Development funding for efforts to tackle air pollution falls far short of what is needed in a world where nine in 10 people breathe air that is damaging their health - a problem thrown into sharp focus by the pandemic, researchers said on Monday.

A report released to mark the first International Day of Clean Air for Blue Skies showed grant funding for initiatives to curb air pollution amounted to $273 million from 2015 to 2019.

That is a tiny fraction of the development aid provided by governments and philanthropic organisations - yet devoting more cash to clean air could boost other global goals too, it said.

Former U.N. Secretary-General Ban Ki-moon noted in a foreword that outdoor air pollution is responsible for more than 4 million deaths each year, but political will to address the problem is increasing as evidence of the damage becomes clearer.

This year, the COVID-19 pandemic has demonstrated how the world can pull together when faced with "an existential threat", Ban wrote. He called for global collaboration and bold leadership to address poor air quality.

"With a strategic and well-resourced approach to cleaning our air, we can improve health, build resilience to future pandemics, boost productivity, reduce health costs, and help tackle climate change," he added.

Inger Andersen, executive director of the UN Environment Programme, told an online event that lockdowns to curb the virus spread showed "clearer skies are possible", but stopping economies and keeping children at home was not the way forward.

In the new report, the nonprofit Clean Air Fund, which works to combat air pollution and raises money for that aim, tracked $118 million in grants from philanthropic foundations to improve outdoor air quality in the last five years.

At least another $155 million came from official donors, including governments and development banks, it found.

That compares to nearly $153 billion in total development assistance from the world's wealthy governments in 2019.

The research showed that loans to improve air quality were far higher than grants, with $2.4 billion going to that purpose in the five-year period, mainly to support activities in China, which launched a major bid to cut pollution.

Read the full article about funding to tackle air pollution by Megan Rowling at Thomson Reuters Foundation.