Griffith knows that all these speculations are mostly for shits and giggles, but there is a value in roping in those who might not think
much about climate models and how they work.
Not exact matches
By improving the understanding of how
much radiation CO2 absorbs, uncertainties in
modelling climate change will be reduced and more accurate predictions can be made
about how
much Earth is likely to warm over the next few decades.
But early on Jenkins realized that the global
climate models are too coarse to tell
much about what's going to happen in the Sahelian zone.
The impact of these results is wide - reaching, and Dr Pullen suggests that it may even change how we think
about global
climate data: «Climate models need to incorporate genetic elements because at present most do not, and their predictions would be much improved with a better understanding of plant carbon demand.
climate data: «
Climate models need to incorporate genetic elements because at present most do not, and their predictions would be much improved with a better understanding of plant carbon demand.
Climate models need to incorporate genetic elements because at present most do not, and their predictions would be
much improved with a better understanding of plant carbon demand.»
Using
climate models and data collected
about aerosols and meteorology over the past 30 years, the researchers found that air pollution over Asia —
much of it coming from China — is impacting global air circulations.
As can be seen your graph, our
climate models make a wide range of predictions (perhaps 0.5 - 5 degC, a 10-fold uncertainty)
about how
much «committed warming» will occur in the future under any stabilization scenario, so we don't seem to have a decent understanding of these processes.
With
about half of
climate models predicting a return to «neutral» conditions, there's even a fair chance the
much - hyped La Niña won't materialise at all.
They do, however, raise serious questions
about the validity of
climate models (which are, of course, used to predict future warming and are used to set public policy and sway public opinion) and how
much we are actually warming.
This point might become clearer once it's realised that
climate models are not developed just to the
climate change problem, but as
much more general tools to quantify the net effects of all the different processes we know
about.
A new study shows that the
climate simulated by a numerical
climate model can depend surprisingly
much of what is assumed
about the snow grain shapes when computing the reflection of solar radiation by the snowpack.
As global methane levels have increased, the impact has been felt twice as
much in the Arctic,
about a half a degree Celsius more of Arctic warming, according to
climate models.
John Christy and Roy Spencer of the University of Alabama published a series of papers starting
about 1990 that implied the troposphere was warming at a
much slower rate than the surface temperature record and
climate models indicated Spencer and Christy (1992).
This point might become clearer once it's realised that
climate models are not developed just to the
climate change problem, but as
much more general tools to quantify the net effects of all the different processes we know
about.
When you think
about the uncertainties of economic
models and how
much money is invested using those
models as a basis, the idea that we don't know enough
about climate change is laughable.
An equatorial volcano occurring during that period would allow
much better
model calibration, for example, settling questions
about transient
climate response.
We used it heavily as part of a Global
Climate Processes course at UW - Madison for later undergrad and grad students, so it has a good deal of flexibility in what you can test (though the
model blows up for extreme forcings like snowball Earth, I used CO2 at
about 140 ppm and couldn't get
much lower than that).
However, that his statement can be quoted in a major US newspaper says
much about the level of public knowledge concerning
climate change and the
models used to try and understand it.
All in all the science of hurricanes does appear to be
much more fun and interesting than the average
climate change issue, as there is a debate, a «fight» between different hypothesis, predictions compared to near - future observations, and all that does not always get pre-eminence in the exchanges
about models.
The pace of ice loss — both its extent and the amount of the older, thicker ice that survives from summer to summer — has been faster than most
models predicted and clearly has, as a result, unnerved some polar researchers by revealing how
much is unknown
about ice behavior in a warming
climate.
John, On the «Presentation: Precautionary Principle...» thread you told me that you think it's «unhelpful to conflate discussion of
climate - science issues like the
modelling of SO2,
about which none of us here know very
much, with discussion of economic projections, where we can have a useful discussion.»
Psychologists studying
climate communication make two additional (and related) points
about why the warming - snow link is going to be exceedingly difficult for
much of the public to accept: 1) people's confirmation biases lead them to pay skewed attention to weather events, in such a way as to confirm their preexisting beliefs
about climate change (see p. 4 of this report); 2) people have mental
models of «global warming» that tend to rule out wintry impacts.
It has already been demonstrated
climate models, the Holy Relic of AGW, are merely paramterized engineering code that thus far can not predict
much of anything correctly, so what is the argument
about?
Brad DeLong expresses qualified Skepticism Toward the Skeptical Environmentalist I think there's a
much more fundamental problem in Lomborg's argument
about global warming, as I argue here The Intergovernmental Panel on
Climate Change cites a range of
model estimates of the costs of implementing Kyoto using market mechanisms.
If the two methods do lead to different estimates of
climate sensitivity, I find it difficult to believe that the 1D
model is more appropriate than 3D to making claims
about how
much the real average temperature will rise due to a given influence.
The
climate scientists that worry
about these issues don't post here (
much - Jeff made a single post) so you aren't really going to see a meaningful discussion on the role of chaos or stochastic processes on
climates, how that is handled in
model building, and what that means in terms of
model verification.
Either WUWT has wrongly concluded what the IPCC's
models show, or the constant ululating
about the fast left - wing / socialist / eco-Nazi /
climate scientist conspiracy is
much ado
about nothing.
