Australia Has Hottest Winter On Record As Climate Change Drives Long-Term Warming Trend

The Independent - Fiona Keating

The danger period for bushfires has moved a month forward into September because of the more arid conditions

Over 200 weather records were broken in Australia during the summer of 2016, with extreme bushfires and heatwaves. Reuters

The hottest winter ever has been recorded in Australia amid a "long-term warming trend" mostly caused by climate change, according to the country's Bureau of Meteorology.
Peak temperatures during the day were up by 1.9 degrees Celsius (3.4 Fahrenheit) on the long-term national average of 21.8C during the period between June and August.
Winter rainfall was also down to the least amount since 2002 and the ninth-lowest on record. Australia started charting the statistics in 1900 for rainfall and 1910 for temperatures.
"You have a long-term warming trend which is largely attributed to changing levels of greenhouse gases," the bureau's senior climatologist Blair Trewin told AFP.
"On top of that, to get an individual extreme year like this one, you also need the more general weather pattern to be favourable to warm conditions as well, as this year was."
The bureau also noted that 19 of Australia’s last 20 winters had seasonal top temperatures that averaged above the long-term national average.
Meteorologist Greg Browning said it was "basically this background warming signal that we're seeing right across the globe associated with global warming".
Victoria was faced with the driest winter in more than 10 years, with rainfall “significantly below average,” Mr Trewin told the Herald Sun.

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More than 200 weather records were broken during the summer of 2016, with extreme bushfires, heatwaves and flooding.
Australia has warmed by around one degree Celsius since 1910, weather bureau and national science body CSIRO reported.
New South Wales’s Rural Fire Service is bringing forward its bushfire danger period to September, a month earlier because of the hotter and more arid conditions.
Research published in Nature Climate Change last week stated that hotter, drier conditions would increase in frequency even if global warming was kept to the Paris Climate Summit target of 1.5C.
The study warned it would be harder to tackle drought events and wildfires.
The highest-ever recorded temperature in Australia was 50.7C (123.3 F) in Oodnadatta on 2 January 1960.
A firefighting Hercules C-130 plane, dubbed ‘Thor’, has returned to Richmond airbase in Sydney from the United States, to prepare for the country's bushfire season. The aircraft is capable of dropping 15,000 litres of water or fire retardant.

Links

• Sydney heatwave expected to break 120-year hot weather record
• Australia wildfires: Firefighters prepare for worst as hot weather
• Australia’s dry June is a sign of what’s to come
• Dry winter primes Sydney Basin for early start of bushfire season
• Sure, winter felt chilly, but Australia is setting new heat records at 12 times the rate of cold ones
• BOM: Australia in winter 2017
• BOM: Climate outlook for winter (June to August)
• Queensland asks 'what winter?' after unseasonably warm weather

Australia-Led Tidal Energy Project Sets New Production Records

RenewEconomy - Giles Parkinson

Atlantis tidal energy turbine being prepared for deployment. Photo supplied by company.

