Why worry about global warming?

[Tim the Plumber]

Chalnoth,

The problem with the site you sent me to is that whilst I understand easily the previous one this is not at all understandable by me. I know I am not a great scientist but when I can understand one lot and the other refutes them with stuff that smells of bull I come to a conclusion.

One could and perhaps should treat the 100 years as 10 sets of 10 years and see whether the observations match any of the ten year periods, but instead what appears to have been done is to use only the one hundred year set by itself.

Why?

The "it does not fit" graph showed the temperature over the time frame before and after 1990 and the IPCC's predictions and compaired them. Yours talked about watts per meter cubed per degree kelvin. What is that all about? Simple /complex. I understand watts per square meter, or radiative heat loss per degree kelvin per meter but the cubic meter?? Joules per meter cubed might make semce but watts???

And I have shown you why the IPCC predictions are underestimating the problem (by around a factor of two!) compared to the best-available science in the case of sea rise. That you have ignored it is your problem, not mine.

Rather than telling me to look at a science paper please explain what it is that causes you to think that the IPCC is out by a factor of +2.

 

[Tim the Plumber]

Excellent. So what proves that the lensing here is caused by gravity?? That info needs to be part of any link you toss out.

The theory of gravitational lensing predicts exactly what we see.

We can tell how far a galaxy is away from lots of means. However, to keep it simple;

Amdromeda is our nearest neiboughing galaxy. We have phots of it from 100 years ago. We can see how far it has rotated in those 100 years. We can measure the speed at which the stars on each side of the galaxy are moving (dopler effect). So we can see easily how big it is. It follows the same rules as we do.

 

[Chalnoth]

Chalnoth,

The problem with the site you sent me to is that whilst I understand easily the previous one this is not at all understandable by me. I know I am not a great scientist but when I can understand one lot and the other refutes them with stuff that smells of bull I come to a conclusion.

Sounds to me more like you're dismissing things that don't agree with your preconceptions without bothering to investigate and find out the truth.

Why?

Isn't it obvious? If you're going to compare a model to 10 years of data, the only valid thing to do is to compare the 10 years of data to 10 years in the model.

The "it does not fit" graph showed the temperature over the time frame before and after 1990 and the IPCC's predictions and compaired them. Yours talked about watts per meter cubed per degree kelvin. What is that all about? Simple /complex. I understand watts per square meter, or radiative heat loss per degree kelvin per meter but the cubic meter?? Joules per meter cubed might make semce but watts???

You keep quoting "the IPCC predictions" as if they were the only IPCC predictions. In reality, they were the 1990 IPCC predictions, and there have been three updated predictions since then. As I've mentioned, we've learned quite a lot since then. The 2001 IPCC predictions, for example, quite closely match the temperature since then.

And furthermore, that graph does not include any IPCC predictions. It includes a linear extrapolation of the IPCC predictions, which is by no means the same thing. Because the temperature is expected to accelerate its increase over time, a linear extrapolation is biased towards exactly the result reported in that website, even if the predictions are entirely accurate.

Rather than telling me to look at a science paper please explain what it is that causes you to think that the IPCC is out by a factor of +2.

I already did. It's a combination of factors:
1. They don't include the worst case temperature in their sea level rise analysis, even for the worst case sea level rise claim.
2. They use a model which underestimates the past sea level rise by 50%.
3. They measure out to 2095, not 2100.

Combine these factors, and you get roughly double the worst-case scenario for sea level rise as reported in the IPCC.

 

[Tim the Plumber]

Where is the water coming from?

 

[Chalnoth]

Where is the water coming from?

What do you mean, "Where is the water coming from?" Most of the sea level rise is due to thermal expansion.

 

[Jazer]

using the corn for gas?

I would rather use corn for gas then to use genetic modified corn for food. We got lots of sugar available, so we can afford to give up some of our corn sweetners to put in our gas tank. We were told that we were going to run out of natural gas in 2012 and we would have if they were not pumping whatever junk they pump into the ground to get the gas to come out.

 

[Chalnoth]

I would rather use corn for gas then to use genetic modified corn for food. We got lots of sugar available, so we can afford to give up some of our corn sweetners to put in our gas tank. We were told that we were going to run out of natural gas in 2012 and we would have if they were not pumping whatever junk they pump into the ground to get the gas to come out.

