Climate change is putting world at risk of irreversible changes, scientists warn

AAAS makes rare policy intervention urging US to act swiftly to reduce carbon emissions and lower risks of climate catastrophe  

Suzanne Goldenberg  

The Guardian, Tuesday 18 March 2014

Download the AAAS report - http://whatweknow.aaas.org/get-the-facts/

The world is at growing risk of "abrupt, unpredictable and potentially irreversible changes" because of a warming climate, America's premier scientific society warned on Tuesday.

In a rare intervention into a policy debate, the American Association for the Advancement of Science urged Americans to act swiftly to reduce greenhouse gas emissions – and lower the risks of leaving a climate catastrophe for future generations.

"As scientists, it is not our role to tell people what they should do," the AAAS said in a new report, What we know.

"But we consider it our responsibility as professionals to ensure, to the best of our ability, that people understand what we know: human-caused climate change is happening, we face risks of abrupt, unpredictable and potentially irreversible changes, and responding now will lower the risks and costs of taking action."

The United Nations' climate science panel, the IPCC, will gather in Yokohama, Japan next week to release the second in a series of blockbuster reports, this time outlining how a changing climate is affecting rainfall and heat waves, sea level and the oceans, fisheries and food security.

But the AAAS scientists said they were releasing their own assessment ahead of time because they were concerned that Americans still failed to appreciate the gravity of climate change.

Despite "overwhelming evidence", the AAAS said Americans had failed to appreciate the seriousness of the risks posed by climate change, and had yet to mobilise at a pace and scale needed to avoid a climate catastrophe.

The scientists said they were hoping to persuade Americans to look at climate change as an issue of risk management. The society said it plans to send out scientists on speaking tours to try to begin a debate on managing those risks.

The report noted the climate is warming at almost unprecedented pace.

"The rate of climate change now may be as fast as any extended warming period over the past 65 million years, and it is projected to accelerate in the coming decades,"

An 8F rise – among the most likely scenarios could make once rare extreme weather events – 100-year floods, droughts and heat waves – almost annual occurrences, the scientists said.

Other sudden systemic changes could lie ahead – such as large scale collapse of the Antarctic and Greenland ice sheets, collapse of part of the Gulf Stream, loss of the Amazon rain forest, die-off of coral reefs, and mass extinctions.

"There is a risk of abrupt, unpredictable and potentially irreversible changes in the earth's climate system with massively disruptive impacts," the report said.

The risks of such catastrophes would only grow over time – unless there was action to cut emissions, the scientists said.

"The sooner we make a concerted effort to curtail the burning of fossil fuels as our primary energy source and releasing the C02 to the air, the lower our risk and cost will be."

Climate action call as 'another angry summer' breaks 156 heat records

Climate Council says the summer was 'another example of climate change tearing through the record books'  

Oliver Milman

The Guardian, Monday 10 March 2014

The Climate Council report is available here - http://www.climatecouncil.org.au/angry-summer

See also - Angry summers will just get madder,  scientists warn, Sarah Whyte, The Age

More than 150 temperature records were broken in Australia during "another angry summer" that highlighted the need for deep reductions in greenhouse gases, a new report has said.

The analysis, by the Climate Council, found that Sydney experienced its driest summer in 27 years, while Melbourne sweltered through its hottest ever 24-hour period, averaging 35.5C. The Victorian capital also had four days in a row above 41C.

Elsewhere, Adelaide had a record of 11 days at 42C or hotter during the summer, while Perth had its second hottest summer on record.

Perhaps unsurprisingly given that 79% of Queensland is now considered to be in drought, the Climate Council findings showed it was the driest summer on record for 45 locations in the state.

In New South Wales, where more than half of the state is in the grip of drought, 38 locations had their driest ever summer.

The highest temperature recorded in the summer was 49.2C in Emu Creek, Western Australia. Overall, 156 temperature records were broken in the 90 days of summer.

Eight of the hottest summers on record have occurred in the past 15 years, the council's report showed. It states it is "virtually certain" that extreme hot weather will become even more frequent and severe in Australia in the coming decades.

Rising temperatures driven by the release of heat-trapping carbon dioxide place Australians at increased risk from extreme weather events, including heatwaves, drought and bushfires, the report stated.

The summer heat followed what was Australia's hottest ever year on record in 2013.

