Sunday, February 15, 2015

Latest information on climate change

Australian Academy of Science
16 February 2016

See also - The Age and the ABC

This publication from the Australian Academy of Science aims to address confusion created by contradictory information in the public domain. It sets out to explain the current situation in climate science, including where there is consensus in the scientific community and where uncertainties exist. The document is structured around nine questions:
  1. What is climate change?
  2. How has climate changed?
  3. Are human activities causing climate change?
  4. How do we expect climate to evolve in the future?
  5. How are extreme events changing?
  6. How are sea levels changing?
  7. What are the impacts of climate change?
  8. What are the uncertainties and their implications?
  9. What does science say about options to address climate change?

Saturday, February 7, 2015

Quantifying the impact of climate change on extreme heat in australia

New ground-breaking scientific research in 2014 can now tell us just how much of an influence climate change has on a single heatwave or heat records.

1. Climate change is making Australia hotter. Hot days are happening more often while heatwaves are becoming hotter, longer and more frequent.

  • The annual number of record hot days across Australia has doubled since 1960. Over the past 10 years the number of record hot days has occurred three times more frequently than the number of record cold days.
  • The annual occurrence of very hot days across Australia has increased strongly since 1950 and particularly sharply in the last 20 years.
  • Over the 1950-2013 period many characteristics of heatwaves have changed across Australia. They are becoming hotter, lasting longer, occurring more often and starting earlier.
  • All extreme heat events are now occurring in an atmosphere that is significantly hotter than it was 50 years ago

2. While it has been clear for many years that climate change is a major factor in intensifying heat, recent scientific advances now allow us to understand the extent of the impact on individual extreme events. Climate change has significantly worsened recent extreme heat events in Australia.

  • The record hot year of 2013 in Australia was virtually impossible without climate change.
  • Climate change tripled the odds that the heatwaves of the 2012/2013 Australian summer would occur as frequently as they did.
  • Climate change doubled the odds that the 2012/2013 heatwaves would be as intense as they were.

3. The new research showing the strong influence of climate change on heat events strengthens the case for strong action on climate change.

  • Carbon emissions must be reduced rapidly and deeply if the worst of extreme heat in the second half of the century is to be avoided.
  • Clean energy technologies are advancing rapidly and international action is ramping up, building momentum towards a decarbonised future.

Sunday, August 24, 2014

'Incredible' rate of polar ice loss alarms scientists

A European satellite has shown ice sheets shrinking at 120 cubic miles a year in Antarctica and Greenland

Robin McKie
The Guardian/The Observer, Sunday 24 August 2014

The planet's two largest ice sheets – in Greenland and Antarctica – are now being depleted at an astonishing rate of 120 cubic miles each year. That is the discovery made by scientists using data from CryoSat-2, the European probe that has been measuring the thickness of Earth's ice sheets and glaciers since it was launched by the European Space Agency in 2010.

Even more alarming, the rate of loss of ice from the two regions has more than doubled since 2009, revealing the dramatic impact that climate change is beginning to have on our world.

The researchers, based at Germany's Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research – used 200m data points across Antarctica and 14.3m across Greenland, all collected by CryoSat, to study how the ice sheets there had changed over the past three years. The satellite carries a high-precision altimeter, which sends out short radar pulses that bounce off the ice surface and then back to the satellite. By measuring the time this takes, the height of the ice beneath the spacecraft can be calculated.

It was found from the average drops in elevation that were detected by CryoSat that Greenland alone is losing about 90 cubic miles a year, while in Antarctica the annual volume loss is about 30 cubic miles. These rates of loss – described as "incredible" by one researcher – are the highest observed since altimetry satellite records began about 20 years ago, and they mean that the ice sheets' annual contribution to sea-level rise has doubled since 2009, say the researchers whose work was published in the journalCryosphere last week.

"We have found that, since 2009, the volume loss in Greenland has increased by a factor of about two, and the West Antarctic ice sheet by a factor of three," said glaciologist Angelika Humbert, one of the study's authors. "Both the West Antarctic ice sheet and the Antarctic peninsula, in the far west, are rapidly losing volume. By contrast, East Antarctica is gaining volume, though at a moderate rate that doesn't compensate for the losses on the other side of the continent."

