I just watched An Inconvenient Truth

[silverslith]

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.

 

I'm sure you are wrong about the geothermal percentage. Its contribution is equal to hydro dams in NZ. Much expansion is in progress. Kawerau for example. Its being touted as the best growth potential for the next few decades for electricity generation. It gets less press than hydro cause its so darn reliable.

 

wrong about the tidal thing. The big potential is kinetic energy of big masses of water not dam technology relying on pressure differential of bodys at different levels. Do we do wind power by damming air?

 

Nuclear is good for 6 years of current world energy consumption without the spectre of transmutation and is already too expensive when you look at the greenhouse gases and radiologic pollution from the mining and extraction industry, let alone the 100's of thousand years+ of serious waste containment issue. (have you seen all the companies on the web boasting about how they designed new packaging and remote transfer systems for waste thats containment has failed after 25 years!)

 

The offshore wind turbines being planned in the nth sea are getting near the scale required. Water is 1000 times denser and flows are more predictable. The biggest problem with wind is the potential extremes.

[waitforufo]

Human beings really have a problem believing they live in a random or chaotic universe. For every effect, we must find a cause. We are most comfortable believing we are the cause. We are just control freaks. Perhaps however, we are just along for the ride.

 

With regard to correlation and causation debate, some of the above discussion suggests we should just assume causation. That argument holds that the potential consequences of global warming will be so bad that it's prudent to head global warming off at the pass.

 

First, who says it's going to be bad? My understanding is that the medieval warming period in the 1200's or so was a great time to live. It was about 2 C degrees warmer than then it is now. There were vineyards in England and Sweden. Vikings settled in Greenland. Receding snow is uncovering more of their settlements every day. The world could just turn in to a pleasantly warm and humid place.

 

Oh yea, things always have to turn to crap. For example, the oceans are going to rise by feet. My guess is that won't happen over night. By the time it does happen, we can move those who are flooded out to Greenland or Alaska. I just read yesterday that the climate of Alaska will become like that in England. Sweet. Can't move lots of people? Perhaps you should read about the settling of North America.

 

Second, we have plenty of problems today without global warming. People often say "If we can put a man on the moon, why can't we do…. Well, we can't to the …. because we spent our so much of our money putting a man on the moon. We have to be careful how we spend our money. With the money we have we can only solve so many problems.

 

Finally, you want to emit less CO2. Well start building nuke power plants. Even the French have figured that one out.

[bascule]

With regard to correlation and causation debate, some of the above discussion suggests we should just assume causation.

 

The only assumption we make is that a realistic set of model inputs will produce model output which matches empirical data.

 

That argument holds that the potential consequences of global warming will be so bad that it's prudent to head global warming off at the pass.

 

First, who says it's going to be bad?

 

The IPCC, in the Impacts and Vulnerabilities section of the TAR. The Fourth Assessment Report has only published the scientific basis, and not their vulnerability assessment.

 

My understanding is that the medieval warming period in the 1200's or so was a great time to live. It was about 2 C degrees warmer than then it is now.

 

No, it wasn't:

 

[1veedo]

The medieval warm period did bring Europe out of the dark ages but this has nothing to do with today. We can grow crops just fine.

[waitforufo]

Bascule,

Perhaps you should check out the ordinate on the graph of yours. I'm not losing any sleep over a few tenths of a degree. Don't you get tired of all the doom? There are plenty of good reasons to conserve energy. That's particularly true when you save cash at the same time. Replacing incandescent bulbs with florescent is brilliant. Throwing money at an unstoppable force of nature is never a good idea.

 

OK, perhaps I was wrong on the temperature extreme the medieval warming period. People still loved it. Any guess why they call the temperature peak during the Holocene period and "Optimum." Try to find a historical warm period described as catastrophic for human beings. Good luck.

 

Also, I did suggest a terrific alternative to generating CO2. Tried and true. Fewer lives lost than any other source of energy used by mankind (including Chernobyl). The is no reason that the US for example could not produce 80% of all electric power from Nuke plants in 10 to 20 years. Think of all the lives that will be saved and the suffering that will be avoided.

[1veedo]

There really is no best temperature for the Earth. If there were rainforests in the arctic, I'm sure we'd get along fine. It might actually be better.

 

But the problem isn't that the earth is getting warmer. The problem is in the rate at which the earth is getting warmer. We (civilization) are suited to particular climates and so are other animals. Any sort of dramatic change has caused many extinctions in the past. A couple almost ended the human species entirely before civilization started. However, right now the earth is warming at a rate 10 times faster then it ever has in the past several million years.

 

If you want to see what happens when the climate changes a full 10 times slower then it is today, read about what happened during the paleocene-eocene maximum. It was, to say the least, catastrophic. Many species, from land animals to deep sea fish, went extinct.

 

The thing about the medieval warm period is that we know what caused it -- mostly orbit around the sun -- and we know what's causing global warming today -- greenhouse gases. Also, the medieval warm period only happened in the northern hemisphere during the summer months. It was also much cooler then today: http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html

 

[SkepticLance]

1veedo

You are referring to a graph that I have to regard with deep suspician. It violates an extremely important scientific principle. That is, do not change test method halfway through a scientific study.

