This is evident from the latest State of the Climate report fromand there is not much good news for Australians.
Our climate has warmed by an average of 1.47℃ since national records began, bringing the continent close to the 1.5℃ limit that the Paris Agreement hoped would never be breached. When average global warming reaches this milestone, some of Earth’s natural systems are predicted to suffer catastrophic damage.
The report released today paints a worrying picture of ongoing and worsening climate change. In Australia, associated impacts such as extreme heat, bushfires, drought, heavy rainfall and coastal flooding threaten our people and our environment.
The report is a comprehensive biennial snapshot of the latest climate trends, with a focus on Australia. It has been compiled by the Bureau of Meteorology and CSIRO, based on the latest national and international climate research.
It synthesizes the latest science on the Australian climate and builds on the previous report from 2020 by including information from the most recent assessment report of the Intergovernmental Panel on Climate Change, for example.
And the message to take home? Climate change continues unabated. The world is warming, sea levels are rising, the ice is melting, the weather is getting worse with fires, flooding is on the rise – and the list goes on.
What follows is a summary of the main findings in three main categories – and an explanation of what it all means.
1. Global warming, extreme heat and wildfires
According to the 2020 report, Australia’s climate has warmed by an average of 1.44℃ since national records began in 1910. That warming has now increased to 1.47 ℃. This reflects trends in the world’s land areas and brings with it more frequent extreme heat events.
The year 2019 was the warmest year on record in Australia. The eight years from 2013 to 2020 are all among the ten warmest on record. Warming occurs both during the day and at night, and during all months.
Since the 1950s, extreme fire weather has increased and the fire season has been extended in much of the country. It has resulted in larger and more frequent fires, especially in South Australia.
2. Rain, flood and snow
In southwestern Australia, rainfall from May to July has fallen by 19% since 1970. In southeastern Australia, rainfall from April to October has fallen by 10% since the late 1990s.
This will come as somewhat of a surprise given the relatively wet conditions in eastern Australia in recent years. But don’t confuse longer-term trends with year-to-year variability.
Less rainfall has led to reduced flow; about 60% of water meters in Australia show a downward trend.
At the same time, heavy rainfall is intensifying – a fact that has not gone unnoticed by flood-stricken residents of Australia’s eastern states in recent months. The intensity of one-hour extreme rainfall has increased by about 10% or more in some regions in recent decades. This often brings flash floods, especially in urban environments. The costs to society are enormous.
Warm air can hold more water vapor than cooler air. That is why global warming is increasing the likelihood of heavy rainfall, even in places where average rainfall is expected to decrease.
Also since the 1950s, snow depth and cover, and the number of snow days, have decreased in alpine areas. The greatest declines occur in the spring and at lower elevations.
Extremely cold days and nights are generally less common across the continent. And while parts of South East and South West Australia have had very cold nights lately, that’s because the cool seasons there have become drier and winter nights clearer there, leading to more heat loss at night.
Any camper will tell you how cold it can get on a clear starry night without the warm blanket of cloud cover.
3. Oceans and sea levels
The sea surface temperature around the continent has risen by an average of 1.05℃ since 1900. The largest ocean warming since 1970 occurred in southeastern Australia and Tasmania. In the Tasman Sea, the rate of warming is now twice the global average.
Continued ocean warming has also contributed to longer and more frequent marine heat waves. Marine heat waves are particularly damaging to ecosystems, including the Great Barrier Reef, which is in danger of destruction if nothing is done to address rising greenhouse gas emissions.
Oceans around Australia have also become more acidic, and this damage is accelerating. The greatest change occurs in temperate and cooler waters in the south.
Sea levels are rising globally and around Australia. This is caused by both ocean warming and melting ice. Ice loss from Greenland, Antarctica and glaciers is increasing and will only get worse.
Around Australia, the greatest sea level rise has been observed in the north and southeast of the continent. This increases the risk of flooding and damage to coastal infrastructure and communities.
What causes this?
All this is happening because the concentrations of greenhouse gases in the Earth’s atmosphere continue to rise. The main driver of these gases is the human combustion of fossil fuels. These long-lived gases form a “blanket” in the atmosphere that makes it more difficult for Earth to radiate the sun’s heat back into space. And so the planet is warming up, with very costly consequences for society.
The report confirmed that carbon dioxide (CO₂) has increasingly accumulated in the atmosphere over the past few decades. Worryingly, methane and nitrous oxide levels have also risen very rapidly over the past two years.
What is next?
None of these problems will go away. Australia’s weather and climate will continue to change over the coming decades.
As the report states, these climate changes are increasingly affecting the lives and livelihoods of all Australians. It goes on:
Australia needs to plan for and adapt to the changing nature of climate risks now and in the decades to come. The severity of the impact on Australians and our environment will depend on how quickly global greenhouse gas emissions can be reduced.
This point is particularly confronting, given the terrible failure of the recent COP27 climate talks in Egypt to build on commitments made by Glasgow just a year earlier to phase out fossil fuels.
So it comes as no surprise that the insurance industry is Getting nervous about issuing new policies to people living on the front lines of climate extremes.
While the urgency for action has never been more urgent, we still hold the future in our hands – the choices we make today will shape our future for generations to come. Every 0.1℃ of warming we can avoid will make a big difference.
But it’s not all bad news. Redesigning our energy and transportation systems to be carbon neutral will create an entirely new economy and job growth – with the added bonus of a more secure climate future.
Do nothing, and these State of the Climate reports will continue to make for grim reading.