The Australian-founded and managed tidal energy company Atlantis Resources has claimed a world record production output for a tidal stream power station from its facility in Scotland’s Pentland Firth.
Atlantis late last week said it had produced 700MWh of electricity in August, taking its total production to 2GWh. It’s not a huge amount of power – the month of August was about enough to power up to 2,000 homes – but it’s a big deal in the tidal energy industry.
“The production performance from the installed turbines on the MeyGen project has been very good,” said David Taaffe, the director of project delivery at Meyden, the company’s main tidal energy project.
“With yet another successful installation campaign expertly completed this week by the Atlantis operations team, we expect to continue to break records throughout the rest of the year generating both predictable power and revenue.”
Atlantis was founded in Australia a decade ago, and then shifted to Singapore to attract investment funds, and then to Edinburgh to be close to its major projects, which are all in the UK.
Its senior management, including CEO Tim Cornelius, newly appointed CFO Andrew Dagley and its head of turbine and engineering services Drew Blaxland are all Australian – and so are half the board of directors.
The Meygen project is the largest tidal stream energy project in the world and – like Carnegie Clean Energy’s wave energy project off Western Australia – it is the first with multiple machines.
The technology is described by Atlantis as like wind turbines under water. Indeed, they are piggy-backing on some of the big developments in offshore wind energy design, and technology pioneered by subsea oil and gas industry, where the likes of Cornelius worked previously.
The company says tidal power projects are typically located close to the shore, so most of the expensive power conditioning equipment is located safely in the onshore substation. Tidal turbines rotate very slowly, so pose no threat to marine life whilst in operation, and are programmed to turn and face into the tide.
Atlantis says the potential is there to produce 20 per cent of the UK’s electricity needs. In Australia, the Australian Renewable Energy Agency in July said it had part-funded e $5.85 million project to assess and map the tidal energy resources in Australia.
So far, four 1.5MW turbines have been installed as part of MeyGen’s “deploy and monitor strategy”, and will act as a precursor to the development of an 86MW project that has received consent so far, although the ultimate project size could be nearly 400MW.
The project is designed to show that the development of tidal array projects is both commercially viable and technically feasible. It is looking at up to 10,000MW of projects in Canada, China, India and Indonesia, as well as those in the UK.
The company is listed on the London AIM Stock Exchange but its principal financial backer has been global investment bank Morgan Stanley.
Cornelius said earlier this month that it the world’s largest tidal power array was continuing to set milestones. “It’s extremely rewarding for all those involved to see the fruits of our collective passion and labour continuing to deliver.”

Links

• Unlocking the potential of Australia’s tidal energy
• World’s largest tidal energy plant gets go-ahead for construction
• Australia-founded wave and tidal energy firms to work together
• World’s biggest wind turbine maker waves oil industry goodbye
• The fight for millions of Australians locked out of rooftop solar

Can Corals Survive Climate Change?

ScienceDaily

Coral reef experts deliver urgent recommendations for future research

There is substantial variability in temperature tolerance among and within coral species. Typically, boulder-like corals survive higher temperatures, while branching corals perish under moderate heat stress. Scientists are striving to understand and harness the molecular mechanisms that underpin this variability. Central GBR, March 2017. Credit: G. Torda

A group of international scientists, including scientists from Australia, have issued advice that more research is urgently required to determine whether corals can acclimatise* and adapt to the rapid pace of climate change.

The team of coral experts, led by Dr. Gergely Torda from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University and the Australian Institute of Marine Science (AIMS), have delivered recommendations for future research.
As the Great Barrier Reef faces unprecedented coral mortality from back-to-back mass bleaching in 2016 & 2017, rising carbon dioxide and other natural and human-induced pressures, scientists advise more research is urgently needed into the poorly-understood mechanisms that corals might use to survive in a rapidly warming world.
"There is still a lot to understand about corals," says Dr. Torda. "While our only real chance for their survival is to reverse climate change, a nugget of hope exists -- that the corals may be able to adapt to their changing environment," he says.
"However, there are major knowledge gaps around how fast corals can adapt or acclimatise to changes in their environment, and by what mechanisms they might use to achieve this," adds co-author Professor Philip Munday of Coral CoE.
"For example," explains Dr Jenni Donelson, co-author at Coral CoE,"recent studies show that fish can acclimatise to higher water temperatures when several generations are exposed to the same increased temperature, but whether corals can do the same, and how they might achieve this, is largely unknown."
Eight research recommendations are published today in the journal Nature Climate Change and arise from a workshop with a team of experts composed of 22 biologists from 11 institutions in five different countries.
The team agrees that further research identifying how corals respond to climate change is critical, as the Earth undergoes an unprecedented rate of environmental change.
AIMS Climate Change Scientist, Dr. Line Bay says, "There is sufficient inertia in the climate system that we will not be able to prevent further climate-related disturbances affecting the reef in the immediate future."
"Solutions are required to help corals adapt and acclimate to near-term future climate pressures while we figure out how to reduce emissions and halt and reverse longer-term climate change."
Co-authors Prof. Timothy Ravasi and Dr. Manuel Aranda from King Abdullah University of Science and Technology (KAUST) warn that the clock is ticking. "The Great Barrier Reef has suffered substantial losses of coral over the past two years. Understanding the mechanisms that could enable corals to cope with ocean warming is becoming increasingly important if we want to help these ecosystems," they say.
The paper is focused on stony, reef-building corals, which are the 'ecosystem engineers' of tropical coral reefs. These corals build the frameworks that provide shelter, food and habitat for an entire ecosystem. When corals are lost, the diversity and abundance of other reef organisms declines, until ultimately the ecosystem collapses.
"Predicting the fate of coral reefs under climate change is subject to our understanding of the ability of corals to mount adaptive responses to environmental change," says Dr. Torda. "Our paper sets out key research objectives and approaches to address this goal."
"The time to act is now, as the window of opportunity to save coral reefs is rapidly closing," he concludes.

