Winter Marked By Record Temperatures Nationally As Big Dry Spreads

Fairfax - Peter Hannam

Winter's grip will finally feel like it's loosened amid a "heat spike" this weekend – even if that season's squeeze was not a particularly tight one.
Nationally, Australia had its warmest winter by maximum temperatures since records began in 1910, with days on average 1.9 degrees warmer than normal. That beat the previous record winter in 2009 by 0.3 degrees.

The large air tanker C-130 Hercules "Thor" does a water drop fly-by as fire authorities gear up for an early and active fire season. Photo: Ben Rushton

One influence driving the abnormally mild condition was the band of high pressures that sat further south than normal over the continent, keeping cold fronts at bay. Climate change was also a factor.
"You have the underlying long-term warming trend," Blair Trewin, senior climatologist at the bureau, said. "Consistent with that, 19 of the last 20 winters have had above-average maximum temperatures."
Nationally, August was less extreme than June and July, with temperature anomalies less pronounced and better rains across south-eastern Australia helping to ease rainfall deficits in many areas.
Forest fire index levels, though, remain high, particularly for inland NSW, as authorities prepare for an early bushfire season.
For Sydney, the city had its driest winter since 2009. The 211.4-millimetre tally for the three months was about a third below average. July and August alone, though, were the driest in 22 years, Weatherzone said.
Sydney had its seventh-warmest winter for daytime temperatures, in line with last year.
The season also included the city's warmest July day on record, with 26.5 degrees on July 30 beating a record that had stood since 1990, the bureau said.
(See bureau chart below of average maximum temperatures.)

Brief burst of spring
Similarly warm conditions should return for the first weekend of spring, encouraging many to venture outdoors amid a "temporary heat spike", Graeme Brittain, a meteorologist from Weatherzone, said.
For those heading to the beach, "sheltered, south-facing beaches will be the place to go", particularly on Sunday when northwesterly winds pick up.
On current forecasts, Sydney is tipped to reach 22 degrees on Saturday and 28 degrees for a clear if windy Sunday.

Warmer conditions are on the way, at least for this weekend. Photo: Nick Moir 

Spring's volatile weather will be on display, with large and powerful surf predicted for Saturday. Winds will also gradually strengthen on Sunday, reaching 50km/h as a cold front moves through, Mr Brittain said.
"It's a very cold air mass," he said, adding that it will knock daytime temperatures below the September average of 20 degrees for much of next week before conditions warm again by next weekend.
The cold front is also a dry one, as is the next one, meaning there is unlikely to be much rain relief soon for Sydney's threadbare playing fields.
"There's no really significant rain forecast for the next 14 days," Mr Brittain said.

Dry times
Those dry conditions also extend across much of the country after the driest winter since 2002.
Rainfall was about 43 per cent below the norm, the bureau said. (See chart below.)

NSW was notably dry, with about half the typical rain, or 58.8 millimetres. It was also the state's driest winter in 15 years.
Good rains in June meant only a small pocket of the state's north-east enjoyed above-average rain for the season.
For Sydney, rain fell on 22 days during winter, down from the average of 34 days. Just five of them had more than 10 millimetres, compared with eight such days in a typical winter.
With fewer rain clouds around, the city enjoyed sunnier-than-usual conditions, particularly in July and August.

Cool nights
One consequence of limited cloud cover, though, were cool nights, particularly for inland areas.
Sydney's nights remained milder above average for the city, but dropped below the winter average in western suburbs. Minimum temperatures in Parramatta, for instance, were 0.6 degrees below normal, the bureau said.
Likewise for NSW, central and southern parts of the state recorded below-average nights, often accompanied with frost.
Dr Trewin said Bathurst stood out as one location enduring extreme conditions during winter.
The town posted its highest average maximums for the season, its coldest average nights since 1927 and its driest winter on record.
Nationally, average minimum temperatures were 0.34 degrees above the long-term norm, although the cold was particularly centred over the country's south-east. (See bureau chart below.)

