Trump pulls out of Paris Agreement – Expert Reaction

News this morning that US President Donald Trump has decided to pull the USA out of the Paris Agreement was widely anticipated.

The USA was one of 195 countries to sign on to the historic agreement, which former President Barack Obama was instrumental in brokering. Trump called the agreement a deal that “hamstrings” the USA while empowering “top polluting countries”.

The SMC asked climate change experts to comment on the implications of the USA exiting the Paris Agreement. Please feel free to use these comments in your reporting.

Our colleagues at the Australian SMC also gathered extensive reaction, which is available on

Professor James Renwick, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, comments:

“My take is that this is a backward step, but it’s hardly game over for the Agreement or for climate change. The US could stay in and do nothing, which would be as unhelpful as pulling out.

“The US stepping away from Paris hands the opportunity to China, the EU, and others, to take the lead and this is already happening. I understand China is already developing an agreement with the EU to push harder on emissions reductions.

“Plus, the President and Washington is not the USA. Individual cities and states are doing their own thing. The Governor of California has already signalled that he’s looking internationally for partners to push emissions reductions.

“So, Trump pulling out may just encourage the rest of the world to do more. The US is pulling back from global leadership and other nations will step in to take over. This move may, in fact, signal the start of China’s real dominance of international affairs.

“Climate change is an incredibly pressing problem. If we are to live up to the Paris Agreement, the global community has somewhere between 5 and 20 years to move on significant emissions reductions. Every nation must strive to lead on this issue, and if the US isn’t there, New Zealand and other countries must step up.”

Prof. Renwick also wrote a piece for The Spinoff.

Associate Professor Bronwyn Hayward, political scientist, University of Canterbury, comments:

“It feels surreal to be listening to Trump’s announcement as I am packing to leave tonight for the author meeting on the Special Report for the IPCC about how to achieve the objectives agreed in Paris to limit global warming to 1.5C above pre-industrial levels.

“I was simply shocked to hear Trump describe a 2 degrees climate rise as “tiny, tiny” amount because a global rise of 2 degrees translates to much higher local temperature changes and changes beyond 2 degrees risks dangerous climate events

  • The Announcement is no surprise – Trump signalled he intended to pull out of the agreement.
  • What is a surprise is how long it took and that Trump has had to leave the door open for his re-entry into the Paris Agreement
  • This decision has taken a very long time and is so equivocal because it is not one that is well supported even amongst his own core vote base. This is why Trump is working so hard to make climate change seem a ‘foreign’ economic threat
  • Despite the deeply partisan political divisions in the USA, a detailed poll this month by Yale University of Americans’ attitudes to climate change revealed only 1 in 5 US voters now support withdrawing from the Paris Agreement and less than a third, just 28% of Trump’s own vote base agrees America should leave the climate agreement

“USA withdrawal also creates significant new problems for the President, which is why he has keep the door open

  1. First are political challenges; the withdrawal of Trump will create a political vacuum which China and EU is already stepping into as new global leaders in technology- there is also significant risk of political isolation of USA. Tillerson’s visit to NZ for example reminds us that the USA needs it’s international allies, but by putting ‘America First’ also reminds domestic populations in the rest of the world that is what is good for America is not necessarily good for their own countries and this will make it harder for other governments to forge alliances with an unpopular USA administration.
  2. Second, the President’s decision creates significant industry challenges. There is no evidence that there will be new jobs created by the old industries, while other significant business leaders of new industries, including Apple, will be very frustrated at changes to US regulations for new investment in clean technology. We can also expect intense lobbying now from some sectors to destabilise the wider global climate agreement by arguing that without USA ‘what is the point?’. However, while the USA makes up about 26% of total global emissions, what the rest of the world does will now matter very much. We can also expect to see intense lobbying from geoengineering sector to position experimental industries like large-scale carbon capture and storage.
  3. Third, this creates  significant leadership challenges for the President as the leadership vacuum allows space for a new generation of younger world leaders and city and state governments to position themselves as offering new vision,  and many like the state of California are already significant global leaders in addressing climate change.”

Dr Hayward is a lead author on the IPCC 1.5C report, but is commenting in her personal capacity.

Dr Adrian Macey, senior associate, Institute for Governance and Policy Studies, Victoria University of Wellington, comments:

“There are two ways to ‘leave’ the Paris Agreement:

  • Formal withdrawal – this would be the ‘nuclear’ option.  It would be seen as a hostile act.  Under the Agreement the process could take 4 years.
  • Change or suspend the NDC (nationally-determined contribution) which is what Trump claims is an unfair burden on the economy. He could change this, as it is not legally binding.  This would mean that a future administration could simply renew/revise the US contribution and restart cooperation.