Links

• Sub-tropical corals vulnerable, new study shows
• Algae fortifies coral reefs in past and present
• Coral skeletons may resist the effects of acidifying oceans
• Current threats to our oceans revealed

The Truth About Harvey And Climate Change Is In The Middle

Washington Post - Jason Samenow*

Floodwaters from Tropical Storm Harvey overflow from the bayous around Houston this week. (David J. Phillip/AP)

Did climate change make Hurricane Harvey’s impact significantly worse? There are a lot of opinions on this out there, and it’s okay if you’re confused. The reality is that some scientists say yes; and some, no.
In answering this question, the safest place is the middle ground: Climate change probably made Harvey a little worse. But you’re on shaky ground to say any less or much more.
Before we delve a little deeper into this question, let’s dispense with the idea that climate change or global warming caused Harvey to form. It did not. Climate change does not cause hurricanes. In the tropics, hurricanes require rising air (from converging winds), heat and moisture to form. These ingredients led to Harvey’s formation just as they have led to the genesis of tropical storms as far back as anyone knows.
The real question is whether climate change made Harvey worse than it would have been otherwise and, if so, how much worse.
There are basically four ways climate change could have intensified the hurricane’s effects. I list them here, from high confidence to low confidence:

1. By raising sea levels, climate change increased the rise in ocean water or storm surge when the storm came ashore and the coastal flooding that resulted.
2. By warming temperatures in the Gulf of Mexico, climate change intensified the storm’s rainfall.
3. By warming temperatures in the Gulf of Mexico, climate change intensified the storm’s peak winds.
4. By slowing down the jet stream, climate change increased the likelihood the storm would stall and unload rainfall over the same areas.

No one disagrees the ocean levels are rising, so it is true that climate change-induced sea level very likely added impact to the area inundated by Harvey’s surge. According to NOAA, sea levels in Rockport, Tex., near where Harvey made landfall, are rising at a rate of about 20 inches per century. So areas that were flooded by storm surge probably have climate change to thank for about a foot and half of extra water.

(NOAA)

But of all of Harvey’s hazards, the surge was probably the least damaging because it affected a relatively sparsely populated area of the coastline. In Hurricane Sandy, for example, the surge was a much bigger problem. Disastrous rain, of course, caused the most issues.
Let’s be perfectly clear: With or without climate change, the rainfall from Harvey would have been catastrophic. But, yes, climate change probably added rainfall for this event.
Our best science indicates there is a 3 percent increase in atmospheric moisture content for every degree (F) of warming in the storm’s environment. As Harvey moved across the Gulf of Mexico, the sea surface temperatures were about 2 degrees warmer than normal, which means rainfall may have been enhanced by 6 percent or so, or a few inches.
The question of whether climate change meaningfully worsened Harvey’s winds is much more ambiguous. According to the latest modeling, more than doubling carbon dioxide in the atmosphere would lead to a 2 percent to 11 percent increase (on average) in hurricane peak winds by the end of this century. So any impact on Harvey’s wind speeds from climate change at this point would theoretically be small. Climate assessments conducted to date have not yet found a “detectable” change in hurricane intensity from rising greenhouse gas emissions.
Finally, there is the question of whether climate change-induced influence on atmospheric steering currents slowed the storm down and enabled it to unload torrential rainfall over the same areas for days. Scientists are uncertain about this.
“There are some ideas in the scientific literature that suggest that global warming may make this situation more probable,” wrote climate scientists Suzana Camargo and Adam Sobel of Columbia University. “However, these ideas are still speculative and not widely agreed upon by scientists.”
Harvey is not the first storm to make landfall in Texas and then stall and dump astronomical amounts of rain. The historical hurricane record is full of examples of storms slowing down and meandering after hitting land masses.
Adding up all of these possible climate change effects on Harvey, how significant were they in reality? That’s where expert opinion diverges.

