[Mattsius]

I just saw a very scary BBC documentary on global dimming and the effect it has on global warming.

We are all seeing rather less of the Sun. Scientists looking at five decades of sunlight measurements have reached the disturbing conclusion that the amount of solar energy reaching the Earth's surface has been gradually falling. Paradoxically, the decline in sunlight may mean that global warming is a far greater threat to society than previously thought.

...

it now appears the warming from greenhouse gases has been offset by a strong cooling effect from dimming - in effect two of our pollutants have been cancelling each other out. This means that the climate may in fact be more sensitive to the greenhouse effect than thought.

...

Even the most pessimistic forecasts of global warming may now have to be drastically revised upwards. That means a temperature rise of 10°C by 2100 could be on the cards, giving the UK a climate like that of North Africa, and rendering many parts of the world uninhabitable. That is unless we act urgently to curb our emissions of greenhouse gases.

If you can get a hold of this documentary in some way, I urge you to do so. Or if you're up for some reading then the program transcript also works quite well. I'm no expert in this area, but if this is even remotely close to the truth, it's a serious problem.

Those living in Finland can watch it next Sunday 2.10 on TV1 starting 14:35 in "Prisma: Luvassa hämärtyvää".

[SakSquash]

I thought this was going to be on how only uneducated people are breeding, which will lead to a de-evolution of the human species.

[pinkgothic]

Fun...

[Stroggy]

Hooray for winter!

[lumi]

Originally Posted by Stroggy

Hooray for winter!

Hell yeah! I keep hoping for a nuclear winter so I can ski forever. And by forever I literally mean forever. I figure that the fallout will mutate my body in such a way that I can manage that.

[pinkgothic]

[Regarding the ice masses on Greenland, a comment in the article reads the following] Take a long time to melt but ultimately it would lead to a sea level rise of seven or eight metres.

What about water expansion thanks to warming? This is often overlooked, I find, and it does not help the person's (Dr Peter Cox) credibility as an authority in regards to Global Warming and Global Dimming if he speaks of ice melting as though it was our worst problem.

*smacks self for being nitpicky again*

I'm not discounting this problem, it just irks me when this sort of thing comes up without the real major issue being adressed.

[Mattsius]

Originally Posted by pinkgothic

What about water expansion thanks to warming? This is often overlooked, I find, and it does not help the person's (Dr Peter Cox) credibility as an authority in regards to Global Warming and Global Dimming if he speaks of ice melting as though it was our worst problem.

Sorry but I don't follow. Do you mean to say that the sea levels will rise even more, when you're talking about water expansion, or what are you getting at? Sorry but I don't get it.

[Kolzig]

Originally Posted by Mattsius

Those living in Finland can watch it next Sunday 2.10 on TV1 starting 14:35 in "Prisma: Luvassa hämärtyvää".

Thanks Mattsius, I'll be sure to record this program, as I'm not able to watch it at that time because I'm away at a floorball camp with my team.

[Trep]

Weird. For some reason I read the thread title as:

Documentary on Global Dining and its environmental effects

For a second I was scared I wouldn't be able to eat tandhoori chicken and garlic nan ever again without it depleting the ozone layer.

[pinkgothic]

Originally Posted by Mattsius

Sorry but I don't follow. Do you mean to say that the sea levels will rise even more, when you're talking about water expansion, or what are you getting at?

Yes, expansion is what I'm getting at.

[Mattsius]

Originally Posted by Trep

Weird. For some reason I read the thread title as:

Documentary on Global Dining and its environmental effects

For a second I was scared I wouldn't be able to eat tandhoori chicken and garlic nan ever again without it depleting the ozone layer.

ROFLMFAO, you're killing me man! That was one of the best comments I've ever seen.

Originally Posted by pinkgothic

Yes, expansion is what I'm getting at.

Eh, care to elaborate. Are you not satisfied with his 7-8 meters prediction or what is your complaint?

[pinkgothic]

Originally Posted by Mattsius

Eh, care to elaborate. Are you not satisfied with his 7-8 meters prediction or what is your complaint?

My complaint is the way it is said makes it sound like it's the melting which will cause most of the rise - which is just not true. And it doesn't help the credibility of those people if they continue trying to make people believe that's the primary causal relationship. Like I said - it's nitpicking from me.

