Climate change is a global challenge and requires a global solution. Through analysis and dialogue, the Center for Climate and Energy Solutions is working with governments and stakeholders to identify practical and effective options for the post-2012 international climate framework. Read more


Projecting and Accelerating U.S. Greenhouse Gas Reductions

Projecting and Accelerating U.S. Greenhouse Gas Reductions

September 2017

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More than 190 nations representing more than 95 percent of global greenhouse gas emissions offered “nationally determined contributions” (NDCs) to the Paris Agreement reached in December 2015. The NDC submitted by the Obama administration on behalf of the United States is an economy-wide target to reduce net greenhouse gas emissions 26 to 28 percent below 2005 levels by 2025. The Trump administration is now weighing whether to “suspend, revise, or rescind” policies to help meet this goal, and has announced its intent to withdraw from the Paris Agreement. President Trump has also suggested the possibility of “re-entry” under revised terms; one option may be a recalibrated U.S. NDC. Analyses suggest that even with some key climate policies rolled back, U.S. emissions in 2025 could range from 14 percent to 18 percent below 2005 levels. In the absence of additional federal policy, stronger action by states, cities and companies can help reduce emissions further. The brief looks at progress in reducing U.S. emissions, how existing and proposed policies may affect emissions through 2025, and additional steps that can achieve stronger reductions.

Doug Vine
Doug Vine

America’s Pledge can drive and tally U.S. climate action

Today, Gov. Jerry Brown and Michael Bloomberg are launching America’s Pledge—an initiative to compile and quantify the actions of U.S. states, cities and businesses to drive down their greenhouse gas emissions consistent with the goals of the Paris Agreement.

America’s Pledge will for the first time aggregate and quantify the commitments of these “non-state actors,” demonstrating to the international community that U.S. climate resolve remains strong despite President Trump’s decision to withdraw from Paris.

The ambitious initiative also will provide a roadmap for increased ambition, outlining steps these groups can take to further reduce their emissions.

Since the president’s announcement, an unprecedented number of U.S. states, cities, and businesses have affirmed their support for the landmark climate deal, including through the “We Are Still In” declaration signed by more than 1,500 businesses, nearly 200 cities and counties, nine states, and over 300 universities. 

This enthusiasm for climate action is as yet unquantified, but it’s vast and varied and growing every day:

  • Just this week, California Gov. Jerry Brown and legislative leaders released a plan to extend through 2030 California’s cap-and-trade program. The program marshals market forces to motivate investment in low-carbon solutions, drive innovation, create jobs, and cut emissions cost-effectively.
  • Also this week, Colorado announced it will be the 14th state in the newly formed U.S. Climate Alliance, whose members together represent over a third of the U.S. population and GDP. The states are committed to the U.S. meeting its Paris target of reducing emissions 26 to 28 percent from 2005 levels by 2025.
  • More than 350 Climate Mayors have adopted the Paris Agreement goals for their cities. And more than 100 U.S. cities both large and small have pledged to transition their communities to 100% clean energy.
  • About two-thirds or more of mayors who responded to a recent survey by C2ES and The U.S. Conference of Mayors said they generate or buy renewable electricity to power city buildings or operations, buy green vehicles for municipal fleets, and have energy efficiency policies for municipal buildings. And they want to partner with the private sector do more.

Why transparency makes the Paris Agreement a good deal

Listening to some of the reasons President Trump cited for his decision to withdraw from the Paris Agreement – how it undermines national sovereignty while other countries do “nothing” – I found myself wishing someone had done a better job explaining to him how the agreement actually addresses his very concerns through increased transparency.

I saw this kind of transparency at work two weeks earlier, at the U.N. climate talks in Bonn, Germany, where countries, including the United States and India, took turns explaining to the international community the steps they’re taking to address climate change.

One of the Paris Agreement’s few binding commitments is for parties to report and be reviewed on their progress toward their climate targets. Under the two existing arrangements that will serve as a model for the new transparency rules being developed under the Paris Agreement, countries report every two years, providing information on emissions and on progress toward their climate goals. These reports are reviewed by a team of experts, and reporting countries undergo “peer review.” Other countries can pepper them with questions about their report, first in writing, then in a publicly broadcast session for all to hear.

