As Dr Judith Curry has tried to communicate to me, the physical science of Climatology is full of deep complexity, with strong ranging on a number of processes.
Just to take a typical example – the Hurricane storm track in the Caribbean. Different years produce different levels of risk, and a constantly updated projection is needed as short-term relevant climatic factors shift.
But despite the likelihood of any particular Tropical Depression forming, the range of its strength and the eventual pathway, there is still a clearly identifiable track that storms take – that Stephen Schneider called “Hurricane Alley”.
This kind of “big picture” of regional and even global phenomena means that we can safely scale out from the inner workings of individual changes in air pressure, prevailing winds and humidity and take in the larger-scale, longer-term trends.
In Paleoclimatology, the study of the history of glaciation and de-glaciation of the planet has shown a remarkable regularity despite numerous interworking complexities – so much so that relatively simple models can be applied :-
Hogg, A. M. (2008). “Glacial cycles and carbon dioxide: A conceptual model”, Geophysical. Ressearch Letters, 35, L01701, doi:10.1029/2007GL032071
“Abstract : The correlation between Antarctic temperature and atmospheric carbon dioxide concentration is a key feature of Quaternary climate cycles. The cycle is characterised by pronounced temporal asymmetry; with rapid increase in both temperature and CO2 at the glacial termination. Here I compare observed climate cycles with results from a simple model which predicts the evolution of global temperature and carbon dioxide over the glacial-interglacial cycle. The model includes a term which parameterises deep ocean release of CO2 in response to warming, and thereby amplifies the glacial cycle. In this model, temperature rises lead CO2 increases at the glacial termination, but it is the feedback between these two quantities that drives the abrupt warming during the transition from glacial to interglacial periods.”
The sum of the complexities is a clearly recognisable, repeated saw-tooth in the ice core records :-
Andrew Hogg notes : “The role of CO2 in the glacial cycle has been the source of much misinformation in recent public debate on climate change, largely because there is no scientific consensus on the mechanism controlling glacial cycles. Here I propose a simple model which predicts the evolution of global temperature and carbon dioxide over the glacial-interglacial cycle. In this model, CO2 acts to amplify, but not trigger, the glacial cycle. Deglaciation is triggered by variation in the earth’s orbit; thus, temperature rises lead CO2 increases at the end of glaciation, but it is the feedback between these two quantities that drives the abrupt warming during the transition from glacial to interglacial periods…”
In his Conclusions he writes, “The model has some features in common with observed temperature records: the temperature range far exceeds that due to global mean insolation alone.”
What this means is that changes in sunlight falling on the Earth due to changes in its orbit around the Sun and its tilt, on their own cannot account for the sawtooth swings.
Complexities in the response of the various parts of the Earth system add up to what is called “non-linear” changes – things are not straight-forward within each tooth of the saw – even though the sawtooth shape is very regular.
The reason why scientists are concerned about the state of the Earth’s climate is that this regular saw-tooth pattern has been broken :-
The sum of complexity has been overshot by an obvious forcing – a pulse of Carbon Dioxide pumped into the Atmosphere by mankind’s activities, including cutting down the trees (to burn them) and digging up hydrocarbon fuels dating from periods of mass extinction on Earth (to burn them).
Citing complexity in the internal workings of the Climate system is not a sufficient reason to prevent Judith Curry, and everyone else, considering the probable implications of this very unusual and quite possible dangerous fact.
2 replies on “The Sum of Complexity”
Jo, if you have been reading what I write, one of my main points is that uncertainty cuts both ways. IMO we have failed to imagine the plausible worst case scenarios for the next century of both both natural variability and anthropogenically forced climate variability. Policies targeted at an optimal CO2 level are doomed to fail: the policy may be inadequate, or it may be unnecessary. Robust policies are needed that can factor in the uncertainty.
[ NOTE FROM JOABBESS.COM : UNCERTAINTY DOESN’T REALLY CUT “BOTH” WAYS. THERE ARE NOT REALLY TWO “SIDES”. YOU EITHER ACCEPT THERE IS A RISK AND ACT, OR JUST KEEP ON WITH BUSINESS-AS-USUAL. NO-REGRETS POLICIES ARE PREFERABLE. DE-CARBONISING THE ENERGY SUPPLY WHILST REVIVING THE INFRASTRUCTURE (WHICH HAS TO HAPPEN ANYWAY) MEANS THE WORLD CAN RESPOND TO THE GREATEST CALCULATED RISK. THE CONTRACTION AND CONVERGENCE FRAMEWORK FOR CARBON REDUCTION COMMITMENTS WOULD BE ABLE TO MEET ANY CARBON DIOXIDE TARGET SPECIFIED IN A LONG-TERM CARBON BUDGET WITHOUT COMPROMISING ECONOMIC DEVELOPMENT. AS FOR RESPONSES TO UNCERTAINTY, SEE HERE. BY THE WAY, YOU WRITE “anthropogenically forced climate variability”. DON’T YOU MEAN “trend” ? IT’S ONLY GOING ONE WAY, YOU KNOW. UP. ]
risk is relative..
or no one would ever get out of bed and face the dangers of the world every dat…
BUT, being in bed has it’s own dangers!!!
