GGDub

Sorry to play devil's advocate here, but be careful with this argument, it can easily be argued the other way now. I personally know people working on their Ph.D.'s who find ways to work the effects of global warming into their research, whether its relevant or not, because it increases their chances of getting grants immensely.

IMHO, this is leading to (if not already) a huge bias in the research being done on it now. Nowadays, if you set out in your proposal to disprove either global warming or the human link, you're likely to get shut out of funding, unless you go to Exxon. This is just as bad as Exxon only paying for research that undermines it. Either way its bad science and bad science always leads to bad policy.

zippered

i appreciate your point that the world needs more action and less talking. it's terribly frustrating to see the big picture, to "get it" and look around at what people are doing (or not doing). i try my best to stay positive, and focus on doing my part, while still trying to educate others, but it's hard!

however, based on the energy that i've seen building in canada the last year or so, i can't help but feel a little bit excited... dare i say even hopeful.

gwd

Climate is what you expect and weather is what you get. Weather and climate share some of the same descriptive variables like temperature and rainfall but when talking about climate the variables are integrated over years while weather is usually described by integrating the measurements over fractions of a day. We conflate the two concepts when we observe unseasonablly warm days and wonder if it is an example of climate warming. The people who predict weather and the people who predict climate deal with the same physical measurements but on very different scales don't they? I'm not convinced that global warming will necessarily be a bad thing for car free living here on the edge of the piedmont in the mid atlantic region. I wonder if the earth will wobble on it's axis when all the polar ice melts. All that ice must weigh alot and when it melts that mass will be redistributed. We might not feel a thing.

kjohnnytarr

Finally, someone who gets what I'm always saying. Thanks! I normally take quite a load of crap when I voice these views.

Scientists are kidding themselves if they think they can seriously predict climate change. They haven't been right yet, as far as I know. Meanwhile, misguided folks take fairy tales seriously, and run around in circles when they could be fixing REAL problems!

Roody

Welcome to the forum, makeinu. I hope you stick around and also read some of the links. No offense, but it sounds like you haven't done a lot of studying about the environment yet. For starters, check out the differences between weather and climate. This is an important distinction that a lot of people don't quite understand. Wikipedia might be a good place to get started.

Basically, the scientific evidence for global warming is actually even stronger than the evidence for the toxic effects of gasoline. At this time, it is the consensus of the thousands of climate scientists worldwide that there is a greater than 90 % probability that global warming is caused by human emissions of carbon dioxide and other gases, and that this climate change will cause "dire consequences" within the next hundred years. The computer models of the climate are very accurate. The main source of error in the predictions is that it's impossible to know exactly how much CO2 will be emitted in the future. Of course, I agree with your analysis of the other harmful effects of dependence on fossil fuels.

Exactly right. However, the free market will NEVER provide disincentives for using cheap energy like coal and oil. Quite the opposite. The free market always pressures producers to use the cheapest and most efficient goods in order to maximize profits. This is a very basic law of economics. The only way to reduce the us of fossil fuels will be through governmnt interventions. This could be in the form of taxes or regulation, or both.

Roody

Maybe you don't understand the basic sience, or maybe you just don't want to understand it. But in case you do want to understand it, here goes:

Basically, scientists have made enormously complex models of the climate, using huge supercomputers. They test the models by seeing if they accurately predict past climate changes. For example, they start the model running with data from 1,000 years ago, and see how close they get to "predicting" the current climate. (This is more accurately called "postdiction.") At this point, the different models basically agree, and their predictions are very accurate. Climate scientists are confident at the 90 % level that they can predict the climate for the next century, given various levels of CO2 emissions.

In 1491 it was common to say something like, "Scientists are kidding themselves if they think they can seriously predict that the world is round. They haven't been right yet, as far as I know." All bets were off a year later!