After a slow start, the ski season got a boost from some big dumps of snow. Spencer's Creek had 189 centimetres of snow at the end of August, the most since 2012.
More snow is expected in the coming weeks, Dr Trewin said.
The bureau's forecasts for spring, updated on Thursday, point to a switch in coming months towards more typical rainfall levels.
That news will be welcomed by farmers but also fire authorities, particularly in NSW, that are gearing up for an early and active bushfire season.
"The seasonal outlook for spring rainfall does lean to wetter-than-average conditions in a lot of the south-eastern corner of Australia, particularly along the east coast," Dr Trewin said.
"It does look like we're going to see a bit of a pattern shift," he said, although the change for some regions may not arrive until October.

Links

• Spring outlook tilts towards wetter conditions eventually
• 'Critical levels': Sydney bushfire warning for September
• Australia’s Record-Breaking Winter Warmth Linked To Climate Change
• 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

In An Era Of Dire Climate Records The US And South Asia Floods Won't Be The Last

The Guardian - Jonathan Watts

From the US to India and China, human impact on the climate is likely to have made droughts and storms more severe – and the trend is only set to continue

Residents are evacuated during the aftermath of Hurricane Harvey in Houston, Texas. Photograph: Brendan Smialowski/AFP/Getty Images

The 17tn US gallons of rain (roughly 26m Olympic swimming pools) dumped on Texas by Hurricane Harvey has set a new high for a tropical system in the US, but it is unlikely to last long as rising man-made emissions push the global climate deeper into uncharted territory.
Images of flooded streets in Texas are mirrored by scenes of inundated communities in India and Bangladesh, the recent mudslides in Sierra Leone and last month’s deadly overflow of a Yangtze tributary in China. In part, these calamities are seasonal. In part, the impact depends on local factors. But scientists tell us such extremes are likely to become more common and more devastating as a result of rising global temperatures and increasingly intense rainfall.
Our planet is in an era of unwelcome records. For each of the past three years, temperatures have hit peaks not seen since the birth of meteorology, and probably not for more than 110,000 years. The amount of carbon dioxide in the air is at its highest level in 4m years.
This does not cause storms like Harvey – there have always been storms and hurricanes at this time of year along the Gulf of Mexico – but it makes them wetter and more powerful.
As the seas warm, they evaporate more easily and provide energy to storm fronts. As the air above them warms, it holds more water vapour. For every half a degree celsius in warming, there is about a 3% increase in atmospheric moisture content. Scientists call this the Clausius-Clapeyron equation.

This means the skies fill more quickly and have more to dump. In Harvey’s case, the surface temperature in the Gulf of Mexico is more than a degree higher than 30 years ago.
Yes, the storm surge was greater because sea levels have risen 20cm as a result of more than 100 years of human-related global warming. This has melted glaciers and thermally expanded the volume of seawater.
As the rain in Texas moved towards the 120cm US record set in 1978, the nation’s meteorologists have had to introduce a new colour for their charts. It may not be the last revision.
“For large countries like the United States, we can expect further rainfall records – and not just for hurricanes,” said Friederike Otto, deputy director of the Environmental Change Institute at the University of Oxford. This is part of a wider trend. “For the globe, we’ll see heat and extreme rainfall records fall for the foreseeable future,” she predicted.
She cautioned that the situation is likely to be different from country to country. Many factors are involved, but human impact on the climate has added to the tendency for more severe droughts and fiercer storms.
High tides have added to the unusually harsh monsoon flooding in India and Bangladesh that has killed about 1,000 people in recent weeks and forced millions from their homes.

Flooding in Lalmonirhat, Bangladesh sparked by heavy seasonal rains and an onrush of water from hills across the Indian borders. Photograph: Zakir Chowdhury/Barcroft Images

Climatologists are able to attribute with growing accuracy the impact of human emissions on extreme weather events, but much remains uncertain.
A key focus now is whether climate change is connected to the “stalling” of storms. In the US, hurricanes usually move inland and diminish in power as they get further from the sea. Harvey, however, was stationary for several days – which is the main factor in its rainfall record.
Scientists have said this may be the single biggest question posed by Harvey. “I’m not aware of anyone asking this before. I’m not sure anyone would have predicted this kind of event,” said Tim Palmer a Royal Society research professor at the University of Oxford.
Researchers have recently identified a slowdown of atmospheric summer circulation in the mid-latitudes as a result of strong warming in the Arctic. But Palmer said such studies of pressure patterns need more powerful analytical tools, including supercomputers.
In the US, however, such research has become highly politicised. President Donald Trump claims climate change is a myth invented by China. He has announced that the US will pull out of the Paris climate treaty and cut funding for related research.
“It shouldn’t be a political matter to try to understand how much more frequent events like Harvey will become in the future,” said Palmer. “It appalls me how basic science has become embroiled in politics like this.”

