When it comes to international environmental diplomacy, America has a chequered past. It stood at the forefront of the international battle to fix the ozone hole and has shaped many key international agreements.
Sadly, US positions are not always built on solid political ground at home. Twice, in the climate change process, this has led to the United States forging an agreement, only to then walk away. This happened with the 1997 Kyoto Protocol which then Vice-President Gore flew to Japan to sign in the full knowledge that a Republican dominated Senate would never ratify the deal. It happened again five years ago, with former President Obama closing that landmark deal (and John Kerry signing at the UN), only for President Trump to tear it up a few weeks later.