Archive for the ‘Science’ Category
Guest post by Roger Bodman, Victoria University and David Karoly, University of Melbourne
Today we released research which reduces the range of uncertainty in future global warming. It does not alter the fact we will never be certain about how, exactly, the climate will change.
We always have to make decisions when there are uncertainties about the future: whether to take an umbrella when we go outside, how much to spend on insurance. International action on climate change is just one more decision that has to be made in an environment of uncertainty.
The most recent assessment of climate change made by the Intergovernmental Panel on Climate Change in 2007 looked at what is known with high confidence about climate change, as well as uncertainties. It included projections of future global warming to the end of this century based on simulations from a group of complex climate models.
These models included a range of uncertainties, coming from natural variability of the climate and the representation of important processes in the models. But the models did not consider uncertainty from interactions with the carbon cycle – the way carbon is absorbed and released by oceans, plant life and soil. In order to allow for these uncertainties, the likely range of temperature change was expanded.
Time to stop hiding behind warming trends
By Roger Jones, Victoria University
Dr Rajendra Pachauri, head of the IPCC, has reportedly acknowledged to Graham Lloyd of The Australian, that there is a “17-year pause in global temperature rises”, a fact that apparently has been suppressed in Australia. Dr Pauchauri endorses debate, saying that people had a right to question the science, whatever their motivations.
But according to Lloyd, Pachauri’s views contrast with arguments in Australia that views outside the orthodox position of approved climate scientists should be left unreported.
Am I an “approved” climate scientist? because I don’t hold that view, nor do I know any who does. What we would like, though, is for science to be reported as science and for opinion to be reported as opinion. And for all reporting to be accurate.
Lloyd makes this claim: unlike in Britain, there has been little publicity in Australia given to recent acknowledgement by peak climate-science bodies in Britain and the US of what has been a 17-year pause in global warming. Britain’s Met Office has revised down its forecast for a global temperature rise, predicting no further increase to 2017, which would extend the pause to 21 years.
This is the Met Office’s latest five-year forecast shown below. Skeptical Science reports the Met Office saying: the latest decadal prediction suggests that global temperatures over the next five years are likely to be a little lower than predicted from the previous prediction issued in December 2011. We’re in the midst of a period of La Niñas, which have a slight cooling effect, as do rising sulphate emissions in Asia. But look at the blue line – do my eyes deceive me? Is it level with the previous black line? It’s warmer? Perhaps Lloyd’s computer has a tilt to the right that makes increases look level.
The Met Office predicts record global mean temperature over the next five years – now that’s news.
News Corporation sells roughly 70% of the newspapers in metropolitan Australia, and its readers are subject to this kind of fudging on a regular basis. It’s no wonder some “approved” scientists are frustrated.
But that’s not the only thing that frustrates me. It is also time to challenge what Lloyd calls the orthodox position of climate science.
Climatology needs to stop hiding behind long-term trends and explain what is in plain sight, and why variations in the rate of warming might be important. I’m working with colleagues at the moment on a National Climate Change Adaptation Research Facility project called Valuing Adaptation to Rapid Change and we’re looking at the economics of rapid change. Non-linear behaviour in climate driving extreme events has the potential to really hurt us.
The first thing to bear in mind is that a trend line is a model. A warming trend is not a theory of how climate changes. If a complex, non-linear system fails to follow a trend, look at the model to see whether it represents the theory sufficiently well.
In a nutshell, the theory says greenhouse gases act like a blanket, trapping heat near the surface. This creates a radiation imbalance at the top of the atmosphere. The earth system warms to return this balance by increasing the heat escaping from the top of the atmosphere so that energy out equals energy in. This is a slow process, taking centuries, because the ocean has to warm sufficiently to support a hotter atmosphere. The scientific confidence in this aspect of climatology is extremely high. A simple trend line is sufficient to measure this process.
But on decadal time scales, the trend-line model fails. Most of the heat trapped in the earth system goes into the oceans. The top 700m of ocean increased in heat content from 3 x 1022 Joules in 1997 to 10 x 1022 Joules in 2010, in a highly non-linear manner, due to mixing rates between the surface and deep ocean. The atmosphere holds as much heat as the top 3m of ocean, about 0.4% of the heat content above. Why on earth then, with highly non-linear processes in the ocean, would we expect a gradual warming trend in the atmosphere?
A paper I published last year shows that most of Australia’s warming occurred in two episodes, one in the late 1960s to early 1970s, when south west WA rainfall also decreased, and the other in 1997-98. The other finding was that most of this warming was anthropogenic. On decadal timescales, step and trend is a much better model for explaining warming than simple trends.
To me, the graph above makes perfect sense: mild trends separated by an instantaneous rise of about 0.3°C. By ignoring non-linearity and projecting future climate change as simple trends, orthodox science is doing us a great disservice. We have not yet woken up to the recent non-linear increases in heatwaves and fire danger in Australia let alone planning for more such changes in the future. The same goes for floods.
It’s time to stop defending orthodox science by hiding behind simple trends and come to grips with the fundamental non-linearity of climate change. That’s the risk we need to mitigate, adapting to changes that can’t be avoided.
Roger Jones receives funding from the National Climate Change Adaptation Research Facility. He is affiliated with Climate Scientists Australia and the IPCC.
This is an excellent article by Andrew Campbell on The Conversation, republished here under a Creative Commons licence.