“The loss of the US would be damaging, for sure, for four reasons:

  • As the world’s second largest emitter, without it, staying within the 2 Degrees target would be much harder, if not impossible
  • It could give an excuse to other countries not to stick to their targets
  • It would signal an end to the leadership of the “G2” (US and China) whose cooperation was essential in getting the Paris Agreement.
  • If it were followed by pulling money out of climate change more widely, it might call into question the very valuable and world-leading research being done in the US eg. by NASA with its various satellite-based research projects.

“And of course, it would mean a huge loss of influence for the US.

“BUT there are mitigating factors:

  • There is already a global shift towards renewable energy (the core of the climate change challenge), quite independent of any international agreements. The economics are changing rapidly, and there are additional benefits in jobs and innovation.  Coal is unprofitable in the US for simple economic reasons, nothing to do with climate change.
  • Other countries are signalling that a US withdrawal won’t lessen their commitment to the Paris Agreement
  • Powerful US states such as California will continue their climate change policies.
  • Major US businesses, even oil companies are moving to address climate change in their long-term plans.
  • China has signalled it intends to retain its global leadership role, and the EU will be keen to step into the gap left by the US – they have been less influential in recent years.

“So …. unfortunate, and a setback but no need to despair.”

Our colleagues at the UK SMC also gathered expert comment on the decision.

Dr Emily Shuckburgh, Darwin College, University of Cambridge, said:

“President Trump’s decision directly affects us, our children and grandchildren here in the United Kingdom. That is because every gramme of carbon dioxide emitted through the activities of an American or anyone else contributes to climate change. The threat this decision poses for our future health, wealth and security is absolutely clear. We can only hope, for the sake of all global citizens, that the promised renegotiation recognises the scale and urgency of the climate challenge.”

Prof Myles Allen, Professor of Geosystem Science at the Environmental Change Institute, University of Oxford, said:

“Withdrawing and then re-entering the Paris Agreement under different terms would, in effect, be identical to revising the US ‘nationally determined contribution’ — something the Agreement specifically allows. But following this extended drum-roll, that would have been a bit of an anticlimax. Once the theatrics are over, much will depend now on how the rest of the world responds to this proposal to ‘renegotiate’ the terms of US participation. If we really want to put the future of the planet first, we need to be thinking hard about how to make the Agreement both more effective and more acceptable to nations with substantial fossil reserves — or the US won’t be the last one to be taking this step.”

Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science, said:

“President Trump’s speech was confused nonsense. He announced that the United States will withdraw from the Paris Agreement on climate change, while also launching negotiations to re-enter the Agreement. But the Agreement states that no country can withdraw within three years of it coming into force, and the process of withdrawal takes a further year to complete. That means the United States cannot complete withdrawal from the Paris Agreement before 5 November 2020, the day after the next Presidential election in the United States. So Mr Trump will not have withdrawn from the Agreement within this Presidential term.

“Furthermore, in making his case for withdrawal, President Trump cited a number of bogus sources, including a fundamentally flawed study by NERA Economic Consulting from March 2017 that calculated the costs of the United States implementing its targets under the Agreement while making many unrealistic assumptions, such as every other country ignoring their targets, and no development of electric vehicles to replace those fuelled by gasoline. And, as his chief economic adviser has warned the President, withdrawal from the Paris Agreement will not save the coal industry in the United States, which is being put out of business by cheaper sources of electricity, particularly shale gas and renewables.”

Prof Venki Ramakrishnan, President of the Royal Society, said,

“This represents a significant and worrying foreign policy break with the vast majority of nations who recognise the risks and are signed up to the Paris Agreement. That agreement was itself the result of a consensus of the world’s leading climate experts.

“America was built on looking to the future and investing in science and innovation has always been a big part of that. The future is in newer, cleaner and renewable technologies, not in fossil fuels. Such technologies will also help in our fight against air pollution and ensure greater energy security globally. President Trump is not putting America first, he is tethering it to the past.”

Prof Julienne Stroeve, Professor of Polar Observation & Modelling at UCL, said:

“President’s Trump decision to pull out of the Paris agreement is very short-sighted. It has become increasingly clear that increases in atmospheric greenhouse gases are causing large changes in our climate system, such as the dramatic loss of the Arctic sea ice cover. The impacts of this will be felt worldwide with unpredictable consequences on our weather and livelihoods.”

Piers Forster, Director of the Priestley International Centre for Climate, University of Leeds, said:

“A sad day for evidence-based policy. Scientists have known for over 50 years that human greenhouse gas emissions are causing the world to warm, yet Trump ignores this evidence. My hope is that he is ignored by his own country and that the individual citizens, businesses and states that make up the U.S.A will increase their ambition to decarbonize.”

