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Sunday 18 November 2007 (updated Mon 19 November 07)

RAPID ROUNDUP: IPCC Synthesis Report - Scientists respond

Australian scientists comment on the IPCC Synthesis Report released in Valencia, Spain, last night. David Karoly and Neville Nicholls spojke to journalists online this morning (due to technical difficulties, only part of the audio file is available)

Feel free to use these comments in your stories or contact AusSMC if you would like to interview any of these scientists on 08 8207 7415.

Read comments from:

Kevin Hennessy is Principal Research Scientist at the Climate Impacts & Risk Group, CSIRO Marine and Atmospheric Research.

William Kininmonth is a meteorologist and an outspoken critic of global warming and the Kyoto Protocol. He was head of the National Climate Centre at the Bureau of Meteorology from 1986 to 1998.

Dr Barrie Pittock was formerly leader of the Climate Impact Group in CSIRO and is author of the book “Climate Change: Turning Up the Heat”.

Dr Graeme Pearman is Director of Graeme Pearman Consulting. Graeme Pearman is a well known climate scientist who was involved in the IPCC Fourth Assessment Report.

Professor Neville Nicholls is in the School of Geography & Environmental Science at Monash University, and was a member of the writing team for the IPCC Synthesis Report.

Ian Lowe is Emeritus Professor at the School of Science, Griffith University, and president of the Australian Conservation Foundation.

Professor Barry Brook is Director of the Research Institute for Climate Change and Sustainability at the University of Adelaide.

Professor Ove Hoegh-Guldberg is Director of the Centre for Marine Studies at the University of Queensland.

Dr David Robson is Deputy Chief Executive of ENSIS and CSIRO Forest Sciences.

Kevin Hennessy is Principal Research Scientist at the Climate Impacts & Risk Group, CSIRO Marine and Atmospheric Research.

"The IPCC Synthesis Report summarises and adds value to the three IPCC reports published earlier this year. It clearly articulates that the evidence for climate change is beyond doubt, with increases in greenhouse gases very likely responsible for most of the warming since around 1950. It also states that more climate change is unavoidable over the coming decades. Significant impacts are expected, becoming more widespread and more severe as global warming proceeds. Managing these risks requires both adaptation and mitigation (emission reductions). The IPCC explores the consequences of six emission reduction scenarios without advocating a particular emission reduction target, but notes that significant reductions can be achieved by 2050 while slowing the growth in global GDP by around a tenth of one percent.

In my view the 7 key statements in the report are:

1. Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.

2. Most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
January 9, 2008 intensities of extreme weather, together with sea level rise, are expected to have mostly adverse effects on natural and human systems.

4. Responding to climate change involves an iterative risk management process that includes both adaptation and mitigation and takes into account climate change damages, co-benefits, sustainability, equity, and attitudes to risk.

5. A wide array of adaptation options is available, but more extensive adaptation than is currently occurring is required to reduce vulnerability to climate change.

6. Many impacts can be reduced, delayed or avoided by mitigation. Mitigation efforts and investments over the next two to three decades will have a large impact on opportunities to achieve lower stabilisation levels.

7. A wide variety of policies and instruments are available to governments to create the incentives for mitigation action."

William Kininmonth is a meteorologist and an outspoken critic of global warming and the Kyoto Protocol. He was head of the National Climate Centre at the Bureau of Meteorology from 1986 to 1998.

“The IPCC Synthesis Report to its Fourth Assessment contains no new material above what was previously published in the individual Working Group Reports. The conclusions of the Synthesis Report are dependent on the emission scenarios of likely carbon dioxide concentration over the coming century, and on the computer models that project future temperature and other climatic patterns. The emission scenarios recognise uncertainty about the magnitude of climate forcing by carbon dioxide over the coming century depending on development paths and mitigation strategies that might be adopted. More importantly, the different computer models cover a wide range of sensitivity in their response to carbon dioxide forcing. There is no analysis by the IPCC on which sensitivities are likely to be the more realistic.

Recent published research identifies that one of the important natural constraints on global temperature rise, the increase of evaporation with temperature, is on average underestimated in the computer models by a factor of three. This is an important impediment which must be rectified because it suggests that even the models with low-end sensitivities are over-stating the climate response to increasing carbon dioxide. With such uncertainty about the potential climate response to increasing carbon dioxide the conclusions of the report are no more than speculation.”

