Climate Change, Wildfires And Air Pollution Damaging Global Health, WMO Warns

Climate change, wildfires and air pollution are locked in a deadly cycle threatening human health, ecosystems and agriculture worldwide, the World Meteorological Organization (WMO) warned on Thursday.

The WMO sounded the alarm in its latest bulletin on air quality and climate, the fourth such publication this year. With a special focus on wildfires, the report analyzes global and regional concentrations of particulate matter pollution and its harmful effects on health and crops in 2023.

Ambient air pollution causes more than four million premature deaths annually in addition to high economic and environmental costs, according to World Health Organization (WHO) figures.

“Climate change and air quality cannot be treated separately. They go hand-in-hand and must be tackled together,” said WMO Deputy Secretary-General Ko Barrett. “It would be a win-win situation for the health of our planet, its people and our economies, to recognize the inter-relationship and act accordingly.”

Fine particulate matter, or PM2.5, is the major health hazard in air pollution. These microscopic particles, about 30 times smaller than human hair, can penetrate deep into the lungs and enter the bloodstream. Sources include fossil fuel combustion, wildfires, vehicles, construction sites and wind-blow desert dust.

Breathing Fire: Wildfire Smoke Linked to Sharp Rise in Dementia Risk

The WMO’s focus on wildfires aligns with emerging research highlighting the unique dangers of wildfire smoke. Recent studies suggest it may be more harmful than other forms of air pollution, potentially increasing risks of dementia, cognitive decline, cancer, heart attacks, pregnancy complications, strokes and attention deficits.

In 2023, Canadian wildfires burned a record area, seven times more than the 1990-2013 average. Smoke from these fires spread across the United States and reached Europe, while Algerian wildfire smoke crossed the Atlantic to Latin America, underscoring the international scope of the threat.

With climate change intensifying fire seasons globally, health risks from wildfire smoke are escalating worldwide, the WMO reported.

“Smoke from wildfires contains a noxious mix of chemicals that affects not only air quality and health, but also damages plants, ecosystems and crops – and leads to more carbon emissions and so more greenhouse gases in the atmosphere,” said Dr Lorenzo Labrador, a scientific officer in WMO’s Global Atmosphere Watch network.

While the bulletin focuses on 2023 data, Barrett noted that the trends have continued into the current year.

“The first eight months of 2024 have seen a continuation of those trends, with intense heat and persistent droughts fuelling the risk of wildfires and air pollution,” he said. “Climate change means that we face this scenario with increasing frequency.”

Record wildfires suffocate ecosystems, agriculture

Air pollution’s dangers extend far beyond human health. Pollutants such as nitrogen and sulphur that settle on Earth’s surface threaten ecosystems and agriculture. These contaminants reduce vital ecosystem services, including clean water, biodiversity and carbon storage

The threat to agriculture is also significant. High concentrations of particulate matter can block sunlight and hinder plants’ carbon dioxide absorption. In heavily polluted areas of India and China, experimental evidence shows particulate matter deposition reduced crop yields by up to 15%, according to the WMO bulletin.

Farming practices in Central Africa, China, India, Pakistan and Southeast Asia — regions most affected by pollution’s impact on agriculture — contribute significantly to particulate matter pollution. These practices include stubble burning, fertilizer and pesticide use, soil tilling, harvesting, and manure management.

Emissions rise in North America, India but fall in Europe, China

The WMO bulletin used two different products to estimate global particulate matter concentrations: the Copernicus Atmospheric Monitoring Service and NASA’s Global Modeling and Assimilation Office.

Both Copernicus and NASA found that North American wildfires caused exceptionally high PM2.5 emissions compared to the 2003-2023 reference period.

Large, persistent fires burned from early May in western Canada until late September 2023, the bulletin said. This worsened air quality in eastern Canada and the northeastern U.S., particularly New York City. Smoke travelled across the North Atlantic to southern Greenland and Western Europe.

Above-average PM2.5 levels were also measured over India, due to increased pollution from human and industrial activities.

China and Europe measured below-average levels, thanks to decreased human-source emissions. This trend has been observed since the first WMO Bulletin in 2021.

In recent years, China, once heavily reliant on coal, has become a world leader in renewable energy, resulting in reduced emissions.

Wildfires spike ozone levels

Wildfires have also spiked ozone levels in several regions.

Devastating wildfires struck central and southern Chile in January and February 2023, killing at least 23 people. More than 400 fires, many intentional, burned vast plantations and woods. High temperatures and winds fuelled the fires in an area affected by a decade-long drought.

Daily short-term ozone exposure increased drastically at several monitoring stations across the country as a result. Chilean authorities declared an environmental emergency in various central Chile regions.

“Concurrent observations of ozone, carbon monoxide, nitrogen oxides and PM2.5 in central Chile show the extreme detriment to air quality caused by intense, persistent wildfire events made more common in a warming climate,” the WMO bulletin reported.

The WMO released the bulletin ahead of Clean Air for Blue Skies Day on Sept. 7 – a U.N.-designated day to highlight air quality and improve cooperation.

This year’s theme: “Invest in Clean Air Now.”

Image Credits: WMO, WMO.