Prof Peter Cox, Professor of Climate System Dynamics at the University of Exeter, said:

“I always hope that common human interests will win the day, but under the Trump administration I’m not surprised when they don’t. Bad news for the world, but even worse news for the US. This can’t be allowed to stop progress towards a more sustainable world. It just means the US may be left behind”.

Prof Mark Maslin, Professor of Climatology at UCL, said:

“We have entered a world of fear and ignorance – when science and well-being of humanity is ignored by the President of the United States as it does not fit his world view. America is by far the largest historic emitted of greenhouse gases and has prospered greatly from the use of fossil fuels. We now know that the use of fossil fuels has the unintended consequence – climate change.

“The Paris agreement set a new benchmark international cooperation to deal with climate change as a global community – which is to be thrown away because Trump wishes to isolate the US and reinvigorate the American fossil fuel economy.

“This is completely counter to the huge green economy developing in the US and the millions of jobs in that sector.

“It shows a President out of touch with the exciting clean tech innovations and developments in his own country which could lead the world to a greener, cleaner, safer future.”

Prof Paul Ekins, Professor of Resources and Environmental Policy at the UCL Institute for Sustainable Resources, said:

“With Donald Trump as US President it is a fine balance as to whether the world’s efforts to mitigate climate change are better off with or without the US in the Paris Agreement.

“With the US at the table there is a real risk that it would oppose ambitious action by other countries at every turn. Without the US, countries can concentrate on bidding up their emissions reductions and gaining the economic benefits that will flow from implementing new low-carbon technologies.

“At some point US business will realise that it has missed out on a new industrial revolution because of a backward-looking government that is fossilised in the era of fossil fuels. Trump’s decision gifts to Europe and Asia a huge opportunity for global leadership in the energy industries that will matter over the next century.”

Prof Dave Reay, Chair in Carbon Management, University of Edinburgh, said:

“The United States will come to rue this day. President Trump has argued that his decision puts economic interests first, that it will cut out interference from foreign bureaucrats and help US business. In fact this move puts all business and economic interests at much greater risk. Climate change knows no borders, its impacts are blind to national flags. If global efforts to limit warming fail then we are all in trouble. From climate change, Mr President, you can run but you can’t hide.”

Dr Friederike Otto, Deputy Director of the Environmental Change Institute, University of Oxford, said:

“This sends a very bad message to the world that the current American president is not interested in doing what is right for people, in particular the young and less wealthy in America and the rest of the world who are dealing and will have to deal with the impacts of climate change.

“Having been at the COP in Marrakesh though, when Trump was elected and when the reaction of all delegates was not dithering or despair but even stronger commitment to Paris, it seems very clear that Trump will not stop the world moving forward.”

Dr. Jeffrey S. Kargel, Department of Hydrology and Atmospheric Sciences, University of Arizona, said:

“In my area of glacier research, the effect of this momentously bad decision to pull out of the Paris Climate Protection agreement will be manifested in more rapidly melting glaciers and an increase of many related natural hazards and disasters.  However, the impacts on nature, people, and economics go far beyond melting ice.

“Trump’s National Security Adviser Gen. H.R. McMaster and National Economic Council Director Gary Cohn explained more about the President’s views in a Washington Post op-ed.  The President, they wrote, offers ‘… a clear-eyed outlook that the world is not a ‘global community’ but an arena where nations, nongovernmental actors and businesses engage and compete for advantage.’

“The Administration doesn’t get it. The Earth as a global system does not care if the world is a global arena of competing nations.  Changing and intensifying storm systems and droughts, increasingly stubborn jet streams, rising sea level, heat waves and air pollution waves will not adhere to national boundaries, but they do respond to fossil fuel burning.

“For the U.S., it means America has abrogated global leadership in environmental and economic matters; others will fill the vacuum but might not be so interested in the global good or as considerate of American interests. As the U.S. government tries to take our country and the world backward to technologies of the 19th and 20th centuries, most nations are still looking forward and they will make economic and environmental leaps, while the U.S. languishes economically with addition of a few hundred thousand outmoded jobs at the cost of lost millions of future-oriented jobs.

“Globally, the backtracking on the Paris agreement removes restraints on developing nations to pollute.  Some countries will use this lapse as an excuse to join the biggest polluters, and our global climate change dilemma will worsen faster than it otherwise would.

“Some factors will partly mitigate the harm done by Trump.  First, the CEOs of major oil companies are alarmed by the climate-change issues and are pressing for corrective actions. In fact, this very morning Exxon Mobil shareholders voted to demand that their company exhibit more climate change accountability. Secondly, California and other states will act on their own to counter the effects of Trump’s bad decision making. Thirdly, the business wisdom of solar power already is global.  Even the Kentucky Coal Museum has shifted to sun power because it is cheaper than coal-powered electricity. Finally, Trump will not be calling the shots indefinitely; but politically, he and his supporters in Congress will indefinitely own climate change impacts.”