Links

• Is tropical storm Harvey linked to climate change?
• South Asia floods: Mumbai building collapses as monsoon rains wreak havoc
• Why more coverage of floods in Texas than in South Asia?
• South Asia floods kill 1,200 and shut 1.8 million children out of school
• South Asia battles flood calamity

Beyond Houston, A World Awash

New York Times - Editorial

This summer, more than 1,000 deaths have been linked to flooding in India, Nepal and Bangladesh. Credit Diptendu Dutta/Agence France-Presse — Getty Images

Houston isn’t the only major city reeling from record rainfall and devastating floods. In Mumbai, India, where summer monsoons are annual events, as much rain fell in 12 hours on Tuesday as normally does over 11 days in a typical monsoon, paralyzing the city, India’s financial capital.
So far this summer, flooding has killed more than 1,000 people in India, Nepal and perennially flood-prone Bangladesh. The United Nations says at least 41 million people have been directly affected by flooding and landslides in South Asia, with homes and croplands destroyed. Floods from heavy rainfall have also ripped through Britain, Ireland, Sudan and Uganda in Africa. On Aug. 14, torrents of water swept through the streets of Sierra Leone’s capital, Freetown, and a massive mudslide left some 1,000 people dead or missing.
Like the calamity in Texas, these unnatural rainfalls carry two messages. One is the risk of unregulated development. As in Houston, officials in India have paid little attention to the consequences of rapid urban growth in low-lying, watery environments with few natural defenses against a deluge when it comes. And, like Houston, which has suffered floods in the past, Mumbai was hit by severe flooding in 2005 that claimed more than 500 lives, yet it did little to address the issues that made that flooding so deadly.
The second message is that unabated climate change does, indeed, exact a price. Warmer weather heats the oceans, which causes more evaporation, which increases moisture in the atmosphere, which then falls as driving rain. Warmer oceans also rise, partly due to thermal expansion, which in turn threatens low-lying areas; among climate scientists, Bangladesh has for years been the poster child of nations that are likely to face famine, flooding and forced migration as a result of rising sea levels caused by global warming.
It does not have to be this bad the next time around. Cities around the world are taking steps to become more resilient, so they can better cope when exceptional weather events occur. Upgrading sewage, drainage and transportation infrastructure; increasing green spaces; restoring wetlands; and using zoning laws to prevent new construction in known flood plains and vulnerable coastal areas are all obvious steps that can help. Early-warning systems, sorely lacking in many developing countries, are also critical, as are evacuation and emergency response plans. Reforestation can help prevent landslides and bolster the capacity for rain to be absorbed upstream.
As the world has long recognized, most recently at the Paris summit meeting on climate change in December 2015, poor nations will need a helping hand from rich ones as they transition to cleaner, low-carbon energy sources. This is not something the Trump administration seems inclined to offer, any more than it seems inclined to listen to the scientists, join with other nations to combat the problem or do something about America’s own greenhouse gas emissions.
That’s unconscionable, even borderline nuts, especially now that President Trump himself has seen at first hand the results of inaction.

Links

• South Asia floods kill 1,200 and shut 1.8 million children out of school
• ‘All We See Is Dead Bodies’: Sierra Leone Floods and Mudslides Ravage Freetown
• More Than 1,000 Died in South Asia Floods This Summer
• Some 66 families hit by floods draw down emergency funds
• Sudan floods: Villages submerged as death toll rises
• Uganda - Floods (UNMA, Media)(ECHO Daily Flash of 25 August 2017)
• UK weather: Heavy rain in Northern England sparks flash flood chaos

BOM: Australia's Hottest Winter On Record, Maximum Temperatures Up Nearly 2c On The Long-Term Average

ABC News - Ben Deacon | Kate Doyle

Higher temperatures and low rainfall dominated Australia's winter weather patterns. (ABC Open contributor: Fran H)

Key points Hottest winter since records began in 1910 Ninth driest winter on record More high pressure systems prevented rain

Winter in Australia this year was hot and dry with the average maximum temperature up nearly 2 degrees Celsius above the long-term trend.
The 2017 winter was the hottest since 1910 when national records began, according to Bureau of Meteorology figures released today.
The average maximum daily temperature recorded across all Australian recording locations for June, July and August 2017 was 23.7C.
That is a whopping 1.9C degrees above the baseline 1961 to 1990 average of 21.8C and smashes the previous record of 23.4C set in 2009.



