Climate change is increasing the intensity and frequency of heat waves. This extreme heat, compounded by wildfires and desert dust, is having a measurable impact on air quality, human health and the environment, according to a new report from the World Meteorological Organization (WMO).
The 2023 WMO Air Quality and Climate Bulletin, the third instalment of an annual series, focuses on heat waves to draw attention to the often-overlooked consequences of extreme heat, including pollution.
The report highlights that heat waves triggered wildfires in the north-western United States and led to dangerous air quality in 2022. Additionally, heat waves accompanied by desert dust intrusions across Europe had adverse effects on air quality. It also features case studies from Brazil, showcasing how green spaces within cities can improve air quality, absorb carbon dioxide, and lower temperatures, benefiting local populations.
Dog days bite back
“Our planet has just endured a season of simmering – the hottest summer on record,” said UN Secretary-General António Guterres, warning “climate breakdown has begun”.
“The dog days of summer are not just barking, they are biting”, continued the UN chief, describing the consequences of humanity’s unleashed fossil fuel addiction.
As the climate crisis provokes more and more extreme weather worldwide, the UN Secretary General called on leaders to “turn up the heat now for climate solutions.”
WMO Secretary-General Prof. Petteri Taalas emphasizes the interconnectedness of climate change and air quality, stating that “heat waves worsen air quality, with knock-on effects on human health, ecosystems, agriculture, and our daily lives.” He stresses the necessity of addressing climate change and air quality as intertwined challenges.
The report’s release coincides with the International Day of Clean Air for Blue Skies on September 7, focusing on the theme “Together for Clean Air.” It highlights the need for strong partnerships, increased investment, and shared responsibility to combat air pollution.
LONG-TERM GLOBAL THREAT
The report underscores that climate change, driven by greenhouse gases, poses a long-term global threat, while air pollution affects a more localized and short-term timescale. Key pollutants, such as ozone and particulate matter, harm human health and are linked to climate change.
The 2022 summer noted as the hottest on record in Europe, resulted in increased concentrations of pollutants like PM (particulate matter) and ground-level ozone. The heat wave led to high levels of ozone across Europe, exceeding World Health Organization guidelines. Additionally, desert dust intrusions combined with high temperatures affected human health and well-being.
Ozone near the Earth’s surface is harmful to human health and can reduce crop yields. Globally, ozone-induced crop losses average between 4.4% and 12.4% for staple food crops, impacting food security.
Heat waves and dry conditions conducive to wildfires lead to increased aerosol emissions, contributing to air pollution. Wildfires also affect ecosystems and biodiversity due to nitrogen-containing compounds released into the atmosphere.
URBAN HEAT ISLANDS
Urban heat islands, caused by urbanization and exacerbated by climate change, lead to higher temperatures in cities, increasing morbidity and mortality, especially during heat waves and at night. However, incorporating green spaces within cities can mitigate the urban heat island effect, benefiting both temperature regulation and CO2 reduction.
The report reinforces the urgency of addressing climate change. It also urges improving air quality. It calls for for collaborative efforts and comprehensive strategies to combat these intertwined challenges.