Gordon Brown has compared the current system of trying to secure 100 billion US dollars (£73.7 billion) in climate finance annually for developing countries to “a charity fundraiser or a begging bowl going around the table”.

The former prime minister and long-serving chancellor in Tony Blair’s government called for a global system of burden sharing equivalent to that used to fund the World Health Organization.

Speaking at Cop26, he said governments needed to strongly make the case for building resilient and low-carbon healthcare systems to their citizens.

But Mr Brown added that investment in healthcare systems must not come at the expense of investment in tackling and adapting to climate change and vice versa.

We are not prepared for pandemics and we are not prepared for the drought and famines and air pollution that needs to be addressed

“You can’t solve the problem of our healthcare crisis without solving climate change, and we can’t solve the problem of climate change without building resilient healthcare systems because they alone emit around 4% to 5% of CO2 throughout the world,” he said.

Delivering on a pledge of 100 billion US dollars annually in finance for adaptation and mitigation against climate change being provided by rich countries for developing nations is one of the key tests of the summit’s success.

In the first week of the conference, the US climate envoy John Kerry said the goal was likely to be reached by 2022 – a year earlier than expected – but more recent communications have been more cautious.

But Mr Brown compared the current approach to hosting an annual charity fundraiser.

“We really have to recognise we are dealing with global public goods,” he said.

He continued: “We are relying on having pledging conferences all the time, we are relying on the equivalent of a charity fundraiser or a begging bowl going around the table whenever there is a crisis.

“We are not prepared for pandemics and we are not prepared for the drought and famines and air pollution that needs to be addressed.”

Mr Brown called for a new conference to be set up to create an agreement on burden sharing to pay for the “public good” of tackling the climate crisis.

“If we don’t reach the target we have set of 100 billion dollars of climate finance for developing countries, then we will deprive them of the opportunity to build not only coastal defences and renewable industry, but also to build the healthcare systems that are necessary for resilience to drought, famine and also to pollution in the air,” he said.

“We need finance ministers to come together to find that money, we need a global burden-sharing agreement over the long term.”

Mr Brown said the public would be likely to support higher taxes to pay for healthcare resilience, adding: “This is such a big issue, people’s health, that I think we would get far more public support if we said we must get a global system that shares the burden fairly, so never again are we in a position that we are not prepared for a pandemic and we are not prepared for the climate crisis we face at the moment.”