 Daily maximum temperatures extremes June to Aug 2017

The warm weather was most pronounced in the north of Australia.
It was the hottest winter on record for Western Australia, Queensland and the Northern Territory, while New South Wales and South Australia made the top three.
Daily minimums were also warmer than average in most of northern Australia but not as far above average as the maximums.
In contrast, inland NSW and northern Victoria had notably cold nights with many areas 1C to 2C below average.
NSW had its coldest average winter nights since 1997.

Rainfall variations to average Australia June to August 2017. (Supplied: Bureau of Meteorology)

Meanwhile nationally it was the ninth driest winter on record. The only large area to record rainfalls significantly above average was a pocket of central NT as a result of one rain event in mid-July.

Skies stay clear
Andrew Watkins, manager of extended and long-range forecasts at the Bureau of Meteorology, said the real reason for the warmth was the persistent high pressure seen particularly during early winter.
"But you also have to add to that the long-term warming trend," he said.

"The higher than average pressure has kept the skies clear and rain away — meaning more heating of the inland from the sun and less evaporative cooling from ample water on the ground."

Australian weather extremes

Source: Bureau of Meteorology

Evaporative cooling is the same process that cools you down when you sweat, taking energy from the surrounding air to convert liquid water into gaseous water vapour, leaving the surroundings cooler.
Without a lot of water on the ground this year, large scale evaporative cooling could not happen.
The clear skies also explain the low minimum or overnight temperatures in the southern states.
Without a blanket of clouds, the heat from the day is lost to space, and temperatures drop overnight.

High pressure prevented cold fronts
But that is not all, Dr Watkins said: "We've also seen fewer cold fronts able to penetrate inland due to the slow moving and more southerly highs acting as a barrier to their normal northward progression".
So not only has high-pressure prevented rain in the north but it has also prevented the cold fronts which normally bring rain in the south during winter.
According to the climate scientists at the Bureau of Meteorology, the story behind the heat in northern Australia is more about what has not been happening.
In a standard winter there would be several south-easterly surges, bringing cold air into the tropics.
This year these surges were almost completely missing — blocked by that high pressure — until very late in the season.

So was the hot weather predicted?
The short answer is yes. The Bureau of Meteorology's 2017 winter outlook released in May, showed a high chance of exceeding median maximum temperatures.
Going into winter, high pressure conditions were likely.

Chance of exceeding the median max temp June to August 2017 (Supplied: Bureau of Meteorology)

"Our reasoning back at the time was that despite neutral ENSO and IOD patterns, the Pacific and Indian oceans were warmer than average, with cooler conditions in the eastern Indian Ocean near WA," Dr Watkins said.
Warm ocean temperatures are an indication of the energy available to the system, while cool temperatures in the eastern Indian Ocean would prevent the lift required to mix up and break down a growing region of high pressure.

What about the long-term warming trend?
Nineteen of the last 20 winters have now had average maximum daily temperatures above the 1961 to 1990 average.
Andrew King, climate extremes research fellow from the University of Melbourne, uses a range of computer climate models created all over the world to tease out the different factors causing extreme weather events.
His analysis of the factors behind this winter's record heat showed that the influence of climate change increased the likelihood of this winter's record warmth by at least sixty-fold.
Dr King said a very clear human influence could be seen in Australia's winter.

Spring outlook
According to BoM's new spring outlook released yesterday, it looks like spring is going to continue to be warmer than average for the north and southeast of the country.
While rainfall will be below average for south-west WA, it will be above average for south-east Queensland and far-east Gippsland.
No matter what comes in spring, winter 2017 is one for the record books.



