Global Warming a real threat?

[sunspot]

We cannot control the heat-up and cool-down cycles of the earth, although we can try to predict and be prepared for them. One also needs to attempt to separate politics and science when dealing with the cause and affects of global warming. Computer simulation is important for predicting whether but hasn't increased the prediction odds much beyond 1950's low tech. It looks prettier, I love the doppler radars, but the models are still all over scales for major predictions.

 

I was watching this special on PBS the other night about natural fires caused by lightning and how some plants and animals have adapted to it. This makes me think that forest fires and such, have been happening for a long time and have contributed to greenhouses gases way before humans, and will continue to add greenhouse gases even if we stopped using fossil fuel. A 40,000 acre forest fire is a lot of CO2 and NOx.

[JustStuit]

I'm not sure but, the CO2 from the fire comes from the CO2 the plants took from the air to convert to oxygen and carbon. Therefore, a forest burning forest could not put anymore carbon (in what ever molecule) than it took in while it was alive. For that matter it could not even put out as much since it leaves most of the trees. Plus, many plants grow back. So the fires aren't as harmful as never having the forest. Is this right?

[ed84c]

Indeed. Although you could say, what if the fire wasnt there and the forest just got bigger, and hence the carbon resevoir got bigger? I dont think that actually can happen in most situations though.

[JustStuit]

Well, part of the carbon is left because the trees are still there, minus some leaves and bark usually. Most forests keeps growing and spreading anyways.

[ed84c]

Indeed.

[SkepticLance]

Cthulhu.

Comments on computer models.

These are not simply calculations on a computer. They are an attempt to simulate an enormously complex system, and those who prepare such models are themselves painfully aware of how inadequate their models are. Not only is the software and the supercomputer used inadequate to the task, but there are parameters which cannot as yet be modelled. eg. the influence of clouds, which we know are MORE important than greenhouse gases in determining temperatures. Yet they cannot be modelled.

 

Computer models can indeed be tested, and they have been. And they have failed the test. The logical test for a computer model is to retroactively test against the 20th Century temperature changes, knowing the greenhouse gas changes that took place in the 20th Century. This has been done, with many computer models. Not one, not a single one, has successfully modelled the 20th Century. They consistently exaggerate the temperature change, and fail to predict the possibility of cooling. Yet substantial cooling took place, 1940 to 1976 (more than one third of that entire time period).

 

If we cannot predict in hindsight, how the hell can we predict the next 100 years?

[Prime-Evil]

That is what I am curious about. Historical levels of biomass.

 

I think normally towards the end of an interglacial period you would have more biomass than we have, and that would drive CO2 levels down and lead to a long slow decent into another ice age. I think it is the combination of deforestation, soil depletion, and fossil fuel burning that is causing CO2 levels to rise so high. In Northern forests at least, before we started logging the forest were less dry, and so they were less susceptible to forest fires.

 

Today, if we leave to much residue after logging it dries out and causes fires. If we don't leave residue the soil gets depleted faster, so we are damned if we do and damned if we don't. I think all the forests of North America are being managed to intensively. This too must change.

[Prime-Evil]

Computer models are not neccessary to identify the problem. Computer models are only neccessary to investigate the problem. The problem is simply that CO2 levels are too high, and that CO2 levels increase with deforestation and fossil fuel burning. The practical question is: How much deforestation and fossil fuel burning should be permitted while the problem is investigated?

[SkepticLance]

Prime Evil. I have no problem with rational means being used to reduce deforestation (use sustainable plantation forestry) and the burning of fossil fuels (research and implement alternatives).

 

However, any action taken should be subject to rational cost/benefit analysis.

On this basis the Kyoto Protocol is just plain stupid. Cost is enormous (one estimate, published in 'The Skeptical Environmentalist' suggests 5 trillion US$ over 100 years), and benefit is miniscule. The same source calculated a reduction in the INCREASE only of greenhouse gases to 95 years worth over 100 years. ie. a 5% reduction in INCREASE. No actual reduction in greenhouse gases.