Rethinking rural research in Australia
By Andrew Campbell, Charles Darwin University
Rural research is vital. It is about 10% of our national innovation system. Annual investment exceeds $1 billion, according to the Rural Research and Development Council. The rural sector and farm-dependent economy accounts for 12% of GDP, 14% of exports, 17% of employment, 60% of the land mass and between half and two-thirds of total water use. (Mining accounts for 9% of GDP, 35% of exports and 2.2% of employment.)
A vibrant, world-leading rural, environmental and agricultural research sector is more strategically important for Australia now than ever. This is clear from authoritative reviews on climate change, biosecurity, drought policy, biodiversity conservation, food security and energy-water-carbon intersections. The Australian Government has also received the Productivity Commission Inquiry into Rural R&D Corporations and the Rural Research and Development Council’s National Strategic Rural R&D Investment Plan.
All these reviews and reports say we need more and better rural research, development and in some cases extension. Read the rest of this entry »
Less than a fortnight ago, I wrote that those barracking for conventional scientific theories often maintain that science is not a matter of belief. Sorry guys, but assessing the probability of t (scientific truth) being T (absolute truth), is a matter of belief, as is anything that goes on in the mind regarding external evidence. But there is a difference between belief and true belief.
And then in a conversation with the Chief Scientist Ian Chubb on communicating science, with specific reference to climate science, The Conversation quotes him as saying:
“We scientists need to talk about evidence, and without being cornered into answering questions like ‘do you believe?’,” Professor Chubb said.
“I get asked that every day and every now and then I make a mistake and say yes or no…It’s not a belief, it’s an understanding and an encapsulation and interpretation of the evidence.”
Ian Chubb was speaking to the Royal Society of Victoria, which launched on August 30th a three-year program aimed at increasing the awareness of science among primary school children. And while I agree with most of what Ian Chubb says in his interview with The Conversation, the belief thing should be called for what it is – a full-blown fallacy.
No, not an exotic Hungarian sandwich, but The Grauniad has an excellent 50th anniversary review of Kuhn’s The Structure of Scientific Revolutions written by John Naughton in their Sundy paper. In a total paradigm shift, the comments aren’t totally trolltown, either. See also, Howard Sankey on the The Conversation.
Before Kuhn, our view of science was dominated by philosophical ideas about how it ought to develop (“the scientific method”), together with a heroic narrative of scientific progress as “the addition of new truths to the stock of old truths, or the increasing approximation of theories to the truth, and in the odd case, the correction of past errors”
After me getting an op-ed in The Age representing real climate science and policy, it’s time for some asshattery, c/- both the Melbourne Age and the Sydney Morning Herald. The Fairfax press has decided to redress the balance of knowledge with some agnotogeny* from Dr David Evans. From his tagline:
Dr David M. W. Evans is a mathematician and engineer who consulted full-time for the Australian Greenhouse Office (now the Department of Climate Change) from 1999 to 2005. He says he changed from being a warmist to a sceptic after ”evidence supporting the idea that CO2 emissions were the main cause of global warming reversed itself from 1998 to 2006”.
Oh purleeze. Read the rest of this entry »
A couple of my recent forays into the media have provoked comment below the articles themselves and in emails sent querying particular points. They are worth unpacking because they reflect on the different between the straight communication of science and framing risk.
One was in reference to a recent op-ed in The Age. In it, I said:
If people accept the 0.0038 and 0.02 degree benefits as valid then they also accept the science behind a 5.3 degrees warming for business as usual (As in the emission scenario created by Treasury for the 2008 Garnaut Review). Who wants to live in a world warming by 5 degrees or more? Major food crops could not be grown in many parts of the world, projected sea level rise would be tens of metres, most of the shelled species in the ocean would not survive, ecosystems would be disrupted as the pace of change outstripped their ability to adapt and millions to billions of people would lose environmental security leading to mass migrations never before seen.
That prompted an email from an earth scientist wanting to know what peer-reviewed reference I was using for the projected tens of metres of sea level rise. I sent back this now famous diagram and a note saying that I wasn’t putting it on a timetable. He then replied suggesting that people could be misled into thinking that the date was 2100 (because that was tied to the two temperature measures) and that I was being alarmist. Because it would take thousands of years to be realised. Read the rest of this entry »
For those who didn’t catch it, during the week an op-ed of mine was Climate Policy will Stay a Mystery until Silent Specialists Join the Debate was published in The Age. It was based on an earlier post where I detailed the benefits of Australia’s climate policy and the tricks used by opponents to make it look more ineffective than it is likely to be. In the op-ed I ask where are the barefoot economists who will challenge untrue statements about climate and the economy? Text reproduced below (with small edits for clarity).
It used to be that visions were religious, as were communicable diseases. Visions of the Virgin Mary, Jesus and God were common in the ancient Christian world. Likewise, diseases were delivered via curses from the devil and his minions.
These days, most visions are products of technology and the modern world. Aliens abound, kidnapping and probing the innocent. Visionary virgins are now rare, mostly hanging on in less technological agrarian societies.
Technology is also delivering new curses and diseases. Nothing is more cursory in the Australian landscape than wind farms, giving rise to wind farm syndrome – an illness with a range of symptoms they ascribe to the presence of wind generators. The scourge of the wind farm syndrome has prompted the Victorian government to mandate a 2 km distance between any new wind generator and a residence, pretty much killing new wind farms in the state.
Simon Chapman, Professor of Public Health at the University of Sydney has written a terrific article on wind farm syndrome, describing it as a nocebo, where a cause and effect relationship that has an illusory physical relationship is charged with causing a negative effect. I made light of it above, but for the people suffering from it, the disease is as real as one caused by a genuine pathogen. This suggests there are two issues that need to be addressed. Read the rest of this entry »