Links

• BOM: Australia in winter 2017
• BOM: Climate outlook for winter (June to August)
• Queensland asks 'what winter?' after unseasonably warm weather

States Leave Federal Government In The Shade When It Comes To Renewables: Report

Fairfax - Peter Hannam

NSW has the most large-scale renewable energy projects under way in Australia, and lifted its share of clean energy markedly in the past year, as states and territories take the lead in decarbonising the electricity sector, a report by the Climate Council has found.
A jump in hydropower helped raise renewable energy share in NSW by 5 percentage points last year to 17 per cent. That was marginally above the national share of 16 per cent, and the second-biggest increase after South Australia.


Which is Australia's most renewable state?
With states taking the lead in the renewable energy push, a report by the Climate Council puts each state's efforts against one another.

The Climate Council, though, rated by the most populous state behind all but Western Australia and the Northern Territory. While NSW has a net-zero economy-wide emissions target for 2050, it has not set a goal for renewables.
By contrast, Victoria gained credit for its efforts to legislate this year a 25 per cent renewable energy share by 2020 and 40 per cent by 2025. Last year, the state's share was 12 per cent, up one percentage point from 2015.

The states are leading the way on renewables, a new report finds. Photo: Jessica Shapiro

How they measure up
Percentage of renewable energy in use by State

SOURCE: CLIMATE COUNCIL

Overall, efforts by states and territories are ahead of the federal government, which continues to dither over whether to set a Clean Energy Target as proposed by Chief Scientist Alan Finkel. The current Renewable Energy Target (RET), to achieve 33,000 gigawatt-hours a year, only runs until 2020.
"Almost all states and territories (except Western Australia) now have higher renewable energy targets or net-zero emissions targets which are stronger than the federal government," according to the council's Renewables Ready: States Leading the Charge report.
The Turnbull government "has not implemented any new policies to support renewable energy investment beyond measures in place before [it] took office" in 2013, it said. The government, though, had taken "some positive steps" to support energy storage schemes, such as the so-called Snowy 2.0 plans to boost capacity of the Snowy Hydro scheme.

Lindsay Anderson is a dairy farmer in Athlone, Victoria. More than one in every five Australian homes has solar panels. Photo: Paul Jeffers

Energy issues remain a hot political issue, with Prime Minister Malcolm Turnbull on Wednesday telling the heads of major electricity and gas firms to help consumers cut their soaring power and gas bills by highlighting the best deals on offer.

About 3 gigawatts of new renewable energy will be under construction in Australia this year.

Big electricity retailers pledged to contact at least 1 million customers currently on default offers to explain how they might get lower tariffs. Longer term cost cuts, though, would depend on "policy certainty and new investment in generation", Matthew Warren, chief executive of the Australian Energy Council, said.
New wind and solar farms, underpinned by the RET, and new rooftop solars are almost the only new capacity being added to the grid.
In terms of large-scale projects, NSW will build eight ventures this year with a 1.018 gigawatts of capacity, roughly a third of the national total, the Climate Council report notes. Queensland is next largest, with 784 megawatts and Victoria third with 687 megawatts.
By comparison, Australia added 265 megawatts of large-scale capacity in 2016 as the sector began its recovery from an investment drought during the Abbott government years.
Among the states, Tasmania last year generated 92 per cent of its electricity from renewables – down from 99 per cent in 2015. South Australia last year lifted its renewable energy share by 7 percentage points to 47 per cent, a ratio lifted in part by the closure of an ageing coal-fired power station.
Rooftop solar, meanwhile, has now reached about 21 per cent of households, or 1.7 million homes, the council's report said.
Queensland appears to be living up to its one-time moniker as the sunshine state, with 31.6 per cent of homes having solar photovoltaics as of April. South Australia trails with 30.5 per cent, and WA 25.4 per cent.
NSW has the second-most installed rooftop panel capacity, at 1.413 gigawatts, behind Queensland's 1.727 gigawatts. Victoria has the third largest capacity at 1.048 gigawatts, the reports said.

