Skip to main content

Could the United States Fall Short of Its Emissions Reduction Pledges?

The United States has acceded to the Paris Agreement, but the country’s current climate policies may not be enough to ensure the the emissions giant meets its pledged cuts by 2025.

By Kate Wheeling


Buildings are cloaked in dirty air shortly after sunrise in Los Angeles, California. (Photo: David McNew/Getty Images)

Earlier this month, the United States and China — the two biggest greenhouse gas emitters in the world — announced that they would officially ratify the Paris Agreement on climate change. Nearly 200 countries agreed to the deal last year, which would commit governments to limiting global temperature increases to 1.5 degrees Celsius above pre-industrial levels. But to actually take effect, at least 55 countries accounting for 55 percent of global carbon emissions have to ratify the agreement.

“We have a saying in America that you need to put your money where your mouth is,” President Barack Obamasaid in a statement at Hangzhou’s West Lake state guesthouse, according to the Guardian. “And when it comes to combating climate change that is what we are doing … we are leading by example.” On the heels of Obama’s announcement, several more countries began the ratification process (including 31 countries in a single day last week), bringing the total number up to 60 and accounting for 47.76 percent of global emissions — nearly enough to bring the agreement into force.

But ratifying the agreement is only the first step. Now, to truly “put out money where our mouth is,” the U.S. needs to meet the emissions cuts pledged—26 to 28 percent below 2005 levels by 2025. In one of the most thorough analyses of existing and planned U.S. climate policies to date, a team of researchers from the Lawrence Berkeley National Laboratory found that the climate policies currently in place may not be enough to meet those targets.

In the study, published today in Nature Climate Change, the team looked at 17 policies across three categories — passed legislation, proposed legislation, and potential or voluntary measures (state-level strategies, for example, that have not been formally proposed on a federal level, but that the nation might someday pursue) — and used the most up to date measurements of energy use and emissions to estimate the likelihood of success.

“I’m optimistic, under the condition that the administration maintains its focus and its commitment to really lowering emissions.”

By 2025, the U.S. has promised to cut emissions equivalent to between 4,553 and 5,478 million tons of carbon dioxide (MtCO2e). But with only the existing legislation, the U.S. will miss the mark by 551 to 1,805 MtCO2e. (For perspective, the average American driver adds roughly one metric ton of CO2 to the atmosphere every two months.) Even if all the proposed legislation is passed, the U.S. may still miss the target by 340 to 1,586 MtCO2e. But if the third category of policies is included, the U.S. has a shot at reaching emissions that are 26 percent below 2005 levels. The predicted emissions under such a scenario range from 356 MtCO2e below the upper limit for 2025 to 924 MtCO2e above it. This means the more measures the U.S. embraces to cut emissions, the better.

And there are plenty to choose from, according to the authors. Transportation policies that favor electric vehicles or even self-driving cars, for example, could someday lower emissions; in the energy sector, an increased focus on biofuels or hydrogen production could do the same; and in agriculture, slow release fertilizers could reduce nitrous oxide emissions.

“I’m optimistic, under the condition that the administration maintains its focus and its commitment to really lowering emissions,” says Jeffrey Greenblatt, a staff scientist at the Lawrence Berkeley National Laboratory, and lead author on the new paper. “We cant sit on our laurels. I think that it’s eminently doable, but its going to require additional policies, additional technologies, and the cooperation of the business community to embrace some of these changes.”

Any number of these emissions mitigation measures could come into play before 2025. “It’s a moving target. The policy landscape is evolving very quickly,” Greenblatt says. Just in the time since the paper was submitted for publication, several proposed policies became law: For example, heavy-duty vehicle standards and methane emissions standards for the oil, gas, and landfill industries were finalized this summer. It’s good news for Greenblatt that more of the policies previously under consideration are now codified, but it doesn’t change the results of the study, which included those potential policies. “If you add it all up we’re still in a situation where we need some additional policies to get all the way to the 2025 target,” he says. “But we’re getting closer.”