 

If you look at the graph, you will see that last 100 years or so is done in red. That is because the results are obtained by a different method. Before that, indirect methods such as tree rings were used. The red bit is direct thermometer readings.

 

I have seen graphs in which the whole thing is done using the same method. One tree ring data graph shows a much lower rate of increase over the past 100 years. My own interpretation of this is to say that the indirect methods underestimate temperature change. The direct readings are more accurate. Applying this interpretation to the previous 1000 years means that the warming/cooling changes are underestimated in your graph.

 

ie. The Medieval Warm Period and the Little Ice Age are much more marked than your graph suggests.

 

This interpretation is backed up by historic data. The Medieval Warm Period involved Nordic settlers growing no less than five crops in Greenland - which cannot be done today. Historic data shows that during the Little Ice Age the North Sea froze as far south as England. Again, your graph would make this impossible. Historic data strongly suggests a much bigger temperature change than your graph would permit.

[bascule]

You are referring to a graph that I have to regard with deep suspician. It violates an extremely important scientific principle. That is, do not change test method halfway through a scientific study.

 

Why do you keep saying this? These are all model reconstructions (see how they're labeled "reconstruction"). The point of showing the instrumental record is to show that the models agree with the instrumental record (if they didn't, we surely wouldn't trust them, would we?)

 

 

If you look at the graph, you will see that last 100 years or so is done in red. That is because the results are obtained by a different method. Before that, indirect methods such as tree rings were used. The red bit is direct thermometer readings.

 

It's all model reconstruction, for the entire period. Yes, things like tree ring data do figure into the models, along with thousands of other types of data which the model must be able to explain and predict.

[1veedo]

ie. The Medieval Warm Period and the Little Ice Age are much more marked than your graph suggests.

 

This interpretation is backed up by historic data. The Medieval Warm Period involved Nordic settlers growing no less than five crops in Greenland - which cannot be done today. Historic data shows that during the Little Ice Age the North Sea froze as far south as England. Again' date=' your graph would make this impossible. Historic data strongly suggests a much bigger temperature change than your graph would permit.[/quote']You dont seem to understand what the medieval warm period actually was. The idea that Vikings were growing crops on greenland is an urban legend. Greenland was called "green" not because it was actually green but because the guy who discovered it thought he could get people to move there if he made it sound appealing. What few people actually came to greenland ended up dying. They couldn't grow any food and the winters, much like the early settlers in America, killed the vast majority of people.

 

http://en.wikipedia.org/wiki/History_of_Greenland

 

There is actually no evidence that the medieval warm period was anywhere near as warm as it is today. At most it was limited to the northern hemisphere and during the summer. Besides, you cannot point to one area and discover anything about climate change. Just because one particular place gets cooler or warmer doesn't mean the entire planet is.

 

The thing about the medieval warm period is that we know what caused it -- mostly orbit around the sun -- and we know what's causing global warming today -- greenhouse gases. That in itself makes the two very different.

[Edtharan]

Also, I did suggest a terrific alternative to generating CO2. Tried and true. Fewer lives lost than any other source of energy used by mankind (including Chernobyl). The is no reason that the US for example could not produce 80% of all electric power from Nuke plants in 10 to 20 years. Think of all the lives that will be saved and the suffering that will be avoided.

Absolutely wrong.

 

There is Solar, Wind, Hydro, Geothermal, Wave, etc that have claimed far less lives that Nuclear, so Nuclear is not the "Safest", it has not kill few people "than any other source of energy used by mankind".

 

With regard to correlation and causation debate, some of the above discussion suggests we should just assume causation. That argument holds that the potential consequences of global warming will be so bad that it's prudent to head global warming off at the pass.

So if you see a truck out of control and heading for you, you won't attempt to jump out of the way, even if you had no chance to avoid it...

 

If we could avoid the effects of global warming, should we?

 

If we could spend money and resources, now, and avoid the suffering of millions of people, should we?

 

Think about the morality of what you are saying here. You are advocating the "head in the Sand" approach to the potential suffering of millions of people, if not billions.

 

Oh yea, things always have to turn to crap. For example, the oceans are going to rise by feet. My guess is that won't happen over night. By the time it does happen, we can move those who are flooded out to Greenland or Alaska. I just read yesterday that the climate of Alaska will become like that in England. Sweet. Can't move lots of people? Perhaps you should read about the settling of North America.

If the sea levels rise too much, then whole countries will disappear into the ocean (look up a country called Tuvalu). Where will these people go. Will your country take them in, will your taxes pay for their relocation? Will you let them compete for your jobs? Will you give a bit of your land to them so that they can have a place to live?

 

There are more places in the world than Greenland and Alaska.

 

Second, we have plenty of problems today without global warming. People often say "If we can put a man on the moon, why can't we do…. Well, we can't to the …. because we spent our so much of our money putting a man on the moon. We have to be careful how we spend our money. With the money we have we can only solve so many problems.

