3 questions to Jonathan B. Wiener

Published on 21 June 2017

3 questions to Jonathan B. Wiener

Jonathan B. Wiener, Perkins Professor of Law, Environmental Policy and Public Policy at Duke University, member of the Scientific Committee Climate Economics Chair (CEC).


  • Do we know when the American withdrawal of the Paris agreement will take place?

    On June 1st, President Trump announced his decision to withdraw the US from the Paris Agreement.  But the Paris Agreement itself requires 3 years after it entered into force (on 4 November 2016), plus another year of notice, before a country may withdraw.  So a US withdrawal would not be legally effective until 4 November 2020 at the earliest.  (Under US law, withdrawal from this type of international agreement is largely up to the President, so it is unlikely that Congress or the courts could change the decision to withdraw.)  Meanwhile, the announced withdrawal is a signal that the Trump administration is also seeking to change US domestic policy, by relaxing regulations on sources of greenhouse gases such as coal-fired electric power plants and gasoline (petrol) burning vehicles.

  • Can the role of the EPA in the regulation of greenhouse gas emissions evolve under Trump administration?

    The policies of the US Environmental Protection Agency (EPA) can change under a new presidential administration, as they have after past elections.  The President appoints the EPA Administrator, and the White House oversees EPA’s budget and regulatory policies.   But such policy changes may be limited by legal rules.   Rescinding or revising a past agency rule requires going through the administrative process again, which can take several years and can be challenged in court.  Generally, under US administrative law, a federal agency cannot simply change a past regulation, but must give good reasons for a significant change.   Moreover, the US Supreme Court held in 2007 that the Clean Air Act does cover greenhouse gases, so even if EPA now rescinds its Clean Power Plan (issued in 2015, but currently tied up in litigation), EPA will still be obligated to address greenhouse gases under some other provision of the Clean Air Act (this too could take several years) — unless Congress amends the Clean Air Act to prevent such regulation.

  • Is the question of a federal carbon tax definitively buried?

    A US carbon tax may be gaining some support, but its success is still a large challenge.  In 2010, the Waxman-Markey bill (proposing a cap-and-trade system) passed the US House, but failed to reach a vote in the US Senate.  After that, and following a 2007 Supreme Court decision, the Obama administration used executive action by federal agencies notably EPA (acting under the Clean Air Act and other laws) to try to reduce emissions.  Now, some Republican former officials are proposing a swap, in which Congress would enact a federal carbon tax while also undoing EPA’s climate regulations.  But it’s difficult to say how likely the enactment of such a law might be.