In Bonn, 29 countries were up for peer review, including Mauritania, the first least developed country to go through the process. These countries publicly answered questions about the steps they are taking to reduce their greenhouse gas emissions and build resilience.

India served as a particularly rich example of the benefits of this “facilitative sharing of views,” as the process for developing countries is called. President Trump suggested that India would take action only upon receiving “billions and billions and billions” of foreign aid. But with the cost of solar power plummeting, India boasts an impressive array of ambitious solar and other renewable energy targets and policies aimed at reducing poverty and expanding access to electricity. Developed and developing countries alike were curious to know how India advanced renewable energy policy in such a short timeframe and how its federal government works with local governments and the private sector to reduce emissions and implement policy.

The United States presented at the “multilateral assessment” for developed countries. A crowded room, while eager to hear how the new administration’s policies would affect U.S. emissions, responded respectfully as the lead U.S. negotiator reiterated that current and future climate policies were under review – no other countries, as the president imagined in his Rose Garden speech, were laughing.

The Paris Agreement

Negotiators gather for COP 21 in Paris, December 2015. Image courtesy of the UNFCCC, via Flickr.

The Paris Agreement strengthens the global climate effort by requiring all countries to set climate goals and by establishing new mechanisms to hold countries accountable and to build ambition over time.

The agreement was reached in December 2015 and entered into force 11 months later.  In June 2017, President Trump announced that the United States would withdraw from the agreement.

A Paris Primer
C2ES answers questions on the talks leading to the Paris climate accord, how the agreement works, key legal issues, the agreement’s status, and next steps.

Summary of the Paris Agreement
A closer look at the core elements, including commitments on emissions, adaptation, finance and transparency, and steps to promote carbon trading.

C2ES Statement on Paris
U.S. leadership and a groundswell of support from mayors, governors and CEOs helped deliver the landmark agreement. 

C2ES Statement on U.S. Withdrawal
The decision to withdraw ignores the many U.S. business leaders – and the strong majority of Americans – who want the United States to stay in the Paris Agreement. 

Business Support for Paris
Leading U.S. companies organized by C2ES signed a letter to President Trump and full-page ads in major newspapers urging him to keep the United States in the agreement.

Toward 2015 Dialogue
C2ES brought together top negotiators from two dozen countries for a series of in-depth discussions that forged common ground on key issues for Paris.

COP 21 Initiatives
A sampling of the many initiatives launched at the Paris Climate Conference by companies, city, state and local governments, and other non-state actors.

Additional Resources:

C2ES Policy Briefs:

Elliot Diringer briefs the Business Roundtable and members of the C2ES Business Environmental Leadership Council on the Paris Agreement

Can the Paris deal be renegotiated?

As eager as President Trump seemed to be to denounce and bolt from the Paris Agreement, he also appeared eager to project a willingness to re-engage. Three times in his speech yesterday in the Rose Garden, he declared an openness to renegotiating the landmark climate agreement or negotiating a new deal “that’s fair.”

It’s hardly clear what the president might have in mind, but let’s consider some of the options.

First, it’s far-fetched to think that other countries are so desperate for the United States stay in that they’re going to shred the Paris Agreement. The agreement is a sensible approach to an urgent challenge, which is why it’s been universally embraced – and universally reaffirmed -- despite Trump’s skepticism.

Other countries would much rather that the U.S. stay in, but they’ve grown weary of accommodating the vagaries of U.S. climate politics. The Paris Agreement, like the Kyoto Protocol before it, was designed largely to U.S. specifications. And in both cases, after getting what it wanted, the U.S. still walked away.

As France, Germany and Italy made clear within hours of the president’s speech, the basic terms of the agreement are not open for renegotiation.

As for a new agreement, if it’s meant as an alternative to Paris, forget it. On the other hand, if the president wants to structure some kind of side deal that would bring the United States back into Paris, other countries may be prepared to listen. Such a deal could, for instance, ramp up international support for clean energy technologies.

That’s only viable, though, if the United States brings something to the table. And that doesn’t seem easy if the president is rolling back climate protections, as he’s directed Scott Pruitt at EPA to do, and drastically cutting funds for technology development, as his proposed budget would do.

So what’s left?

President Trump harped repeatedly on the “unfairness” of Paris. One relevant metric is how the U.S. target compares to other countries’ emissions-cutting goals. Another he cited is how much the U.S. spends to support developing countries. Whether or not one accepts his notions of fairness, the reality is that both of these are within his control.