The researchers say they detected the biggest elevation changes caused by ice loss at the Jakobshavn glacier in Greenland, which was recently found to be shifting ice into the oceans faster than any other ice-sheet glacier, and at Pine Island glacier, which like other glaciers in West Antarctica, has been thinning rapidly in recent years.

The discovery of these losses of ice is particularly striking and represents yet another blow to claims by some climate-change deniers, who argue that the rapid loss of ice in the Arctic currently being observed is being matched by a corresponding increase in Antarctica. CryoSat's measurements show that Antarctica – although considerably colder than the Arctic because of its much higher average elevation – is not gaining ice at all. Indeed, it is – overall – losing considerable volumes, and in the case of West Antarctica is doing so at an alarming rate.

This point was stressed by Mark Drinkwater, the European Space Agency's CryoSat mission scientist. "These results offer a critical new perspective on the recent impact of climate change on large ice sheets. This is particularly evident in parts of the Antarctic peninsula, where some of the more remarkable features add testimony on the impact of sustained peninsula warming at rates several times the global average."

Sunday, June 1, 2014

Australia's past two years the hottest on record, Climate Council says

The Age, June 2, 2014   

Read and download the Climate Council Seasonal update here - 

Australia has experienced its hottest two-year period ever recorded as the country feels the impact of climate change, a report released today finds.

Australia in the second half of 2014 will probably have an El Nino event, which often brings drought, extreme heat and bushfire risk to rural areas, according to the Climate Council  relaunched as a nonprofit group after Prime Minister Tony Abbott scrapped the government's Climate Commission last year.

"El Nino exacerbates the longer-term warming trend," Will Steffen, a researcher at the Australian National University in Canberra who helped compile the report, said. "People have been saying, hasn't the warming trend stopped? In no way has it stopped. If anything it has intensified."

Deep cuts in greenhouse gas emissions are needed to limit an increase in extreme weather, including heat waves, drought and bush fires, according to a study from the group earlier this year. The government accepts the science of climate change and is committed to meeting its promised 5 percent reduction in emissions by 2020, Environment Minister Greg Hunt said in April.

Australia's climate change plans are in the spotlight because Abbott is hosting meetings of the Group of 20 nations this year. The US has encouraged Australia's prime minister to include climate change on the G-20 agenda.

"The real policy question is what plan does the government and the opposition have for decarbonizing the Australian economy around mid-century," Steffen said. "The 2020 target is pretty immaterial. The long-term target is what's very important to hit, and as far as I can see we don't have clarity from either side of politics about what they're going to do."

Record May
The 24 months through April set an Australian record for the hottest average temperature over a two-year period, the Climate Council said. Sydney had 19 straight days with temperatures of at least 22 degrees Celsius (71.6 degrees Fahrenheit) between May 10 and May 28, 10 days longer than the previous record, according to the council.

Sydney, Melbourne and Adelaide also broke records for the number of consecutive days with temperatures of 20 degrees Celsius or above in May.

The Abbott-led government has vowed to replace Australia's carbon levy with an alternative program that would provide funds to companies and projects that reduce emissions. The government plans to get rid of the Australian Renewable Energy Agency and the $10 billion Clean Energy Finance Corp., set up by Abbott's predecessor to spur investment in the industry.

Thursday, April 17, 2014

Mitigation of Climate Change – Part 3 of the new IPCC report

RealClimate, 17 April 2014

Guest post by Brigitte Knopf

Global emissions continue to rise further and this is in the first place due to economic growth and to a lesser extent to population growth. To achieve climate protection, fossil power generation without CCS has to be phased out almost entirely by the end of the century. The mitigation of climate change constitutes a major technological and institutional challenge. But: It does not cost the world to save the planet.

This is how the new report was summarized by Ottmar Edenhofer, Co-Chair of Working Group III of the IPCC, whose report was adopted on 12 April 2014 in Berlin after intense debates with governments. The report consists of 16 chapters with more than 2000 pages. It was written by 235 authors from 58 countries and reviewed externally by 900 experts. Most prominent in public is the 33-page Summary for Policymakers (SPM) that was approved by all 193 countries. At a first glance, the above summary does not sound spectacular but more like a truism that we've often heard over the years. But this report indeed has something new to offer.