How about just: If we caused this problem the it is our responsibility to fix it.

 

Putting a man on the moon was just 2 countries (and they weren't even working together)...

 

What if we had every country in the world working together?

 

What if we had the 6+ billion people all striving for the same goal?

 

Would we have a chance then?

 

I'm not losing any sleep over a few tenths of a degree.

The atmospheric and oceanic systems (these are at the heart of what is called global warming) are Complex (wikipedia) systems. What this means is that small changes can produce big effects. So "a few tenths of a degree" could produce big effects.

 

Don't you get tired of all the doom?

Yes, I do. So I'd like to do something so that we can avoid it if possible.

 

Throwing money at an unstoppable force of nature is never a good idea.

Have you got proof that it is unstoppable? Is the attempt to do so worthless? Is the technologies that we develop in the attempt not worth something in their own rights? Are the lives and well being of other people worth so little to you?

 

Do you not think about your future that you would refuse to spend a bit of money now to save a lot of money in the future? There is a saying: Those that fail to plan, plan to fail.

[SkepticLance]

Edtharan said :

 

There is Solar, Wind, Hydro, Geothermal, Wave, etc that have claimed far less lives that Nuclear, so Nuclear is not the "Safest",

 

This is correct, but not very helpful. The four big generations methods are coal, gas, nuclear and hydro. Each produces more than 12% of global power. Wind produces less than 2%, and the others produce less than 1%. It would be seriously unlikely that any of your alternatives will ever compete with the big four. I sincerely hope wind power stays small. I have seen land where wind farms predominate and they are ugly, ugly, ugly!

 

If we could avoid the effects of global warming, should we?

 

Mitigate rather than avoid is a better word. The answer to the modified question is yes. However, we need to be sure that the cure is not worse than the disease. Many methods of panicky global therapies would be humanitarian disasters. Any action should be carefully thought out and applied by careful management. First world countries have a nasty habit of doing things for their own benefit and letting impoversished third world countries collect the garbage.

 

If the sea levels rise too much, then whole countries will disappear into the ocean (look up a country called Tuvalu). Where will these people go. Will your country take them in,

 

Current sea level rise is less than 2 mm per year. Tuvalu is actually in a spot where sea level is falling, though this is a fact never mentioned by the media.

Tuvalu had the fortune to have a lot of coral sand moved during WWII to make an airfield. The place where the sand was taken filled with water, which was photographed. Said photos are on the internet, and newspapers buy those photos to illustrate articles on global warming and sea level rise. In other words, to support a big lie. Sea level rise is real, but not in Tuvalu.

[Edtharan]

Current sea level rise is less than 2 mm per year. Tuvalu is actually in a spot where sea level is falling, though this is a fact never mentioned by the media.

Tuvalu had the fortune to have a lot of coral sand moved during WWII to make an airfield. The place where the sand was taken filled with water, which was photographed. Said photos are on the internet, and newspapers buy those photos to illustrate articles on global warming and sea level rise. In other words, to support a big lie. Sea level rise is real, but not in Tuvalu.

Yes, I have seen those photos and heard that explanation, however, I was not referring to that. The fact remains that Tuvalu is not very high above the water line. In cyclones, the whole country can be submerged under water. If the oceans rise the same amount that it does in those cyclones, then the country will be submerged. Permanently (or until the next ice age).

 

The sea level might be falling there (I have never heard this my self, so could you explain how it is occurring), but if sea level continue to rise, this will not continue to be the state of affairs.

 

And the figure of 2mm a year of sea level rise, is that an average or do you have a source that says that it has been a constant rate of rise. If it is an average, then this might conceal an increase in the sea level rise in recent times (eg: just say that 200 years ago it was rising by 1mm, 100 years ago it was rising by 2mm and now it is rising by 3mm) and also over what period was this estimate taken.

 

Mitigate rather than avoid is a better word. The answer to the modified question is yes. However, we need to be sure that the cure is not worse than the disease. Many methods of panicky global therapies would be humanitarian disasters. Any action should be carefully thought out and applied by careful management. First world countries have a nasty habit of doing things for their own benefit and letting impoversished third world countries collect the garbage.

Actually it was a hypothetical question. IF we could avoid the effect should we.

 

I agree that all we can do now is to mitigate the effects. But, if we have a chance to halt the effect entirely, should we do it? It is meant to highlight the moral problem of the attitude of "It's too expensive for me to do something now, let us leave it to our children to do something when it occurs".

 

I also agree about the problem with knee jerk reactions. Take Malaria and DDT as an example. Scientists discovered an excellent insecticide, but before the long term health effects were known, the governments were using it on mass to kill mosquitoes and other insect pests and when it was discovered that DDT had side effects on people and other animals, they had to ban it.

 

In this case, the problem is simple (continued emissions of greenhouse gasses) but the solutions are many. There are many viable solutions, it is just people arguing over which one we should use.

 

It is a bit like people arguing over which direction they should jump to avoid an on coming train. While they argue the train gets closer and closer. There comes a point when jumping either way would have been better than getting hit by the train.