GGDub

[QUOTE=Roody]

Basically, scientists have made enormously complex models of the climate, using huge supercomputers. They test the models by seeing if they accurately predict past climate changes. For example, they start the model running with data from 1,000 years ago, and see how close they get to "predicting" the current climate. (This is more accurately called "postdiction.") At this point, the different models basically agree, and their predictions are very accurate. Climate scientists are confident at the 90 % level that they can predict the climate for the next century, given various levels of CO2 emissions.

QUOTE]

This is a bit erroneous, building a model in which you know the answer and back calculate (calibration) your input variables is very different from from creating a model to predict an outcome. I know, because I've done it with groundwater flow and contaminant transport models.

Back calculating your variables can lead to a non-unique solution (i.e. you can calibrate to today's climate using many different values for your input parameters). With something as complex as a climate model, you can have a lot (meaning millions) of choices for input parameters. Scientists obviously have to simplify in order to even get started, and this involves making assumptions and best estimates. These estimates are decided up and given a certain range of error. The range of error for oceanic CO2 fixation for example, is much larger than the estimate for anthropogenic CO2 emmissions.

In my experience running groundwater flow and transport models (finite element based), all it takes is one wrong input parameter to throw you predictions way off (which is why we rarely stray away from order of magnitude predictions). This is just for a (relatively) simple finite element model used to predict where a plume of contaminant may end up under an an acre field with 20 m of soil.

On top of all this, the equations which govern these models are constantly changing and errors and limitations in the older governing equations are being found all the time. I know the same thing is happening with atmospheric thermodynamic equations.

So when I hear climate scientists say they are 90% confident they can accurately predict what the climate will be in the next century I smell media BS. Especially when its based solely on CO2. Given the climate of our planet is governed by much more than the concentration of CO2, saying scientists are 90% confident they can accurately predict the climate based on our CO2 emmissions is like me predicting how fast a paper airplane will reach the ground by only taking into account its mass and the force of gravity and completely disregaring wind, plane shape, humidity etc.

I'm not putting this out there to sow the seeds of doubt of climate change, because I believe there is very strong evidence backing it, but because I believe the amount of panic about it is a bit unfounded given then enormous lack of knowledge we have regarding our own climate.

gwd

[QUOTE=GGDub]This isn't how I read Roody's post. He wrote "test" not "calibrate". These are two different things. I would build a model with one dataset and test it with an independent dataset. For example build the model with data for years 1800 - now and test it against data for years 1400-1600, or the other way.

timmhaan

[QUOTE=GGDub]nobody has suggested that...not even the media. the 90% figure is the percentage of certainty that humans are the cause of global warming - particularly due to burning fossil fuels and give a range of temperatures (2.5-10.4 degrees) over a century that we might we see. and from what i understand, these figures are conservative.

GGDub

[QUOTE=gwd]Its the same thing. You calibrate, or test your models, when you know your answer and need to see if your input parameters are correct. And neither solves the uniqueness problems. Here's the (very simple) analogy,

I know the answer is 5. I believe the answer is the result of two numbers x an y. I run my model knowing the answer is 5 and my model says x = 1 and y = 4. However, its pretty obvious that x could equal 3 and y could equal 2. But, I could run the model a bunch of times and find out that most of the time, the model says x = 1 an y = 4. So I'm satisfied, these are most likely the right answers.

However, if my intitial theory, that the answer is only the result of x and y, is wrong, and it turns that its actually the result of three numbers, x, y and z then my model can be giving me totally the wrong answer.

Now imagine trying to get a unique answer in climate modelling where you have to take into account thousands of variables most of which you disregard (or may not know they exist) and the ones you do use are not direct measurements but are estimates determined from tree rings and ice cores, which are subject to their own errors. By the time you get to the point where you're trying to estimate the temperature in Nigeria in 2060, your degree of error, due both to estimation error and non-uniqueness, will be larger than your estimate itself.

