Today, President Biden announced that the United States would pledge to reduce its greenhouse gas (GHG) emissions by at least 50 percent by 2030, compared to a 2005 base year.  While his administration has been vague on how to achieve that target, our analysis indicates that it would require steep, aggressive annual reductions over the course of the decade that would be unparalleled in U.S. history.

What a 50% reduction looks like

The GHGs implicated in climate change are primarily carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases, like hydroflourocarbons. While the Biden Administration plans to reduce non-CO2 emissions as part of its nationally-determined contribution (NDC) under the Paris Agreement, the greatest focus will be on energy-related CO2 emissions, which account for 80 percent of U.S. greenhouse gases.

In 2005, President Biden’s baseline year, U.S. energy-related CO2 emissions stood at roughly 6.0 gigatons (Gt). So to meet his goal, America would need to reduce our CO2 emissions by 3.0 Gt within 8 years. Last year, U.S. carbon dioxide pollution fell by a sharp 11 percent, largely due to the societal and economic disruptions caused by efforts to contain the COVID-19 pandemic. This year, U.S. CO2 emissions are tracking a rebound, with estimated levels of 4.8 Gt expected by December 31.

To reach 3.0 Gt by the beginning of 2030, the United States would need to cut, on average, 0.225 Gt in energy-related CO2 each year to halve its emissions, compared to 2005.  If the intended target is the end of 2030, we would have to cut an average of 0.2 Gt of CO2 each year.

A pessimistic track record

The only times we have managed to reach that level of emissions reductions were during the COVID-19 pandemic last year and during the Great Recession in 2009. Otherwise, the U.S. has never reduced emissions by that much in a single year. Assuming that the Biden Administration would prefer to grow and not shrink the U.S. economy, if we only look at years where the U.S. economy grew since 2005, the U.S. has achieved an average emissions reduction rate of 0.055 Gt per year, a far cry from the 0.225 Gt annual reduction needed to achieve the Biden target.

The adoption curve

We are skeptical that the Biden administration’s 2030 target can be achieved without serious, significant costs to the U.S. economy, shifting our own carbon emissions to other countries with less stringent regulation, and widescale job destruction.  Even if the Biden administration and Congress adopted an ambitious climate mitigation agenda through regulation and legislation, it would take at least several years for those emissions reductions to be realized, suggesting that that in order to make up for what is sure to be a slow start in reducing CO2, a reduction rate of much greater than 0.225 Gt per year would be required as we approach 2030 – perhaps even greater reductions than those we experienced under COVID-19.  Further, according to the emission abatement curve, as each ton of emissions becomes more difficult to abate than the last, the cost associated with that abatement goes up. Even though the proposed emissions reduction target is roughly double the United States’ pledge under President Obama, the anticipated costs would be more than double.

Reputational risks

While we support continued U.S. leadership in reducing GHGs and a return to robust engagement in international climate discussions, we find that such a target risks further undermining the global community’s trust in the United States.  We fear that driving an international agenda that is not based on facts, and without broader political endorsement beyond the administration, may do more harm than good as the U.S. commitments will be viewed with skepticism on their achievability and endurance, and fail to induce reciprocation from foreign emitters.

The scale of the challenge facing the global community is substantial.  The United States should drive an international innovation agenda focused on reducing the costs of clean technologies so that they will be adopted by developing economies, which are not willing to pay the “green premium” that richer countries can afford.   The United States, in coordination with its close allies and partners, should also work to ensure that China reduces its GHG emissions now – instead of giving China, which has roughly double U.S. annual emissions, a free pass to further increase its emissions for the remainder of the decade.

A better solution, from the Constitution

For the United States to be a reliable partner in global climate conversations, we urge the development of a national consensus on climate change, including our approach to the Paris Agreement.  Our nation is currently an outlier amongst representative democracies in that our legislature has no role in helping shape the U.S. pledge under Paris.

The Constitution invests in Congress the power to legislate, ensuring that those who represent and are directly accountable to the people are responsible for codifying the decisions most likely to impede upon our fundamental rights and freedoms. Although the Founding Fathers did not likely contemplate climate change when establishing our great republic, by assigning Congressional responsibility over budgeting and appropriations, and through enumerated powers such as the War Powers clause, the framers made it quite clear that American democracy demands a strong decisionmaking voice for the people over matters that can so dramatically change our way of life and our international standing.

With that understanding, legislation such as the recently introduced H.R. 2578 Paris Transparency and Accountability Act seeks to give Congress a voice and provide greater clarity to the American people and the international community on how the United States plans to achieve climate goals like its Paris Agreement pledge.