Moderated Global Warming Discussion

[Dancing David]

Right but plant a bazillion trees and problem solved. I'm not trying to make light of it but the earth is not going to turn into an iceball ala The Day After Tomorrow.

It's hype. We are moving forward to solve problems. Dire to me means, nothing we can do about it and right now we're out of time.

That's simply not the case.

When we talk about a patient having dire consequences we mean if they don't change it they could die. But the earth is not going to die. (The people are....thank you George Carlin) If we want a better environment for people we need to plant more trees and stop stripping rainforests etc etc and move towards cleaner fuels.

We're doing that. So why is it dire?

Truethat, where I live a 3-5 degree rise in the mean glaobal temperatures would be very bad. The winter temperatures are expected to rise but not as much as the summer temperatures (that average thing). Given that a 3-5 degree rise is for the global temperatures, the temperatures here in the middle of the continent are going to be on the extreme end of the rise in summer, we do not have the ocean effect to moderate the high temperatures. Then add to that the potential ( and a fairly high one) for a change and decrease in the rain fall in June, July and August, we are talking about something very serious.

If the trends continue as they have in the last three decades the problem is not 100 degree highs here in the center of Illinois, those have occurred in the past. It is the consistent number of days years after year of temps in the 100s and high 90s. This puts considerable stress on the crops. And if the rain fall which is low to begin with in the summer months decreases, then you have no crops.

You could grow sorghum and winter wheat, but maize would be out as would most soya. You can not irrigate this away.

 

[Dancing David]

That's not what they say about Krakatoa. They said it cooled the planet for decades and cooled it by 22 degrees. So if that can happen in one week and the planet isn't freezing solid why do you think raising the temperature 1 degree in a decade would do worse.

Like I said not trying to be contrary here, it just seems like a who heck of a lot of overreacting.

And one degree the next decade, and another and another until the new norm is stable.

 

[Dancing David]

Ah I see, so the cooling comes from the ash blocking the sun and you are saying the CO2 issue is worse. Ok that makes sense. But take Mt St Helens or any other recent eruptions or even Tsunamis etc. The damage to the trees would definitely have an impact on the CO2 levels. So while the pollution in the air is problematic, of course, no debate, the solution is to plant more trees. And trees need time to grow.

There is not going to be that much arable land to compensate for the methane release from the permafrost.

 

[Trakar]

You mean with the Obama win....could be.

Hopefully.

There was a reference in the victory speech, I hope that was more than flirtation, ...time will tell. Advance previews of some sections of the 2014 IPCC report should start making their appearance in the next quarter or two. My time will free back up a bit after the upcoming Holidays. I look forward to rejoining discussions here then.

You all be safe and enjoy the Holidays!

T.S.

 

[lenny]

dear lomiller,
a few direct yes/no answers might significantly clarify the discussion of the Fildes and Kourentzes paper. these are not intended to be trick questions, rephrase then slightly or qualify your answer if you dislike my wording; given a "yes" or a "no", we can move on productively to discuss the paper...

perhaps i misunderstood your position, do you agree that empirical models outperform climate (simulation) models, but this fact does not bother you?

... Climate modelers are running these in the hopes they can find ways to improve the model itself, the results are not all that useful for anything nor is does an accurate result on these scale necessarily mean anything for the real work climate models are used for.

simple yes or no: "empirical models outperform climate (simulation) models"

simple yes or no: "The Met Office uses HADCM3 for decadal predictions"
(as in: real climate models are used for decadal prediction by real climate modellers, "how climate models are used in practice")

evidence from http://www.metoffice.gov.uk/research/modelling-systems/unified-model/climate-models/depresys

DePreSys is the decadal prediction system developed and run at the Met Office.

DePreSys uses the Hadley Centre Coupled Model version 3, HadCM3. Initialisation is achieved by relaxing to full-depth analyses of ocean temperature and salinity (Smith and Murphy, 2007), and atmosphere analyses of winds, temperature and surface pressure.

inside the metoffice, DePreSys is often pronounced "depress-us",

and could you provide evidence for this claim:

Again, predictions on these time scales have almost nothing to do with the longer time scales these models are actually used for.

the idea that you can get the planet badly wrong for a decade, and then get it "right" later seems physically absurd to me; the earth system is not some simply forced linear system where the "signals" come out of the "noise" in a trivial way as time passes. consider precipitation, consider circulation changes, consider feedbacks. the basic science strong, climate change risk is very very high. the details are not extractable from today's models.

if we oversell our models rather than admitting their limitations, we potentially damage the credibility of the science. the science here is strong, the models are weak. the science is strong enough to inform the policy without dangerous oversell/misrepresentation of the fidelity of today's models.