 

There are clear measures that can be taken that do not carry this enormous cost, and will, in the long term, be far more potent than Kyoto. Such as developing a hydrogen based energy economy. Such as developing new generation nuclear power.

 

If we need to do something, let's do it in a sane and rational manner.

[Prime-Evil]

What is the defered cost of putting CO2 into the atmosphere? I am not sure if anyone really knows yet, but it cost something. The Kyoto protocol allows for this to be determined in a free market. In this way, CO2 reductions would be pursued where it is most economical to do so.

 

What is it about this that you disagree with?

[Cthulhu]

Cthulhu.

Comments on computer models.

These are not simply calculations on a computer. They are an attempt to simulate an enormously complex system' date=' and those who prepare such models are themselves painfully aware of how inadequate their models are.[/quote']

 

Models are inadequate, but not useless. They have come a long way.

 

Not only is the software and the supercomputer used inadequate to the task, but there are parameters which cannot as yet be modelled. eg. the influence of clouds, which we know are MORE important than greenhouse gases in determining temperatures. Yet they cannot be modelled.

 

How do you know clouds are more important in determining greenhouse gases if it is an unknown parameter? Clouds are the least understood part of modelling climate, but I guarantee that even when clouds are accurately understood and factored into the models the skeptics will still not accept they have any accuracy.

 

Computer models can indeed be tested, and they have been. And they have failed the test. The logical test for a computer model is to retroactively test against the 20th Century temperature changes, knowing the greenhouse gas changes that took place in the 20th Century. This has been done, with many computer models. Not one, not a single one, has successfully modelled the 20th Century. They consistently exaggerate the temperature change, and fail to predict the possibility of cooling. Yet substantial cooling took place, 1940 to 1976 (more than one third of that entire time period).

 

I don't believe that is true. Models that include aerosol forcings do predict the cooling during the 1940-1976. For example: http://www.gfdl.noaa.gov/~tk/early_20th_cent_warming.html

 

If we cannot predict in hindsight, how the hell can we predict the next 100 years?

 

Arguably we can. The models that best fit the 20th century temperature trends are the ones that predict warming of something like 1-5C by 2100. There is no basis to say there will be no warming or there will be 10C of warming by 2100. To the best of our knowledge, and that is far from guessing, it is constrained to the range 1C-5C depending on what the future trends in carbon emissions are. Im sure when clouds are better understood this projection will be refined, but I doubt it change dramatically.

[SkepticLance]

Prime Evil.

Sorry, but I do not think you read my posting well enough. Kyoto is a BUST, and always has been.

 

Cthulhu.

You, at least appear to argue intelligently, and read what I have to say. Thank you for that. A few comments on your last posting.

 

Clouds and their importance. Clouds are made of water vapour and can have one of two possible effects.

First : They might dramatically increase the greenhouse effect. Water vapour is the most potent greenhouse 'gas' of all. It has been estimated to make up 70% or more of the total greenhouse effect. Increasing clouds increases greenhouse effect.

Second : Clouds increase the Earth's albedo. Reflects heat out into space - a cooling effect.

Does the first effect or the second have the biggest impact? No-one knows.

 

Your reference suggesting a prediction of cooling effects from aerosol influence. Sorry. I read it carefully, and it does not say that.

 

Predictions of the next 100 years. Your suggestions are reasonably sensible. You suggest a 1 to 5 Deg. C. increase. I think a better suggestion is 0.5 to 1 Deg C., based on history (extend the line on the graph). However, though we disagree, yours is more sensible than most such suggestions I have seen.

[Prime-Evil]

Prime Evil.

Sorry' date=' but I do not think you read my posting well enough. Kyoto is a BUST, and always has been.

 

Cthulhu.