Michael Mann, professor of meteorology at Pennsylvania State University, posted on Facebook that climate change “exacerbate[d] several characteristics of the storm in a way that greatly increased the risk of damage and loss of life.”

But Cliff Mass, a professor of meteorology at the University of Washington, who called global warming a serious issue, concluded that its effects on Harvey were “immaterial.” He also accused some scientists and media of “using hand-waving arguments to push an agenda.”
Where do I come out on this? I take the middle ground between Mann and Mass. Climate change probably made Harvey worse, but I wouldn’t say profoundly worse. This is a storm that, irrespective of climate change, was going to be terrible.
Also, and this is an important point, no one should be under the impression that if we slash greenhouse gas emissions radically, these storms are going to stop or become significantly less severe. Devastating storms ravaged our coasts long before human-made climate change was a thing.
While reducing greenhouse gas emissions is a critical strategy for avoiding the worst consequences of climate change, it will take many decades or longer for those reductions to have a detectable impact on hurricane intensity. This is why it is so important to think about how to make our cities more resilient to these storms.
Because climate change most likely is and will continue to make these storms more severe, we can’t ignore the role it plays. But we shouldn’t pretend it’s a bigger deal than it is or that it’s nothing to worry about at all. Instead, we should consider it among all of the factors, including infrastructure and urban planning, that play a critical role in the impact storms have on our society and have constructive conversations about how to deal with them and implement sensible policy.

*Jason Samenow is the Washington Post’s weather editor and Capital Weather Gang's chief meteorologist. He earned a master's degree in atmospheric science, and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association.

Links

• Climate change did not cause Superstorm Sandy, but probably intensified its effects
• Harvey is a 1,000-year flood event unprecedented in scale
• The forgotten but freakish damage from Hurricane Harvey’s eyewall in Rockport, Tex.
• Is the media scaring the public too much about climate change and extreme weather?

We Don’t Deny Harvey, So Why Deny Climate Change?