Dr Barrie Pittock was formerly leader of the Climate Impact Group in CSIRO and is author of the book “Climate Change: Turning Up the Heat”.

“The new Synthesis Report is the result of work by hundreds of scientists. It has been adopted with the approval of the governments that signed the UN Framework Convention on Climate Change, including countries like the UK, China, India, Australia and the United States. It is the most authoritative report yet available on the subject of human induced climate change and on the likely consequences of policy options to adapt to climate change impacts and to reduce the magnitude of climate change.

The Report confirms that climate change is happening now and is largely due to human influences, and that it is already having noticeable impacts that are going to get worse.

The Report under-estimates some of the risks because it is based on published research only up to the middle of 2006. Many new studies since then show that greenhouse gas emissions, climate change and sea-level rise are happening faster than the climate models so far have indicated.

Despite that, it has many useful things to say.

Most relevant to impacts on Australia, the Report confirms that mid-latitude storm tracks in the Southern Hemisphere are expected to move further polewards, leading to reduced rainfall in southern Australia. This is already happening, resulting in the prolonged “droughts” in the southwest and more recently in southeastern Australia. The present water crisis in southern Australia is a combination of natural variability and climate change. We are moving into a more arid climate and are unlikely to pull out of the present 'drought'.

The Report highlights, in its Table SPM-2, four major areas of adverse impacts on Australia. This should motivate Australians to insist that we do something to reduce greenhouse gas emissions. Projected impacts in many other countries, including those of Asia and North America similarly should motivate other key countries to act as well, notable China, India and the United States. The report thus provides a basis for international action arising out of the common threat to all major countries.

Regarding sea-level rise, the Report notes that the numerical estimates given for sea-level rise do not include recent evidence for more rapid discharge of ice from Greenland and Antarctica that could lead to more rapid sea-level rise. Global greenhouse emissions and sea-level rise are already tracking at the highest levels of the range of uncertainty reported by IPCC. My judgement, based on this new evidence is that sea-level rise by 2100 is unlikely to be under 1 metre, and could be considerably larger. This will have enormous implications for present coastal infrastructure and slow down coastal development.

The Report lists, in its Table SPM-4, a wide range of measures to adapt to climate change that could well be undertaken. Similarly, in Table SPM-5 it provides a large shopping list of measures that could be taken to reduce greenhouse emissions. Both these lists need to be studied carefully and many implemented in Australia, urgently. The Report also notes the important achievements of the Kyoto Protocol in stimulating appropriate actions, despite the failure of the United States and Australia to ratify the Protocol. While not yet sufficient, these achievements are a good start.

The Report clearly states that “Delayed emission reductions significantly constrain the opportunities to achieve lower stabilisation levels and increase the risk of more severe climate change impacts.”

The key information, in Table SPM-6, is that concentrations of greenhouse gases (including carbon dioxide, methane and others) somewhere between 445 and 490 parts per million, expressed as equivalent amounts of carbon dioxide, will likely lead to global warmings of 2.0 to 2.4ºC. This concentration is widely considered by most climate scientists to be close to 'dangerous', although that is a value judgement that IPCC, as an advisory body, cannot make.

To stabilise concentrations at this level, Table SPM-6 indicates that emissions need to be reduced by 50 to 85% by 2050, that is, by some 2 to 3% each year from now. In fact this target concentration has already been reached, with carbon dioxide concentrations alone reaching about 384 ppm. So we will have to reduce greenhouse gas emissions drastically to stop further rises in concentration, and eventually take carbon dioxide out of the atmosphere.

The Report provides, in Table SPM-7, estimates of the global economic costs in 2030 and 2050 of reducing emissions to targets as low as 445 ppm (CO2 equivalent). It finds that the resulting reduction in GDP in 2050 is less than 5.5%, which means that the annual GDP growth rates is at most some 0.12% less.

The IPCC Report finishes with the statement that “balancing the economic costs of more rapid emissions reductions now against the corresponding medium-term and long-term climate risks of delay” is at the centre of the policy debate regarding emissions reduction. The Report provides evidence that reducing global greenhouse gas emissions can be done at quite moderate costs, far less than the costs of failing to do so. To date, we in Australia, and indeed the world community, do not have policies in place to do what is necessary.”

Dr Graeme Pearman is Director of Graeme Pearman Consulting. Graeme Pearman is a well known climate scientist who was involved in the IPCC Fourth Assessment Report.

