Removing excess carbon dioxide from the atmosphere is a critical step in tamping down global temperature rise and meeting the Paris Agreement's long-term temperature goal, energy experts told Congress on Tuesday.
Experts from the U.S. Department of Energy, energy research centers and consulting firms, and the educational system testified at a hearing before the Senate Committee on Energy and Natural Resources. The panel sought information on the development of large-scale carbon dioxide management technologies in the United States.
"It is now becoming clear that technologies to permanently remove carbon dioxide from the air and the ocean are not only real, but they are needed," Chairwoman Lisa Murkowski, R-Alaska, said. "They're certainly worth pursuing when coupled with the increased deployment of low- and zero-emission technologies."
Sen. Joe Manchin, D-W.Va., said carbon dioxide removal is critical to achieve net-zero emissions because it is not feasible to eliminate all human-caused sources of greenhouse gas over the next few decades.
"Technologies that reduce or avoid further emissions, including renewables nuclear, carbon capture and storage must be advanced aggressively, together with carbon dioxide removal options, to make the net-zero goal possible," he said.
The Paris Agreement -- which President Donald Trump withdrew the United States from -- targets net-zero emissions by 2050. Some state governments and major companies in the United States are promoting net-zero emission targets to rapidly reduce greenhouse gas emissions by the middle of this century. S. Julio Friedmann, a senior research scholar at the Center for Global Energy Policy at Columbia University, said net-zero means that any residual carbon dioxide emissions must be balanced by removal.
"Any carbon taken from the earth must be returned to the earth. It must go back to the geosphere," Friedmann said. "We need all approaches, both engineered systems as well as the work in managed ecosystems."
According to a study from the U.S. National Academies, constraining global warming prudently will require a ramp up to 10 gigatons of carbon dioxide removal by mid-century. Steven Winberg, the assistant secretary for fossil energy at the U.S. Department of Energy, said the necessity of carbon dioxide removal is highlighted by the power sector, as well as other sectors that are harder to decarbonize, including transportation, industry and agriculture.
He added that scientists separate the approaches to carbon dioxide removal into three major categories: natural, such as forestation; technology, such as direct air capture; and technologically enhanced natural, such as the development of new cultivars with deep root systems.
"The CDR innovation program needs to be supercharged starting now if we got to have the necessary optionality in time," Winberg said.
The Section 45Q tax credit helps increase deployment of carbon capture projects in the United States, reducing the costs and risks to private capital of investing in the deployment of carbon-capture technology across a range of industries. On May 28, the Department of the Treasury and Internal Revenue Service issued proposed regulations for Section 45Q. However, the finalized guidance from the Department of the Treasury still has not come out, increasing uncertainty to the rule.
Winberg said the Department of Energy will work with the IRS on the final rulemaking in the future.
"I can commit to you that we will do everything that we can to assist IRS, not only to make sure that the rule accommodates projects, but does it as expeditiously as possible," Winberg said.