"The latest summer was an another example of climate change tearing through the record books," said the Climate Council's Tim Flannery. "It's not just about one summer but an overall trend to more extreme weather.

"Things are getting bad and if we want to stop them getting worse this is the critical decade for action. We need to cut the emission of greenhouse gases and we need to do it urgently."

Arctic melt speeding up

Climate News Network, 9 March 2014
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http://www.climatenewsnetwork.net/2014/03/arctic-melt-speeding-up/

By Tim Radford

See also - In the Arctic,  winter's might doesn't have much bite, NSIDC, March 3, 2014

It's long been established that Arctic ice is on the retreat but it's the pace of change that's surprising scientists: latest studies show the region is at its warmest for 40,000 years.

LONDON, 9 March - Ice in the Arctic continues to retreat. The season without ice is getting longer by an average of five days every 10 years, according to a new study in Geophysical Research Letters.  And in some regions of the Arctic, the autumn freeze is now up to 11 days later every decade.

This means that a greater proportion of the polar region for a longer timespan no longer reflects sunlight but absorbs it. This change in albedo – the scientist's term for a planet's reflectivity – means that open sea absorbs radiation, stays warmer, and freezes again ever later.

Warming accelerates
None of this is news: sea ice in the Arctic has been both retreating and thinning in volume for four decades. Researchers have tracked the retreat of the snow line to find tiny plants exposed that had been frozen over 40,000 years ago: the implication is that the Arctic is warmer now than it has been for 40 millennia.

This warming threatens the animals that depend for their existence on a stable cycle of seasons  and is accelerating at such a rate that the polar ocean could be entirely free of ice in late summer in the next four decades.

So Julienne Stroeve, of University College London and her colleagues have provided yet further confirmation of an increasing rate of change in the region in their latest study.

The scientists examined satellite imagery of the Arctic for the last 30 years, on 25 square kilometer grid, to work out the albedo of each square for every month they had data.

Their headline figure of five days is an average: in fact the pattern of freeze and thaw in the Arctic varies. In one region the melt season has been extended by 13 days, in another the melt season is actually getting shorter.

Energy increases
This increasing exposure to summer sunlight means that ever greater quantities of energy are being absorbed: several times the energy of the atomic bomb dropped on Hiroshima hits every square kilometer of the open Arctic Ocean.

"The extent of sea ice in the Arctic has been declining for the last four decades," said Professor Stroeve, "and the timing of when melt begins and ends has a large impact on the amount of ice lost each summer.

With the Arctic region becoming more accessible for longer periods of time, there is a growing need for improved prediction of when the ice retreats and reforms in the water." - Climate News Network

Australia’s climate: time to act on rising heatwaves and fires

THE CONVERSATION, 4 March 2014

Neville Nicholls, Professor at Monash University

Download the report here - http://www.csiro.au/Outcomes/Climate/Understanding/State-of-the-Climate-2014.aspx

For further reading -

Australia has warmed by 0.9C since 1910,  with more in store, Michael Hopkin, Editor at The Conversation

State of the Climate 2014? It's warmer. Huw Morgan, CSIRO News

Australia experiencing more extreme heat,  high fire danger days,  says the latest State of the Climate report, Peter Hannam, ENVIRONMENT EDITOR,  THE SYDNEY MORNING HERALD

Climate forecast for Australia: hot days,  higher fire risk,  more severe droughts, Paul Farrell, The Guardian

Australia's climate extremes increasing as carbon dioxide levels continue to rise,  report reveals, Environment and science reporter Jake Sturmer and Alex McDonald, ABC News

On climate,  these guys know their stuff, By ABC's Sara Phillips, The Drum

The State of the Climate 2014 report, released today by the CSIRO and the Bureau of Meteorology, confirms that Australia is heating up. It has warmed by 0.9C since 1910, with more in store thanks to the carbon dioxide the world has already emitted.

As a result, severe heat events are becoming more frequent, and the climate drivers of bushfire activity are intensifying.

Other climate changes are also occurring, such as sea-level rise, ocean acidification, increasing tropical rainfall, and significant declines in winter rainfall in both the southwest and southeast of Australia over the past few decades.

But whereas the full impact of some of these changes may not be felt for some time to come, we are already seeing the impact of more severe heat events and more weather conducive to fire activity.