Under the Paris Agreement, every party sets its own emissions goal (or “nationally determined contribution”) and is free to adjust it at any time. While a downward adjustment would hardly be in the spirit of the agreement, it’s an option available to the president, and one way he could say he’s secured a “better deal.”

This option was being actively considered in the White House and, judging from what senior aides told the press after the president’s remarks, doesn’t appear to be off the table. Maybe what we’re seeing is a political calculation that the president can play to his base now by fulfilling a campaign pledge to withdraw, while keeping open the option of “rejoining” later with a lower target.

As for support for developing countries, if the president thinks the Paris Agreement commits the United States (or any other country) to a specific level of funding, he’s misinformed. It doesn’t. It reaffirms a general commitment the U.S. made in 1992 (in the Senate-approved U.N. Framework Convention on Climate Change) to help developing countries address and cope with climate change. But, as with emission reductions, Paris leaves it to each country to decide its level of contribution.

President Obama had earlier pledged $3 billion toward the newly established Green Climate Fund, and delivered a third of that. It’s now up to President Trump and Congress whether the U.S. gives any more, and there’s very little expectation internationally that it will, at least any time soon.

Fairness is a tricky thing and, ultimately, is in the eye of the beholder. A durable deal is feasible only if all governments feel they can defend their commitments as fair both at home and to the international community. Paris works in part because it gives countries the flexibility to calibrate their commitments – and recalibrate them, when necessary – to meet this two-part test.

As far as other nations (and the atmosphere) are concerned, no country bears greater responsibility for climate change than the United States – cumulatively, still the world’s largest greenhouse gas emitter.   Yet President Trump evidently feels some recalibration is in order. If fairness in his eyes is a question of the U.S. target and U.S. support for developing countries, he has the power to adjust both, without leaving Paris. Maybe those are the makings of his “better deal.”


Bob Perciasepe's statement on on climate change discussions at the G7 Summit in Taormina, Italy

Statement of Bob Perciasepe
President, Center for Climate and Energy Solutions

May 27, 2017

On climate change discussions at the G7 Summit in Taormina, Italy:

President Trump is returning to Washington with a much clearer sense of the overwhelming global support for the Paris Agreement.  As he considers next steps, we hope the president pays close attention to the many U.S. business leaders who are telling him that staying in the agreement is good for U.S. jobs, growth and competitiveness.

U.S. emissions are at a 25-year low and the transition toward cleaner energy is well underway.  Cities, states and companies are all stepping up their efforts. We’re confident a balanced and thorough analysis will show that the U.S. can maintain or even strengthen its climate ambition, with significant economic gains.

The Paris Agreement is a sensible global response to a truly global challenge.  Pulling out would undermine the climate effort, damage U.S. relations, and put U.S. companies at a competitive disadvantage.  World leaders, business leaders and a strong majority of Americans think the U.S. should stay in Paris.  President Trump will hopefully arrive at the same conclusion.

To talk to a C2ES expert, contact Marty Niland at


About C2ES: The Center for Climate and Energy Solutions (C2ES) is an independent, nonpartisan, nonprofit organization working to forge practical solutions to climate change. Our mission is to advance strong policy and action to reduce greenhouse gas emissions, promote clean energy, and strengthen resilience to climate impacts. Learn more at

HFO-1234yf: An Examination of Projected Long-Term Costs of Production

HFO-1234yf: An Examination of Projected Long-Term Costs of Production

April 2017

By David Sherry, Maria Nolan, Stephen Seidel, and Stephen O. Andersen

Download the paper (PDF)

This paper seeks to inform the discussion on what the price of HFO-1234yf (2,3,3,3-tetrafluoropropene) might be over the longer term when application and process patents have expired, economy of scale is achieved at production facilities using the most efficient processes, more producers are involved, and a fully competitive global market takes hold. The analysis focuses on the estimated costs of production based on one process currently in use, and a different process at a recently completed facility. We expect that long-term market prices will reflect broader factors of supply and demand. It is also possible over time that new or improved production processes will allow production of HFO-1234yf at lower costs and prices than estimated here.

