I just watched An Inconvenient Truth

[gib65]

I just watched An Inconvenient Truth. That's a scary movie. I had believed in Al Gore's "misconception #1" - that we're not sure if global warming is a real thing, and if it is, how much we're contributing to it. From the data he shows us, we are clear causing global warming every since middle of the 20th century. The sharp increase in CO2 imissions since the 60s/70s is so strongly correlating with the sharp increase in the average temperature of the Earth's atmosphere. And it's increased to about 3 times the temperature it's ever been in hundreds of thousands of years. That ain't no natural occurence.

 

He keeps refering to the "scientists". "The scientists say..." he says. Well, this is a community of scientists. What do the scientist really say?

[blackhole123]

Well, I'm no scientist but I saw him speak in Chautauqua and most of what he said made sense. I can't imagine why someone would deny that global warming exists.

[ecoli]

The sharp increase in CO2 imissions since the 60s/70s is so strongly correlating with the sharp increase in the average temperature of the Earth's atmosphere.

 

What's the key word here...

 

Until you can definitively prove causation, then the neigh sayers have a case.

[Dak]

imo, whilst not 100% certain, theres enough reason to believe in global warming that it seems prudent to assume gw is occouring.

 

completely modifying all our industries etc and then finding out that gw is a myth will waste alot of effort; not doing anything and then finding out that gw is happening may wreck our planet.

[ecoli]

imo, whilst not 100% certain, theres enough reason to believe in global warming that it seems prudent to assume gw is occouring.

 

completely modifying all our industries etc and then finding out that gw is a myth will waste alot of effort; not doing anything and then finding out that gw is happening may wreck our planet.

 

That's basically my take on it. In the meantime, we can do things to curb CO2 emmisions, which are not healthy for the environment even if they don't cause global warming, like investing in alternative fuels, etc. If GW is anthropogenic, then we'll be thanking ourselves, if not than we'll be thanking ourselves anyway when oil runs out.

[gib65]

What's the key word here...

 

Until you can definitively prove causation, then the neigh sayers have a case.

 

But I think the proof is in. In the movie, Al Gore shows a graph of the overall temperature of the world over the past 650,000 years, and it goes through fairly regular fluctuations of ice ages and warm ages, until we get to the twentieth century where the average temperature becomes double what it's ever been. Likewise, he shows a graph of the amount of CO2 in the atmosphere. The CO2 levels go up and down almost perfectly with the temperatures of the Earth, and they go shooting up at the same point, and by the same amount, as when the temperatures goes shooting up.

 

Now, you can say this is just a corelation, but then there are three possibilities: either global warming is causing CO2 levels to go (which is possible), CO2 levels are causing global warming (which is more likely), or a third factor is causing both (can't imagine how this would be). The is something we know for fact, however, and it's that we are emitting tons of CO2 into the atmosphere everyday, and we can measure exactly how much. When we take these measurements, the amount to precisely the deviation we see in the overall CO2 levels. So we know we're causing this increase in CO2. There isn't any uncertainty about it.

[ecoli]

But I think the proof is in. In the movie, Al Gore shows a graph of the overall temperature of the world over the past 650,000 years, and it goes through fairly regular fluctuations of ice ages and warm ages, until we get to the twentieth century where the average temperature becomes double what it's ever been. Likewise, he shows a graph of the amount of CO2 in the atmosphere. The CO2 levels go up and down almost perfectly with the temperatures of the Earth, and they go shooting up at the same point, and by the same amount, as when the temperatures goes shooting up.

Yes, I've seen these graphs presented in a hundred different ways, but they still don't go past correlation. There is no proof that the changing temperatures are anything other than a natural cycle.

 

Now, you can say this is just a corelation, but then there are three possibilities: either global warming is causing CO2 levels to go (which is possible), CO2 levels are causing global warming (which is more likely), or a third factor is causing both (can't imagine how this would be). The is something we know for fact, however, and it's that we are emitting tons of CO2 into the atmosphere everyday, and we can measure exactly how much. When we take these measurements, the amount to precisely the deviation we see in the overall CO2 levels. So we know we're causing this increase in CO2. There isn't any uncertainty about it.