New York Times - Nicholas Kristof

Spring, Tex., on Tuesday. Credit Ilana Panich-Linsman for The New York Times

Imagine that after the 9/11 attacks, the conversation had been limited to the tragedy in Lower Manhattan, the heroism of rescuers and the high heels of the visiting first lady — without addressing the risks of future terrorism.
That’s how we have viewed Hurricane Harvey in Houston, as a gripping human drama but without adequate discussion of how climate change increases risks of such cataclysms. We can’t have an intelligent conversation about Harvey without also discussing climate change.
That’s awkward for a president who has tweeted climate change skepticism more than 100 times, even suggesting that climate change is a Chinese hoax, and who has announced he will pull the U.S. out of the Paris climate accord. Scott Pruitt, President Trump’s head of the Environmental Protection Agency, says it’s “misplaced” to talk about Harvey and climate change.
Really? To me, avoiding the topic is like a group of frogs sitting in a beaker, fretting about the growing warmth of the water but neglecting to jump out. Climate scientists are in agreement that there are at least two ways climate change is making hurricanes worse.
First, hurricanes arise from warm waters, and the Gulf of Mexico has warmed by two to four degrees Fahrenheit over the long-term average. The result is more intense storms.
“There is a general consensus that the frequency of high-category (3, 4 and 5) hurricanes should increase as the climate warms,” Kerry Emanuel, a hurricane expert at M.I.T., tells me. Likewise, three experts examined the data over 30 years and concluded that Atlantic tropical cyclones are getting stronger.
Second, as the air warms, it holds more water vapor, so the storms dump more rain. That’s why there’s a big increase in heavy downpours (“extreme precipitation events”). Nine of the top 10 years for heavy downpours in the U.S. have occurred since 1990.
“Climate change played a role in intensifying the winds and rainfall associated with Hurricane Harvey,” says Charles Greene, a climate scientist at Cornell. He notes that there’s also a third way, not yet proven, in which climate change may be implicated: As Arctic sea ice is lost, wind systems can meander and create blockages — like those that locked Harvey in place over Houston. It was this stalling that led Harvey to be so destructive.
Frankly, it’s staggering that there’s still so much resistance among elected officials to the idea of human-caused climate change.
Last year was the third in a row to set a record for highest global average surface temperature, according to NASA. The 10 years of greatest loss of sea ice are all in the last decade. And poor Houston has suffered three “500-year floods” in the last three years.
Remember also that we in the rich world are the lucky ones. We lose homes to climate change, but in much of the world families lose something far more precious: their babies. Climate change increases risks of war, instability, disease and hunger in vulnerable parts of the globe, and I was seared while reporting in Madagascar about children starving apparently as a consequence of climate change.
An obvious first step is to embrace the Paris climate accord. A second step would be to put a price on carbon, perhaps through a carbon tax to pay for tax cuts or disaster relief.
We also must adapt to a new normal — and that’s something Democratic and Republican politicians alike are afraid to do. We keep building in vulnerable coastal areas and on flood plains, pretty much daring Mother Nature to whack us.
We even subsidize such dares through the dysfunctional National Flood Insurance Program. This offers underpriced insurance, encouraging people to live in low-lying areas — compounded by flood maps that are old and unreliable. One Mississippi home flooded 34 times in 32 years, resulting in payouts worth almost 10 times what the home was worth.
The truth is that what happened in Houston was not only predictable, it was actually predicted. Last year, ProPublica and The Texas Tribune published a devastating article about Houston as a “sitting duck for the next big hurricane” and warned that Texas was unprepared.
In other domains, we constantly manage risks that are uncertain. We address a threat from the Islamic State or North Korea even when it’s complicated and hard to assess. So why can’t our leaders be as alert to climate risks that in the long run may be far more destructive?
Sure, definitively linking any one storm to climate change is difficult. Likewise, when a particular person contracts lung cancer, it may be impossible to prove that smoking was the cause that time. But it’d be absurd for America to discuss the challenge of lung cancer only through the prism of suffering patients and heroic doctors (and the high heels of the visitors in the cancer ward!) without also considering tobacco policy.
A week and a half ago, Republicans and Democrats traveled to see the solar eclipse and gazed upward at the appointed hour, because they believed scientific predictions about what would unfold. Why can’t we all similarly respect scientists’ predictions about our cooking of our only planet?

Links

• What Climate Scientists Want You to See in the Floodwaters
• AP EXCLUSIVE: Toxic Waste Sites Flooded in Houston Area
• Covering Water Damage-Flood Insurance Around the World
• You Fix It: Can You Stay Within the World’s Carbon Budget?
• The Rush to Exploit the Arctic
• Climate Lessons from California
• Climate Report Could Force Trump to Choose Between Science and His Base

“Drawdown” — The Definitive Guide To Combating Climate Change

CleanTechnica - Steve Hanley

Drawdown is a compendium of every idea known to humanity at the present time that can slow or reverse the devastation of climate change. The Paris climate change protocols set out the lofty goals agreed to by all of the world’s governments except two in December of 2015. Drawdown is the nuts and bolts guide to implementing those goals.

Maps, Measures, & Models
Edited by Paul Hawken, the book “maps, measures, models, and describes the 100 most substantive solutions to global warming. For each solution, we describe its history, the carbon impact it provides, the relative cost and savings, the path to adoption, and how it works. The goal of the research that informs Drawdown is to determine if we can reverse the buildup of atmospheric carbon within thirty years. All solutions modeled are already in place, well understood, analyzed based on peer-reviewed science, and are expanding around the world.”
At 240 pages in length, this review cannot delve into each nook and cranny of the environmental toolkit proposed by the authors. Suffice to say, if you are interested in how humans can address climate change in an effective way, Drawdown is a must-read book.
Every aspect of every idea is explored in detail. The recommendations are peer reviewed. The science behind each one is extensively footnoted so anyone who wants to can go to the source. What I found most remarkable about the book begins on page 222 — Summary Of Solutions By Overall Ranking.

