Understanding Climate Risk

Science, policy and decision-making

Archive for the ‘Risk’ Category

Announcing a Special Issue on Managing Nonlinear Climate Risk

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I am guest editor for a Special Issue on “The Implications of Nonlinear, Complex System Behaviour for Managing Changing Climate Risk” that will appear in the MDPI AG journal Atmosphere. Researchers, policymakers and practitioners are invited to submit a paper for consideration to this special issue.

With the IPCC Sixth Assessment Report in its early stages, there is a very limited literature on managing the risk of nonlinear climate change on decadal timescales, yet nonlinear change poses a much greater risk than gradual change. If climate change on decision-making timescales proves to be fundamentally nonlinear, as we maintained in a paper published earlier this year, there will be a substantial gap in the assessment. This special issue invites submissions on all aspects of the implications of nonlinear climate change for risk management, from theory through to practice.

More details can be found at:
http://www.mdpi.com/journal/atmosphere/special_issues/nonlinear_climate_risk (link)

 

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Written by Roger Jones

December 19, 2017 at 6:15 pm

Trolling. It’s more important now than ever.

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When contrarian commentator Bret Stephens was hired by the New York Times as a columnist, there was an immediate outcry from climate scientists and the pro-climate policy community. Some cancelled their subscriptions:

Stephens had been on record as describing climate change as an ‘imaginary enemy’. The timing was odd. NYT has just hired a high-profile climate team and was selling itself with the slogan “Truth. It’s now more important than ever.”

Credit: Think Progress for the link. Ad from The New York Times’ marketing campaign. Credit: The New York Times via AdAge

The hire was defended by James Bennet, editorial page editor: Read the rest of this entry »

Written by Roger Jones

April 29, 2017 at 8:53 pm

Step change hypothesis and working paper

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Imagine you didn’t know anything about climate change and the greenhouse effect but were interested and you know a bit about general science. Would you accept the following story?

“Earth’s climate is a large, complex system, affected by forces that produce both linear and nonlinear responses. Shortwave radiation – basically UV – from the sun comes in and heats up the planet, producing infrared radiation. Some UV gets reflected straight back out by clouds, snow and ice and stuff. The land can heat up quite a lot, but it cools back down again and doesn’t store much. If a forest is cleared and replaced by buildings, it will warm up a bit but the effect is only local.”

“But the ocean – that’s another story. It absorbs a lot of radiation, so is taking up heat all the time. Huge streams of energy are entering and leaving the ocean store each year. Some is ‘dry’ or sensible heat, which is ordinary warmth. Some is ‘wet heat’ or evaporated moisture. Energy gets taken up when the moisture is evaporated and it will be released again when the moisture cools, condenses and then gets rained out. In this way, the oceans provide a lot of heat to the land every year, largely as rainfall and a bit of snow.”

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But is it just red noise?

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I gave a seminar yesterday at the ARC Centre of Excellence for Climate System Science at the University of New South Wales. Thanks Alvin Stone and Andrea Taschetto for organising it. It’s the first time I’ve had the opportunity to go through the entire ‘step change’ hypothesis of how the climate changes, the theoretical background, structural models developed from that and how the testing was set up, prior to showing a whole raft of test results.

One of the questions I got at the end, which also comes up quite often in the literature, was about the potential cause of the step changes in temperature data. It came from a question as to whether we had tested the step change model with artificial data that had been ‘reddened’ – that is, made dependent on the previous data. Such time series can have long-term persistence and contain a number of different quasi-periodic timescales, so do not conform to a single statistical model. This line of questioning alludes to whether a step or nonlinear response in a time series needs to be have an underlying cause that can be linked to an external source or whether it’s the result of random variations (see paper by Rodionov for a more more technical description). I gave a somewhat flip answer – because there is real energy in the system we are assessing (the climate system), whether a rapid shift is due to red noise or not matters less than understanding what that means for risk.

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Written by Roger Jones

May 29, 2016 at 8:35 pm

End of the hiatus

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Understanding Climate Risk has been in something of a hiatus, or a pause for the last couple of years due your host being almost fully submerged, but maybe it’s time to rise to the surface and get things going again.

This is for a few reasons. One is that research, especially public good research and especially in CSIRO, is under serious threat in Australia. We have a government who tout innovation, but who wilfully ignore the role of the generation of underpinning knowledge in fuelling such innovation. They are interested only in commercial innovation – public-good innovation is not only being ignored, it is being excluded from processes such as the Cooperative Research Centre bids currently under way. Having sustainable cities, catchments and ecosystems is impossible without public good research and social innovation, with funding that extends across the sciences, the humanities and the arts. With an election going on, these harms need to be publicised. Read the rest of this entry »

Written by Roger Jones

May 22, 2016 at 1:19 pm

A message from our sponsor

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Dear All,

in a devastating blow to the 97% of deluded climatologists who continue to pull the wool over their own eyes, human-induced global warming has been disproven…

Empirical evidence disproves, no less! What ho! Egads! Science crumbles in the face of such devastating analysis. There are so many zingers here that Bill Shortninbread should look out.

And now, read on… Read the rest of this entry »

Written by Roger Jones

August 25, 2015 at 10:39 pm

Pell hoists himself on his own logic

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We have been waiting for Cardinal George Pell to comment publicly on Pope Francis’ encyclical Laudato Si’ because it professes pretty much the opposite to Pell’s public omnipotence on all things climate change.

Speaking to the Financial Times in a story on his reform of Vatican finance, Pell says this:

“It’s got many, many interesting elements. There are parts of it which are beautiful,” he says. “But the church has no particular expertise in science . . . the church has got no mandate from the Lord to pronounce on scientific matters. We believe in the autonomy of science,” added Cardinal Pell.

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Written by Roger Jones

July 19, 2015 at 1:28 pm