You, at least appear to argue intelligently, and read what I have to say. Thank you for that. A few comments on your last posting.

 

Clouds and their importance. Clouds are made of water vapour and can have one of two possible effects.

First : They might dramatically increase the greenhouse effect. Water vapour is the most potent greenhouse 'gas' of all. It has been estimated to make up 70% or more of the total greenhouse effect. Increasing clouds increases greenhouse effect.

Second : Clouds increase the Earth's albedo. Reflects heat out into space - a cooling effect.

Does the first effect or the second have the biggest impact? No-one knows.

 

Your reference suggesting a prediction of cooling effects from aerosol influence. Sorry. I read it carefully, and it does not say that.

 

Predictions of the next 100 years. Your suggestions are reasonably sensible. You suggest a 1 to 5 Deg. C. increase. I think a better suggestion is 0.5 to 1 Deg C., based on history (extend the line on the graph). However, though we disagree, yours is more sensible than most such suggestions I have seen.[/quote']I don't think you read your own postings well enough.

 

Whether or not Kyoto is bust is not the point of this forum.

This is not a political forum.

[SkepticLance]

Prime Evil.

Kyoto is a bust. This is not political. This is a simple calculation of cost versus benefit. Your continued reference to Kyoto as something to be desired shows that, unless you come up with something new, that you are arguing a rather defunct point. As I said, I have no problem with action to reduce deforestation or other activities that burn fossil fuels. However, they have to be intelligently thought out, and a proper cost/benefit analysis carried out. Kyoto does not live up to that criterion. And that is based on maths, not politics.

[Prime-Evil]

Can you name one government in the world that denies the facts of climate change as you do?

[JustStuit]

What would a government have to do with it? Or is this political? Governments aren't always right anyway.

[SkepticLance]

First, Prime Evil, I do not deny any facts. It is interpretations of facts that I am occasionally in dispute with. If you are talking about conclusions drawn from computer models, you should realise that these are not facts. These are little better than speculations.

 

Dr. Andrey Illarionov, an economic advisot to President Putin of Russia, visited NZ two years ago, and said that the government of Russia is not convinced of the paradigm you espouse. However, they have gone along with it as a matter of political expediency. One of the main reasons for this is that the Russian economy 'imploded' and ended up with carbon dioxide emissions that are lower than in 1990. Consequently, under Kyoto, they will receive $$$$$$$ from nations that release too much.

 

I suspect that Russia is not alone, and that a lot of national governments are not convinced of this paradigm, and 'go along' with it for political reasons.

[Prime-Evil]

To me the computer models are not neccessary to identify the problem. The rate at which fossil fuels are being burned and carbon dioxide is increasing is sufficient. Also population increase, deforestation, soil degradation and erosion, desertification, and decreasing biodiversity. You don't need a computer model to identify a problem. But in my opinion global warming is a threat, but not the greatest threat. The greatest threat is decreasing biomass and biodiversity as a result of human activity and population increase. It's a no brainer that our way of life and living must change dramatically this century, but our political futures are guarded just as carefully as our political histories. Most of us take comfort in this.

 

Personally, I would let the government do my taxes before I let them do my homework.

.

[SkepticLance]

Prime Evil.

I do not dispute global warming. The world is warming up. I do not dispute that anthropogenic greenhouse gases (AGGs) are increasing. I do not dispute that AGGs have the property of increasing the insulating properties of the lower troposphere. And I do not dispute the logic that an increase in AGGs should result in an increase in global warming.

 

However, logic has no place in science. The most important and most basic rule in science is this :

"Any scientific idea must be confirmed by substantial empirical testing."

 

Simple isn't it?

And the global warming catastrophist paradigm has not been confirmed by substantial empirical testing. For those who do not know, empirical means derived from experiments or observations, as opposed to theory.

 

Theory often is the enemy of good science. Once global warming catastrophism has been confirmed in the proper scientific way, I will accept it. However, we are a long way off that so far.

