Thousands of lives lost to air pollution, inactivity and unhealthy diets could be saved each year if the UK takes the action needed to tackle climate change, researchers have said.

Across the world, millions of lives could be saved if countries raise ambitions on cutting emissions to limit global warming to well below 2C above pre-industrial levels, as they have committed to in the global Paris climate accord.

The researchers said the findings highlighted the added incentive of improvements to human health from tackling climate change.

Research from The Lancet Countdown on Health and Climate Change looked at the health impact of boosting national climate action plans to meet the Paris targets to avoid dangerous climate change across nine countries, including the US, China, Brazil and the UK.

The world is currently off track to meet the Paris goals, but the research found strengthening commitments to curb temperature rises in line with the international agreement would also have significant benefits for health.

Tougher measures to curb emissions would save lives through better, more plant-based diets, more physical activity from active travel such as walking and cycling and cuts to air pollution from burning fewer fossil fuels.

The research, published in a special issue of The Lancet Planetary Health journal, looked at three scenarios: carrying on their current path, increasing efforts to achieve the Paris goals, and a more ambitious scenario which put health at the heart of tackling climate change.

In the UK, implementing policies to meet international climate goals would save 98,420 lives a year by 2040 through better “flexitarian” diets which involve less meat and more vegetables, legumes and fruit.

Some 21,486 lives could be saved by people taking more exercise and 3,458 from reductions in air pollution.

If even more ambitious plans were put in place to make sure health was the focus of climate policy, 100,100 lives a year could be saved through dietary changes, with 50% adopting flexitarian diets and 50% going vegan.

A further 5,771 lives could be saved from cuts to air pollution and 38,441 from more active travel, with 75% of people walking or cycling over the course of a week, the modelling suggests.

Across all nine countries, implementing national climate plans which meet the Paris goals could save 5.8 million lives due to better diet, 1.2 million lives due to cleaner air, and 1.2 million lives due to increased exercise.

The health co-benefits of ambitious climate policies have an immediate positive impact

And putting explicit health objectives in their plans, known as nationally determined contributions or NDCs under the Paris accord, could lead to a further reduction of 462,000 deaths due to air pollution, 572,000 from diet, and 943,000 from physical inactivity a year by 2040.

Lead author Ian Hamilton, executive director of The Lancet Countdown on Health and Climate Change, said: “Our report focuses on a crucial but often overlooked incentive for tackling climate change.

“Unlike the direct benefits of carbon mitigation which are ultimately long term and understood in terms of damage limitation, the health co-benefits of ambitious climate policies have an immediate positive impact.”

He said the report’s message was stark.

Mr Hamilton said: “Not only does delivering on Paris prevent millions dying prematurely each year, the quality of life for millions more will be improved through better health.

“We have an opportunity now to place health in the forefront of climate change policies to save even more lives.”