Climate change: is the science really settled?

[IROC]

Originally posted by fastpat
While Global Warming may be occuring, it's well within ranges that have been documented in the past. As someone else pointed out, Global Warming has been underway, with ups and downs, since the last period of glaciation.

Support Global Warming grow more food.

The world was a much different place when the temps were much higher in the past, though. Glaciation and "ice ages" didn't occur until the continents started moving apart from each other. Prior to that point in time, I would suspect that a much larger portion of the Earth was covered in water (since it obviously wasn't ice).

Just because higher global temps have been recorded in the past doesn't mean that the current warming isn't a product of carbon dioxide in the atmosphere. The world is a very different place now than it was then.

Mike

[Jim Richards]

Originally posted by thrown_hammer
Here’s a little experiment for you. Fill a glass with ice. Next fill it with water. Measure the level of the water. Now sit and watch the ice melt. Wait until all the ice melts, every last bit of it. Now measure the water level again. Now compare the levels. Did the water level go up? Down? Stay the same?

Maybe I am simple but could someone explain how the world is going to flood when the ice caps melt based on this experiment?

Damn! I was hoping that I'd end up with beachfront property.

[Aurel]

Originally posted by thrown_hammer

Maybe I am simple but could someone explain how the world is going to flood when the ice caps melt based on this experiment?

It is not so much the ice melting that will make the sea level rise, but rather the water expansion due to the increase in ocean temperatures.

Aurel

[lendaddy]

Originally posted by Aurel
but rather the water expansion due to the increase in ocean temperatures.

Aurel

huh?

[thrown_hammer]

I am also going to place a flat rock in a bowl. I will fill it with water up to the edge of the rock. I will put all the ice on the rock. I will measure the water level. Then I will watch the ice melt. After total melt down I will measure the water level again. I will also mark the location of Jim’s house on the rock and measure the distance to the water’s edge before and after total meltdown. I will report back tomorrow.

[Dottore]

Originally posted by thrown_hammer
I am also going to place a flat rock in a bowl. I will fill it with water up to the edge of the rock. I will put all the ice on the rock. I will measure the water level. Then I will watch the ice melt. After total melt down I will measure the water level again. I will also mark the location of Jim’s house on the rock and measure the distance to the water’s edge before and after total meltdown. I will report back tomorrow.

Your experiment with ice cubes is quite pointless.

Ice cubes are full of trapped air. So when they melt, they actually lower the water level - because the air trapped inside the ice displaces a significant amount of water.

Glacial ice is however very dense, and does not contain air bubbles. When glacial ice melts, water levels rise.

I know this, because we used to sail up the Alaska coast and fill the freezer full of glacial ice for our Scotch. A chunk of glacial ice is completely clear and looks like an uncut diamond. It will sit in your Scotch glass all night without melting.

[Aurel]

Originally posted by lendaddy
huh?

What is it you don`t understand about thermal expansion?

Aurel

[fastpat]

Seriously....

[Jim Richards]

Shawn, I appreciate your experiment. It might be worthwhile to consider that my Jetta is parked a few levels underground in the building's garage. Will I have to abandon it? Thankfully, my Porsche is tucked away safely in a higher, dryer location.

[Aurel]

Originally posted by fastpat
Seriously....

Educate yourselves some more:

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

Aurel

[fastpat]

Originally posted by Aurel
Educate yourselves some more:

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

Aurel

The sea once covered over half of South Carolina, shall I get excited over a 17 inch rise over the next 100 years now, or wait?

[thrown_hammer]

Originally posted by Dottore
Your experiment with ice cubes is quite pointless.

Ice cubes are full of trapped air. So when they melt, they actually lower the water level - because the air trapped inside the ice displaces a significant amount of water.

Glacial ice is however very dense, and does not contain air bubbles. When glacial ice melts, water levels rise.

I know this, because we used to sail up the Alaska coast and fill the freezer full of glacial ice for our Scotch. A chunk of glacial ice is completely clear and looks like an uncut diamond. It will sit in your Scotch glass all night without melting.

So if glacial ice can sit in a glass of Scotch and never melt then this whole "ice caps melting" thing is total paranoia.

Jim how far underground is the Jetta? I will need this figure to make this an accurate experiment.

[lendaddy]

Originally posted by Aurel
Educate yourselves some more:

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

Aurel

Certainly we understand thermal expansion, but I honestly can't believe thermal expansion will be the cause of catastrophic rises.

It is ofcourse difficult to think on such large scale but what percent increase in volume is there per degree?

[Dottore]

Originally posted by thrown_hammer
So if glacial ice can sit in a glass of Scotch and never melt then this whole "ice caps melting" thing is total paranoia.

It would appear so.

[Jim Richards]

Originally posted by thrown_hammer
Jim how far underground is the Jetta? I will need this figure to make this an accurate experiment.

Figure 50 feet, Shawn.

[lendaddy]

I found this, someone do the math

Due to the high specific heat and low conductivity of water, only the uppermost 10% of the oceans is able to undergo any significant temperature change.
The natural variation in ocean levels is about 10 cm from September to March.

By how much does the mean temperature of the upper ocean change during this time?

Global warming is likely to cause a rise in sea level for a number of reasons, one of which is the thermal expansion of water. Determine the rise in sea level for every 1.0 C° temperature increase in the upper ocean.

Data for the Oceans
surface area 3.61 × 1014 m2
mean depth 3794 m
mean temperature, overall 3.5 °C
mean temperature, top 10% 10 °C

[Aurel]

Originally posted by lendaddy
I found this, someone do the math

Due to the high specific heat and low conductivity of water, only the uppermost 10% of the oceans is able to undergo any significant temperature change.
The natural variation in ocean levels is about 10 cm from September to March.

By how much does the mean temperature of the upper ocean change during this time?

Global warming is likely to cause a rise in sea level for a number of reasons, one of which is the thermal expansion of water. Determine the rise in sea level for every 1.0 C° temperature increase in the upper ocean.

Data for the Oceans
surface area 3.61 × 1014 m2
mean depth 3794 m
mean temperature, overall 3.5 °C
mean temperature, top 10% 10 °C

Others have done it already:

"For the period 1985-2025 the estimate of greenhouse-gas-induced warming is 0.6-1.0°C. The concomitant oceanic thermal expansion would raise sea level by 4-8 cm."

http://sedac.ciesin.columbia.edu/mva/WR1987/WR1987.html

Aurel

[Aurel]

Not a catastrophic rise, I`ll give you that

Aurel

[thrown_hammer]

Originally posted by Rick Lee
I'm more worried about the moon's orbit increasing by almost 2" per year or the sun's expansion. Eventually, the sun will engulf the inner planets, boil off our oceans and become a red giant. That's what I call global warming.

So if the oceans rise but the moon is farther away, then the tide won’t come in as far? Pretty much even steven right?

[fastpat]

Originally posted by Aurel
Others have done it already:

"For the period 1985-2025 the estimate of greenhouse-gas-induced warming is 0.6-1.0°C. The concomitant oceanic thermal expansion would raise sea level by 4-8 cm."

http://sedac.ciesin.columbia.edu/mva/WR1987/WR1987.html

Aurel

There is no "greenhouse gas" induced warming. That's alchemy at its' finest. If Global Warming is occuring, it's a natural and expected phenomenon that has occurrd many times in the past. Further, as has been pointed out here several times, the recovery from the last ice age is still underway. So, of course, the earth is getting warmer, it's about time.