A lot of these problems with modelling are being addressed through stochastic approaches and the use of fractal mathematics, but this is still in its infancy. Plus, we've only had the ability to run good 3D finite element models in hydrogeology for about 5 years, and by good, I mean order of magnitude good, because our understanding of groundwater flow and solute transport is still very limited. It cannot be any different for climate science, in fact, given they have way more variables to deal with than us, I'm sure climate scientists have a harder time.

kjohnnytarr

As a rule, I don't take advice on science from people who can't even spell it right.

It's pretty much an established fact that no matter how big the computer, you're not going to have much of a chance of predicting something as complex as climate. And as you said, climate is enormously complex. Last year, scientists had a terrible time predicting hurricanes. If they can't predict weather, why should they be able to predict climate? (I am aware they are different things)

Don't kid yourself thinking you can foretell the future with enough Crays; you can't. That's chaos theory.

timmhaan

so, what's the alternative? throw our hands up in the air and say "i give up?".

should we do that with cancer research? afterall, nobody has cured that yet. it must be too complex. maybe it's not worth trying to save the rain forest either. afterall, we can't possibly understand the various interactions of the all species and their importance in the ecosystem. too complex. lets give up. how about alzheimer's disease? clearly that research isn't going anywhere either. we haven't found a cure. come to think of it, we can't cure many diseases yet. they must be too complex and not worth looking into.

AlanK

To some extent I do understand your point. But while the scientific forecast might not be exact, they have established beyond any reasonable empirical doubt that human activities at the very least contribute significantly to global warming.

Are other factors involved? Most likely yes. As you stated previously climate is related to numerous interactive variables. But the scientific evidence is conclusive: the more GHG that are released into the atmosphere, the more heat remains trapped = higher temperatures (ie global warming).

That said, I'm hopeful for the best, but expect the worst on this issue. Not just because from what I know many US residents are unwilling to compromise their lifestyle (drive significanly less, use less energy in general, buy fewer products, etc), but because so many other countries are developing: Countries like China and India are rapidly industrializing, which means higher oil consumption and more pollution. Even if the US and other developed countries significanly curb GHG emissions, it would be difficult and hypocritical to expect developing countries to not to go through this process.

GGDub

That's not what we're saying, most skeptics out there believe in anthropogenic global warming, just not all the stuff about it in the media. A great example is the UN's hurricaine expert who quit after the head of the IPCC said that global warming was to blame for increased hurricaine activity, they didn't have evidence to say so and he told them so, but they went ahead and told the world that very thing. He was so p!ssed he quit. He believed in climate change (or else why would he join the panel) just not in how they were conveying the science.

When the ice sheet collapsed in Antartica, everybody immediately blamed it on global warming, but there's evidence that's the result of natural current fluctuations (look up DR. Duncan Wingham). But hardly anyone is paying attention to this because panic is setting in.

Fear sells everything from B-52's to grant money to prestigious positions on the IPCC. If "An Inconvienient Truth 2" comes out and Al Gore is riding a bike and taking the train (and not a lear jet) to do his presentation, I'll start getting really worried. Until then, the research MUST be done right and with as little bias as possible. The way its playing out right now, some rash decisions may be made that could collapse economies. That could probably be the worst thing for the environment. Russia and Argentina are great examples of this. If you want to be able to find solutions, you need money to do so, and killing your tax base will not bring in more money.

KnhoJ

Not just funding, but the peer review process and publication in anything short of the National Enquirer. Objectivity isn't optional in scholarly research.
That 90% may be implied from the error range of the calculations; the remainder of give or take 5%. Error bars play an important part in the objective presentation of scientific research, by providing for variables such as the ones you've presented.
Or other variables, such as the spectacular volumes of hot air generated over the possibility of hot air. Without doing some careful research, almost everything readily available on the subject is, objectively, baloney. Also known as Philosophy; unfortunately much more authoritative among the cross-eyed masses than unbiased, peer reviewed, and independently verified measurement.
Even playing the part of a skeptic, I'm not ready to debate the merits of whether something's bad for us or very, very bad for us. Fossil fuel has fueled a miraculous burst in industrial and technological advancement, to the point where we have a choice: We could carefully cut back on harmful applications and shift towards the most productive uses of the stuff without catastrophic adjustments. Or, we could light it all on fire and rot out our lungs, if the suv's don't squish us first. And that's the best case scenario.