 

You're wrong... there are more than three possibilities. The fact is that temperature of the earth has flucuated greatly before humans evolved, and will probably continue to flucuate long after we're gone. It's possibly that the temperature raise we are seeing is due to NATURAL global warming events, without any anthropogenic forcings. If this is the case, there is nothing we can do to stop global warming. Another possiblity is that there is some combined affect from anthrogenic and natural cyclical sources, in which case, we are having an effect, perhaps one that's causing a positive feedback mechanism to push global warming. In this case, we can curb greenhouse gas emisions, but global warming will still occur, if not to the full effects we fear.

 

There are certain things we know. Humans are releasing CO2 into the atmosphere, which is causing atm. CO2 levels to rise. We know that global warming is occuring, and we know the mechanism by which it occurs. But, if you look at global temperature graphs throughout history, temps are cyclical. The earth has been warmer than it currently is, but we don't really understand the mechanisms by which natural temperature variation occurs. So, we can't say that the earth is not warming up due to natural temperature variation.

 

The situation is still very much fluid. I recently attended an excellent lecture from a professor at my school, who is a head of the environmental department, and a well respected scientist. And even he admitted that the anthropogenic answer was not clearly defined yet, and that we still need a lot more research before we can say anything that definitive.

 

Now, I'm fully receptive to the idea that people may be causing global warming, but what I do not want, is wide spread panic over an idea that still in the development stages. I definately want to see more research into the area. This research is being done, which is good, but I don't people to jump the gun, and draw conclusions on either side before all the info is available. To do so would be intellectually dishonest and unscientific.

[TriggerGrinn]

Yes, I've seen these graphs presented in a hundred different ways, but they still don't go past correlation. There is no proof that the changing temperatures are anything other than a natural cycle.

 

Its a tough case to answer, I agree.

 

But even if it was a natural cycle we have an issue!

 

When you see the data of tempeatures in certain areas that have raised so high as to kill people and or render them imobile.. its certaintly not good.

 

We have this argument at hand of whether we are contributing or not...

 

Here's the the facts.

 

-We pollute too much we know that.

-whether natural or not the tempeatures are rising and creating unlivable conditions in many areas

-with the whole global warming issue asside, we know we should reduce emissions

-we know that if we do not change our ways, we are screwing this place over.

 

I can't not see why or how people get hung up on the issue if its part natural or part man made.

 

Those who say there have been lots of natural changes on earth, they are absolutely right! But you know, there has also been alot of mass extinctions on earth from those natural changes. My question is, who cares who is right, do you wanna go extinct? or create un-needed extinction? or create a shit enviroment for our children?

 

Maybe we have to fight nature? Maybe it isnt us creating it.. It might be better to figure out how to lower the tempeature in comparison to allow it to raise.

[gib65]

ecoli,

 

Okay, maybe we need more research to be certain. I don't want to jump to conclusions and create widespread panic any more than the next guy. And, yes, I'm basing what I say in this thread purely on An Inconvenient Truth. But if I may do this, then what the data shows is that the current rise in temperature is anything but natural. We have never had a rise as sharp or as high as this in the past 650,000 - not even close. You say that the world has been warmer than it already is, but that's not what Gore said. The world goes through periodic warm and cold cycles, and he clearly pointed out that it never goes above a certain temperature. In the late twentieth century, we went past that ceiling by two times!

[SkepticLance]

Global warming is real, and it is at least partly caused by human activity - greenhouse gases.

 

Having said that, I need to point out that Al Gore is above all else a politician. And he is using his film for political purposes. His facts are seriously questionable, and almost certainly exaggerated. He appears to be using a computer model, known as the Canadian model, which predicted that the 20th Century warming for the United States was 1.5 Celsius (It was, in fact, 0.5 Celsius). This model predicts 5 Celsius for the 21st Century. Could that prediction be 300% exaggerated?

 

Current global average warming is 0.16 Celsius per decade as a long term trend. Over the next 100 years, it may increase, or get less. We just don't know. However, it is worth noting that each century, at least for the last 400 years, there has been at least one period, lasting decades, of global cooling. This is due either to reductions in sunspot activity or to volcanic activity. The last one was 1940 to 1976, where global temperatures dropped 0.2 Celsius.