 

[lenny]

Anybody and their dog will tell you that near-term climate prediction is a waste of time and effort. It's too noisy.

as W.D. noted, near-term climate prediction now consumes significant resource at the MetOffice, most of the centres contributing to the AR5, and soon to come out under the banner of "Climate Services" from the WMO.

so could we have evidence on who exactly deprecates the institutions above for doing this? who thinks it is "a waste of time and effort" and

Decadal simulations and observations are on too short a timebase to reliably show anything, it's too open to volcanic events such as Pinatubo, or particularly strong or weak ENSO events (such as the denialists favourite year of 1998).

re volcanic events: these predictions are "projections" in the sense that they are conditioned on no volcano going off. the introduction of "project" was an own goal, as ALL predictions are conditioned on something... but we are stuck with it for a while now.

re ENSO: do you think a model could provide actionable simulations for 100 years hence, if it cannot get the statistics of ENSO events realistically?

 

[lenny]

There are established methods to test the skill of a model.

yes there are: they are one focus of: The Journal of Forecasting. (where the Fildes paper was published)

Fildes and Kourentzes compared DeRreSys to another model, but model skill is something that stands on it’s own merits. You do not need to compare one model to another to determine its skill.

that is an interesting idea, how might one do that? (to avoid misunderstanding, i note at the outset that in weather-like forecasting i would count as a model climatology [or any other prior distribution].)

 

[bobwtfomg]

More bad news
http://www.sciencemag.org/content/338/6108/792

John Fasullo, one of the researchers, said: "There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide. Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."

 

[Pixel42]

re ENSO: do you think a model could provide actionable simulations for 100 years hence, if it cannot get the statistics of ENSO events realistically?

Long term underlying trends are easier to predict than short term (mostly random) variations. That's why it's easier to predict whether the tide will be in or out in 100 years time than it is to predict whether the next wave up the beach will come higher or lower than the previous one. Likewise it's easier to predict what will happen to average global temperatures as a result of a steady rise in atmospheric CO2 over the next century than it is to predict whether next year will see La Nina or El Nino conditions.

 

[lomiller]

dear lomiller,
a few direct yes/no answers might significantly clarify the discussion of the Fildes and Kourentzes paper.

Not going to play that game. You are the one defending the paper, you need to be providing the evidence and defending it.

"empirical models outperform climate (simulation) models"

Do you judge papers by whether they give the results you want to see?

"The Met Office uses HADCM3 for decadal predictions"

That was never in question, the question was what the decadal predictions are used for.

yes there are: they are one focus of: The Journal of Forecasting. (where the Fildes paper was published)

Comparing one set of model results to another doesn't impact the skill of either. One or both or neither may have skill but the skill of one model is not a function of the skill of another.

the idea that you can get the planet badly wrong for a decade, and then get it "right" later seems physically absurd to me

Incredulity isn't a valid argument. I've already explained in detail, but here it is again.

Climate models are normally used to generate a different realization of the same physical system. Such realizations will follow the same trends over longer time periods but their specifics will be very different. This occurs even from one model run to the next even if the two runs are set up in exactly the same way.

What's happening in these decadal predictions is very different, instead of generating a different realization and then use statistical analysis to forecast future trends they try predict the actual realization of the real world system. (A task that is effectively impossible past a relatively short time window in chaotic systems)

BTW, climate models don't get shorter time scales "badly" wrong, they get results well within the range of expected weather patterns they just don't predict the actual weather.

 

[bit_pattern]

Long term underlying trends are easier to predict than short term (mostly random) variations. That's why it's easier to predict whether the tide will be in or out in 100 years time than it is to predict whether the next wave up the beach will come higher or lower than the previous one. Likewise it's easier to predict what will happen to average global temperatures as a result of a steady rise in atmospheric CO2 over the next century than it is to predict whether next year will see La Nina or El Nino conditions.