 

In choosing a solution to GW, which way we jump will be meaningless once we hit a point of no return (and according to some models we have already past that point). As there is a big variation in the different models and their predictions of the point of no return, we can not be really sure when we have hit it. IT is a bit like arguing over which way to jump to avoid an oncoming train and not knowing how far away that train is.

 

It would be better to jump sooner rather than later.

 

In terms of GW. It would be better to do things that will be low impact (people wise) now and keep investigating the best solution, than argue over which would ultimately be the best solution in the long term and do nothing until then.

 

This is correct, but not very helpful. The four big generations methods are coal, gas, nuclear and hydro. Each produces more than 12% of global power. Wind produces less than 2%, and the others produce less than 1%. It would be seriously unlikely that any of your alternatives will ever compete with the big four. I sincerely hope wind power stays small. I have seen land where wind farms predominate and they are ugly, ugly, ugly!

I have heard people say that some of the wind farms are aesthetically pleasing. Well each to their own.

 

As for the fact that solar does not produce more than 1%, well that is all about funding. There are many subsidies and tax breaks that apply to power generation (it depends on the country you are in as to what and how much these are). If we removed these, then the prices of Solar and other alternative systems would be more competitive in pricing.

 

Also, billion upon billions have already been sunk into establishing these polluting power sources. IF the same funding was applied to the alternative power, then they too could be producing the same as the "big 4".

 

Take Nuclear. For a while Solar was actually competitive with it. But Nuclear got more funding and they are now one of the big 4. What if, instead of the pressures of the Cold War facilitating the funding of Nuclear, it had been Solar, or Wave power that got that funding. The world would be very different.

 

A lot of money is sunk into these big 4, and it is precisely because so much money and resource have been sunk into them that they are the "Big 4" in the first place.

 

Solar has had far less funding than any of the Big 4, but it is well on it's way to becoming competitive (price wise). And if it becomes cheaper, then you will start to see it producing more than the 1% it currently is.

 

So if we put more funding into researching alternative/renewable energy source to make them more cost effective than the big 4, this will start us on the path to lower pollution levels.

 

Solar seems the best option out of the lot. The plants have not been described as eye sores, they don't make loud noises (like wind and wave power), they don't produce pollution, they can be located in places far removed from people, etc. The only thing is that the technology is not mature. And the only reason the technology is not mature is that it doesn't receive a lot of funding for research or production.

 

We could, now, convert all our power to Solar, but it would take time and be expensive. However, in the long run, the prices would drop as the technology gets more funding and subsidies. As more research is being done (there are some solar technologies that could produce power far cheaper than any others, but there is not enough funding to bring these to maturity).

[SkepticLance]

Edtharan asked about Tuvalu

 

The sea level might be falling there (I have never heard this my self, so could you explain how it is occurring),

 

It is an unusual situation. Ocean currents on a large scale are moving in a circle (actually, an ellipse, but who's counting) and this creates a wide scale effect of dropping sea level. Since these currents have intensified, the sea level has dropped.

 

2 mm per year is a global average and it varies. It is often hard to tell if sea level is rising or land is falling. For example : there is a group of islands off Papua New Guinea that is rapidly becoming the 'new Tuvalu' for the media, since they are washing away, and the people will need to be evacuated. Sea level change there is 20 mm per year. The media call it global warming. In fact, these islands are in a tectonically active area and there is a slow slumping of the entire area. The sea is not rising (more than 2 mm per year). Instead, the land is falling.

 

Take Malaria and DDT as an example.

 

Let's not. Modern testing has reversed a lot of early conclusions about the deleterious effects of DDT. It is now staging a come-back in places like South Africa as a means of controlling malaria.

 

It would be better to jump sooner rather than later.

 

I am not arguing against taking measures. Just being sure that they will not cause humanitarian harm. The best approach is to develop new technology and introduce it. As far as oil based fuels are concerned, we are going to burn all easily extractable oil anyway, regardless of the rhetoric. It will take 30 years to use up most of that resource, which gives us a bit of breathing space. The real threat is coal. It contains far more carbon than oil, and the logical progression when oil gets scarce is to move to liquid fuels made from coal. We need to develop alternatives and introduce them before too many coal to liquid fuel plants are built. Similarly, power plants burning coal need to be stopped. As far as I am concerned, at this point in time, only nuclear is a solid, viable alternative.

 

Solar seems the best option out of the lot. The plants have not been described as eye sores, they don't make loud noises (like wind and wave power), they don't produce pollution, they can be located in places far removed from people, etc. The only thing is that the technology is not mature. And the only reason the technology is not mature is that it doesn't receive a lot of funding for research or production.

 

You need to specify which kind of solar. Solar cells? Mirrors turning water to steam for turbines? Giant solar chimneys creating rising air? What?

 

There are lots of alternatives for energy generation. However, the big four are the ones that electricity generators world wide spend most investment on. And this is true in nations where there are no subsidies. Solar may come into its own. Who knows? Right now, the big four are the ones to concentrate on. Coal and gas make greenhouse gases. Hydro is close to capacity. This leaves only nuclear as having the potential right now of taking over from coal burning.