What can one do…
Why waste trillions, just in case. because the feedbacks, actually turn out to be negative, and any small amount of warming actually turns out to be beneficial?
[ NOTE FROM JOABBESS.COM : THINK A WHILE ABOUT THE TRIDENT MISSILE PROGRAM AND THE IRAQ AND AFGHANISTAN WARS AND ASK YOURSELF “WHY WASTE TRILLIONS, JUST IN CASE…” ? NOBODY HAS IDENTIFIED PERMANENT NEGATIVE FEEDBACKS ON A LARGE SCALE THAT OPERATE IN THE SHORT-TERM, WHICH EXPLAINS WHY THE WARMING IS STILL CONTINUING. MOST OF THE WORLD’S SCIENTISTS CONCUR THAT THE NEAR-TERM CLIMATE SENSITIVITY OF THE EARTH SYSTEM IS IN THE REGION OF 3 DEGREES CELSIUS FOR A DOUBLING OF ATMOSPHERIC CARBON DIOXIDE. JAMES HANSEN CALCULATES THAT THE COMBINATION OF NEAR-TERM AND LONGER-TERM CLIMATE SENSITIVITY IS OF THE ORDER OF 6 DEGREES CELSIUS, THE REVERSE DIFFERENCE BETWEEN NOW AND THE LAST ICE AGE. THAT’S NOT A SMALL AMOUNT OF WARMING. ALREADY THE CLIMATE CHANGE DAMAGES ARE OUTWEIGHING ANY POSITIVE GAINS POSITED FROM INCREASED ATMOSPHERIC CARBON DIOXIDE AND ENHANCED TEMPERATURES, AND IT IS LIKELY TO GET WORSE. ]
Of course those trilions wasted on pursueing, a catastrohic man made co2 delusion, could have solved every real pressing environmental problem, fed the world, given the world clean water, etc,etc..
[ NOTE FROM JOABBESS.COM : WITHOUT SOLVING CLIMATE CHANGE, WE CANNOT SOLVE ANY OTHER ENVIRONMENTAL PROBLEM – CLIMATE CHANGE IMPACTS ON THEM ALL. ]
I want to ‘save the planet’ probably as much as you or anyone else..
[ NOTE FROM JOABBESS.COM : IF YOU WANT TO SAVE ANYTHING, START BY PUTTING SOME TIME ASIDE TO READ SOME POPULAR CLIMATE CHANGE BOOKS – SUCH AS MARK LYNAS’ “SIX DEGREES”. ]
I just don’t see man made co2 as a big problem, ie empiracl evidence relative to other issues.
[ NOTE FROM JOABBESS.COM : HAVE YOU GOT A DEGREE IN ATMOSPHERIC PHYSICS, CLIMATOLOGY OR ANY OTHER RELATED, RELEVANT SUBJECT ? HAVE YOU READ WIDELY OUTSIDE THE ACADEMIC REALM ? HOW CAN YOU RELY ON YOUR OWN OPINION ABOUT CARBON DIOXIDE ? WHY DO YOU BELIEVE THAT YOUR JUDGEMENT ABOUT THE EFFECTS OF INCREASED ATMOSPHERIC CARBON DIOXIDE IS THE BEST GOING ? WHO TOLD YOU TO BELIEVE IN YOURSELF ON THIS SUBJECT ? ARE YOU SUCH A POST-MODERN FELLOW THAT YOU BELIEVE EVERYTHING YOU TELL YOURSELF – OR DO YOU CONSULT OTHERS WHO HAVE DONE RELEVANT RESEARCH ? ]
People need persuasion with evidence, not emotion and accusatiuons of ‘denial’.
[ NOTE FROM JOABBESS.COM : IF SOMEBODY DENIES SOMETHING FOR WHICH THERE IS ADEQUATE EVIDENCE, THEN IT IS APPROPRIATE TO CALL THEM A DENIER. IT IS NOT AN EMOTION-LADEN TERM, AN ACCUSATION OR NAME-CALLING. IT IS A DESCRIPTION. YOU DENY THE DETRIMENTAL EFFECTS OF GLOBAL WARMING THROUGH ENHANCED LEVELS OF ANTHROPOGENIC CARBON DIOXIDE IN THE ATMOSPHERE AND SO I’LL DESCRIBE YOU AS YOU BELIEVE – A DENIER. I’M SURE YOU’RE A VERY NICE PERSON AND YOU LOVE YOUR MUM – BUT YOU ARE DENYING THE EVIDENCE OF DANGEROUS GLOBAL WARMING AND DAMAGING CLIMATE CHANGE. I’M SURE THERE IS NOTHING THAT I COULD SAY TO PERSUADE YOU TO RECONSIDER, AS YOU ARE IN DENIAL. IF ONE DAY THE VEIL LIFTS AND YOU REALISE HOW YOU HAVE BEEN CONNED BY THE ANTI-SCIENCE “TRIBES”, AND THAT THERE MAY BE SOMETHING IN THIS CLIMATE CHANGE THING, AS AGREED BY ALL THE WORLD’S TOP SCIENTISTS, INSTITUTIONS AND ACADEMIES, THEN YOU WILL NO LONGER DESERVE TO BE CALLED A DENIER. UNTIL THAT DAY, A DENIER YOU REMAIN. ]