Death toll shows extreme air pollution events a growing urban threat

New Curtin University-led research has estimated that 1454 avoidable deaths (one person every five days) occurred in Australian capital cities in the past 20 years because of fine particle air pollution from extreme events such as bushfires and dust storms, wood-heater smoke or industrial accidents.

The study also found that nearly one-third of deaths from extreme air pollution exposure days could be prevented if pollution events were reduced by as little as 5 per cent.

Lead researcher Dr Lucas Hertzog from Curtin's World Health Organisation Collaborating Centre for Climate Change and Health Impact Assessment said the findings highlighted the urgent need for effective strategies to manage air quality, particularly during extreme weather events like bushfires and dust storms, which are becoming more common due to climate change.

"Using data from 2001 to 2020 from air pollution monitoring sites, combined with a range of satellite and land use-related data, we modelled the exposure to exceptional levels of particulate matter air pollution (PM2.5) for each extreme pollution exposure day," Dr Hertzog said.

"Despite relatively low daily PM2.5 levels generally (compared to global averages), Australian cities experience days with extreme pollution levels where PM2.5 concentrations exceed the WHO Air Quality Guideline standard.

"Sydney and Melbourne reported the highest number of deaths attributable to extreme air pollution events, with 541 and 438 deaths respectively, followed by Brisbane and Perth with 171 and 132 deaths."

"Adelaide and Hobart were the cities that showed, across the 20-year period, fewer days exceeding WHO air quality exposure recommendations, with Adelaide recording only five days and Hobart 11 days above the threshold.

"Darwin, despite its relatively low number of deaths due to PM2.5 exposure events, experienced a high number of days exceeding WHO recommendations, ten times more than cities like Melbourne."

Dr Hertzog said the findings show how extreme air pollution events could seriously affect health in urban areas, and understanding this link was crucial, as climate change may increase the frequency and intensity of such pollution events.

"Diseases associated with particulate matter air pollution include asthma and COPD (chronic obstructive pulmonary disease) as well as cardiovascular disorders," Dr Hertzog said.

"Our study's insights can aid in protecting public health by helping to inform policy development and actions to reduce impacts from extreme air pollution events.

"While responding to bushfires and dust storms is an increasingly challenging task, authorities have a crucial role in land use management. They also regulate energy policy and control wood heater regulations. Additional strategies to reduce emissions from industrial accidents or road transport-related smog events could enhance the control of sources of air pollution and improve well-being.

"It is also possible to reduce the burden of mortality by improving public health warnings and increasing community awareness of smoke avoidance behaviours."

Read more at Science Daily

Record heat in 2023 worsened global droughts, floods and wildfires

Record heat across the world profoundly impacted the global water cycle in 2023, contributing to severe storms, floods, megadroughts and bushfires, new research from The Australian National University (ANU) shows.

The findings are outlined in a new report released today by the Global Water Monitor Consortium and led by ANU researchers.

Lead author Professor Albert van Dijk, from ANU, said the report underscores the consequences of persistent fossil fuel burning on natural disasters, water resources, biodiversity and food security.

"Record-breaking heat waves swept across the globe in 2023, shattering previous records, from Canada to Brazil and from Spain to Thailand," Professor van Dijk said.

"The lack of rainfall and high temperatures exacerbated multi-year droughts in South America, the Horn of Africa and around the Mediterranean.

"Extremely hot and dry conditions inflicted extensive ecological damage on the world's largest forests. Massive wildfires ravaged Canada during the northern summer, while the Amazon rainforest and rivers rapidly descended into severe drought in late 2023."

Some of the worst disasters of 2023 were linked to unusually strong cyclones bringing extreme rainfall to New Zealand, Mozambique and Malawi, Myanmar, Greece, Libya and Australia.

According to Professor van Dijk, who is also Chair of the Global Water Monitor Consortium, rising sea surface and air temperatures caused by fossil fuel burning have been intensifying the strength and rainfall intensity of monsoons, cyclones and other storm systems.

This was also evident closer to home, where Cyclone Jasper battered northern Queensland and severe storms hit southeast Queensland.

"Some areas around Cairns recorded more than 800 millimetres of rain. The torrential rains caused widespread flooding. That was because the cyclone moved much slower than expected," he said.

"The recent cyclones and intensive storms in Queensland and elsewhere in Australia should not be seen as isolated freak events but part of a global pattern that was quite clear in 2023.

"In 2023, we saw cyclones behave in unexpected and deadly ways. The longest-lived cyclone ever recorded battered southeastern Africa for weeks.

"Warmer sea temperatures fuelled those freak behaviours, and we can expect to see more of these extreme events going forward."

Professor van Dijk said the last two decades have seen increased air temperatures and declining air humidity, causing increased heat stress and water requirements for people, crops and ecosystems, while intensifying droughts.

Relative air humidity over the global land surface in 2023 was the second driest on record after 2021, continuing a trend towards drier and more extreme conditions.

2023 was Earth's hottest year on record, showing what a typical future year with 1.5 degrees warming may look like.

"A total of 77 countries experienced the highest average annual temperature in at least 45 years," Professor van Dijk said.

Professor van Dijk said 2023 was a year of extremes, with increasing extreme dry and wet conditions and more unprecedented weather events.

This is in line with ongoing changes in the water cycle over the last two decades.

"The events of 2023 show how ongoing climate change is threatening our planet and lives more with every passing year," he said.

"Globally, we're seeing an increase in the frequency and intensity of rainfall events and river flooding. But at the same time, there are also more frequent and faster developing droughts, or 'flash droughts'.

"That can cause crop failure and destructive wildfires in a matter of weeks or months. With the global food challenge, biodiversity crisis and an extremely urgent need to reduce carbon emissions, these droughts and wildfires are among our greatest global threats."

The research team used data from thousands of ground stations and satellites orbiting the Earth to provide real-time information on rainfall, air temperature, air humidity, soil and groundwater conditions, vegetation, river flows, flooding, and lake volumes.

Read more at Science Daily