[swansont]

Take Malaria and DDT as an example.

 

Let's not. Modern testing has reversed a lot of early conclusions about the deleterious effects of DDT. It is now staging a come-back in places like South Africa as a means of controlling malaria.

 

It never went away in some places, so that's not really a comeback. It has had use as an anti-malarial agent during all of that time. It just hasn't had the same use as an agricultural product, but a lot of that can be attributed to resistance buildup rendering it less effective. Indoor use as an antimalarial doesn't have the same environmental impact potential.

 

Do you have cites for the "conclusion reversal" claim? Preferably something other than Steven Milloy, or other such material.

[BhavinB]

So it looks like I'm joining this debate a little late.

 

I live with an atmospheric environmental scientist. She told me that it is common belief that the ice ages occur due to regular variations in the earths orbit eccentricity. It's interesting to note that data also claims that CO2 levels dip at the same time as the ice ages. Wondering if anyone knows what the connection is here.

[SkepticLance]

To Swansont.

Sorry. I lost the exact reference. The main claim about DDT now shown incorrect was that it is a potent human carcinogen. The main study I read about involved WWII veterans - some of whom were absolutely doused in DDT powder on return home to kill lice, and some of whom were not treated at all. Apparently, the later cancer rate between the two groups was the same.

 

To BhavinB

The relationship you are talking about was during the glacial and interglacial periods of the current Ice Age. Carbon dioxide rises a little after warming takes off and drops a little after cooling sets in. Probably mainly due to solubility changes of carbon dioxide in warm and cold oceans.

[1veedo]

So it looks like I'm joining this debate a little late.

 

I live with an atmospheric environmental scientist. She told me that it is common belief that the ice ages occur due to regular variations in the earths orbit eccentricity. It's interesting to note that data also claims that CO2 levels dip at the same time as the ice ages. Wondering if anyone knows what the connection is here.

It's a positive freedback system. If you look at yearly CO2 levels, they rise during the summer and fall during the winter. Every year of course it goes up a little higher and doesn't drop as low. CO2 does not cause the summers/winters, the sun does, but CO2 makes it even warmer then it would be. (and from what I understand, this makes the latter part of summer warmer then the beginning even if it's getting less sunlight???)

 

It's a complex correlation. We all know that correlation does not imply causation.

 

But what scientists have found out is that while CO2 causes the temperature to rise, higher temperatures also cause C02 levels to go up.

 

The same thing that is true w/ our seasons is also true with ice ages. Orbital variations cause ice ages approximately every 25k,40k, and 100k years. Every 25, 40, and 100k years, you can see both CO2 and temperature rising/falling.

 

There's a neat graph located here,

http://www.grida.no/climate/ipcc_tar/wg1/fig2-22.htm

[SkepticLance]

1veedo said :

 

The same thing that is true w/ our seasons is also true with ice ages. Orbital variations cause ice ages approximately every 25k,40k, and 100k years. Every 25, 40, and 100k years, you can see both CO2 and temperature rising/falling.

 

The key point is that carbon dioxide changes follow AFTER the warming or cooling. While this is not proof, it does imply causation, with the warming/cooling being cause, and the carbon dioxide concentration change being the effect.

[Edtharan]

The key point is that carbon dioxide changes follow AFTER the warming or cooling. While this is not proof, it does imply causation, with the warming/cooling being cause, and the carbon dioxide concentration change being the effect.

What you seem to be missing here is the concept of a positive feedback loop.

 

CO2 causes warming, this warming thaws area that were in permafrost. This then releases more CO2 and the temperature will continue to climb.

 

Positive feed back.

 

So yes, the records should sow that as the Earth Warms the CO2 levels rise. But it is also these rising CO2 level that is causing the warming.

 

That is why it is called Feedback.

 

It is an unusual situation. Ocean currents on a large scale are moving in a circle (actually, an ellipse, but who's counting) and this creates a wide scale effect of dropping sea level. Since these currents have intensified, the sea level has dropped.

So you can't really use it as proof that the sea levels are not rising. It is experiencing an unusual situation that temporarily reverses the effects of sea level rise.

 

What happens if those currents stop, or change so that situation is no longer occurring? One of the effects of GW is to change the pattern of oceanic currents.

 

Let's not. Modern testing has reversed a lot of early conclusions about the deleterious effects of DDT. It is now staging a come-back in places like South Africa as a means of controlling malaria.

As you said the Carcinogenic effects might not be what they initially though, but DDT does not only produce cancer. IT cases birth defects, and other non cancerous problems. These effects have well and truly been linked to DDT usage, the incidents even when down when DDT stopped being used. Are the people that wish to bring back DDT considering these problems?

 

I am not arguing against taking measures. Just being sure that they will not cause humanitarian harm.

So would taking funding out of polluting power generation and using it to develop renewable/non polluting power cause human harm? Would developing cars that didn't use petrol or other fossil fuels cause human harm? Would implementing the Carbon emissions trading cause human harm?