Links

• renewables ready: states leading the charge - Climate Council
• States powering ahead on climate targets despite federal inaction, report shows
• SA, Tasmania and ACT leading the renewables race: Climate Council
• EU policy: opening markets for corporate renewable energy buyers
• The false burden of social cost on renewable energy
• Australia now generates enough renewable energy to power 70% of homes
• Energy storage project proposals sought for South Australia's AUS$150m renewables fund
• South Australia calls for “the next generation” of renewable energy and energy storage projects

Coalition Watering Down Finkel Review Climate Ambitions

The Guardian - Michael Slezak

Exclusive: Draft implementation plan lacks electricity emissions trajectory, Paris agreement alignment and low-income subsidies

(L-R) Josh Frydenberg, Barnaby Joyce, Malcolm Turnbull and Scott Morrison meeting with energy company heads on 30 August. Photograph: Dean Lewins/AAP

The climate ambitions of the Finkel review appear to be being watered down by the government as it is implemented, according to a draft Coag Energy Council implementation strategy obtained by the Guardian.
The draft implementation plan removes a key recommendation for an agreed emissions trajectory for the electricity system, alignment with the Paris agreement and subsidised solar and batteries for low-income houses.
Sources tell the Guardian the document was prepared by the federal government and distributed to state and territory representatives on the morning of the meeting, leaving little time for state representatives to analyse it.
A final version of the document is expected to be delivered to Coag today.
The federal environment and energy minister, Josh Frydenberg, declined to comment on the document, saying: “It is not appropriate for any government to comment on draft documents of the Council of Australian Governments.”
Described by the prime minister, Malcolm Turnbull, as a “blueprint for the once-in-a-century transformation currently taking placing in Australia’s energy system”, the Finkel review presented 50 recommendations to the Council of Australian Governments (Coag).
Those recommendations were intended to solve the energy “trilemma” – delivering affordable and reliable electricity, while lowering emissions.
The review itself was widely criticised for lacking in ambition when it came to action on climate change, and failing to align with Australia’s commitments made in the Paris climate agreement.
The key recommendation of the review was a clean energy target, which Frydenberg has so far failed to get approved by the joint Coalition party room, which includes a number of climate change deniers.
But the party room agreed to the other 49 recommendations, which the Coag Energy Council is now advising heads of government on how to implement.
At a teleconference on Friday last week, state and territory energy ministers were presented with a draft implementation plan for discussion.
That document, obtained by the Guardian, appears to water down those recommendations in relation to climate change, and removes some altogether.
One key recommendation in the Finkel review that has been severely weakened in the draft implementation document is a change that would force the electricity market to align efforts to meet government emissions reduction commitments made as part of the Paris agreement.
Finkel’s recommendation said Coag leaders should agree to a new Australian Energy Market Agreement, which commits all parties to “a nationally consistent approach to energy policy that recognises Australia’s commitment in Paris to reduce emissions and governments’ commitment to align efforts to meet this target with energy market frameworks.”
But the draft implementation document removes the reference to international emissions reduction commitments, instead saying merely that the agreement will “reaffirm Australian governments’ commitment to the [national electricity market] and a national, integrated approach to energy and emissions reduction policy”.
Among Finkel’s key recommendation for an “orderly transition”, he called for three things: the clean energy target; a three-year notice of closure for existing large generators; and “an agreed emissions reduction trajectory”. All three moves were part of one recommendation, numbered 3.2.
The Coalition has not agreed to adopt the clean energy target but it has agreed to the three-year notice-of-closure rule, which appears in the implementation plan. However, the plan does not contain any mention of an agreed emissions reduction trajectory.
Frydenberg told the Guardian his view is that the Coag Energy Council did not agree to the emissions reduction trajectory because it is part of the clean energy target.
“The Coag Energy Council has agreed to implement the recommendations of the Finkel review except for the clean energy target, which includes the national electricity market emissions trajectory which the federal government is currently considering.”
It is unclear why the emissions trajectory is considered part of the clean energy target, since the Finkel review makes clear that there are a number of mechanisms that could achieve such a trajectory. Finkel modelled several such mechanisms, including an emissions intensity scheme.
Another Finkel recommendation calls for low-income households to be given subsidised access to “energy efficient appliances, rooftop solar photovoltaic and battery storage systems”.
Explicit references to renewable energy has been removed in the draft implementation plan and replaced with “energy efficiency and demand management technologies”.
Sources say representatives of the ACT raised the question of the trajectory being removed, and asked for it to be included. Representatives of Queensland and Victoria also apparently raised concerns about some of the other changes.
Sources said the document, which was prepared by the federal government, was circulated to state energy ministers only hours before the meeting was held, leaving little time for proper scrutiny.
The document is expected to be finalised and sent to heads of government today.

