The world does not need a miracle to tame global warming, just leadership, American presidential hopeful Michael Bloomberg told UN climate talks in Madrid on Tuesday, calling for an end to government handouts to oil, gas and coal companies.

The billionaire and former mayor of New York took a detour from his bid to capture the Democratic Party nomination and earn the right to run against President Donald Trump, who has aggressively promoted fossil fuels and dismissed climate change as a hoax.

“Beating climate change won’t require a miracle, it won’t require limitless resources, it will require leadership and common sense,” Bloomberg told a roundtable on climate finance organised by the Spanish government.

“The next president of the United States should end all subsidies to fossil fuel companies and fossil fuel extraction, and that includes tax breaks and other special treatment,” he said, taking aim at long-standing policies as well as new ones put in place by Trump.

The money saved could be invested in clean energy “to create a lot of jobs”, he added. “If we take these steps, I’m really optimistic we can succeed.”

Bloomberg arrived at the 196-nation talks, set to close on Friday, with A-list actor Harrison Ford and outgoing Bank of England Governor Mark Carney, newly appointed as the UN’s Special Envoy for Climate Change and Finance.

Carney called for mandatory disclosures from companies worldwide on their environmental footprint, instead of the current patchwork of voluntary schemes.

He also announced that the Bank of England would begin climate “stress tests” for financial institutions, calculating the risk climate change poses to their balance sheets.

“It is about a transition of the whole economy,” Carney said.”And those companies need to be rewarded or penalised if they are on the right or wrong side of the transition history.”

In the wake of the 2015 Paris Agreement for combating global warming, Carney and Bloomberg launched an initiative to encourage businesses to evaluate and communicate their exposure to climate risk.

“Businesses understand what’s at stake and they are not waiting for better leadership in Washington,” Bloomberg said.

‘Lack of courage’

Harrison Ford accused the Trump administration of “a lack of courage” by deciding in 2017 to withdraw from the Paris agreement.

“We know what to do, we know the facts, what we need now is the courage to act,” he told conference attendees.

Last week, Nancy Pelosi headed a 15-strong US Congressional delegation that brought the same message to the UN talks, where major economies have balked at boosting pledges to reduce greenhouse gas emissions.

Elan Strait of the World Wildlife Fund told AFP that the world was “desperate to hear real American leadership on climate change”.

Bloomberg is prioritising the climate in his election bid and a study from a think tank he owns draws a clear line in the sand between himself and Trump on the fate of the planet.

Climate change experts quoted in the report, from the University of Maryland and the Rocky Mountain Institute, estimate the United States is presently set to reduce emissions by 25 percent by 2030 if sub-federal climate ambitions remain at their current levels.