 

If these "activities" would not cause human harm, then why have the governments stalled their implementation, why do people resist doing something?

 

Nuclear Power can only take us so far, otherwise why hasn't it got more than 12% of current power supply. If we cut out Coal power, then we need something to take it's place, could Nuclear supply 24% of out power needs without being too expensive (the more Nuclear plants the higher the costs of the fuel).

 

I think that if, world wide, Coal power plants were completely replaced by Nuclear the cost of the Fuel would more than Double. This would make Nuclear far too expensive as a power source. It's also the reason that coal doesn't have much more than the 12%, as more plants mean more coal is used and the demand and therefore the price of coal goes up and makes it too expensive to use.

 

So Nuclear power is not likely to be a viable power source as it would make it too expensive.

 

Therefore we need some other power supply that either uses renewable fuel or no fuel. The only viable ones are Hot Rock/Geothermal, Solar, Wind and Wave/Tide power.

 

Wind and Wave/Tide power are noisy and the Wind some people find objectionable.

 

This really only leaves Solar or Geothermal.

 

Geothermal would be capable of supplying all the worlds power many times over, but it is expensive to maintain (the gasses in the Earth around Hot Rocks are corrosive). Therefore, considering long term solutions, Solar is the most likely to stand the test of time.

 

But currently it receives very little funding and so progress on it has been slow.

 

You need to specify which kind of solar. Solar cells? Mirrors turning water to steam for turbines? Giant solar chimneys creating rising air? What?

Well that's the thing. Because there has been so little funding, almost no research has been done to actually see which of these would be the most viable. This is what I am talking about.

 

Solar cells might be viable for small plants (like on the roofs of houses), but as a large scale plant, not likely. The solar chimneys have a similar problem to the wind turbines, but fortunately the positioning of the plant is much more flexible than for Wind.

 

The mirrors turning water into steam might be the most viable for a large scale plant as they do not "stick up" like Wind turbines or Solar Chimneys do and avoid the aesthetics problem.

 

However there are some promising discoveries being made with solar cells that might make them a viable option for a large scale plant (improved efficiency is the key here so that the plants can be made smaller).

 

There are lots of alternatives for energy generation. However, the big four are the ones that electricity generators world wide spend most investment on. And this is true in nations where there are no subsidies.

This is true. But in the big 4 producing nations (America, China, Japan and Europe) they are.

 

The plants also might not be subsidised, but the mining process for coal and Nuclear is in many of the countries that they get their fuel form.

 

So the costs for running the plants are subsidised and therefore artificially reduced. If these support funding were removed the costs of renewable would be far more competitive.

 

Solar may come into its own. Who knows? Right now, the big four are the ones to concentrate on. Coal and gas make greenhouse gases. Hydro is close to capacity. This leaves only nuclear as having the potential right now of taking over from coal burning.

Only for a short term, knee jerk reaction. But as you said, you wanted to avoid those.

 

We have to think long term.

 

Coal and Gas are out as they are greenhouse gas polluters. Hydro is near to capacity, and increasing Nuclear will increase the cost of power and has issues with storage of the radioactive wastes (long term here).

 

So if we are thinking of supplying power to a growing population (world wide) and more power needed to drive the power hungry developed and developing countries, then we can not use Nuclear as the prices would sky rocket and we would need places to store the spent fuel for tens of thousands of years.

 

Nuclear can only, therefore, be a short term solution at best. Nuclear might allow us to get over our addiction to fossil fuels, but we have to be careful not to get addicted to it too.

 

It is an economic problem. The more power plants we have that need a non renewable "Fuel" to operate, the higher the price of power will be. Therefore any power generation system that uses such fuels can not be a long term solution for a growing and increasingly technological world. The costs will grow exponentially.

 

Yes, Nuclear might be the only economically viable power source to take over from coal within the next 30 years or so, but what happens after that?

 

Even if there was no greenhouse gas problem, the fact is that the world population is growing and the demand of power per person is also growing. This means that a non renewable power source will become increasingly more and more expensive. For this reason alone we need to switch to a renewable power source, sooner or later. But due to GW, we need to abandon the greenhouse gas polluting power generators sooner rather than later.

[SkepticLance]

To Edtharan.

 

I agree with you that building more and more coal burning power stations is a very bad thing, for several reasons. Currently, in my own very humble opinion, the biggest problem for the immediate future is the enormous number of such plants going up in China.

 

I do not see any alternative for some decades to nuclear power. You talk about solar and geothermal. OK. They may become important. However, my point is that they are not suffciently developed as of right now. Nuclear is. If we want to build more power stations that do not pump out GHGs, then nuclear is the only viable option.

 

By the way. There is a major flaw in your argument about the cost of nuclear fuel. Fuel is one of the small costs in running a nuclear power station. The biggest costs are building the station, and in decommissioning it when finished. Fuel by comparison is a small cost. Thus a doubling in cost of fuel will not anywhere near double the cost of nuclear power. We may run low on high purity Uranium ores. However, we can and will develop ways to extract it economically from lower purity sources, and there are plenty of these, and the total amount of Uranium available in these ores is enormous. This source will be available when needed, and any increase in cost will not, as shown above, be a real problem.