Actually, corn is about the worst biofuel there is. It basically breaks even in terms of energy, which just makes using corn as a biofuel a complete waste of time and farmland. And since it's a waste of farmland, it contributes to higher costs of food, which in turn contributes to world hunger and additional clearing of the rainforests. In other words, using corn as a biofuel is worse for the environment than using oil.

In fact, as it turns out, land use issues prevent most biofuels from being that effective. However, Brazil has done quite well with sugar ethanol, and algal biofuels show tremendous promise.

 

[Split Rock]

I would rather use corn for gas then to use genetic modified corn for food. We got lots of sugar available, so we can afford to give up some of our corn sweetners to put in our gas tank. We were told that we were going to run out of natural gas in 2012 and we would have if they were not pumping whatever junk they pump into the ground to get the gas to come out.

Actually, corn is about the worst biofuel there is. It basically breaks even in terms of energy, which just makes using corn as a biofuel a complete waste of time and farmland. And since it's a waste of farmland, it contributes to higher costs of food, which in turn contributes to world hunger and additional clearing of the rainforests. In other words, using corn as a biofuel is worse for the environment than using oil.

In fact, as it turns out, land use issues prevent most biofuels from being that effective. However, Brazil has done quite well with sugar ethanol, and algal biofuels show tremendous promise.

Absolutely correct. Ethanol from corn gives you a measley 1.1 ratio of output to input. It is not green at all. The subsidized corn-ethanol industry also raises the price of soybean, since more farmers are encouraged to grow corn for ethanol instead. This in turn encourages more rain forest destruction by burning in Brazil so farmers there can grow more soybeans. Sugar cane ethanol production on the other hand works, because is more efficient, since you are going directly from sugar to ethanol (rather than starch to sugar to ethanol). The plants in Brazil are also self-sufficient, burning the green remains to run the plants.

 

[Jazer]

Brazil has done quite well with sugar ethanol,

I would go electric if they would give me lithium batterys. But they are afraid of them blowing up right now. Lithium is great for photography and flashes, because it does not have to recover and it maintains a consistant output right up to when you have to charge it.

 

[Chalnoth]

I would go electric if they would give me lithium batterys. But they are afraid of them blowing up right now. Lithium is great for photography and flashes, because it does not have to recover and it maintains a consistant output right up to when you have to charge it.

As I understand it, batteries these days are no less safe than gasoline. However, they do carry their own environmental costs, and don't solve the CO2 emission problem in and of themselves: they merely shift the problem to the electrical grid.

That said, if you recharge at night, the CO2 cost is negligible, so electric cars can be a good thing, if their charging is managed intelligently.

Electric vehicles, however, are not a panacea: transportation in general doesn't make up that much of emissions, and electric cars have limited range. So I think fuels like gasoline and diesel will always be with us, but fortunately there are ways to obtain these fuels from biological sources. Additionally, other avenues for fighting global warming will be necessary.

 

[Tim the Plumber]

Thermal expansion:-

The change in volume of water due to the change in it's temperature.

The change in water temperature will be dictated by the change in air temperature and the amout of thermal energy availble to do it.

This is why the concept of thermal forcing is so important.

How much thermal forcing do you expect to happen?

The ocean will never expand 1m due to this. Ever. It is impossible.

The ocean's temperature below 100m is mostly determined by the fact that water is at maximum density at 4 degrees c. The deep ocean is cold for this reason. The top 100m can change temperature but it takes 800 years or so for it to do so. The change in volume of the top 100m will never be 1m unless you heat it by 20 degrees.

 

[Chalnoth]

Thermal expansion:-

The change in volume of water due to the change in it's temperature.

The change in water temperature will be dictated by the change in air temperature and the amout of thermal energy availble to do it.

This is why the concept of thermal forcing is so important.

How much thermal forcing do you expect to happen?

The ocean will never expand 1m due to this. Ever. It is impossible.

The ocean's temperature below 100m is mostly determined by the fact that water is at maximum density at 4 degrees c. The deep ocean is cold for this reason. The top 100m can change temperature but it takes 800 years or so for it to do so. The change in volume of the top 100m will never be 1m unless you heat it by 20 degrees.

And what, pray tell are you basing this on? You keep throwing out assertions with nothing to back them up.

But by the way, I've looked into it in a bit more detail, and it looks like the main concerns now are ice sheet melt, not thermal expansion. So it seems I was a bit mistaken on that point. The problem with ice sheet melt, however, is that it is an extremely non-linear process. There are a number of positive feedbacks. For example, a stable ice sheet tends to have a surface covering of snow, which is generally very white and reflects most of the sunlight that comes in. Once that surface layer melts, it uncovers a layer of darker ice, which absorbs a much greater fraction of the incoming solar energy, accelerating the melting process.