“If we are going to avoid a 2C rise in global temperatures, as the EU says we must to avoid dangerous climate change, reductions in emissions need to have occurred between 2000 and 2014 – so we’re right in the middle of this period now. The bottom line is that it’s now urgent.”

Professor Neville Nicholls is in the School of Geography & Environmental Science at Monash University, and was a member of the writing team for the IPCC Synthesis Report.

“The greenhouse gases we are pushing into the atmosphere already have committed us to warming of about 1ºC, and unless we take action now that could blow out to 4°C by the end of the century. That may not sound like much, but quite small warming can have devastating impacts. The 2003 European heat wave caused about 15,000 deaths in France, in a year when the annual average Paris temperature was only 0.1°C warmer than the previous record annual average temperature. In Melbourne the mortality rate of those aged over 65 jumps 20% on hot days, even now. Further warming will put us into uncharted territory regarding heat waves and deaths. There are reasons for concern.

The Synthesis Report is really a “citizen’s guide to climate change”. It is short, readable (as readable as a report written by hundreds of scientists is likely to be), and addresses the most important questions. The Synthesis has selected the most important messages from these reports, and juxtaposes the relevant information from the three reports. The extra time available since the three working group reports were finalised has meant that there has been some fine-tuning of the way the science is expressed (although the science content has not changed). We hope that many people (and every politician) can find an hour to read the Synthesis Report.”

Ian Lowe is Emeritus Professor at the School of Science, Griffith University, and president of the Australian Conservation Foundation.

“The new report underlines the urgency of a concerted response to climate change. Whichever party is elected next Saturday has to ratify the Kyoto protocol, set strong 2020 targets to reduce emissions, boost renewable energy and dramatically improve the efficiency of turning energy into services. Voters should recognise that this is the most important challenge for our generation. Unless we act now, future Australians will see us as having been criminally irresponsible.”

Professor Barry Brook is Director of the Research Institute for Climate Change and Sustainability at the University of Adelaide.

"Everyone MUST read this synthesis report. It is science policy at its most compelling, with our very future at stake.

The IPCC Synthesis Report (summary for policy makers) is basically a precis of the previous three 4th Assessment Working Group reports, released in 2007, on the science of climate change (WGI), likely impacts and adaptation (WGII), and paths to mitigation (WGIII). As such, you could be forgiven for thinking that there would be little or nothing new here. Yet I sense that there is. The language used to describe the looming risks seems less clinical - more emotive, than that in the previous summary for policy makers (SPM). The generally conservative assumptions are laid bare, rather than hidden away.

A good example of what I mean is the description of sea level rise. A number of scientific papers have, during just this last year (so too late to be included in the AR4 main report), seriously raised the prospect of metres, rather than centimetres, of sea level rise by 2100 (and much more beyond). In this synthesis report - perhaps in response to this growing recognition - it is made abundantly clear that the predictions of 18-59cm rise is patently a lower bound, because rapid future ice flow dynamics are not included. In essence, what they mean by this is "...because we can't adequately model the unexpectedly rapid loss of Arctic sea ice and accelerating disintegration of Greenland and West Antarctica and put a number on how fast this will proceed, we have no choice but to leave it out of our projections..." (and thus risk conveying a gross underestimate of the true possibility). At least now they say it in the SPM.

Figure SPM.7 is a simply stunning summary. Unlike the previous version in WGII, this explicitly links impacts to mitigation scenarios. In doing so, it clearly shows that under the most stringent mitigation scenario proposed (scenario I, in which CO2 equivalent is limited to 445-490 ppm, global cuts of 50-85% in emissions are achieved, and warming of 2-2.4C is realised), there is a high confidence that a slew of what can only be described as catastrophic impacts (30% species loss, major coastal flooding, most corals bleached, significant global water stress), will unfold! The fossil-fuel intensive business-as-usual scenario runs off the chart, with a disturbingly plausible risk of up to 6.8-8.6C warming - truly "game over" for humanity and most other life on this planet.

Indeed, it is a damning indictment on our collective vacillation, inaction and deliberate stalling to date, in facing up to this problem (Australia and the US as two prominent curmudgeons), that we are now facing the stark choice between a bad situation, a catastrophic situation, or a civilization-terminating situation. The EU has defined "dangerous anthropogenic interference with the climate system" (what we were supposed to avoid, according to the 1992 UN Framework Convention on Climate Change) as being anything over 2C warming - and many claim this is already too much for comfort, given the changes we are witnessing now at 0.8C warming. There is some dark humour to be had in contemplating Table SPM.6 then - because only 6 of 177 mitigation scenarios reported therein actually allow for the possibility of avoiding 2C!