[sunspot]

When forest fires burn they release CO2. As the level of CO2 rises in the atmosphere this promotes plant growth. Commerical growers will often add CO2 to the greenhouses to increase productivity. Greenhouse gases in a greenhouse, now isn't that cool.

 

Besides plants, CO2 is also scrubbed from the atmosphere by rain water to form the water soluble, nongaseous, H2CO3 or carbonic acid. This rains into the oceans, which have a pH around 7.8, which is basic. This forms CaCO3 for the shell fish, which is nongaseous. The only CO2 that we got to worry about is the CO2 which gets above the earth surface (plants) and above the clouds (water). Even forest fires can add CO2 up there. In the Nova program they said that smoke from big forest fires rise 100,000+ ft.

 

If we have drought or even snow due to an ice age his means less water in the atmosphere scrubbing the CO2 and less plant life to absorb CO2. The result will cause CO2 to increase. What is good about global warming is that it adds more water to the atmosphere, through evaporation, and will help scrub out the excess CO2, while increasing plant life, so it can increase its contribution.

 

As far as global warming. It is happening. We should embrace the change since new species will evolve.

[Prime-Evil]

I would agree with much of you said if it wasn't so twisted.

 

We need to take major steps to increase forest and soil biomass rather than continue to reduce it. We have larger forest fires since we started logging, because our forests less moist. The changes we have caused are not creating new species, but are destroying existing species. Biomass and biodiversity are decreasing not increasing. I think the world could better handle higher temperatures if it had more biomass and natural habitat. Polar Bears could migrate south and depend more on caribou until the next cold period, but we do not allow them to do this. Cities can rebuild as ocean levels rise, but savanah turns into desert much easier than taiga turns into boreal forest. There simply isn't enough soil or sunlight in the near polar regions to make up for increasing desertifation in the near equitorial regions. We should not embrace 500ppm CO2 or even 380ppm because there is nothing natural about those levels of CO2 during this geological epoch and continental land mass configuration.

 

North Americans should not embrace change if they are a likely cause of it and it will causing problems in other countries. The other countries should have a voice. Furthermore, if we create conditions which are so unlike the past 100,000 years, how can we predict the future with any certainty based on the past. What is nature with fewer species and less life? What is to embrace?

[SkepticLance]

Prime-Evil.

Consider this. This is almost a natural law.

Warm areas ALWAYS have greater biodiversity and greater biomass than cold. Is it therefore so undesirable for the world to warm up a bit?

[Prime-Evil]

Not a lot of biodiversity in the Sahara desert, last time I checked. I think whatever restores and maintains total biomass will most likely keep us on the right track. I don't see a problem with 400ppm and an extra degC or maybe even two, as long as we use the opportunity to restore and sustain forest and soil biomass, which we are not. It is where we are headed for at 500pm with less forest and soil biomass and 10 billion people than concerns me the most.

[SkepticLance]

Prime Evil.

I am not terribly thrilled about 500 ppm carbon dioxide either, but not because I think it will lead to global warming catastrophe. However, such a massive change may have other, unpredicted effects.

 

Worth noting, though, that some researchers believe the world had 10 times historic levels of carbon dioxide in parts of the Cretaceous, and the temperature was 10 Deg. C. warmer than now. If these researchers are correct, and they may not be, then it implies that a mere doubling of carbon dioxide will not result in the catastrophe you fear.

 

I am not keen either, on the idea of massive forest cover loss. I suspect, though, that if this happens, it will be due to people cutting down said forest, rather than any temperature increase. If the forests are left to themselves, increased carbon dioxide actually speeds tree growth.

 

Another interesting datum not often mentioned in these discussions. The stomata in plants open wide to obtain the carbon dioxide needed for photosynthesis. Experiments have shown that, when added carbon dioxide is available, the stomata do not open as wide. This cuts down on the main area of water loss from plants, and makes them more drought resistant.