"The decision by the world’s second-largest emitter to retreat from UNFCCC is regrettable" (W. Hoekstra)

European reactions to the U.S. withdrawal from UNFCCC and IPCC

"Europe will continue to pursue its agenda of climate action." (W. Hoekstra, Commissioner)

• "The UNFCCC underpins global climate action. It brings countries together to support climate action, reduce emissions, adapt to climate change, and track progress. The decision by the world’s largest economy and second-largest emitter to retreat from it is regrettable and unfortunate. We will unequivocally continue to support international climate research, as the foundation of our understanding and work. We will also continue to work on international climate cooperation. And at home, we will continue to pursue our agenda of climate action, competitiveness, and independence."

Wopke Hoekstra, Commissioner for Climate, Net-Zero and Clean Growth

"The departure from IPCC was predictable." (F. Gemenne, IPCC expert)

• "Yesterday, the United States officially withdrew from the IPCC and the United Nations Framework Convention on Climate Change. The Climate Convention was signed at the Rio Earth Summit in 1992. It is the treaty that establishes the legislative framework for the COPs, and on which most international climate cooperation mechanisms depend, starting with the Paris Agreement. Above all, it was a treaty that had achieved universal ratification: no country, not even the United States, had ever withdrawn from it. The IPCC's departure was also predictable. Until now, the six assessment reports published by the IPCC since 1990 had been approved by all the world's governments, meaning that all governments recognised the state of science on climate change. It was a different world."

François Gemenne, Political scientist and co-author of the sixth IPCC report

"Other countries will have to compensate for the budgetary losses of the IPCC" (J.-P. van Ypersele, former IPCC Vice-chair)

• "The withdrawal of the U.S. from the IPCC isolates the country from the international community's efforts to preserve the habitability of the only planet on which American citizens also live. To claim that participation in the work of the Climate Convention and the IPCC would be 'contrary to the interests of the United States' is simply nonsensical. Let us remember that the creation of the IPCC was facilitated in 1988 by an agreement between Ronald Reagan and Margaret Thatcher, who can hardly be described as 'woke'. Climate and the environment are not a matter of ideology or political affiliation: they concern everyone. One example suffices: the Palm Beach area of Florida, where Mr Trump's Mar-a-Lago residence is located, is among the areas most vulnerable to sea level rise due to global warming. The U.S. is not immune to this problem. The participation of American scientists in the work of the IPCC is essential. This withdrawal will make such participation a little more difficult, particularly because other countries will have to compensate for the budgetary losses, but the IPCC will continue its work in the service of all."

Jean-Pascal van Ypersele, Former IPCC Vice-chair (2008-2015)

American reactions to the withdrawal

• "Today, President Trump announced the U.S. is leaving 66 anti-American, useless, or wasteful international organizations" (M. Rubio, U.S. Secretary of State)

• "Today, President Trump announced the U.S. is leaving 66 anti-American, useless, or wasteful international organizations. Review of additional international organisations remains ongoing. These withdrawals keep a key promise President Trump made to Americans - we will stop subsidising globalist bureaucrats who act against our interests. The Trump Administration will always put America and Americans first."

Marco Rubio, U.S. Secretary of State

"The Trump Administration attempts to undermine climate science." (Al Gore, Former U.S. Vice-President)

• "For decades, the world’s scientists and governments have worked together to tackle the most significant challenge of our lifetimes: the climate crisis. The ongoing work of the IPCC, UNFCCC, and other global institutions remains essential to safeguarding humanity’s future. The Trump Administration's decision to remove the United States from these vital organizations sends the wrong message to our allies abroad and fails to protect Americans from the increasingly dangerous impacts of the climate crisis at home. By withdrawing from IPCC, UNFCCC, and other vital international partnerships, the Trump Administration is undoing decades of hard-won diplomacy, attempting to undermine climate science, and sowing distrust around the world. Fortunately, 198 minus one does not equal zero."

Albert A. Gore, former U.S. Vice-President (1993-2001)