Donald Trump could slow down US progress towards a lower carbon economy, but he will be unable to halt it because businesses and local governments have committed to a low-carbon path, a former climate negotiator for the US has said.

Through measures such as slapping import tariffs on solar products, scrapping incentives to renewable energy and promoting coal power, the US president could try to alter the economics of pursuing low-carbon energy.

However, many American states, towns and businesses are moving to renewable energy as it is proving lower cost than conventional sources. The recent rise in the price of oil has underlined the volatility of fossil fuels.

Paul Bodnar, a lead US negotiator in the climate talks under former president Barack Obama, told the Guardian that Trump possessed “powerful instruments”, such as import tariffs and quotas, that could hamper the growth of low-carbon technology. “If he chooses, he could use them,” he said. But he warned this would be short-sighted, as China is forging ahead with low-carbon power and the US would risk losing any technological lead.

“It is clear the way the market is driving – towards lower carbon. It would be difficult for a Republican administration to take action that is clearly counter to the forces of the market,” he said.

Coal, he said, was losing ground in the market, even without penalties on carbon output. “A huge percentage of US coal is just flat out uneconomic,” said Bodnar. “Ratepayers are being asked to pay more for incumbent industries. Questions are going to be asked about why that is. It would cost a lot to make coal great again.”

He added: “The direction of travel [for businesses] has been set, and it is lower carbon. The only question is the pace at which that happens. And the pace is important because this is an urgent problem. Trump has the ability to slow that pace, but he cannot reverse it.”

States, mayors, local governments and businesses from the US have gathered together to present an alternative vision to Trump’s policies at the ongoing UN climate talks in Bonn. On Saturday, they will unveil a new initiative to move forward with low-carbon plans in spite of the White House’s opposition.

Trump has begun the process of withdrawing the US from the landmark Paris agreement of 2015, signed and ratified by the US under Obama, but under UN rules this process cannot be completed until November 2020, with the prospective official withdrawal date falling the day after the next presidential election.

Earlier this week, the Syrian government became the final functioning state to sign up to the Paris agreement. It was the last holdout nation, following the decision by Nicaragua to join the agreement shortly before the current talks. This leaves the US as the only nation poised to reject the 2015 agreement.

Looking to the potential progress at the COP23 talks, Bodnar pointed to China’s actions in pursuing low-carbon policies, in contrast to the US. He said the country’s stance at the UN talks would be key, in part because the US, though present and still a party to the Paris agreement, is taking little active part in the talks, which are focused on upping countries’ commitments to reduce carbon emissions. Current emissions targets are inadequate to keep the Paris goal of limiting global warming to no more than 2C, which scientists say is the limit of safety beyond which the ravages of climate change are likely to become catastrophic and irreversible.

Countries will be expected to come forward in the next few years with new targets that match scientific advice. Bodnar said that in the process of increasing countries’ carbon-cutting, some countries had more room to manoeuvre than others. “What’s interesting is to ask whether some countries left something on the table in 2015 [when setting carbon targets]. Countries that came to Paris with high ambition may find it difficult to crank that up, but others that were more conservative will have room to make higher commitments. China is very important.”

He said he was hopeful that this round of talks would produce momentum leading to higher goals. “It’s a question of perceived self-interest. At Copenhagen in 2009, it wasn’t the case that everyone perceived [cutting carbon sharply] to be in their self-interest. That changed in the run-up to Paris, and now governments do see that they are acting in their own interests by signing up [to higher goals].”

A US state department official at the Bonn COP23 talks said: “This administration believes in corporate federalism and is therefore supportive of states and cities making their own choices within their respective borders.”