Links

• How Australia's climate policies came to be poisoned by pragmatism
• Analysis 13 ways Frydenberg sold 'climate policy' to coal-loving MPs
• Jay Weatherill renews warning Labor states could go it alone on energy policy
• Energy price rises due to policy uncertainty hurt poor most – report
• 'Too early to say' if Coalition will back clean energy target, Frydenberg says
• Finkel review: renewable energy to face new security and reliability regulations
• BlueScope Steel backs low emissions target as way to achieve energy balance
• Tony Abbott warns against low emissions target ahead of Finkel review
• Renewable energy spike led to sharp drop in emissions in Australia, study shows
• Shorten fails to specify cost of Labor's renewables policy when asked four times

Arctic Sea Ice Outlook At Worst Point In 125,000 Years

Cosmos - Andrew Masterson

Though temperatures were warmer during the last interglacial period, the greenhouse effect of atmospheric C02 is now melting more Arctic sea ice.

Sediment cores reveal that during the last interglacial period atmospheric CO2 levels were about 290 parts per million (ppm). Now the level is about 400 ppm. Peter Orr Photography / Getty Images

The prognosis for summer Arctic sea-ice loss over the next few decades is worse than it was 125,000 years ago during the last interglacial period, despite the fact temperatures were higher then.
That is the sobering conclusion reached by researchers at the Alfred-Wegener Institute in Germany. Their findings are published in the journal Nature Communications.
A team led by paleoclimatologist Rüdiger Stein combined sediment core data and climate models to estimate historical ice levels in the Arctic Ocean, in light of evidence-weighted predictions that such ice may disappear during the northern summer in the next 50 to 100 years.
Even though “the high latitudes were significantly warmer than today” during the interglacial period, the scientists state, “sea ice existed in the central Arctic Ocean during summer”.
The key climatic difference between then and now, they found, was the amount of carbon dioxide in the atmosphere. Sediment cores revealed that during the interglacial period, atmospheric CO2 levels were about 290 parts per million (ppm). Now the level is about 400 ppm.
Modelling used by the Intergovernmental Panel on Climate Change predicts CO2 levels will increase to 500 ppm over the next few decades. Plugging these values into their models, Stein and colleagues predict sea ice in the central zone of the Arctic Ocean will decline rapidly over the next several decades and disappear completely in about 250 years.
Rising CO2 levels add layers of complexity to Arctic climate models because it alters the feedback mechanisms that operate between ice, sunlight and seawater.
Wide, thick ice sheets reduce the biological fecundity of the waters beneath them but also have a strong albedo effect – reflecting sunlight back into atmosphere and thus limiting the energy absorbed by the ocean.
As CO2 levels increase, the ice sheets become less robust, shrinking and thinning. The albedo effect is proportionately reduced, potentially boosting ocean biomass through increasing light and heat.
The researchers write that sea ice, because it is involved in several key climate feedbacks including ice-albedo feedback and cloud-radiation feedback, “plays a substantial role in the global climate system variability, known as polar amplification”.
To assess sea-ice thickness more than 100,000 years ago, Stein and his team used biomarkers – specifically, signatures of a species of algae that exists beneath moderate sea ice sheets.
The absence of algal traces at points in the sediment cores is clear evidence of periods when the ice sheet was too thick for the species to inhabit the location.
The researchers concede their modeling and the ice core evidence contain inconsistencies that limit the predictive power of their findings. However, they term the paper an “important groundtruthing” exercise. They call for more detailed data and more sophisticated models that examine, in particular, “external forcings and related internal feedback mechanisms” to further improve results.

Links

• Arctic Ocean sea ice cover during the penultimate glacial and the last interglacial
• Why is Antarctica's sea ice spreading as the Arctic's shrinks?
• Arctic sea ice hits a record low wintertime maximum
• Thinning Arctic sea ice means wildlife must adapt or die