Drawdown Surprises
We here at CleanTechnica, we focus heavily on the electrification of the transportation sector. That is critically important, of course, but would you care to guess what the one area is that we as a people have total control over and that has the potential to keep more carbon dioxide out of the atmosphere than making every car and truck on the planet run on electricity?
#1 is something we have touched on here only briefly — refrigerant management. Read more about it on page 164. The authors estimate that this one area could keep nearly 90 gigatons of carbon dioxide from entering the atmosphere. Electric cars? About 4 gigatons.
Here are the other 9 items on the Top 10 list and their carbon reduction potential:

• Wind Turbines (Onshore) — 84.60 gigatons
• Reduced Food Waste — 70.53 gigatons
• Plant-rich diet — 66.11 gigatons
• Tropical Forests — 61.23 gigatons
• Educating Girls — 59.60 gigatons
• Family Planning — 59.60 gigatons
• Solar Farms — 36.90 gigatons
• Silvopasture — 31.19 gigatons
• Rooftop Solar — 24.60 gigatons

There are 80 items on the list. Total cost if all were fully implemented? $27.4 trillion. That’s a lot of cash, right? However will we pay for all that? With savings, people — or deferred costs. The authors estimated total economic savings at just under $74 trillion.

Deferred Gratification
The trick, of course, is that the costs come up front. The savings often come later. Human beings seem genetically incapable of making hard choices today that will have extraordinary benefits later. Deferred gratification could be the death knell for the capitalist model prevalent in most countries today. Pie-in-the-sky projections about future savings are discounted. Either they are treated as irrelevant or derided as #FakeNews.
The world operates on what I like to call the Wimpy Theory. Wimpy was a character in Popeye cartoons (some of you may be old enough to remember watching cartoons on television on Saturday mornings). Wimpy had one line that he used all the time. It went like this: “I will gladly pay you Tuesday for a cheeseburger today.” It’s the “kick the can down the road” theory of global management and it will kill us all if we don’t stop — all except the lucky few who can escape to Mars aboard Elon Musk’s magic carpet.

Empowerment Of Women
We have recently written some articles on refrigeration. We have also touched on educating girls and the empowerment of women. Each of those areas makes the Top 10 list in Drawdown. Electric cars are #49. Combined, educating girls and empowering women are rated as saving more carbon dioxide emissions than any other element in the hierarchy of suggestions for combating climate change compiled by the editors.
And yet, the US government, spurred on by the hatred and bigotry of the so-called Religious Right (which is neither, by the way), has reimposed the so-called “global gag rule” that prohibits the spending of $1 to assist women in other countries from having access to family planning services. Here at home, the US Congress is howling like a pack of jackals in search of ways to defund Planned Parenthood.

Changes In Attitude Needed
Want to make an impact in the fight to limit the ravages of climate change? Buying an electric car and putting solar panels on your roof is laudable. But advocating for women’s rights and access to adequate health care should be your first priority. What Drawdown makes abundantly clear is that putting shackles on women to satisfy some cultural notions of male privilege or the ravings of so-called religious leaders like Pat Robertson and Franklin Graham is a death warrant for the earth.
It’s easy to throw platitudes around and advocate for our favorite fix for global warming. Drawdown shows us that fixing our attitudes about each other will be more important in the long run than all of Elon Musk’s astonishing inventions, all the solar panels, and all the Gigafactories in the world. It’s shocking to realize electric cars will eliminate only 4% of the carbon dioxide added to the atmosphere in coming years compared to the combination of educating and empowering women.
Shocking it may be, but as Mark Twain once said: “It’s not what you don’t know that kills you, it’s what you know for sure that ain’t true.”

Links

• South Asia’s Worst Monsoon Flooding In Years — 1,200 Dead Across India, Bangladesh, & Nepal
• Leveraging Behavior To Combat Climate Change
• China To Begin Paying Farmers To Convert Livestock Waste To Fuel & Fertilizers
• Unlocking Universal Access To Community Solar

Australia’s Record-Breaking Winter Warmth Linked To Climate Change

The Conversation - Andrew King

This winter had some extreme low and high temperatures. Daniel Lee/Flickr, CC BY-NC

On the first day of spring, it’s time to take stock of the winter that was. It may have felt cold, but Australia’s winter had the highest average daytime temperatures on record. It was also the driest in 15 years.
Back at the start of winter the Bureau of Meteorology forecast a warm, dry season. That proved accurate, as winter has turned out both warmer and drier than average.
While we haven’t seen anything close to the weather extremes experienced in other parts of the world, including devastating rainfalls in Niger, the southern US and the Indian subcontinent all in the past week, we have seen a few interesting weather extremes over the past few months across Australia.