Good analogy, I'm going to "borrow" that one

 

[spin0]

Regarding the frequently repeated dogwhistle "alarmism".

Climate change prediction: Erring on the side of least drama?

Abstract

Over the past two decades, skeptics of the reality and significance of anthropogenic climate change have frequently accused climate scientists of “alarmism”: of over-interpreting or overreacting to evidence of human impacts on the climate system. However, the available evidence suggests that scientists have in fact been conservative in their projections of the impacts of climate change. In particular, we discuss recent studies showing that at least some of the key attributes of global warming from increased atmospheric greenhouse gases have been under-predicted, particularly in IPCC assessments of the physical science, by Working Group I. We also note the less frequent manifestation of over-prediction of key characteristics of climate in such assessments. We suggest, therefore, that scientists are biased not toward alarmism but rather the reverse: toward cautious estimates, where we define caution as erring on the side of less rather than more alarming predictions. We call this tendency “erring on the side of least drama (ESLD).” We explore some cases of ESLD at work, including predictions of Arctic ozone depletion and the possible disintegration of the West Antarctic ice sheet, and suggest some possible causes of this directional bias, including adherence to the scientific norms of restraint, objectivity, skepticism, rationality, dispassion, and moderation. We conclude with suggestions for further work to identify and explore ESLD.

ESLD. I kinda like that. It's good to have names on things when they actually describe something.

 

[aleCcowaN]

About "Antarctica is gaining ice"

Wind-driven trends in Antarctic sea-ice drift

The sea-ice cover around Antarctica has experienced a slight expansion in area over the past decades1, 2. This small overall increase is the sum of much larger opposing trends in different sectors that have been proposed to result from changes in atmospheric temperature or wind stress3, 4, 5, precipitation6, 7, ocean temperature8, and atmosphere or ocean feedbacks9, 10. However, climate models have failed to reproduce the overall increase in sea ice11. Here we present a data set of satellite-tracked sea-ice motion for the period of 1992–2010 that reveals large and statistically significant trends in Antarctic ice drift, which, in most sectors, can be linked to local winds. We quantify dynamic and thermodynamic processes in the internal ice pack and show that wind-driven changes in ice advection are the dominant driver of ice-concentration trends around much of West Antarctica, whereas wind-driven thermodynamic changes dominate elsewhere. The ice-drift trends also imply large changes in the surface stress that drives the Antarctic ocean gyres, and in the fluxes of heat and salt responsible for the production of Antarctic bottom and intermediate waters.

 

[Mikemcc]

as W.D. noted, near-term climate prediction now consumes significant resource at the MetOffice, most of the centres contributing to the AR5, and soon to come out under the banner of "Climate Services" from the WMO.

so could we have evidence on who exactly deprecates the institutions above for doing this? who thinks it is "a waste of time and effort" and



re volcanic events: these predictions are "projections" in the sense that they are conditioned on no volcano going off. the introduction of "project" was an own goal, as ALL predictions are conditioned on something... but we are stuck with it for a while now.

re ENSO: do you think a model could provide actionable simulations for 100 years hence, if it cannot get the statistics of ENSO events realistically?

So it appears to be an experiment to see if such predictions are useful. Yet the Met Offices own results to date show that the they should be viewed with extreme caution.

http://www.metoffice.gov.uk/science/specialist/long-range/global/decadal_fcst_global_t.png
(taken from this page: http://www.metoffice.gov.uk/science/specialist/long-range/global/decadal_fc.html)

Note the deviation from the previous predictions for Mt Pinatubo, the 98 El Nino and the present La Nina. Also note the confidence levels of the present DePreSys prediction upto 2020.

As for whom I based my view on this, that would be Ben Santer, who said:

"Because of the pronounced effect of interannual noise on decadal trends, a multi-model ensemble of anthropogenically-forced simulations displays many 10-year periods with little warming. A single decade of observational TLT data is therefore inadequate for identifying a slowly evolving anthropogenic warming signal. Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature."

