The Trump administration has formally released a report that details the growing threats of climate change.
With hurricanes, floods and other impacts of climate change becoming increasingly destructive, countries urgently need to step up their ambitions to cut emissions if they are to keep global warming within safe limits, experts said ahead of UN climate talks starting in Germany on Monday.
About 163 countries have submitted plans on how they will contribute to meeting the Paris climate agreement goal to limit global warming to well below 2 degrees Celsius above pre-industrial levels.
But put together, the plans are likely to lead to a 3 degree temperature rise this century, according to the United Nations.
Out-of-control wildfire tore through parts of California, US, in October.
Nicholas Nuttall, spokesman for the UN Framework Convention on Climate Change, said the national plans delivered in advance of Paris, "were well known at the time to fall short of the Paris Agreement's long-term goals".
But the agreement also calls for countries to take stock of international progress on climate action and ratchet up the ambition of their national plans accordingly.