Smoke from the North Black Range Parelang fires west of Braidwood during the Black Summer (2019-2020) wildfires. Photo: Jara Knowles.
More extreme heatwaves, heavy rainfall, longer fire seasons, rising sea levels: highlights in the latest State of the Climate report.
A biennial paper released by the Bureau of Meteorology and CSIRO warned that Australians would experience “ongoing changes” to the country’s weather and climate, particularly in the southern and eastern regions.
Australia’s climate has increased by an average of 1.47°C since national records began in 1910, and sea surface temperatures have increased by an average of 1.05°C since 1900.
“[We’re projected to experience a] Cool season rainfall on average continues to decrease across many parts of southern and eastern Australia, and drought duration is likely to be longer, but continued climate change will lead to short periods of heavy rainfall. could occur,” the report said. said.
“[There’s also a] In southern and eastern Australia, the fire season is lengthening as the number of days of hazardous weather with fires continues to increase. “
ACT Climate Change Council Chair Professor Mark Howden said in plain language:
“There aren’t many joys in this part of the world,” he said.
“The gap between the wet and dry seasons will get bigger, and the wet season will get wetter, and the drought will become more severe, which will exacerbate the problem.”
He said the paper showed a continuation of what previous reports had shown, that climate variability continues to increase.
This was partially caused by climatic factors such as La Niña, El Niño, the Indian Ocean Dipole phenomenon and the Southern Ocean impact, but risk factors as a result of climate change also played a role.
‘Whether it’s rainfall variability or temperature extremes, these combinations increase the risk of fire,’ says Professor Howden.
“It’s a combination of very hot, very dry and very windy conditions with a strengthening cold front.”
Since the 1950s, much of the country has seen an increase in extreme fire weather and longer fire seasons, according to the report.
Meanwhile, southeastern Australia has seen about a 10% decrease in rainfall from April to October since the late 1990s, and high mountain regions have seen a decrease in snow cover, snow cover and snow days since the late 1950s.
Change in the number of days per year (July to June) where the wildfire risk index exceeds the 90th percentile between July 1950 and June 1986 and July 1986 and June 2022. Photo: State of the Climate 2022.
There’s also a worrying trend about how dangerous the fire season is getting.
“There has been a significant increase in the frequency of dangerous fires in recent decades in many parts of Australia, particularly in the south and east,” the report said.
“There is a noticeable trend in some parts of southern Australia to have more days of extreme bushfires and possible thunderstorms within the plumes of smoke.
“Thunderstorms from these fires can lead to very dangerous fire conditions, such as the Australian Black Summer Fires (2019-20), the Canberra Fires (2003) and the Victorian Black Saturday Fires (2009). I have.”
Professor Howden said this is a concern as the risk has “increased significantly”.
“They are [fire storms] It’s gone from something that was rarely reported to now to a common occurrence, so it’s something to worry about,” he said.
According to the report, heavy rain events occurring over a period of less than a day are becoming more intense, with the duration of short (hourly) extreme rain events increasing by more than 10% in some regions.
This is because the warmer the atmosphere, the more water it can hold.
“This relationship alone could lead to a 7% increase in atmospheric moisture for every 1°C increase in temperature, all other things being equal,” says the report.
“This could make heavy rains more likely even in parts of Australia where average rainfall is expected to fall.”
Rate of sea level rise around Australia measured using satellite altimeters from 1993 to 2020. Photo: State of the Climate 2022.
Sea levels are also rising, increasing the risk of flooding and damage to coastal infrastructure and communities.
Based on observations since 1993, the rate of sea level rise in northern and southeastern Australia is “significantly higher” than the global average.
“The energy of the waves is also increasing, which means they are stronger and more erosive,” says Professor Howden.
But not everything should be brooding and ruinous.
Professor Howden noted ACT’s commitment as a global leader in both climate policy and greenhouse gas reduction activities.
He also said we need to start adapting to the changes we’re seeing.
Professor Howden advised, “We need to stop building in areas with fire and flood problems, build environmentally friendly infrastructure, and change social practices in response to climate change.”
“We must worry, but we must also hope.”
Original article published by Claire Fenwicke on Riotact.