There is one bit of good news, if policy makers will just take heed. Table SPM.7 shows, quite clearly, that the costs involved in moving fast to address the emissions problem are incredibly small, or perhaps even beneficial overall (and that's before we count the social and environmental cost of not taking action). To achieve the most stringent mitigation of 445-535 ppm CO2e, the reduction in GDP by 2050 is 3-5.5%. This means, roughly, that we become twice as rich (in real dollar terms - equivalent to the average yearly Australian wage now being over $120K instead of $60K), in July 2050 instead of January 2050. So the catch is, in making this choice, that you have to be willing to wait 6 months, to save the planet.”

Professor Ove Hoegh-Guldberg is Director of the Centre for Marine Studies at the University of Queensland.

“The Intergovernmental Panel on Climate Change (IPCC) is one of the most rigorous scientific processes of modern times. In the synthesis report released today, it reasserts the undeniable evidence that the earth is warming rapidly due the rise of anthropogenically generated greenhouse gases such as carbon dioxide and methane. These changes are being driven by the burning of fossil fuels and the massive destruction of natural landscapes such as forests.

The changes that we are seeing are unprecedented in the last several million years. Events thought to be unlikely, such as the breakup of the polar and Greenland ice sheets are now happening. The report indicates that natural ecosystems are changing rapidly, water availability is diminishing and that impacts on food supply for many countries will continue to grow. This report is yet another wake-up call to the seriousness of anthropogenic climate change.

Coral reefs are indicative of the changes that are occurring in natural ecosystems. Worldwide coral reefs are responsible for supporting the subsistence food supply for at least 100 million people. If coral reefs disappear, as the IPCC report warns, there would be catastrophic consequences for many societies throughout the tropics and sub-tropics. For Australia, a loss of coral reefs would have serious economic consequences for boom economy states like Queensland. At present, the second-largest industry in Queensland is the tourist industry generated by the beauty and ecologically pristine nature of the Great Barrier Reef. Without the Great Barrier Reef, this $6 billion per year industry would dwindle.

The IPCC synthesis report also provides the very strong case that the consequences for human societies everywhere will be catastrophic if we don't act right now. Decisive, non-partisan action is required. This action must heed the science and the seriousness of the problem. It must act on that science. Anything less is foolhardy and negligent.

Without acting right now we will miss the only opportunity to act. Strong leadership is required that sets clear targets that must reduce our emissions to less than 10% within the next three decades. We have not seen that leadership in Australia or elsewhere as yet. Currently, with Australia leading the world as the highest emitter of CO2 per person, changing our current disastrous track will require some strong and clever decisions. Given this and the fact that we are wealthy as a nation, we should be leading the world rather than dragging our feet.

While both sides of politics in the recent electoral debates have recognized the issue of climate change as being important, both sides have been reluctant to specify the action that they will take to reduce emissions over the next few decades. This is unfortunate given that we need strong leadership not only to adapt to climate change (which is where most of the money has gone so far) and also to specify strong emission reduction targets that are commensurate with the scale of this global emergency. This decade may be among the last in which we can choose between a future during which humans continue to prosper in many regions, versus one in which we will continually struggle to survive as the climate becomes more and more hostile, and beyond our control.”

Dr David Robson is Deputy Chief Executive of ENSIS and CSIRO Forest Sciences.

“Biosequestration is an obvious and often overlooked option to mitigate against climate change. The planting of trees is scientifically proven to be part of the climate solution and the science behind the carbon accounting within forests is well developed.

Further greenhouse accounting research has recently proven that carbon is stored in wood products long after the tree is sustainably harvested and remains in many cases up to 70 years. Unfortunately many of Australia’s current energy rating and environmental assessment schemes don’t take into account the full life-cycle benefits of stored carbon in timber.

The Australian Greenhouse office estimates that wood products in service in Australia (from 1944 onwards) are storing about 95.6 million tonnes of carbon.

One current scientific question is around solving the interrelationship between carbon stocks like forests and the increased atmospheric CO2. We expect increased growth rates but there are still questions around a decreased reliance on water and the interrelationship between fire incidences and intensity.”