Much of the country had drier conditions than average, especially in the southeast and the west. Bureau of Meteorology

Drier weather than normal has led to warmer days and cooler nights, resulting in some extreme temperatures. These include night-time lows falling below -10℃ in the Victorian Alps and -8℃ in Canberra (the coldest nights for those locations since 1974 and 1971, respectively), alongside daytime highs of above 32℃ in Coffs Harbour and 30℃ on the Sunshine Coast.
During the early part of the winter the southern part of the country remained dry as record high pressure over the continent kept cold fronts at bay. Since then we’ve seen more wet weather for our southern capitals and some impressive snow totals for the ski fields, even if the snow was late to arrive.
This warm, dry winter is laying the groundwork for dangerous fire conditions in spring and summer. We have already had early-season fires on the east coast and there are likely to be more to come.

Climate change and record warmth
Australia’s average daytime maximum temperatures were the highest on record for this winter, beating the previous record set in 2009 by 0.3℃. This means Australia has set new seasonal highs for maximum temperatures a remarkable ten times so far this century (across summer, autumn, winter and spring). The increased frequency of heat records in Australia has already been linked to climate change.

Winter 2017 stands out as having the warmest average daytime temperatures by a large margin. Bureau of Meteorology

The record winter warmth is part of a long-term upward trend in Australian winter temperatures. This prompts the question: how much has human-caused climate change altered the likelihood of extremely warm winters in Australia?
I used a standard event attribution methodology to estimate the role of climate change in this event.
I took the same simulations that the Intergovernmental Panel on Climate Change (IPCC) uses in its assessments of the changing climate, and I put them into two sets: one that represents the climate of today (including the effects of greenhouse gas emissions) and one with simulations representing an alternative world that excludes our influences on the climate.
I used 14 climate models in total, giving me hundreds of years in each of my two groups to study Australian winter temperatures. I then compared the likelihood of record warm winter temperatures like 2017 in those different groups. You can find more details of my method here.
I found a stark difference in the chance of record warm winters across Australia between these two sets of model simulations. By my calculations there has been at least a 60-fold increase in the likelihood of a record warm winter that can be attributed to human-caused climate change. The human influence on the climate has increased Australia’s temperatures during the warmest winters by close to 1℃.

More winter warmth to come
Looking ahead, it’s likely we’re going to see more record warm winters, like we’ve seen this year, as the climate continues to warm.

The likelihood of winter warmth like this year is rising. Best estimate chances are shown with the vertical black lines showing the 90% confidence interval. Author provided

Under the Paris Agreement, the world’s nations are aiming to limit global warming to below 2℃ above pre-industrial levels, with another more ambitious goal of 1.5℃ as well. These targets are designed to prevent the worst potential impacts of climate change. We are currently at around 1℃ of global warming.
Even if global warming is limited to either of these levels, we would see more winter warmth like 2017. In fact, under the 2℃ target, we would likely see these winters occurring in more than 50% of years. The record-setting heat of today would be roughly the average climate of a 2℃ warmed world.
While many people will have enjoyed the unusual winter warmth, it poses risks for the future. Many farmers are struggling with the lack of reliable rainfall, and bad bushfire conditions are forecast for the coming months. More winters like this in the future will not be welcomed by those who have to deal with the consequences.

Climate data provided by the Bureau of Meteorology. For more details about winter 2017, see the Bureau’s Climate Summaries.
You can find more details on the specific methods applied for this analysis here.

Links

• Australia’s dry June is a sign of what’s to come
• Dry winter primes Sydney Basin for early start of bushfire season
• Sure, winter felt chilly, but Australia is setting new heat records at 12 times the rate of cold ones
• BOM: Australia in winter 2017
• BOM: Climate outlook for winter (June to August)
• Queensland asks 'what winter?' after unseasonably warm weather