“In January we are going to inaugurate a president whose relationship with climate change is captured by the words ‘hoax’ and ‘fossil fuels’, Mr Podesta said.
“He has vowed to dismantle our environmental safeguards and once again withdraw the United States from the Paris Agreement.”
“That is what he has said, and we should believe him.”
The 2015 Paris agreement saw countries agree to try to keep global temperature rise below 1.5C.
Leaders from nearly 100 countries will address the meeting in the coming days.
COP29 had been billed as an opportunity to solve the crucial issue of getting money to poorer countries to help them deal with the impacts of climate change and help them prepare for it.
But expectations for what the summit can achieve have been lowered by a Trump victory that makes Biden administration negotiators from one of the world’s largest carbon emitters a lame duck in this process and unable to really promise much.
However, the election wasn’t the end of the struggle, Mr Podesta told reporters.
He believed that as a result of the policies put in place by President Biden and with the support of states and cities, US emissions would continue their downward trajectory, albeit at a slower pace.
“The fight is bigger than one election, one political cycle and one country. This fight is bigger still because we are living through a year defined by the climate crisis in every country of the world.”
COP29 got underway amid a welter of scientific gloom. The UN’s World Meteorological Organization (WMO) said in a report released to coincide with the conference’s start, that 2024 is on track to be the world’s warmest year on record.
Its latest State of the Climate report also finds that our oceans are heating up rapidly and glacier melt is accelerating.
“We are on the road to ruin,” Mukhtar Babyaev, president of COP29 said in his opening remarks.
He went on to list examples of climate impacts now around the world, saying “these are not future problems” as rising temperatures were doing huge damage around the world right now.