace their brand new car with an electric vehicle,” Torn said. “The point is, efficient, low-carbon technologies must be used when replacing current equipment.”

The sectors studied have net costs ranging from 0.2% to 1.2% of GDP, with higher costs resulting from certain compromises, such as limiting the area of ​​land allocated to solar and wind farms. In the least expensive sectors, around 90% of electricity production comes from wind and solar energy. One scenario showed that the United States can meet all of its energy needs with 100% renewable energy (solar, wind and bioenergy), but it would cost more and require more land use.

“We were pleasantly surprised that the cost of transformation is lower today than in similar studies we conducted five years ago, even though it allows for a much more ambitious reduction in carbon emissions,” said Torn. “The main reason is that the cost of wind and solar power and batteries for electric vehicles has fallen faster than expected.”

The scenarios were generated using new energy models complete with details of energy consumption and production – such as the entire US building stock, vehicle fleet, power plants, etc. – for 16 geographic regions in the United States. Costs were calculated using projections for fossil fuels. and renewable energy prices from DOE’s Annual Energy Outlook and NREL’s Annual Technology Baseline Report.

The costs would be even lower if they included the economic and climatic benefits of decarbonizing our energy systems. For example, less dependence on oil will mean less money spent on oil and less economic uncertainty due to fluctuations in oil prices. Climate benefits include the avoided effects of climate change, such as extreme droughts and hurricanes, avoided air and water pollution from the burning of fossil fuels, and improved public health.

The economic costs of the scenarios are almost exclusively investment costs linked to the construction of new infrastructure. But Torn points out that there is an economic benefit to this spending: “Anything that this infrastructure builds equates to jobs, and potentially jobs in the United States, as opposed to sending money overseas for buy oil from other countries. There is no doubt that it will take a well thought out economic transition strategy for industries and communities based on fossil fuels, but there is no doubt that there are many jobs in building an economy. low carbon emissions.

The next 10 years

An important finding from this study is that the actions required over the next 10 years are similar regardless of the long-term differences between the courses. In the short term, we need to increase the production and transmission of renewable energy, ensure that all new infrastructure, such as cars and buildings, are low-carbon, and maintain the current capacity of natural gas for the time being for the future. reliability.

“This is a very important discovery. We don’t need to have a big battle now on issues like the short-term construction of nuclear power plants, because new nuclear in the next ten years doesn’t need to be on a net emissions trajectory. zero. Instead, we should be adopting policies to drive the steps we know are needed now, while accelerating R&D and further developing our options for the choices we need to make from the 2030s onwards, ”the author said. Study Principal Jim Williams, Associate Professor of Energy Systems Management. at USF and a scientist affiliated with the Berkeley Lab.

The negative net case

Another important achievement of this study is that this is the first published work to give a detailed roadmap on how the US energy and industrial system can become a source of negative CO2 emissions by the middle. of the century, which means more carbon dioxide is removed from the atmosphere than added.

According to the study, with higher levels of carbon capture, biofuels and electric fuels, the US energy and industrial system could be “net negative” to the tune of 500 million metric tons of CO2 removed from the atmosphere each. year. (This would require more power generation, land use, and interstate transportation.) The authors calculated that the cost of this net negative path was 0.6 percent of GDP – barely more than the cost of the main carbon neutral route of 0.4% of GDP. “It’s affordable for society just for energy reasons,” said Williams.

Combined with the increase in CO2 uptake by land, primarily by changing agricultural and forestry management practices, the researchers calculated that the net negative emissions scenario would put the United States on the right track with a trajectory global goal to reduce atmospheric CO2 concentrations to 350 parts per million (ppm) some distance in the future. The 350 ppm endpoint of this global trajectory has been described by many scientists as what would be needed to stabilize the climate at levels similar to pre-industrial times.

Reference: “Carbon-Neutral Pathways for the United States” by James H. Williams, Ryan A. Jones, Ben Haley, Gabe Kwok, Jeremy Hargreaves, Jamil Farbes and Margaret S. Torn, January 14, 2021, AGU Advances.
DOI: 10.1029 / 2020AV000284

The study was supported in part by the Sustainable Development Solutions Network, a United Nations initiative.