As for your last comment, that is disingenious. Long term models can afford to use previous long term measurements of ENSO to predict future events, they are not designed to try and catch the unknowables of extreme ENSO events anymore that they could predict volcanic effects. That said, it depends on the mechanisms controlling ENSO fluctuations remaining the same, and that is not a given.

 

[r-j]

Of course it begs the question what else they got away with. It's a brazen attempt at covering up information they feel compromises their position. But, since the statute of limitations has expired that exonerates them... or something.

While that point even so is argued, what is astounding about it, is that six months statute of limitations on evading the FOIA. If you can simply evade detection/prosecution for six months after committing a crime, nobody can do anything about it.

 

[r-j]

Long term underlying trends are easier to predict than short term (mostly random) variations. That's why it's easier to predict whether the tide will be in or out in 100 years time than it is to predict whether the next wave up the beach will come higher or lower than the previous one.

That is a terrible example. Tides are not influenced by random factors, nor are they the same as waves.

And it is easy to predict the height of the next wave on a beach by observing the height of the wave offshore as it starts to break, before it gets to the beach.

While the point you are trying to make may stand, the example comparing tides to wind created waves has nothing to do with it.

 

[r-j]

Anyone who knows more about this stuff than me want to address this one specifically?

I'm no expert but I have some thoughts about this.

1. If it were really that easy somebody would have thought of that already because it's such an obvious idea.

The history of humankind shows us that obvious ideas can be ignored for thousands of years. As for carbon capture, it seems bogs (peat) capture and store carbon better than forests. The draining of wetlands (to create farmland) is a factor in increasing CO2 that you don't see mentioned much. Burning the peat as fuel is a double whammy for increasing the CO2 levels.

Same for burning tropical forests to graze cattle.

 

[aleCcowaN]

While that point even so is argued, what is astounding about it, is that six months statute of limitations on evading the FOIA. If you can simply evade detection/prosecution for six months after committing a crime, nobody can do anything about it.

It's nice of you to make a follow up of a message posted two years and four months ago, which was already discussed, and doing it with the sole intention to show that denialism hasn't abandon the thread. Good for you.

Besides, who couldn't agree with your general statement " If you can simply evade detection/prosecution for six months after committing a crime, nobody can do anything about it"? But it hadn't to do with the subject already discussed and finished.

 

[bobwtfomg]

That is a terrible example(1). Tides are not influenced by random factors(2), nor are they the same as waves.

And it is easy to predict the height of the next wave on a beach by observing the height of the wave offshore as it starts to break(3), before it gets to the beach.

While the point you are trying to make may stand, the example comparing tides to wind created waves has nothing to do with it(4).

(1)It's not an example, it's an analogy
(2)the height of the next high tide is influenced by air pressure, wind speed and direction.
(3)I'm skeptical,there must surely be other factors at play than just wave height,do you have any evidence or was it just pure speculation?
(4)Again it's an analogy and imo a fairly good one, my understanding of it is that in the same way as recording the height of succesive waves on a beach for a short period of time won't neccessarily tell you whether the tide is going in or out, recording temperatures over a short period won't neccessarily tell you whether global warming is happening or not.

 

[r-j]

(1)It's not an example, it's an analogy

In any case, it's not the same as what it is being compared to. Tides are not effected by trends of any kind.

(2)the height of the next high tide is influenced by air pressure, wind speed and direction.

And sea level, and earthquakes, and land movement, as well as complex long term cycles. There isn't some long term trend that can be predicted a hundred years out.

(3)I'm skeptical,there must surely be other factors at play than just wave height,do you have any evidence or was it just pure speculation?

There are several other factors that influence wave run up on a beach, the most important one is the previous wave height. The back wash down the beach from a large wave will influence the next wave, as well as the slope of the beach. But it is quite possible to predict based on observation. What is impossible is to predict the next days behavior, as well as any other length of time in the future. One can get a general idea based on the swells at sea, as well as storm action and local wind, but again, predicting the behavior of waves any distance in the future is impossible.

(4)Again it's an analogy and imo a fairly good one, my understanding of it is that in the same way as recording the height of succesive waves on a beach for a short period of time won't neccessarily tell you whether the tide is going in or out, recording temperatures over a short period won't neccessarily tell you whether global warming is happening or not.

No, it's a terrible example. Waves do not have a relation to tides like temperatures have to climate.