Stephen O. Andersen
Stephen Seidel

Year Ahead: We must strengthen climate action wherever possible

When I wrote a blog a year ago taking stock of the strengthening climate change effort, I reflected on a year of unprecedented progress, capped by the Paris Agreement, and outlined ways we could build on those successes.

At the beginning of the new U.S. administration, the outlook is unfortunately far different.  Now, our challenge is to preserve as much of this progress as we can, and to devise new strategies to continue strengthening climate action wherever possible.

Despite coming setbacks, it’s worth reminding ourselves that we have a solid base to work from. Thanks in part to strong policies, but also to growing market forces, the U.S. is on the path to a clean-energy transition, and the continued momentum is strong.

A few examples, just since the election:

·      Some of the world’s wealthiest entrepreneurs, including Bill Gates, Richard Branson, and Mark Zuckerberg, launched a billion-dollar fund to invest in cutting-edge clean energy technologies.

The new policy landscape won’t be clear for some time and is likely to evolve. But as we monitor the early signs, and take soundings with policymakers and stakeholders around the country and around the world, we are coming to a clearer view of immediate imperatives, and of opportunities that may lie ahead.

One imperative is ensuring that the United States remains a reliable partner in the global climate effort – by staying in the Paris Agreement, and by working constructively with other countries to establish sound rules for its implementation. 

We were encouraged to hear Secretary of State nominee Rex Tillerson note the importance of the United States staying at the table. Indeed, the Paris Agreement reflects long-standing bipartisan principles. It fully preserves national sovereignty while providing a means of holding other countries accountable. U.S. businesses benefit from full access to the clean energy markets the agreement helps drive.

We were encouraged also to hear EPA Administrator nominee Scott Pruitt express respect for the “endangerment finding” underpinning the regulation of greenhouse gases under the Clean Air Act. What is critical is how EPA chooses to fulfill the inherent legal obligation to regulate emissions, starting with the power sector.

While the Clean Power Plan appears unlikely to survive, decarbonization of the power sector is already underway. Thanks to improved energy efficiency and a more diverse energy mix, emissions dropped more than 20 percent over the last decade. Last year was the third in a row that renewables accounted for more than half of new U.S. power capacity.

Continued tax credits enjoying strong bipartisan support will help sustain that growth.  State-level conversations on lower carbon energy policies are continuing as states, cities and utilities find economic opportunity in modernizing the power sector. But the imperative remains: We need an overarching federal framework to deliver sustained, cost-effective emission reductions. We urge the new administration and Congress to get on with the job.

In the near term, we see opportunities for bipartisan steps that benefit both the climate and the economy and strengthen the foundation for a longer-term clean energy transition. These include:

Incentivizing carbon capture, use and storage.

Carbon capture technologies like those deployed this month in Texas are essential to meeting the climate challenge. Senate Majority Leader Mitch McConnell was among the bipartisan sponsors of a bill last year to help advance these technologies by supporting the use of captured CO2 in enhanced oil recovery, as recommended by a coalition of industry, labor, and environmental groups we help lead. We expect similar legislation in this Congress.

Advancing nuclear energy.

Bipartisan bills have already been introduced in the House and Senate to spur advanced nuclear technologies. Nuclear is our largest source of zero-carbon energy and the only one that provides continuous baseload power. It will have to play a significant role in any realistic long-term climate strategy.

Modernizing our infrastructure.

A viable infrastructure package could open significant opportunities to address climate change while creating jobs and growth. Examples include:

  • A modernized electric grid that can better distribute renewable power and is more climate-resilient.
  • Expanded charging and refueling networks for electric, natural gas and hydrogen vehicles.
  • Roads and bridges that can better withstand more frequent extreme weather.

One reason we’re confident of continued momentum is that the vast majority of the American people support it. In a Yale survey conducted after the election, nearly 70 percent favored staying in the Paris Agreement. And 70 percent – including a majority of Republicans – supported strict carbon limits on existing coal plants.

Business leaders, too, recognize the growing risks of climate impacts, and the opportunities to create new products, services and jobs.

And a growing number of cities are finding they can save money and create jobs by encouraging energy efficiency and clean energy and transportation.

At C2ES, while we are bracing for setbacks, and are prepared to defend against reversing course, we also will continue working as hard as ever to bring diverse interests together to make progress wherever we can. We face significant new challenges. But from the local to the global level, we’ve got strong momentum. And we can’t turn back.