In as
much as none of the
model scenarios can be validated, all predictions
about future
climate conditions amount to nothing more that, «Wait to see if our predictions come true; you'll see then.
As others have noted, the IPCC Team has gone absolutely feral
about Salby's research and the most recent paper by Dr Roy Spencer, at the University of Alabama (On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth's Radiant Energy Balance), for one simple reason: both are based on empirical, undoctored satellite observations, which, depending on the measure required, now extend into the past by up to 32 years, i.e. long enough to begin evaluating real
climate trends; whereas
much of the Team's science in AR4 (2007) is based on primitive
climate models generated from primitive and potentially unreliable land measurements and proxies, which have been «filtered» to achieve certain artificial realities (There are other more scathing descriptions of this process I won't use).
«Uncertainty»
about whether or not something (very costly), which we do (in the «uncertain» attempt to change our
climate from an «uncertain»
model - generated threat) will have «uncertain» unintended negative consequences, which could be
much more severe than the «uncertain» threat we are attempting to mitigate against in the first place, seems to ba a reasonable justification for NOT doing this mitigating action.
I found the
climate models unconvincing (they help us learn
about climate but I don't think have predictive capability) but I accepted IPCC without giving it
much thought.
This is not too surprising because (a) CO2 concentrations didn't actually increase
much until
about the 1950s, and (b) the current
climate models don't include many mechanisms to account for natural global warming.
The rapid melting of the Arctic sea ice, then, illuminates the difficulty of
modelling the
climate — but not in a way that brings
much comfort to those who hope that fears
about the future
climate might prove exaggerated.
Much of what we know and conclude
about climate change is based on computer
models, which have proven to be inaccurate over the years, and the Antarctic sea ice growth is another example of where the
model went wrong.
Miller observed that estimates from CMIP5
climate models were
much lower —
about 1.1 deg C — from which he deduced that things were worse than we thought.
Based on temperature records from 1864 to 2002, the odds of such a heatwave occurring are
about 1 in 10 million.4 An event like the 2003 heatwave becomes
much more likely after factoring in the observed warming of 2 °F over Europe and increased weather variability.5 In addition, comparing computer
models of
climate with and without human contribution shows that human influence has roughly quadrupled the odds of a European summer as hot as or hotter than the summer of 2003.6
The disagreement is not so
much about observational evidence, but rather
about the epistemic status of
climate models, the logics used to link the observational evidence into arguments, the overall framing of the problem and overconfident conclusions in the face of incomplete evidence and understanding.
Klapper seems to feel that the
models need some fixing to better match past
climates, and seems unwilling to accept that there may be not
much that can be done
about it, due to inaccuracies.
A new study shows that the
climate simulated by a numerical
climate model can depend surprisingly
much of what is assumed
about the snow grain shapes when computing the reflection of solar radiation by the snowpack.
That we tend to see
much more discussion
about global warming is I think because of the limitations of the
climate models when they go to more regional and seasonal predictions and refinements of max versus min temperature trends.
Translating the above to
climate science, if you tell me that in 100 years earth inhabited by your children is going to hell in a handbasket, because our most complicated
models built with all those horrendously complicated equestions you can find in math, show that the global temperatures will be 10 deg higher and icecaps will melt, sea will invade land, plant / animal ecosystem will get whacked out of order causing food supply to be badly disrupted, then I, without
much climate science expertise, can easily ask you the following questions and scrutinize the results: a) where can I see that your
model's futuristic predictions
about global temp, icecaps, eco system changes in the past have come true, even for
much shorter periods of time, like say 20 years, before I take this for granted and make radical changes in my life?
Neither approach is likely to help them
much if for no other reason than that both approaches will drive the debate into complex arguments
about whose
climate or economic
modelling is using the best assumptions, data etc..
The failure by man and
model to fully understand and explain them reflects that neither man nor
model really knows all of that
much about climate mechanisms at this time.
Everyone interested in global warming
climate change 7 maths and physics should read about «Climate as a random walk» as a model fit its much much better than anythin
climate change 7 maths and physics should read
about «
Climate as a random walk» as a model fit its much much better than anythin
Climate as a random walk» as a
model fit its
much much better than anything else.
Much of the controversy
about uncertainties comes from these areas, most notably from
climate modeling.
You would get
much better results lowering the tone and being less hyperbolicsesquedalimiystic
about climate models.
However, statistical analysis very clearly support the theory, which also imply that the
climate sensitivity to CO2 doubling is
about 1.5 K. And
models made using this hypothesis are able to explain the temperature patterns since 1850 very well,
much better than any IPCC CMIP5
models.
By consulting
climate records and
modeling extreme events with and without added greenhouse gases, scientists can talk
about how
much global warming has increased the chances of extreme events — without blaming any one event on warming.
Tests of
models using those estimates of
climate sensitivity predict
about twice as
much warming as actually occurred.
«I said that the
models don't tell us
much about how the jet stream is affected by
climate change.
Collins, yesterday on Twitter: «I said that the
models don't tell us
much about how the jet stream is affected by
climate change.