Could Australia’s bushfires aerosols actually decrease global temperature?

Asked by: Wendy Irvin

Writing in the journal Geophysical Research Letters last week, scientists at the National Center for Atmospheric Research reported that those Australian fires poured so much smoke into the Southern Hemisphere’s atmosphere it triggered a “strong and rapid” global cooling effect of about 0.06°C ( 0.01°F).

How much carbon did Australian bushfires emit?

That’s the takeaway from a study published last month in AGU Advances that examined the impact of the record-breaking blazes on the Australian carbon cycle. These fires likely released somewhere around 186 million tons of carbon into the atmosphere, the research found.

What will happen to Australia with global warming?

Australia is experiencing higher temperatures, more extreme droughts, fire seasons, floods and more extreme weather due to climate change. Rising sea levels add to the intensity of high-sea-level events and threaten housing and infrastructure. The number of days that break heat records has doubled in the past 50 years.

Has the overall forest fire risk in Australia increased or decreased?

Forests in Australia experienced an annual average increase of 350% in burned area between the first (1988-2001) and second (2002-2018) half of the record, and an increase of 800% when including 2019.

Do bushfires release carbon dioxide?

Bushfires release significant amounts of carbon dioxide, but generally recover over time, generating a significant carbon sink in the years following the fire.

Is Australia a carbon sink?

Our results suggest that Australia was a carbon sink of −0.41 ± 0.08 PgC yr⁻¹ compared to the prior estimate 0.09 ± 0.20 PgC yr⁻¹ (excluding fossil fuel emissions). Most of the carbon uptake occurred in northern Australia over the savanna ecotype and in the western region over areas with sparse vegetation.

How did the Australian wildfires affect the atmosphere?

The intensity of the fires has led to the development of small-scale weather systems. Due to the large amounts of carbon dioxide released in the atmosphere, thunderstorms have been triggered, which further worsens the problem as the bolts of lightning caused the spread of the fire even further.

What happens if the Earth warms 3 degrees?

A rise of 3°C in global temperatures above pre-industrial levels by 2100 would be disastrous. Its effects would be felt differently around the world, but nowhere would be immune. Prolonged heatwaves, droughts and extreme weather events could all become increasingly common and severe.

Will Australia become a desert?

A United States climate study says global warming will cause Australian deserts to get bigger and expand to the south.

Will Australia still be habitable?

Australia is facing an “insurability crisis” with one in 25 homes on track to be effectively uninsurable by 2030, according to a Climate Council report. Another one in 11 are at risk of being underinsured.

Are bushfires good for the environment?

Bushfires can cause poor air quality, which can affect human and animal health, and can have long-lasting impacts to soil and water quality. Bushfires can also have devastating impacts on plants, animals and ecosystems. For example, NSW experienced extensive bushfires in spring and summer 2019–20.

Do wildfires contribute to climate change?

Yes. Wildfires release carbon dioxide (CO₂) emissions and other greenhouse gases (GHG) that contribute to climate change.

Does prescribed burning contribute to global warming?

Fuel reduction by prescribed burning must cease because it releases carbon dioxide into the atmosphere, thus exacerbating global warming and the occurrence of megafires.

Was Australia ever green?

Regions in the Southern Hemisphere including Australia, southern Africa, and temperate South America contributed 80% of the change, especially their savannas and other semi-arid areas. That winter, June to August 2011, Australia was the greenest that it has ever been seen in the satellite period (since 1982).

Is Australia getting greener?

On average, Australia is “greener” today than it was two decades ago. This is despite ongoing land clearing, urbanisation and the recent droughts in some parts of the country. However, the increase in vegetation has not been uniform.

Is grass a better carbon sink than trees?

Unlike trees, grasslands store most of their carbon underground, in their roots and the soil. And that makes them more reliable “carbon sinks” than forests, according to a 2018 University of California at Davis study.

Are bushfires carbon neutral?

Scientists typically consider bushfires in the long run to be carbon-neutral events. When vegetation burns, greenhouse gases—primarily carbon dioxide (CO₂)—are released through the process of combustion.

What percentages of global carbon dioxide emissions come from forest fires?

Although estimates vary and still carry uncertainties, some experts say wildfires account for up to 20% of total global greenhouse gas emissions. They are estimated to increase by a few percent to roughly 30% by the end of this century depending on how the climate changes.

Do wildfires add to global warming?

Although wildfires produce a number of greenhouse gases and aerosols including carbon dioxide, methane, and black carbon, the plants that re-colonize burned areas remove carbon from the atmosphere, generally leading to a net neutral effect on climate.