C2ES again ranks among top environmental think tanks

Press Release
January 26, 2017
Contact Laura Rehrmann,

C2ES again ranks among top environmental think tanks

WASHINGTON -- The Center for Climate and Energy Solutions (C2ES) is honored to be recognized once again as one of the world’s leading environmental think tanks.

C2ES ranked fourth among environment policy think tanks in the University of Pennsylvania’s 2016 Global Go To Think Tank Index, based on a worldwide survey of more than 2,500 scholars, academics, public and private donors, policymakers, and journalists.

C2ES was also recently named the top U.S. energy and environment think tank by Prospect magazine for helping lay the groundwork for the Paris Agreement.

“C2ES’s consistently high ranking is a tribute to our unique ability to bring together diverse stakeholders to achieve practical, commonsense solutions,” said C2ES President Bob Perciasepe. “We work with companies, cities, states, and national governments to develop and implement economically sound, innovative policies to reduce greenhouse gas emissions, promote clean energy, and strengthen resilience to climate impacts.”

“I congratulate and thank our outstanding staffers, supporters, partners, and board members, including Board Chairman Ted Roosevelt IV, who have helped C2ES achieve and maintain our success,” Perciasepe said.

This is the 10th year for the University of Pennsylvania’s Think Tanks and Civil Societies Program to rank the world’s 6,846 leading think tanks. According to the report, the top environmental think tanks “excel in research, analysis and public engagement on a wide range of policy issues with the aim of advancing debate, facilitating cooperation between relevant actors, maintaining public support and funding, and improving the overall quality of life.”


About C2ES: The Center for Climate and Energy Solutions (C2ES) is an independent, nonpartisan, nonprofit organization working to forge practical solutions to climate change. Our mission is to advance strong policy and action to reduce greenhouse gas emissions, promote clean energy, and strengthen resilience to climate impacts. Learn more at

International Intern


Center for Climate and Energy Solutions, Arlington, VA  

The internship provides the ideal candidate the opportunity to work with the International team. This team works with governments and stakeholders to identify practical and effective options for an international climate framework. C2ES engages with international policymakers in the United States and other key countries; regularly convenes informal discussions among climate negotiators; and organizes conferences, workshops, and briefings on international climate policy developments. Prior to being hired, the selected candidate must be able to provide proof of academic credit or funding from an accredited college, university, or third party for research. Funding must cover at least minimum wage.

Major Responsibilities:

  • Support C2ES’s informal discussions, workshops, briefings, etc.;
  • Contribute as needed to research and analysis of international climate policy issues;
  • Maintain and improve content of international portions of the C2ES website; and
  • Contribute as feasible to C2ES blog and publications.


  • Bachelor’s degree or higher in environmental policy or related fields, with focus on international issues; Masters level student preferred;
  • Familiarity with international environmental agreements, particularly the United Nations Framework Convention on Climate Change;
  • Top-notch writing, editing, research, and analytic skills; journalism/advanced writing skills a plus;
  • Attention to detail;
  • Willingness to learn and pitch in at all levels.

Status: Part-time/Full-time internship

About the Center for Climate and Energy Solutions: C2ES is an independent, nonpartisan, nonprofit organization working to forge practical solutions to climate change. Our mission is to advance strong policy and action to reduce greenhouse gas emissions, promote clean energy, and strengthen resilience to climate impacts. A key objective is a national market-based program to reduce emissions cost-effectively. We believe a sound climate strategy is essential to ensure a strong, sustainable economy.

C2ES is the successor to the Pew Center on Global Climate Change, and is widely recognized as an influential and pragmatic voice on climate issues. We are:

•    A Trusted Source – Ranking regularly among the top environmental think tanks in the world, C2ES provides timely, impartial information and analysis on our pressing climate and energy challenges.

•    A Bridge-Builder – We bring city, state, and national policymakers together with businesses and other stakeholders to achieve common understanding and consensus solutions.

•    A Policy Innovator – We develop market-based solutions and other practical policy approaches that deliver real and lasting climate progress.

•    A Catalyst for Business Action – We work with Fortune 500 companies to strengthen business action and business support for effective climate policy.

For more information about the C2ES visit

To apply - send cover letter, resume, and writing sample to:

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