Heat events and bushfires already cause increased death and illness, as well as destroying property and damaging infrastructure. The recent increases in the climate drivers of severe heat events and bushfires have exacerbated the risks.

These heatwaves and bushfires are bringing home the reality of climate change. They affect Australian families and their homes – they are not something that happens to other people a long way away, or will happen to us a long time in the future. They are a clear and present danger to us, right now.

Beating the heat

Luckily, we are starting to adapt to these risks. After the record heatwave in Europe in 2003 that led to the death of many thousands of people, governments around the world intensified efforts to develop heatwave alert systems. A prototype Victorian heatwave alert system, based on research identifying the temperature threshold at which deaths start to happen, was in place just in time for the January 2009 heatwave.

Victoria's heatwave alert system has since been further adapted and improved. In the days leading up to January's significant heatwave in southeast Australia, the public was given a great deal of information about how to cope with the extreme heat, through the news media and other outlets.

This alert process was helped by the highly accurate temperature forecasts provided by the Bureau of Meteorology, which is now piloting a national heatwave alert service.

Heatwaves still kill too many people, and cause too much other damage and dislocation. But without the heatwave alerts and other adaptations already in place, the damage would be even greater.

Fiery future

With higher temperatures come more destructive bushfires. Governments, fire services and bureaucrats have been working together for several decades to improve how we tackle the increasing bushfire risk. The measures include banning the lighting of fires or the use of dangerous equipment on days with severe fire risk, increasing the equipment and personnel available to fight fires before they spread, and setting up targeted information campaigns to ensure that people understand the risks and what can be done to reduce them. True, these measures were not introduced specifically in response to global warming, but a warming climate makes them more necessary than ever.

As with heatwaves, bushfires still threaten lives and damage too much property. But without the efforts of fire services and others over recent years, the threat and damage would have been even greater.

We will need to intensify our adaptation efforts in the future because heatwaves are expected to increase still more in frequency and severity over the coming decades. The Intergovernmental Panel on Climate Change recently assessed the scientific literature regarding possible changes in a wide variety of climate and weather extremes. For many of these extremes – such as droughts, floods, and tropical cyclones – it is difficult to assess whether or not these have increased in recent decades or whether global warming will exacerbate them in the future. But there is much more certainty surrounding hot days and heatwaves.

The State of the Climate report highlights the ample evidence that the numbers of hot days and nights have increased in recent decades, and this has happened across the world, not just in Australia. There is considerable confidence among scientists that the frequency and severity of heatwaves will increase in the future, as greenhouse gas emissions continue to rise. Similarly, the report notes that the weather associated with enhanced bushfire risk is anticipated to continue to increase in coming decades.

Unknown territory

As global warming continues, this will push us into unknown territory. As we begin to experience heatwaves and bushfire risks that our current population has never before experienced, how do we even estimate how bad the impacts will be?

New record heatwaves and fire risks could push us into a truly catastrophic situation. We will need to rely on politicians, bureaucrats, the medical and fire services, and scientists to identify more ways to ensure communities, health services, and vulnerable people are better prepared for these changed conditions. Doing this will save lives now, as well as in the future, even if we do nothing to reduce our greenhouse gas emissions.

Of course, it will be easier to deal with this problem if politicians and industry also manage to slow the emissions of greenhouse gases. Anything they can do now to reduce emissions will reduce the chances of catastrophic heatwaves and bushfire risks in the future.

Australia should cut emissions by 19 per cent to play fair role: Climate Change Authority report

Tom Arup, Environment editor 

The Age, February 27, 2014   

The CCA Review is available at - http://climatechangeauthority.gov.au/caps

Australia should reduce emissions by 19 per cent from 2000 levels by the end of the decade – a significantly stronger target than the current pledge of a 5 per cent cut – to play its part in stopping dangerous global warming, expert advice to the government says.

A review by the independent Climate Change Authority has also found Australia should then dramatically ramp up its efforts in the following decade through a target to cut 40 to 60 per cent of its emissions by 2030.

This would be a fair contribution to limiting climate change to relatively safe levels, it says.

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In what could be the last significant act of the authority– the Coalition is moving to axe it along with the carbon tax – it has declared Australia's current unconditional pledge to cut emissions by 5 per cent by 2020 is ''inadequate''.

World leaders have agreed to keep global warming to an average of two degrees across the planet. Between 1880 and 2012 the planet warmed by an average 0.85 degrees.

