• Declining air quality, exacerbated by the climate crisis, is a major problem worldwide and poses a grave threat to human health and the environment.

  • As we mark International Day for Clean Air, the United Nations says global partnerships, investments and shared responsibility are more essential than ever.

  • The four UpLink innovators noted below aim to help us breathe more easily.

Air quality is rapidly declining worldwide, exacerbated by the effects of global warming and causing serious health and environmental concerns. According to the World Health Organization, 99% of the global population breathes polluted air, resulting in approximately 7 million premature deaths each year due to indoor and outdoor air pollution.

As the world marks the United Nation’s (UN) fourth International Day for Clean Air under the theme of "Together for Clean Air", the agency says the need for global partnerships, investments and shared responsibility to combat air pollution has never been more urgent.

Trees are vital to our survival on the planet and the fight to reverse the climate crisis.They not only help lower temperatures, maintain soil health and help sustain animal life, but also remove billions of tonnes of carbon dioxide from the atmosphere.

Pollution: the latest data

The stats on the risk to health from air pollution are stark, as outlined in the latest Air Quality Life Index (AQLI) annual update. It poses the greatest threat to human health, with an impact to life expectancy as high as that of smoking, potentially shortening the avergage person’s life by 2.3 years.

The global pollution picture differs region to region, largely as a result of unequal opportunities to improve it, the AQLI says. Wildifires this summer in Europe, Canada and the US may have dominated the headlines, but such levels of pollution are a daily fact of life in other parts of the world. According to the report, just six countries account for three-quarters of its impact on global life expectancy – Bangladesh, India, Pakistan, China, Nigeria and Indonesia.

“The entire continent of Africa receives under 300,000 USD in philanthropic funds toward air pollution. Just 1.4 million USD goes to Asia (outside of China and India). Europe, the United States, and Canada receive 34 million USD, according to the Clean Air Fund,” the latest AQLI report notes.

Infographic illustrating the air quality for selected cities based on annual average,

Two Indian cities top the list of polluted urban environments, worldwide. Image: Statista

Air pollution is responsible for one-third of stroke deaths

The health impact of air pollution is devastating, with tiny, invisible particles of pollution infiltrating our lungs, bloodstream and bodies. These pollutants are responsible for about one-third of deaths from stroke, chronic respiratory disease and lung cancer, and one-quarter of deaths from heart attacks, the UN says.

Additionally, ground-level ozone, formed from the interaction of various pollutants in sunlight, exacerbates asthma and other chronic respiratory illnesses. Women, children and the elderly – particularly in developing countries – bear a disproportionate burden. This is because of exposure to high levels of ambient and indoor air pollution from cooking and heating with wood fuel and kerosene.

On the climate front, short-lived climate pollutants (SLCPs) present a dual challenge, impacting both health and the planet's near-term warming. They persist in the atmosphere for varying durations, ranging from a few days to several decades. Reducing SLCPs can have immediate health and climate benefits for those residing in areas where levels are high.

Trees help clean the air

Air pollution is a transboundary issue that requires joint action from local, national, regional and global partners, the UN says. It urges governments, corporations, civil society and individuals to come together, transcending borders and sectors, to combat air pollution effectively.

Forests play a crucial role removing carbon dioxide from the air through the process of photosynthesis. Trees absorb carbon dioxide – the primary greenhouse gas responsible for climate change – and release oxygen, a vital element for human survival. This natural carbon sequestration helps mitigate the harmful effects of air pollution, contributing to cleaner air and a healthier environment.

However, deforestation remains a critical concern, with roughly 10 million hectares (100,000km2) of forest lost each year, globally. In 2020, the World Economic Forum launched a global initiative to grow, restore and conserve 1 trillion trees around the world – in a bid to restore biodiversity and help fight climate change. The 1t.org project aims to unite governments, non-governmental organizations, businesses and individuals in a "mass-scale nature restoration".

Here are four innovators from the Forum’s Uplink platform working to improve global air quality.

Acacia Eco – bringing trees back to India

“Our commitment to trees is real. We don‘t have all the solutions, but our role is clear – we will plant enough trees to have an impact,” says Acacia Eco co-founder Ajaya Mehta.

The company plants trees across urban spaces like schools, factories and community plots – so far it has planted more than 825,000 trees in 91 urban forests, restoring more than 36.4 hectares (364,000m2) in the process.

It uses the Miyawaki method pioneered by Japanese botanist Dr Akira Miyawaki. This involves planting trees close together to avoid the loss of topsoil from rainwater. The technique has proven successful in the most adverse soil and climate conditions, and can help create fast-growing urban forests that are self-sustaining within two years.

India has pledged to increase its forest cover to 33% by 2030, up from around 25% today.

SUGi – connecting donors with forest makers

SUGi is a global platform that connects donors with communities of Forest Makers and Ocean Gardeners restoring ecosystems around the world. The company funded its first pocket forest in Beirut, Lebanon in May 2019, now there are 160 worldwide, including Cameroon, the UK, the US and Australia.

These Miyawaki mini-forests thrive in climates ranging from humid tropical, to semi-arid and temperate oceanic to Mediterranean. As of 2022, the total area of forests planted covers 93,905m2 and includes 237,411 plants.

Last year the individual forest size also increased, with forests averaging 661.3m2, compared to 396.3m2 between 2019 to 2021.

Donors can invest as little as $5 and either subscribe to donate regularly or make one-off contributions.

Earthwatch Europe – planting a network of tiny forests in the UK

Three years ago Earthwatch Europe planted the UK’s first Tiny Forest in Witney, Oxford. Since then, it has created over 200 of these urban oases across the UK.

A Tiny Forest is a dense, fast-growing native woodland using the Miyawaki method. Earthwatch says it identifies suitable sites in urban locations where nature is most needed and then engages with local communities to plant, maintain and monitor their forest over time.

In 2022, 80 Tiny Forests were monitored by volunteers, engaging almost 3,500 citizen scientists. These included the programme's national network of Tree Keeper volunteers, and members of local communities, schools and businesses.

The company collects environmental and social data for every forest it plants to help assess the benefits they provide over time and between different forests. Earthwatch has already found that forests help people connect with nature and raise awareness of the climate crisis.

Urban Reef – 3D-printing living landscapes

Urban Reef is a Dutch start-up that creates so-called “reefs” – effectively 3D-printed sculptures or urban furniture made of living materials like mycelium, river dredge, sea shells and clay – to increase biodiversity in cities.

They can absorb water and feature a range of microclimates, providing habitats that enable a wide variety of plants, insects and animals to live and thrive in cities.

“We believe that to live in harmony with our surroundings, we need to give more space to wilderness and nature, both physically and in our thinking,” co-founders Pierre Oskam and Max Latour said. “To this end, we view cities as living landscapes.”