Another feedback comes from lubrication: once the ice at the surface melts, it tends to burrow through the ice, forming pools of water under the glacier. These pools of water act as a lubrication that allow the glacier to move more rapidly towards the sea.

Because these systems are massively non-linear, the rates of mass loss (and therefore sea level rise) at higher temperatures are going to be much, much higher than the rates at current temperatures. And the Greenland ice sheet holds enough ice to raise the sea level by 7.2m, while the Antarctic sheet holds enough to raise the sea level by 70m. If the stability of these ice sheets is seriously compromised, which is a distinct possibility, 1m of sea level rise will look like child's play. For example, 3 million years ago, the world was about 2-3C warmer, while sea levels were about 25m higher.

For more on this:
http://arxiv.org/pdf/physics/0703220v1
(this is a summary article with references to research therein)

 

[dad]

As I understand it, batteries these days are no less safe than gasoline. However, they do carry their own environmental costs, and don't solve the CO2 emission problem in and of themselves: they merely shift the problem to the electrical grid.

That said, if you recharge at night, the CO2 cost is negligible, so electric cars can be a good thing, if their charging is managed intelligently.

Electric vehicles, however, are not a panacea: transportation in general doesn't make up that much of emissions, and electric cars have limited range. So I think fuels like gasoline and diesel will always be with us, but fortunately there are ways to obtain these fuels from biological sources. Additionally, other avenues for fighting global warming will be necessary.

Would not the power for electric cars still have to come from somewhere? For example a coal fired plant...or nuclear...etc?

 

[dad]

I would rather use corn for gas then to use genetic modified corn for food.

That may be OK for you, but what about those that will go hungry, especially with the corn and etc being used for gas? Maybe they would chose less than perfect organic corn over starving!

By the way, how is the modified corn harmful?

We got lots of sugar available, so we can afford to give up some of our corn sweetners to put in our gas tank.

Well, any food type stuff that goes into gas I am not for personally...just doesn't sit right. Kind of like the space program.. If they gave me all the money spent on it, and I gave 1/2 to charity mankind would be better off

 

[Chalnoth]

Would not the power for electric cars still have to come from somewhere? For example a coal fired plant...or nuclear...etc?

In principle yes. But the majority of power plants are unable to change their production more quickly than a few days. So most power plants run hard enough to supply the highest amount of power that is used in any given day (plus some extra to prevent brownouts), and they have to run at that level day and night. So if you charge the cars during the night, when power consumption goes way down, there is almost no cost in terms of fossil fuel usage.

 

[dad]

In principle yes. But the majority of power plants are unable to change their production more quickly than a few days. So most power plants run hard enough to supply the highest amount of power that is used in any given day (plus some extra to prevent brownouts), and they have to run at that level day and night. So if you charge the cars during the night, when power consumption goes way down, there is almost no cost in terms of fossil fuel usage.

A free lunch, then. OK.

 

[Chalnoth]

A free lunch, then. OK.

Not entirely. As I mentioned, the batteries themselves come with their own environmental costs. And in general, batteries aren't always going to be charged at night, so at times they will add to the strain on the electrical grid.

 

[dad]

Not entirely. As I mentioned, the batteries themselves come with their own environmental costs. And in general, batteries aren't always going to be charged at night, so at times they will add to the strain on the electrical grid.

A grid powered by coal...and etc.


Maybe the whole system is flawed? If a need was not there to drive so far to work, for example, maybe there would be less of a need to drive. No solution is possible in a sinful world I guess.

" At an nationwide average drive-time of about 24.3 minutes, Americans now spend more than 100 hours a year commuting to work,"
http://usgovinfo.about.com/od/censusandstatistics/a/commutetimes.htm

 

[Chalnoth]

A grid powered by coal...and etc.

Maybe the whole system is flawed?

Well, yes. It is also important to change the power grid to renewable energy sources. Nuclear would also be an improvement.

If a need was not there to drive so far to work, for example, maybe there would be less of a need to drive.

Yes, better public transportation would also help significantly.

No solution is possible in a sinful world I guess.

Now that's just plain wrong.

 

[Lillen]

The reason why I don't believe in global warming as a doomday waterworld, is because of the rainbow!