 

If we apply current warming trends with the probability of a cooling period this century, we get a predicted warming by the year 2100 AD of about 1 Celsius. This is a hell of a lot less than the Al Gore prediction of 5 Celsius!

[ecoli]

Okay, maybe we need more research to be certain. I don't want to jump to conclusions and create widespread panic any more than the next guy. And, yes, I'm basing what I say in this thread purely on An Inconvenient Truth. But if I may do this, then what the data shows is that the current rise in temperature is anything but natural. We have never had a rise as sharp or as high as this in the past 650,000 - not even close. You say that the world has been warmer than it already is, but that's not what Gore said. The world goes through periodic warm and cold cycles, and he clearly pointed out that it never goes above a certain temperature. In the late twentieth century, we went past that ceiling by two times!

 

Just because temperatures are increasing more steeply than we've seen before in natural cases, doesn't mean that current global warming patterns isn't natural. It makes a stronger case for anthropogenic sources, but it doesn't prove it.

 

If I had to guess, I would expect a combination of factors to be contributing to global warming.

[JHAQ]

I accept global warming is real but it & its opposite have happened many times in the past . I have difficulty separation man made effects from natural cyclic phenomena . PS I AM a scientist ( or was before retirement ) with degrees in both physical & life sciences .

[gib65]

Just because temperatures are increasing more steeply than we've seen before in natural cases, doesn't mean that current global warming patterns isn't natural. It makes a stronger case for anthropogenic sources, but it doesn't prove it.

 

If I had to guess, I would expect a combination of factors to be contributing to global warming.

 

What do you mean by "natural"? I'd say it's not natural in the sense that it's irregular. Not natural in the anthropogenic sense? Well, I guess that's the question. Gore seems to think it's definitely anthropogenic, and if he's presenting the truth accurately and fully, then I'm satisfied that this is proof.

 

I guess not everybody agrees though. But even if we're contributing only a marginal percentage to the greenhouse gases, the fact is CO2 levels are going up and it is causing global warming. So my question is, why in the world would we keep contributing to the problem? Even if we're not the major cause, we shouldn't be a cause at all. We should be trying to fix the problem.

[ecoli]

What do you mean by "natural"? I'd say it's not natural in the sense that it's irregular. Not natural in the anthropogenic sense? Well, I guess that's the question.

yes, natural as in non-anthropogenic, and as such humans cannot control or stop the warming.

Gore seems to think it's definitely anthropogenic, and if he's presenting the truth accurately and fully, then I'm satisfied that this is proof.

But is he doing that? Even important and well studied climatologists are willing to discuss non-anthropogenic sources as a possibile cause of the global warming situation. Why should I believe some politician with an obvious agenda over non-biased scientists?

 

I guess not everybody agrees though. But even if we're contributing only a marginal percentage to the greenhouse gases, the fact is CO2 levels are going up and it is causing global warming.

This has not been proven past correlation yet.

 

So my question is, why in the world would we keep contributing to the problem? Even if we're not the major cause, we shouldn't be a cause at all. We should be trying to fix the problem.

 

The economics argument. If we aren't causing global warming with CO2 emmisions, than why spend the billions of dollars it would take to decrease emmision levels. It's simply a waste of money and, especially for nations with low GDP and high CO2 emmisions, spending this money could be devastating for their economies.

[gib65]

This has not been proven past correlation yet.

 

Let me get this straight. You're saying that the currently accepted theory about CO2 acting like a greenhouse, trapping heat from the sun, and therefore causing temperature to rise, is too speculative to treat as fact?!?!

 

The economics argument. If we aren't causing global warming with CO2 emmisions, than why spend the billions of dollars it would take to decrease emmision levels. It's simply a waste of money and, especially for nations with low GDP and high CO2 emmisions, spending this money could be devastating for their economies.

 

Not really. It may take billions of dollars to decrease emmisions, but we will make money by creating new jobs. Alternate energy sources is a growing industry and the more need there is for it, the more economically viable it will become. Also, it would open up several international markets because, currently, there are countries like China to whom the US cannot sell their vehicles to because they don't meet the environmental standards. This won't burden the economy, it will only cause a shift in it.