 

You said :

 

What you seem to be missing here is the concept of a positive feedback loop.

 

On the contrary. I am very aware of positive and negative feed-back loops. For the graphs we were discussing, a positive feed-back is not indicated. On such a graph, this would be shown as an acceleration of warming, or cooling. The graph does not show that.

 

 

So you can't really use it as proof that the sea levels are not rising. It is experiencing an unusual situation that temporarily reverses the effects of sea level rise.

 

I was not trying to say that. Tuvalu is a red herring. That is all I was saying. Sea levels continue to rise steadily at 2 mm per year as a global average.

 

 

Are the people that wish to bring back DDT considering these problems?

 

The current use of DDT in South Africa is very sensible. It appears that the Anopheles mosquito has the habit of landing on a surface somewhere before swooping to suck blood. This is exploited by spraying DDT on the inside surface of the huts people live in. The mosquito lands and dies. No bite. Since the DDT is just a thin film on a restricted surface, there is no health or environmental problem.

 

You suggest we have to think long term. In fact, we have to think short term and long term, both. Short term, as I said, we have to go with proven technology. Long term, we develop new technology. We introduce new technology over a period.

 

In spite of all the people running round panicking, like headless chickens, nothing dramatic is likely to happen for the next 30 years. Oil will still be extracted and burned in cars etc. However, a slow introduction of new methods will happen, and within 50 years, our energy economy will be seriously different.

[1veedo]

The key point is that carbon dioxide changes follow AFTER the warming or cooling. While this is not proof' date=' it does imply causation, with the warming/cooling being cause, and the carbon dioxide concentration change being the effect.

...

On the contrary. I am very aware of positive and negative feed-back loops. For the graphs we were discussing, a positive feed-back is not indicated. On such a graph, this would be shown as an acceleration of warming, or cooling. The graph does not show that.[/quote']No, that's simply not true. For 5/6 of our geological history, temperature and CO2 rose together. CO2 rarely ever lags behind temperature. This clearly shows that, obviously, CO2 is a cause as well as an effect of temperature. And one of the main reasons we even see the 10% in the first place is because of certain orbital variations that cause uneven distribution of sunlight on the planet. For instance, the northern hemisphere commonly gets more sunlight then the southern. This is one of the reasons for the medieval warm period; like I said above, the medieval warm period only happened during the summer and in the northern hemisphere.

 

The problem is that the extra sunlight melts ice in the north which is one feedback loop and then CO2 comes in a little latter as another feedback loop. The effects of these feedback loops is the reason scientists are concerned today -- we see the exact same things happening, only much larger. As ice melts, many scientists are concerned that it will amplify the speed at which the Earth warms.

 

If you take a look at this page, you can see why this is.

http://www.realclimate.org/index.php?p=13

 

The sun, all by itself, would not causes the temperature to vary anywhere near as much as it has. In order for us to have ice ages and warm periods, we need CO2 to feed back into the system. W/o CO2, changes in temperature would be very small. This is just a simple fact, we understood how all this worked before we started noticing global warming.

 

For an example of CO2 causing global temperatures to rise, you can just look at the past two hundred or so years. Even though we are moving away from the sun, temperatures are rising. The only possible cause is an increase in greenhouse gases. Therefore, there must be high levels of greenhouse gases right now. And if you look at the data, what do you find? That greenhouse gases are higher then they ever have been for hundreds of thousands of years!

http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png

By the way. There is a major flaw in your argument about the cost of nuclear fuel. Fuel is one of the small costs in running a nuclear power station. The biggest costs are building the station, and in decommissioning it when finished. Fuel by comparison is a small cost. Thus a doubling in cost of fuel will not anywhere near double the cost of nuclear power. We may run low on high purity Uranium ores. However, we can and will develop ways to extract it economically from lower purity sources, and there are plenty of these, and the total amount of Uranium available in these ores is enormous. This source will be available when needed, and any increase in cost will not, as shown above, be a real problem.

Uranium isn't the only fuel source for nuclear power plants. Plutonium, which can be found in huge stockpiles of nuclear weapons, can also be used. Of course I guess it's too liberal to suggest we get rid of nuclear weapons by creating electricity, but you never know.

[SkepticLance]

1veedo said :

 

For 5/6 of our geological history, temperature and CO2 rose together. CO2 rarely ever lags behind temperature. This clearly shows that, obviously, CO2 is a cause as well as an effect of temperature.

 

The data I have seen relates to the last million years. For most of that time, warmings have been followed by carbon dioxide rising. Coolings by it falling. For the period 1910 to 2006, we have seen substantial carbon dioxide rising, and warming also. It is probable that carbon dioxide is a main driver of that warming. However, this does not apply for the previous million years.

 

Uranium isn't the only fuel source for nuclear power plants. Plutonium, which can be found in huge stockpiles of nuclear weapons, can also be used. Of course I guess it's too liberal to suggest we get rid of nuclear weapons by creating electricity, but you never know.