donrhummy

While I understand that as humans we're darn near unlikely to ever be able to "fix" the problem, I do NOT believe it is physically (scientifically?) impossible. The atmosphere is not some solid object that has had pieces torn out of it like a piece of paper that cannot be reattached. If we can figure out a way to generate the proper ratio/mixture of gases/contents, I don't see why that can't "fix" or replenish the atmosphere/ozone.

gwd

[QUOTE=GGDub]No they are different, when you calibrate you might take the results of a test and use them to adjust the parameters. When you just test you determine how good the model is. If you don't understand the distinction you should get out of the mathematical modeling business. You should definately stop mis-informing people. Roody's post had the word test not calibrate.

Roody

[QUOTE=gwd]Yes, I think the skeptic who shares the President's initials doesn't get the concept of "postdiction" or testing models by using them to predict current states based on past data.

The computer models are insufficient in one regard. They pretty accurately take account of natural "forcings" like solar input and atmospheric composition, but nobody can predict the human forcings, specifically the amount of GHGs that we emit in the future. In this sense, future climate does depend in part on us, and we are notoriously bad at predicting what we will do. The only problem more complex than the climate is human thought and behavior.

Roody

First, greenhouse gases and ozone depletion are very different issues.

But why can't we just use science and chemistry to "fix" the damage we've done to the atmosphere. I don't know all the reasons, but I will try to explain one reason. This has never happened before. CO2 levels have fluctuated in the past, but never with the rapidity that is occurring now. Also, the levels are already higher than they have been before, and they will continue to rise for some time, no matter what we do. Since the current condition of the atmosphere is new and unprecedented, we have no basis for understanding what might "fix" it. Anything we do is to some extent a crap shoot, and we run the risk of making the problem worse, or creating a new problem, if we mess around trying to fix the current problem.

Roody

I'd be interested in reading some support for your assertion that climate scientists are hoodwinking the public. Preferrably something more logical than "Ther is no global warming because Gore rides around in a hummer."

Roody

You got anything more convincing than this argument?

Roody

The NY Times had a great article about the snowballing acceptance of global warming theory. The evidence is so strong now that all but the flat-earth crowd are accepting it, even right-wing pols:

This is great news and I welcome it. Of course a couple BF members won't be convinced, but they have no leg to stand on, as you can see if you've been following this thread.

Roody

I did look up Dr. Wingham. He does not deny anthropogenic global warming. Here's a quote from him in the British paper, the Register:

GGDub

[QUOTE=Roody]#1 I was pointing out innaccuracies in what you were reading, not making a personal insult. I don't share initials with "the" president. He's your president, not mine. Don't pretend to know my politics. Trust me, they are probably farther left than anything you could vote for in the US. I'm a scientist, who tries to do my work with as little bias as possible, so my politics tend to mean crap as far as that is concerned.

#2 I fully get the concept of "postdiction", I've done it more times than I can count and more times than you've read about it online. From groundwater flow models for gold mines in nevada to big oil sands projects here in Alberta. Do you understand the differences between finite element models and finite difference models? Do you understand the limitations of the atmospheric thermodynamic governing equations? Do you know what I mean when I say governing equation.

#3 How can these models accurately predict natural forcings like solar input and atmospheric composition when they can't accurately predict when the sun may flare or a volcano may erupt? Its much easier to predict the relative increase of anthropogenic CO2 emmisions.

GGDub

Duh, and read my posts, neither was I. I was pointing out the dangerous bias thats developing in climate science right now, which is to blame everything on global warming.