[ecoli]

Let me get this straight. You're saying that the currently accepted theory about CO2 acting like a greenhouse, trapping heat from the sun, and therefore causing temperature to rise, is too speculative to treat as fact?!?!

no, no... The greenhouse phenomenon is a known fact, I'm not disputing that, of course. But, I'm saying that there maybe other sources of temperature rises other than anthropogenic greenhouse gases.

 

 

Not really. It may take billions of dollars to decrease emmisions, but we will make money by creating new jobs. Alternate energy sources is a growing industry and the more need there is for it, the more economically viable it will become. Also, it would open up several international markets because, currently, there are countries like China to whom the US cannot sell their vehicles to because they don't meet the environmental standards. This won't burden the economy, it will only cause a shift in it.

 

It does depend how we tackle the problem.

 

The Economics of the Kyoto Protocol

by Christopher N. MacCracken, James A. Edmonds, Son H. Kim and Ronald D. Sands (PNNL, Pacific Northwest National Laboratory, Washington, DC)

 

Abstract: In this paper we use the Second Generation Model to develop an assessment of the energy and economic implications of achieving the goals of the Kyoto Protocol. We find that many of the details of the Protocol that remain to be worked out introduce critical uncertainties affecting the cost of compliance. Our analysis shows that the cost of implementing the Protocol in the United States can vary by more than an order of magnitude. The marginal cost in 2010 could be as low as $26 per tonne of carbon if a global system of emissions mitigation could be quickly and effectively implemented. But it could also exceed $250 per tonne of carbon if the United States must meet its emissions limitations entirely through domestic actions, and if mitigation obligations are not adequately anticipated by decision-makers."

 

My point is, that we have to tread with care.

[SkepticLance]

In science, we need to clearly differentiate between data and deduction.

 

The fact that the world is warming, is data.

The fact that carbon dioxide levels in the atmosphere is increasing is data.

The conclusion that greenhouse gas increase causes global warming is deduction.

 

This does not, of course, make the deduction wrong. In this case, the deduction is a very strong one, and is almost certainly true. There are other factors possible.

 

Two very strong possibilities are volcanic action and sunspot activity. There is a clear correlation between vulcanism and global cooling. By no coincidence, the 20th Century was one with less than the long term average level of vulcanism. This meant one less influence to counter global warming.

Sunspot activity correlates with warming. During the Little Ice Age, sunspot activity was very low. During the 1940 to 1976 cooling event, sunspot activity fell. Today, with strong warming, sunspot activity is at its highest level for 8000 years.

 

However, the world continued to warm at a substantial rate over the last 20 years, and sunspot activity increased only very slightly. That would suggest another influence. The leading candidate is greenhouse gases.

 

I think the case for anthropogenic greenhouse gases being a powerful force pushing global warming is very strong. Not perfect, but strong.

[bascule]

Yes, I've seen these graphs presented in a hundred different ways, but they still don't go past correlation. There is no proof that the changing temperatures are anything other than a natural cycle.

 

The evidence that greenhouse gasses are the primary culprit behind the present (i.e. past 50 years) rapid rise in global surface temperatures comes from dozens of independently developed models of Earth's entire climate system (known as General Circulation Models, or GCMs). Here's the data from temperature reconstructions of various GCMs graphed:

 

 

After decades of work, these various models are all starting to give the same or very similar numbers, and CO₂ has emerged as the primary forcing to which climate change can be attributed:

 

 

(Notice that, like SkepticLance mentioned, there are many other forcings at work, primarily solar, ozone, and volcanic activity)

 

Here's an excellent article on the issue of CO₂ climate change attribution:

 

http://www.realclimate.org/index.php/archives/2006/10/attribution-of-20th-century-climate-change-to-cosub2sub/

 

Note that I agree Kyoto does not make sense economically. I see the solution in the form of utilizing CO₂ for constructive purposes, rather than simply exhausting it into the atmosphere.

 

Let me start a thread on that.

 

Ed: Thread created!

 

http://www.scienceforums.net/forum/showthread.php?p=318986

[TriggerGrinn]

Yes, I've seen these graphs presented in a hundred different ways, but they still don't go past correlation. There is no proof that the changing temperatures are anything other than a natural cycle.