Prof Martin Siegert, Co-Chair of the Grantham Institute at Imperial College, said:

“The United States intention to withdraw from the Paris Agreement is a disappointment, but it won’t kill it. International action on climate change is assured by the deal’s 194 other signatories. If the US invests heavily in outdated fossil-fuels, the country will become progressively isolated economically and technologically while the global low-carbon economy, led by Europe and China, continues to grow without US involvement.

“I and other scientists in the UK will continue to work with and support our US colleagues, whose research is key to understanding the human influence on our climate now, and projections of this association into the future. For us in the international science community this is a line crossed, and I expect a concerted and collective reaction to this decision from all Americans who recognise their future prosperity hangs in the balance.”

Prof Stefaan Simons, Chair of the Institution of Chemical Engineers’ Energy Centre, said:

“Donald Trump’s decision to withdraw from the Paris accord poses a significant threat to attempts to limit the global average temperature increase to 2 degrees.  Whilst there will no-doubt be ripple effects from this decision the transition to a low-carbon global economy must continue, and the principles of the accord must be upheld by remaining signatories.

“Global leaders must continue to develop a unified and coherent strategy for reducing emissions and moving beyond fossil fuels without the United States’ involvement in the short term, whilst working towards new ways of collaborating with them in the future. Green technology in the US employs more people than in coal; renewables are an emerging sector that will have a positive impact for the economy.

“Whilst their withdrawal from the agreement presents a range of challenges, there is also an opportunity for those countries who remain committed to become leaders in the fields that will be integral to the energy mix in the future. By intensifying research and development efforts and championing technologies such as nuclear energy, carbon capture and storage, energy and resource efficiency and bioenergy, they will be well placed to reap the benefits once the transition occurs. The expertise of chemical engineers will play a vital role in these efforts, and the IChemE Energy Centre looks forward to supporting them to do so. If the other 146 signatories who have ratified the Agreement hold firm, ultimately it will be the US that lose out.”

Prof Sir Brian Hoskins, Chair of the Grantham Institute, Imperial College London, said:

“I feel that Donald Trump has declared war on us and our planet. I hope that the very positive actions in many US States, cities and companies and the support from the majority of its people will matter more.”

Prof Chris Rapley, Professor of Climate Science at UCL, said:

“The essence of climate change can be captured in 10 words: ‘It’s Clear: It’s Real; It’s Us; It’s Bad; There’s Hope’.

“That the President of the United States cannot understand, or rejects, these realities places future human wellbeing at increased risk.

“But world leaders – especially those of China, India, and Europe – are realists and are committed to action.

“So are influential groups and individuals at the state and city level within the USA.

“And the market drivers of the transition to a world powered by ‘green and clean’ technologies have become unstoppable.

“The age of fossil fuels is drawing to a close.

“So the President’s decision may well prove inconsequential.”

Quotes issued before the announcement:

Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science, said:

“Today’s rumours from unnamed sources at the White House are an indication that some of President Trump’s ideology-driven advisers are trying to bounce him into withdrawal from the Paris Agreement. However, I hope that the President will be swayed instead by the rather sensible advice he is receiving from his Secretary of State, his Secretary of Defense and his Chief Economic Adviser, who have all recommended against withdrawal.

“It is also clear that many American business chiefs, as well as other world leaders, are making a strong case for continuing to participate in the Paris Agreement. A withdrawal from the Paris Agreement is likely to make it more difficult for the United States Government and companies to make trade and business deals with their counterparts in other countries where there is greater understanding of the risks of climate change and of the benefits of low-carbon economic growth.”

Prof Gabi Hegerl FRS, Professor of Climate System Science at the University of Edinburgh, said:

“We know with great confidence that human influences have caused most of the observed warming in the past decades. We know from understanding of the observed change together with climate modelling that warming will continue if we continue to add greenhouse gases to the atmosphere.

“We also know that to limit warming and the impacts it causes, we need to limit the total amount of carbon added to the atmosphere. This can only be done if the world economies work together. If Paris is abandoned or weakened, I fear for the future of our children. Even more, I fear for the future of children in developing countries, who have contributed little to the problem and will feel the impacts first. Where will they go?”

Prof Jonathan Bamber, Director of the Bristol Glaciology Centre at the University of Bristol, said:

“While it would be unfortunate if Trump pulled the US out of the Paris agreement, the momentum is so great and supported by so many nations that it will be no more than an unwelcome bump in the road rather than anything more serious. Individual states such as California will carry on doing what the rest of the world knows is the right thing to do on combatting climate change”.