[Mattsius]

Originally Posted by pinkgothic

My complaint is the way it is said makes it sound like it's the melting which will cause most of the rise - which is just not true. And it doesn't help the credibility of those people if they continue trying to make people believe that's the primary causal relationship. Like I said - it's nitpicking from me.

Well when the ice melts it gets warmer and hence takes up more space, so basically he's talking about the same thing as you.

And the melting of the ice isn't really the topic of this documentary anyway. It's more about the, until now unknown, balance between global dimming and global warming and the problems it involves.

[pinkgothic]

Originally Posted by Mattsius

Well when the ice melts it gets warmer and hence takes up more space, so basically he's talking about the same thing as you.

Er, of course he might be considering this inwardly, but fact is, he's talking about it like the added water from the melted ice is the main issue of water rise. The added water is almost moot. The water expansion (primarily of the big whooping percentage of "water already there") is what really makes the sea levels rise.

Originally Posted by Mattsius

And the melting of the ice isn't really the topic of this documentary anyway.

I know. Hence why I pointed out twice already that I'm nitpicking.

[Tinariwen]

it is just sick, what we are doing to the world!

[gillyruless]

Originally Posted by pinkgothic

Er, of course he might be considering this inwardly, but fact is, he's talking about it like the added water from the melted ice is the main issue of water rise. The added water is almost moot. The water expansion (primarily of the big whooping percentage of "water already there") is what really makes the sea levels rise.

Pinksie, do you have any links that compare the two causes? Most of the articles on the sea level rise that I have read tend to focus on the melted ice as the cause. Loss of Greenland and West Antartica ice sheets (different from the polar ice caps or moutain glaciers) in particular can cause the sea level to rise as much as 10 meters, which is definitely not moot. It will take several centuries of loss of ice sheets to cause the rise but it still poses a serious concern.

[Stroggy]

Originally Posted by Tinariwen

it is just sick, what we are doing to the world!

Well we could all go live in caves again.

[pinkgothic]

Originally Posted by gillyruless

Pinksie, do you have any links that compare the two causes? Most of the articles on the sea level rise that I have read tend to focus on the melted ice as the cause. Loss of Greenland and West Antartica ice sheets (different from the polar ice caps or moutain glaciers) in particular can cause the sea level to rise as much as 10 meters, which is definitely not moot. It will take several centuries of loss of ice sheets to cause the rise but it still poses a serious concern.

Well, http://en.wikipedia.org/wiki/Sea_level_rise for one. IPCC results might be best. Remember that "110 to 430 mm" means "0.11 to 0.43 m", for reference, the change threw me off at first, though maybe that's just me. Anyway, it gives you this:
Thermal expansion: 110 to 430 mm
Everything else there: –263 to 425 mm or –213 to 305 mm
Give or take in case I miscalculated.

I'm finding other things, but they're confusing to read (hell, even the wikipedia article is confusing to read)... will post if I find something that's a bit less technical.

[pinkgothic]

I got a couple more pages, and some of them saying the ice melt has been underestimated, etc. In the end, though, my point stands - in all serious variants. Where people talk about ice melting, they should mention thermal expansion, too. It's not something you can simply neglect. To quote:

The two factors leading to global sea-level rise are thermal expansion due to ocean warming and melting on continental glaciers (melting sea ice has no effect on sea level). Miller and Douglas (2004) report that estimates of volume increase due to global warming give a 0.5 mm/yr contribution to sea level rise. Estimates of the contribution from melting continental ice are less than 0.5 mm. But actual measurements of sea-level rise from tide gauges give a value between 1.5 and 2.0 mm/yr. The analysis of Miller and Douglass (2004) suggests that the tide gauge measurements are accurate and that the contribution from melting ice has been underestimated.

http://www.geology.iastate.edu/gccou...l/thermal.html

Even if you consider the remaining bits to be from ice, it would (let's work with the 2 mm version for simplicity's sake) still be 25% thermal expansion. No one's going to tell me that's something you shouldn't be mentioning if you mention the sea level rise.

[gillyruless]

Thanks for the links, Pinksie. I don't know, maybe it's becasue ice melt is just a sexier concept than thermal expansion but most of the stories on the sea level rise in public media tend to focus solely on ice melt. Some people I have discussed this issue with have never even heard of thermal expansion causing the rise in sea level! You are right though, both do make significant contribution and need to be understood.