 

Let me shorten my reply.

 

That doesnt mean nature won't fry our asses or our children's. lol

[swansont]

Yes, I've seen these graphs presented in a hundred different ways, but they still don't go past correlation. There is no proof that the changing temperatures are anything other than a natural cycle.

 

...

 

There are certain things we know. Humans are releasing CO2 into the atmosphere, which is causing atm. CO2 levels to rise. We know that global warming is occuring, and we know the mechanism by which it occurs.

 

So to say that there is no proof (or rather, evidence) that humans are causing global warming is, by your own statement, false. We can measure the amount of CO₂ we are dumping into the atmosphere, and we can experimentally determine what kind of effect that should have. It's clear that CO₂ has a warming effect. The degree to which anthropogenic forcings are responsible is the real question.

 

 

But, if you look at global temperature graphs throughout history, temps are cyclical. The earth has been warmer than it currently is, but we don't really understand the mechanisms by which natural temperature variation occurs. So, we can't say that the earth is not warming up due to natural temperature variation.

 

At the risk of poisoning the well, I say this: Of the two, I think the "we have no clue" stance is the intellectually dishonest one. The tactics used to attack global warming studies are the same ones used by the tobacco industry to attack smoking studies. The same rhetoric: it's not clear...further studies need to be made. The same style used by creationists, too, in questioning science, implying that any dissenting voice is equal and reinforcing the mistaken notion that if something isn't 100% certain then it is completely uncertain. They are "teaching the controversy" here, too, and in much the same way. Now, pointing out the tactics doesn't actually prove a thing, and I don't offer it as such, as it would be a rhetorical poisoning of the well if I did. But it gives me pause when debaters use such tactics, since they are outside of the science. Yes, the science is complicated, and understanding is not complete, but that doesn't mean that nothing is understood.

 

The economics argument. If we aren't causing global warming with CO2 emmisions, than why spend the billions of dollars it would take to decrease emmision levels. It's simply a waste of money and, especially for nations with low GDP and high CO2 emmisions, spending this money could be devastating for their economies.

 

Risk/reward. The environment isn't going to turn on a dime. If we wait, and the predictions are correct, how much damage would be done in the interim, and how much will that cost? As gib65 already pointed out, this money would be spent developing new technology and stimulate the economy. It's not wasted money.

[silverslith]

Everyone is obsessed with who did it.

Its happened lots before. We probably did do it this time but jumps between equilibrium positions have happened a lot before with the earths climate systems and what we can do about it is not a guilt issue.

I am worried about atmos carbon levels at the highest level in tens of millions of years when the sun is now hotter by 25% than when we had 10degC hotter temps in the cretaceous. They had several% of co2 then though.

Anyway, we should use geothermal and tidal power to turn the atmospheric carbon into useful hi performance building materials. build a ring and space elevators to speed the release of life spores into space. The yolk is almost consumed. if life does not hatch from the earth then venus is what we can expect for a habitat eventually.

[SkepticLance]

Silverslith said

 

Anyway, we should use geothermal and tidal power to turn the atmospheric carbon into useful hi performance building materials. build a ring and space elevators to speed the release of life spores into space. The yolk is almost consumed. if life does not hatch from the earth then venus is what we can expect for a habitat eventually.

 

Just a couple of points to, perhaps, put your comments onto a more practical footing.

 

First; geothermal and tidal power combined contributes less than 0.5% of the world's electricity needs, in spite of many decades of development. They are unliely to make a more than token contribution in the future, since the problems of today will continue.

 

Wind power, which is the darling of the greens, contributes less than 2%, in spite of whole forests of wind turbine towers sprouting in places like Germany (and incredibly ugly they are, too). They are seriously unlikely ever to contribute more than about 5%. Their growth is driven by dogma, and the fact that electricity companies use them as public relations tools - "See, we are green too!"

 

There are still only four methods than contribute substantially. Coal, natural gas, hydroelectric and nuclear. Coal and gas have emission problems. Hydroelectric is almost at its potential maximum. Only nuclear has potential for major expansion.

 

By the time we get to the stage you see as so desirable (space elevators etc), we will also have nuclear fusion.