The 2-degree limit

For the first time, a detailed analysis was performed of how the 2-degree limit can be kept, based on over 1200 future projections (scenarios) by a variety of different energy-economy computer models. The analysis is not just about the 2-degree guardrail in the strict sense but evaluates the entire space between 1.5 degrees Celsius, a limit demanded by small island states, and a 4-degree world. The scenarios show a variety of pathways, characterized by different costs, risks and co-benefits. The result is a table with about 60 entries that translates the requirements for limiting global warming to below 2-degrees into concrete numbers for cumulative emissions and emission reductions required by 2050 and 2100. This is accompanied by a detailed table showing the costs for these future pathways.

The IPCC represents the costs as consumption losses as compared to a hypothetical 'business-as-usual' case. The table does not only show the median of all scenarios, but also the spread among the models. It turns out that the costs appear to be moderate in the medium-term until 2030 and 2050, but in the long-term towards 2100, a large spread occurs and also high costs of up to 11% consumption losses in 2100 could be faced under specific circumstances. However, translated into reduction of growth rate, these numbers are actually quite low. Ambitious climate protection would cost only 0.06 percentage points of growth each year. This means that instead of a growth rate of about 2% per year, we would see a growth rate of 1.94% per year. Thus economic growth would merely continue at a slightly slower pace. However, and this is also said in the report, the distributional effects of climate policy between different countries can be very large. There will be countries that would have to bear much higher costs because they cannot use or sell any more of their coal and oil resources or have only limited potential to switch to renewable energy.

The technological challenge

Furthermore – and this is new and important compared to the last report of 2007 – the costs are not only shown for the case when all technologies are available, but also how the costs increase if, for example, we would dispense with nuclear power worldwide or if solar and wind energy remain more expensive than expected.

The results show that economically and technically it would still be possible to remain below the level of 2-degrees temperature increase, but it will require rapid and global action and some technologies would be key:

Many models could not achieve atmospheric concentration levels of about 450 ppm CO2eq by 2100, if additional mitigation is considerably delayed or under limited availability of key technologies, such as bioenergy, CCS, and their combination (BECCS).

Probably not everyone likes to hear that CCS is a very important technology for keeping to the 2-degree limit and the report itself cautions that CCS and BECCS are not yet available at a large scale and also involve some risks. But it is important to emphasize that the technological challenges are similar for less ambitious temperature limits.

The institutional challenge

Of course, climate change is not just a technological issue but is described in the report as a major institutional challenge:

Substantial reductions in emissions would require large changes in investment patterns

Over the next two decades, these investment patterns would have to change towards low-carbon technologies and higher energy efficiency improvements (see Figure 1). In addition, there is a need for dedicated policies to reduce emissions, such as the establishment of emissions trading systems, as already existent in Europe and in a handful of other countries.

Since AR4, there has been an increased focus on policies designed to integrate multiple objectives, increase co‐benefits and reduce adverse side‐effects.

The growing number of national and sub-national policies, such as at the level of cities, means that in 2012, 67% of global GHG emissions were subject to national legislation or strategies compared to  only 45% in 2007. Nevertheless, and that is clearly stated in the SPM, there is no trend reversal of emissions within sight – instead a global increase of emissions is observed.

Trends in emissions

A particularly interesting analysis, showing from which countries these emissions originate, was removed from the SPM due to the intervention of some governments, as it shows a regional breakdown of emissions that was not in the interest of every country (see media coverage here or here). These figures are still available in the underlying chapters and the Technical Summary (TS), as the government representatives may not intervene here and science can speak freely and unvarnished. One of these figures shows very clearly that in the last 10 years emissions in countries of upper middle income – including, for example, China and Brazil – have increased while emissions in high-income countries – including Germany – stagnate, see Figure 2. As income is the main driver of emissions in addition to the population growth, the regional emissions growth can only be understood by taking into account the development of the income of countries.

Historically, before 1970, emissions have mainly been emitted by industrialized countries. But with the regional shift of economic growth now emissions have shifted to countries with upper middle income, see Figure 2, while the industrialized countries have stabilized at a high level. The condensed message of Figure 2 does not look promising: all countries seem to follow the path of the industrialized countries, with no "leap-frogging" of fossil-based development directly to a world of renewables and energy efficiency being observed so far.

