Archive for the ‘Managing uncertainty’ Category
By Roger Jones, Victoria University and Celeste Young, Victoria University
The Intergovernmental Panel on Climate Change (IPCC) is the accepted global authority on climate change. It produces reports that are collectively agreed assessments of the scientific literature by leading researchers. The Fifth Assessment Report (AR5) is being delivered over 2013–2014, starting this weekend.
What an IPCC report is
An Intergovernmental Panel on Climate Change (IPCC) report is an assessment that collects and summarises current knowledge in relation to climate change. This is done using literature from peer reviewed and unreviewed (grey) sources.
It is considered the leading review globally of climate change and is produced by a team of hundreds of scientists and specialists from a diverse range of disciplines.
The following statements are typical of the gradualist adaptation narrative:
- Within limits, the impacts of gradual climate change should be manageable.
- Therefore, climate change adaptation can be understood as: (a) adapting to gradual changes in average temperature, sea level and precipitation.
- Gradual climate change allows for a gradual shift in the mix of crops and to alternative farming systems.
So why are Gauss and Newton in the bath and Ed Lorenz in the hot tub?
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.
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).
Welcome to the live blog for I Can Change Your Mind About … Climate on ABC1 from 8:30 pm AEST. From the show’s blurb:
Separated by a generation, and divided by their beliefs, two passionate, intelligent and successful Australians go on a journey of mutual discovery to see if they can change each other’s minds about the most divisive issue in Australia today: climate change.
It’s a pity we don’t have cards for climate change bingo to mark off squares for “It hasn’t warmed since 1998″, “scientists are only in it for the grant money”, “the temperature record cannot be believed” and so on. Likewise, I don’t recommend drinking games. You’ll be on your ear by 9. Read the rest of this entry »
The full IPCC Special Report Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) has been released. The download of the entire report (44 Mb) is here, the Summary for Policymakers is here, the press release is here and slide presentation (pdf) here. Also on the site are individual chapters for download, review comments, process information, graphics and the grey literature library.
As I posted late last year with the release of the SPM, the great benefit of this special report is the coming together of the climate change and disaster management expert communities. A marriage, which I’m told, got a bit rocky at times. The report emphasises the need to address both biophysical and social-economic aspects of changing climate extremes and the systems exposed to those changes. Read the rest of this entry »
First week of December I was at the American Geophysical Union Fall Meeting in San Francisco. This meeting is big: an estimated 20,000 attendees this year dealing with all matters geophysical from global change to stressed rocks. I had a poster to give, and being super organised, spent the first two days of the meeting preparing it. The AGU’s 24 hour poster print service got me a big 6’ x 4’ poster by the Thursday session.
And it was a complicated poster, let me say, though there were simple bits in it. When you want to overturn a paradigm, a simple “it ain’t so because it ain’t” doesn’t cut it. The main thesis is that the signal-to-noise model, which assumes a smooth anthropogenic change signal within a background of noisy natural variability, is wrong. Instead the climate follows a deterministic non-periodic pathway, to coin Ed Lorenz of butterfly complexity, where the forcing produced by increasing greenhouse gases does not gradually change climate, but comes in steps. The bulk of the energy is stored in the ocean, with climate showing little warming, only to be released in periodic bursts influenced by the processes associated with climate variability.
I have an article on The Conversation Spinning uncertainty? The IPCC extreme weather report and the media. This works up some of the material in my previous post on the IPCC Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation Summary for Policymakers (IPCC SREX SPM). It gives, I reckon, a pretty good overview of the SPM and puts some of The Australian newspaper’s reporting of it under the spotlight. Go read.
One thing I didn’t mention was that there was a second story in The Australian tagged November 19 12:00 am that quoted Benny Peiser, directors of the Global Warming Policy Foundation, a UK climate change foggery set up by Lord Nigel Lawson. (It was reposted on the GWPF site). He said:
“there was not a strong empirical link between anthropogenic climate change and weather events”.
“It is unlikely there will be one for 20 to 30 years,” he said.
He said any suggestion that recent weather events could be directly linked to climate change went directly against the general scientific consensus.
Ummm, extreme temperatures? Right now?
The Summary for Policymakers (SPM) for the IPCC Special Report Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) was released late last night our time. The final plenary was held in Kampala Uganda, finishing on the 17th before the release yesterday. As usual, it is gone through line by line by IPCC country member representatives and the co-ordinating lead authors to craft a document that contains key policy messages while retaining true to the science in the report.
The SPM is complex and has already been given a number of interpretations in the press. The ABC news says extreme weather to worsen with climate change. The Australian focuses on the uncertainty Climate change effects unknown: IPCC report. A quick survey of Google news suggests that most outlets are focusing on extremes to worsen, or the qualified some extremes to worsen.
The Australian is different. Its header says:
GREAT uncertainty remains about how much of an impact climate change will have on future extreme weather events, the world’s leading climate scientists have found.
While there has been an increase in warm days and a decrease in cold nights, the likely impact on future weather events would not be evident for decades because of natural variability, the scientists say in a key review prepared for the UN’s Intergovernmental Panel on Climate Change.
This completely ignores the thrust of the report, which is to address the risks of extreme climate-related events and disasters and manage changing risk through adaptation. The great value of the report is not so much in its headline findings, which are complex but are in bringing the climate, adaptation and disaster communities together. These two communities had a hard time of it in the writing of the report bringing together different language, concepts, views of risk and methods of assessing vulnerability and adaptation. Read the rest of this entry »