Scientists warn that warming of more than two degrees would spark dangerous climate change including significantly more frequent and intense extreme weather events and higher sea levels.

In a major review released on Thursday, the authority found a 5 per cent cut by 2020 was not a credible step towards Australia meeting its contribution to keeping warming to two degrees.

''It would leave an improbably large task for future Australians to make a fair contribution to global efforts,'' said the authority, which is chaired by former Reserve Bank governor Bernie Fraser.

It found that action being taken by other countries, including China and the US, meant Australia's minimum commitment was out of step with current global efforts.

The authority recommended that Australia adopt a minimum 15 per cent cut to emissions by 2020, but it found the target should be strengthened with a surplus of international carbon credits Australia has obtained for undershooting its emissions goal under the first stage of the Kyoto Protocol. That would raise the goal to a 19 per cent cut.

The authority calculated the maximum greenhouse gas emissions Australia that should be allowed to release between 2013 and 2050 to play its role in meeting the two degree target.

To meet that budget the authority recommended Australia make a cut of 40 to 60 per cent on 2000 emissions by 2030, with the range to be reviewed periodically.

Launching the report in Canberra Mr Fraser said the Authority's findings were driven by the climate science. He described the recommendations as a: ''step up, but its doable.''

The report finds growth in gross national income would only be 0.02 per cent lower in 2020 with the 19 per cent target in place then compared with a 5 per cent reduction target. Per person that that would mean the average income rise would be just $100 less in 2020 than it would have been the lower five per cent target in place.

The authority said given the complexity of the climate change challenge it makes sense to adopt a wide range of policies to cut emissions, including carbon pricing and emissions trading – which the Abbott government is opposed to – and regulations and industry standards, such as limits on emissions from cars.

It finds costs could be kept relatively low if the government was prepared to buy international carbon permits to meet the higher emissions reductions being proposed in the review. If international credits were used entirely to move from a 5 to 19 per cent cut it would cost between $200 and $900 million.

This assumes an average carbon credit cost of $0.50 to $2. Current prices are below $1.

While the Coalition has vowed to meet the five per cent cut without buying international carbon credits, the authority recommended a government fund be established to buy international carbon credits to close any gap between domestic cuts emissions and the recommended targets but forward in the review.

It concluded an ''emissions budget'' of 10.1 billion tonnes of carbon dioxide was Australia's fair share of the total emissions allowable by 2050 to have a two-thirds chance of keeping warming to two degrees. That represents about 1 per cent of what global emissions by mid-century should be limited to.

Australia is expected to come under increasing global pressure to detail its emissions cuts for post–2020 in the coming year. The United Nations led climate talks are aiming to finalise a new climate treaty change by the end of next year.

UN Secretary-General Ban Ki-moon has invited world leaders to a special meeting on climate change later this year. He is expected to push for countries to make stronger commitments to cut emissions.

While in recent times the Abbott government has emphasised the unconditional 5 per cent emissions cut for 2020, Australia has said in international forums it would move to a stronger cut of up to 15 and 25 per cent by 2020 depending on global action.

The Coalition has previously supported this range. It says it will review Australia's emissions targets next year.

Climate Council: heatwaves are getting hotter and more frequent

The Conversation

18 February 2014

Will Steffen, Adjunct Professor, Fenner School of Environment and Society at Australian National University   

Lesley Hughes, Head of the Department of Biological Sciences at Macquarie University   

Sarah Perkins, Post Doctoral Research Fellow at University of New South Wales 

Heatwaves are one of the most important climate-related risks for Australians. Sometimes called the "silent killers", they cause the greatest number of deaths of any natural disaster type in Australia, and have significant impacts on infrastructure, agriculture and biodiversity. As the climate continues to warm, heatwaves are becoming hotter, longer and more frequent.

The extreme heat in Melbourne that frazzled the Australian Open tennis tournament and the record-breaking heat in large areas of Queensland this summer remind us of the risks that heatwaves pose. Hot on the heels of the "angry summer" of 2012/2013, this summer's heat is part of a longer-term trend towards hotter weather.

Heatwaves on the rise

The Climate Council's latest report – "Heatwaves: Hotter, Longer, More Often", which we co-authored – delivers four key findings.