But the fact that today's emissions especially rise in countries like China is only one side of the coin. Part of the growth in CO2 emissions in the low and middle income countries is due to the production of consumption goods that are intended for export to the high-income countries (see Figure 3). Put in plain language: part of the growth of Chinese emissions is due to the fact that the smartphones used in Europe or the US are produced in China.

The philosophy of climate change

Besides all the technological details there has been a further innovation in this report, that is the chapter on "Social, economic and ethical concepts and methods". This chapter could be called the philosophy of climate change. It emphasizes that

Issues of equity, justice, and fairness arise with respect to mitigation and adaptation. […] Many areas of climate policy‐making involve value judgements and ethical considerations.

This implies that many of these issues cannot be answered solely by science, such as the question of a temperature level that avoids dangerous anthropogenic interference with the climate system or which technologies are being perceived as risky. It means that science can provide information about costs, risks and co-benefits of climate change but in the end it remains a social learning process and debate to find the pathway society wants to take.


The report contains many more details about renewable energies, sectoral strategies such as in the electricity and transport sector, and co-benefits of avoided climate change, such as improvements of air quality. The aim of Working Group III of the IPCC was, and the Co-Chair emphasized this several times, that scientists are mapmakers that will help policymakers to navigate through this difficult terrain in this highly political issue of climate change. And this without being policy prescriptive about which pathway should be taken or which is the "correct" one. This requirement has been fulfilled and the map is now available. It remains to be seen where the policymakers are heading in the future.

The report :

Climate Change 2014: Mitigation of Climate Change – IPCC Working Group III Contribution to AR5

Brigitte Knopf is head of the research group Energy Strategies Europe and Germany at the Potsdam Institute for Climate Impact Research (PIK) and one of the authors of the report of the IPCC Working Group III and is on Twitter as @BrigitteKnopf

This article was translated from the German original at RC's sister blog KlimaLounge.

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Sunday, March 30, 2014

IPCC report finds world might be irreversibly changed

Tom Arup, Environment editor,  The Age
The Age, March 31, 2014 

New report and Summary for Policy Makers now available here -

Climate change is already being felt in all corners of the globe and some parts of the natural world may already be undergoing irreversible change, a major assessment by the UN Intergovernmental Panel on Climate Change has found.

The report on the impact of climate change – the first of its kind in seven years – stresses that the likelihood climate change will cause severe and irreversible damage to the planet grows if greenhouse gas emissions continue is high and the planet warms significantly.

The report is the result of years of work by a team of 309 lead global researchers. It is the second part of the IPCC's fifth assessment of climate change and focuses on its impact and how the world might adapt.

A 48-page summary released on Monday says some threats from climate change are considerable at just one or two degrees warming above pre-industrial levels. The average temperature across the globe has risen 0.85 since 1880.

The threat becomes high to very high under four degrees warming. Risks under this scenario include severe and widespread damage to unique and threatened human and eco-systems, substantial species extinction and threats to global food security.

The report identifies the world's poor as the most likely to be most under stress as climate hazards multiply the pressures already faced. But the impact of current extreme weather events, such as bushfires and floods, show a lack of preparedness in all countries, regardless of the level of development.

Dr Chris Field, co-chair of the research team behind the report, said climate change was not something that would happen in the future.

"We look around the world and see widespread impacts of the climate changes that have already occurred. Many of these have real consequences," he said.

"Vulnerability, the susceptibility to be harmed by climate change, is really widespread in society... there are vulnerable people, vulnerable activities, distributed around the world."

The report says there is still uncertainty about the timing and severity of the impact of climate change. It pitches the challenge as needing to identify the risks and deciding how to manage them.

The summary identifies eight global risks that it considers high probability and irreversible.

They include death, injury and disrupted livelihoods due to storm surges, coastal flooding and sea-level rise in low-lying communities; the breakdown of critical service such as electricity, water supply and emergency services due to extreme weather; food insecurity due to warming, drought flooding and extreme rainfall, particularly in poorer countries.