 

Uranium can be used relatively safely, because the 235 isotope can be blended with the 238 isotope to make a mixture that will work in a reactor but not in a bomb. We cannot do that with Plutonium. It is always easy to purify to a strength capable of making a bomb. This creates a real problem with Plutonium. How can we use it for peaceful nuclear energy without it being potentially available to be stolen by those who want to make a terrorist bomb?

[1veedo]

The data I have seen relates to the last million years. For most of that time' date=' warmings have been followed by carbon dioxide rising. Coolings by it falling. For the period 1910 to 2006, we have seen substantial carbon dioxide rising, and warming also. It is probable that carbon dioxide is a main driver of that warming. However, this does not apply for the previous million years.[/quote']Well you've finally got ahold of the concept that we are causing global warming but it still seems that you dont understand how it works. This isn't something that's up for debate; if you were to take a course in climate science at your local university, you would find out that CO2 acts as a positive feedback agent on temperature and has been doing so for the past million years.

 

http://www.realclimate.org/index.php?p=13

 

The sun, all by itself, would not causes the temperature to vary anywhere near as much as it has. In order for us to have ice ages and warm periods, we need CO2 to feed back into the system. W/o CO2, changes in temperature would be very small. This is just a simple fact, we understood how all this worked before we started noticing global warming.

Uranium can be used relatively safely, because the 235 isotope can be blended with the 238 isotope to make a mixture that will work in a reactor but not in a bomb. We cannot do that with Plutonium. It is always easy to purify to a strength capable of making a bomb. This creates a real problem with Plutonium. How can we use it for peaceful nuclear energy without it being potentially available to be stolen by those who want to make a terrorist bomb?

Uranium itself breaks down into plutonium. There have been lots of recent developments in nuclear energy, one of them being the utilization of plutonium, because you can take the byproduct of a uranium nuclear reaction (plutonium) and then reuse it to produce more energy.

 

The debate about nuclear energy being "dangerous" because terrorists can take plutonium comes from uranium based nuclear power plants. Your issue of "How can we use it for peaceful nuclear energy without it being potentially available to be stolen by those who want to make a terrorist bomb?" applies for ALL nuclear power plants, not specifically plutonium. I think the bit that you don't understand is iths, "

Uranium can be used relatively safely, because the 235 isotope can be blended with the 238 isotope to make a mixture that will work in a reactor but not in a bomb."

 

238 does not react to produce energy at all. 238 is also the most abundant isotope in uranium, comprising literally 99% of it. This is why people talk about "enriched" uranium -- enriched means it contains a little more 235 then "normal" uranium. 235 does not blend with 238 so to speak. 238 uranium turns into plutonium. 235 provides the energy. But, this 99% of uranium that turns into plutonium can be reused to make more energy. That's what's so great about it. A plutonium power plant would actually be safer, as far as terrorism goes, because the plutonium from the uranium reaction gets used in another reaction instead of building up in piles and being shipped to radioactive waste dumps.

[SkepticLance]

To 1veedo.

I think you should take another look at your own reference.

 

The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming.

 

I am not a fan of the realclimate web site, since it is as biased towards global warming alarmism as certain other sites are biased towards global warming scepticism. However, in this case, at least they are honest enough to admit that their dogma has a high degree of uncertainty. They used the words "could have' instead of the unmodified word "caused".

 

The reason I have said carbon dioxide does not cause a positive feed-back loop in the warming periods of the last nine odd interglacial periods is because the data shows no acceleration of warming. The very nature of positive feed-back implies an accelerating effect, at least for a time.

 

The argument that carbon dioxide increase a million years ago has something to say about carbon dioxide increase today is so much nonsense also. The two situations are distinctly different. I accept that today's increase is anthropogenic, and that it is a major cause of current warming. That is quite different to previous times.

 

You said :

 

I think the bit that you don't understand is iths, "

Uranium can be used relatively safely, because the 235 isotope can be blended with the 238 isotope to make a mixture that will work in a reactor but not in a bomb."

 

I am not a nuclear physicist, but puhlease! That is so basic.

 

I am fully aware of U235 vs U238 and which is used for what. I do not think you understood my point about Uranium being safer, because the active U235 can be diluted with U238 making it impossible to use in a bomb. To enrich the Uranium again to make it explosively fissable requires technology beyond a terrorist organisation. However, Plutonium can be purified using simple chemical means, which is well within the ability of said terrorists. This means that if terrorists steal Uranium reactor fuel (ie purity too low to make a bomb) they will not be able to make a bomb. But if they steal Plutonium, they will.

[bascule]

I am not a fan of the realclimate web site, since it is as biased towards global warming alarmism as certain other sites are biased towards global warming scepticism.

 

The site is run by a PhD climate scientist and includes collaboration from other PhD climate scientists. Can you find me a "global warming skeptic" web site run by a PhD climate scientist?

 

The site is hardly "alarmist", he merely presents the scientific basis of climate change to the best of his ability. If you disagree with the scientific basis of climate change as understood by the climate science community, then your interpretation may vary.