First, climate change is already increasing the likelihood and severity of heatwaves across Australia. Second, heatwaves have widespread impacts including increased deaths, reduced workplace productivity, damage to infrastructure such as transport and electricity systems, mortality of heat-sensitive plants and animals, and stress on agricultural systems. Third, record hot days and heatwaves are expected to increase further in the future. And finally, limiting future increase in heatwave activity requires urgent and deep cuts to greenhouse-gas emissions.

Since 1950, the annual number of record hot days across Australia has more than doubled, and both maximum and minimum temperatures have increased by around 0.9°C. Over the past decade, the frequency of record hot days has been more than three times the frequency of record cold days. The hottest area-averaged national maximum temperature ever recorded was 40.3°C on 7 January 2013, and extreme temperature records were broken in every state and territory throughout the course of the 2012/2013 summer.

Almost all of Australia has experienced a lengthening of the heatwave season, with the first heatwave event occurringmuch earlier than it did 60 years ago. The intensity of heatwaves, as measured by the temperature of the hottest day (the peak of the heatwave), is also increasing.

This summer, Australians again endured record-breaking, extreme heatwaves and hot weather. On 3 January, Queensland experienced its hottest area-averaged day on recordand for the week ending 4 January, average maximum temperatures were a staggering 8°C or more above normal in the southern inland part of the state.

Record high maximum temperatures occurred over 8.8% of Australia during the first four days of January, including 17% of New South Wales, 17% of the Northern Territory, 16% of Queensland and 8% of South Australia. On 2 February, Adelaide reached a new February record of 44.7°C, some 15°C above average.

The global picture

Heatwaves are also on the increase worldwide, with severe heatwaves affecting many countries and regions in the last 10-15 years. One of the most severe was the European heatwave of July and August 2003, with France and Switzerland particularly affected. This heatwave was followed in 2010 by an even more intense and widespread heatwave, which scorched large swathes of Eastern Europe, including western Russia, Belarus, Estonia, Latvia, and Lithuania.

Long-term temperature reconstructions show that these were the hottest summers that Europe has experienced for at least 500 years. North America has also experienced several recent heatwaves, with a major heatwave affecting the state of Texas in July 2011 and a heatwave covering a greater area of the country in 2012.

Diverse impacts

The impacts of heatwaves are surprisingly large and diverse. The Bureau of Meteorology has dubbed heatwaves "the most under-rated weather hazard in Australia". While heatwaves do not result in obvious violent effects on the landscape, unlike many other weather-related disasters such as high-intensity storms and bushfires, their impacts on health, the workplace, infrastructure, agriculture, and the environment are serious, costly and long-lasting.

While the 2009 Black Saturday bushfires killed more than 170 people, the preceding heatwave killed double this figure. The economic burden of heatwaves is significant, through the demand placed on emergency services, infrastructure stress and breakdown, and agricultural losses. For example, as temperatures soared during the 2009 heatwave, the Basslink electricity cable between Tasmania and Victoria reached maximum operating temperature, causing the system to shut down and resulting in widespread blackouts in Melbourne.

Plants and animals are also susceptible to extreme heat events, with flying foxes, birds and rainforest marsupials being particularly vulnerable. Marine heatwaves can trigger coral bleaching events, affecting large areas of reefs. Bleaching events on the Great Barrier Reef have occurred repeatedly since the late 1970s, with none reported before then. These bleaching events have contributed to the observed 50% loss of coral cover in the Great Barrier Reef over the past 30 years.

The case for decarbonisation

As greenhouse gases continue to rise in the atmosphere, heatwaves will continue to worsen.

According to the Intergovernmental Panel on Climate Change's 2012 Special Report on Extremes and last year's release of the first part of the IPCC Fifth Assessment Report, it is virtually certain that hot extremes will increase and cold extremes will decrease through the century compared to the current climate. It is also very likely that the length, frequency and/or intensity of heat waves will increase over most land areas around the globe.

This is the critical decade for action. Global emissions are still rising and Australian emissions are yet to make a decisive turn downwards. Despite the promising developments in low-carbon technologies and energy-efficiency measures, there is not yet widespread acceptance in Australia of the urgent need to decarbonise our economy and implement policies to facilitate a decarbonised future. This challenge must be met if we are to minimise the risk of worsening heatwaves and other extreme events for ourselves, our children and grandchildren. It's time to get on with the job.

The Climate Council is a crowdfunded body that advises the Australian public on climate change. You can read its Heatwave Report here.