The report finds Artic-sea ice and coral reefs are at very high risk under two degrees of warming beyond that observed in 1986 and 2005.
The risk of extreme weather events such as heatwaves, extreme rainfall and coastal flooding is already considered moderate and will become high if temperatures rise another degree above 1986 to 2005 levels.

The report notes governments and industry are already beginning to change their practices to help key sectors adapt to a changing climate. In Australasia, planning for sea-level rise and reduced water availability is common. But while sea-level rise planning has evolved considerably over the past 20 years, its implementation remains piecemeal.

It says there are a wide range of measures that can help the world adapt to climate change and would result in a more robust, resilient and secure planet.

The IPCC had significantly more scientific research at hand than for its previous assessment in 2007. The report says impact due to climate change already observed includes:

• Changes to rainfall patterns and melting snow that are altering the quantity and quality of water systems.
• Land and sea species shifting their geographical range, seasonal activities, migration patterns and interaction.
• More negative than positive impact on crops yields.
• A relatively small burden on human health compared to other stresses.
• Significant vulnerability to extreme climate events, such as bushfires and heatwaves for some ecosystems and many human systems.

The report also assesses research into the projected future impact of climate change. Findings are that:

• Land and freshwater species face rising risk of extinction during and beyond the 21st century.
• The fraction of people facing water scarcity and affected by river flooding will increase in the 21st century as warming rises.
• Major food crops – rice, wheat and maize – are projected to be affected under temperature increases of two degrees above the levels of late-last century – though some individual locations may benefit.
• Global economic losses are difficult to estimate, but an additional two degrees warming could lead to between 0.2 to 2 per cent loss of global income. Losses are considered more likely to be greater than this range than smaller.
• Ill-health is expected to increase in many regions, especially developing countries.
The report follows the release last year of the first report looking at the physical science of climate change. A third part looking at options to cut greenhouse gas emissions will be released in mid-April.

Saturday, March 22, 2014

New IPCC climate report predicts significant threats to Australia

Tom Arup Environment editor 
The Age, March 23, 2014 

Australia's multibillion-dollar mining, farming and tourism industries face significant threats as worsening global warming causes more dangerous and extreme weather, the world's leading climate science body will warn.

A final draft of a five-year assessment by the UN's Intergovernmental Panel on Climate Change (IPCC) - seen by Fairfax Media - details a litany of global impacts from intensifying climate change including the displacement of hundreds of millions of people, reduced crop yields and the loss of trillions of dollars from the global economy.

The report is the second part of the IPCC's fifth major assessment and focuses on climate change's impacts and how the world might adapt. It will be finalised at a meeting in Japan next weekend before its release on March 31.

The final draft Australasia chapter also outlines significant local threats if human-caused climate change gets worse, in particular high confidence that fire seasons, particularly in southern Australia, will extend in high-risk areas.

There is also significant risk of increased damage and death from heatwaves resulting from more frequent extreme high temperatures. Flood risk too would be worse.

The draft says these new extremes imply Australia's mammoth mining industry is increasingly vulnerable without adaptation measures. The report points to significant loss of coal exports revenue of $5 billion to $9 billion when mines were flooded in 2011.

Tourism also faces some significant threats, the draft says. The Great Barrier Reef is expected to degrade under all climate change scenarios, reducing its attractiveness to visitors.

Australia's $1.8 billion ski industry is identified as most negatively affected, with little option for it to counteract threats.

For Australian farming a 4 per cent reduction in the gross value of beef, sheep and wool is expected with 3 degrees of warming above a 1980-99 baseline.

Dairy output is projected to decline in all regions, except in Tasmania.

Out of the major risks identified for Australia in the draft, the loss of montane ecosystems and changes in coral reefs, appear to be very difficult to avoid. The draft also finds modelling consistently indicated the range of many wildlife species will contract.

And there is high confidence climate change is already affecting Australia's oceans, with climate zones and species shifting hundreds of kilometres southwards.

Professor Jean Palutikof - a review editor of the assessment and director of Australia's National Climate Change Adaptation Research Facility - said while adaptation measures were important, there were limits to what the world could do and it was important to cut global emissions to ensure these thresholds are not reached.

''I think it is quite black and white, there is a risk we will go beyond the limits of the natural environment and human society to adapt to the climate'' she said.