[ecoli]

Skepticlance...

 

Is there any inherent reason why any forms (like wind) won't be able to grow much more than they're current usage?

 

Also, you neglected to mention direct solar energy as a potential resource.

 

and, why do you thinkg wind turbines are ugly? I think they're quite nice.

[silverslith]

Silverslith said

 

Anyway, we should use geothermal and tidal power to turn the atmospheric carbon into useful hi performance building materials. build a ring and space elevators to speed the release of life spores into space. The yolk is almost consumed. if life does not hatch from the earth then venus is what we can expect for a habitat eventually.

 

Just a couple of points to, perhaps, put your comments onto a more practical footing.

 

First; geothermal and tidal power combined contributes less than 0.5% of the world's electricity needs, in spite of many decades of development. They are unliely to make a more than token contribution in the future, since the problems of today will continue.

 

Wind power, which is the darling of the greens, contributes less than 2%, in spite of whole forests of wind turbine towers sprouting in places like Germany (and incredibly ugly they are, too). They are seriously unlikely ever to contribute more than about 5%. Their growth is driven by dogma, and the fact that electricity companies use them as public relations tools - "See, we are green too!"

 

There are still only four methods than contribute substantially. Coal, natural gas, hydroelectric and nuclear. Coal and gas have emission problems. Hydroelectric is almost at its potential maximum. Only nuclear has potential for major expansion.

 

By the time we get to the stage you see as so desirable (space elevators etc), we will also have nuclear fusion.

 

Oh come on! geothermal and tidal power both have the potential to supply many times humans current energy consumption.

 

Look at New Zealand- 20% of power from natural hydrothermal reservoirs, with the couutrys best systems-White Island for example with 500degC supercritical fields. and if you got into hot rock systems theres a 200km across magma bubble under the north Island with enough heat to power the planet for millions of years. Many other countries have just as much potential. Underwater reserves are probably 100 times this in NZ's economic zone. Tidal turbines are a new technology but there is projects planning to use these in cook strait (enough resource there to provide the globes energy needs) and the Kaipara harbour mouth (15 cubic km of water every six hours at up to 20kph).

Nuclear has no expansion potential other than through extremely dangerous (~50000x more radioactive than conventional u235 reactors like chernobyl)Breeding of synthetic actinide fuel eg U238- plutonium239 and thorium232-U233(50000x as radioactive as natural U238/235). Actually breeding tech would result in constant reprocessing of fuel(certainly not technologically possible at present) for hundreds of years. with ever higher actinides with more and more serious radioactive consequences. Its very atrractive to big money because of barriers to entry for competition-potential energy monopoly. Any move to this transmutationtech will result in the multiplication of the unsafe stored radioactivity on our planet by thousands to millions of times.

 

Wind turbines need much larger scale to present designs to contribute much. something like a lighter than air 500m wide model on a 2 km tether. They are beautiful elegant sculptures in 4 dimensions whatever the size. Its the profits made by the landowners that drives them in Germany. Much better than cows or sheep.

 

The best Solar at present is by the biomass route. Excellent CO2 capture technology included.

[SkepticLance]

Silverslith.

Predicting the futue is a hazardous undertaking, with a strong likelihood of being embarassed. You might be correct in suggesting that geothermal and tidal will become very important. However, based on what little I know, that seems unlikely.

 

Incidentally, New Zealand does not gain 20% from geothermal. Not quite sure the exact number, but it is way less. Something like 5% if my memory is right. And the easy resources for geothermal have already been tapped.

 

Tidal power requires specialised situations with big rise/falls of sea water. OK, they do exist, but finding some easily tapped is difficult. It seems unlikely to become a major contributor for quite a while.

 

Wind power from high altitude energy is theoretically possible, but there is a long way to go before the technology is developed to the point of practical application.

 

Nuclear is current, and can, in theory, be expanded very substantially - probably at least 20 fold. While fuel is limited in high yield ores, it is extremely abundant in lower yield ores, and these can be mined and exploited.

We can speculate about all sorts of future energy sources, and some may eventually become important. However, based on todays technology, nuclear is the best immediate bet for large scale generation expansion.