A spokesman for Environment Minister Greg Hunt said the government recognised the importance of adapting to the impacts of climate change, pointing to the refunding of the National Climate Change Adaptation Research Facility, which it has asked to ''focus on putting practical adaptation information in the hands of decision-makers so we can build a stronger, more resilient Australia''.

The world is hungry and increasingly so. Demand for the three staple food crops - rice, wheat and maize - is expected to grow 14 per cent a decade to 2050.

Meeting that demand will be hard at the best of times. CSIRO's Dr Mark Howden says the food produced (yields) by most primary crops is presently growing by only about 1 per cent a decade.

Then there is climate change. The draft IPCC assessment finds with global warming average global crop yield will decline by up to 2 per cent a decade .

Dr Howden is a lead author of the food security chapter in the report. He says food crops will remain relatively stable with less than 1 degree of warming. But as temperatures rise above that they will feel the heat. And the more heat, the less crops will produce.

''Confidence that things will get more and more negative is stronger and stronger as we go out to higher temperatures,'' he says.

More extreme weather will also mean the amount of food produced will vary wildly year-on-year.

The draft findings of the fifth assessment differ from the IPCC's last report, which found crop losses in some areas would be offset by gains elsewhere. Five years on and more negative impacts are now being observed than positive.

Dr Howden says adaptation can improve yields by about 10 to 15 per cent above what they would otherwise have been - enough to feed a billion people. The draft says adaptation can be effective at about two degrees of warming, but at four degrees the gap between production and demand will become increasingly large in many regions, even with adaptation.

The work to be able to adapt food production to a hotter and more variable world must begin now, Dr Howden says. One example is the need to breed varieties that can handle the new climate, while to date we breed for historic conditions.

At the top of Australia's mountains the world is closing in. As the planet warms, snow is disappearing and the montane environment is receding. The animal and plant species that call it home, such as the mountain pygmy-possum, have a significant problem - their chance of extinction is growing.

Macquarie University biologist, Professor Lesley Hughes, says habitat contraction is one of the key challenges emerging as a result of climate change.

Professor Hughes is a lead author of the Australasian chapter. She says if warming intensifies over the coming decades the overall global picture for ecosystems, plants and animals is bleak. A leaked draft of the report concludes many species are already shifting their range, seasonal activities, migration patterns, and interactions.

''There are lots of species that have proved to be very sensitive to warming of even less than 1 degree,'' Professor Hughes says.

''In some cases species have moved several hundred kilometres to cooler areas towards the poles, particularly in the marine world, where there are less barriers to movement than on land.''

She says that at up to 2 degrees of warming, the main driver of extinction, will continue to be land-use change, but at any higher rate of warming, climate change will become the predominant factor.

Professor Hughes says most species cannot evolve at the same speed as the planet is changing, and there is little humans can do to help out.

Wars between great nations and millions of refugees driven from home by rising seas. These are the nightmare security scenarios envisaged under climate change.

In a sign of concern about global warming's security impact the Intergovernmental Panel on Climate Change has for the first time assessed what problems may emerge. 

Professor Jon Barnett, a political geographer at Melbourne University, is a lead author of the security chapter. He says published evidence is clear that extreme weather will displace large numbers of people. But it also shows people tend to return once a threat subsides, meaning displacement is often temporary.

What about long-term deterioration, such as sea level rise? The draft report says by 2100, without help, hundreds of millions of people will be displaced by coastal flooding and land loss.

Will that mean great numbers of refugees fleeing to other countries? Professor Barnett says there is no clear evidence for that. And the real concern will be the poor and vulnerable who will have no escape means.

''Only some groups have the wherewithal to move as conditions deteriorate. Typically, it is the most vulnerable who are left behind and that is where the greatest social and humanitarian problem is,'' Professor Barnett says.

The IPCC assessment also looks at whether climate change will cause more armed conflicts, an area which he says is deeply contested. The draft assessment concludes climate change will indirectly increase the risk of conflict by exacerbating factors that cause violence, such as poverty and economic shocks.

While the link between climate change and war is not clear, it may shape security policy and heighten tensions between nations over factors such as shared water resources and fish stocks. But Professor Barnett says these can be managed peacefully with strong international institutions.