Global Warming....

[Green]

Ah, right. What kind of impact does 7 degrees latitude have, then (apart from the migration of species)? I have trouble with picturing how much that is

[Lenny]

It's apparently enough to divert the Gulf stream right past England - no more heating for us.

If the giant ice shelves in Iceland melt, that'll havethe same type of impact... only ten times faster.

[jackokent]

This program suggests that the climate change will mean that British Isles will be surrounded in sea ice and many rain forests in other side of the plant (for some reason that went way over my head) will vanish because there will be no rainfall there at all.

The scarey thing was the speed of this thing happenning. They were saying if the flow stopped (which it definately will one day) it will stop suddenly, we'll get no warning and all the other stuff will happen.

[Dave]

Originally Posted by mosaix

Since the start of the industrial revolution the amount of carbon dioxide in the atmosphere has risen from 260ppm to 380ppm (I think it was ppm could have been ppb, either way this is a 46% increase).

It is ppmv. I think I've posted these links before, but they make it more clear:
CO2 Trends Mauna Loa 1957-1999
Mauna Loa is a volcano in Hawaii. High up and not near any local source of pollution. If you look closely at the graph it is not a straight line. It goes up and down every single year. It goes up in the Winter and down in the Summer. Only it always goes up more than it goes down.

CO2 Trends Law Dome 1008-1999
Law Dome is in Antarctica and this graph uses ice core samples. In some ways it is even more graphic. The graph becomes exponential in the last few years.

I first saw these graphs 25 years ago. They had a profound effect on me then, yet nothing has changed in the years since. Even if you still believe there is no global warming, or you think that global warming is unrelated to the level of CO2, you must at least say that such a large scale experiment that we are conducting on the Earth's atmosphere is a bad idea.

The Earth has had higher levels of CO2 before. But it was a time of more primitive plants and animals, and there have also been countless mass extinctions in the past too.

[Green]

Originally Posted by Dave

If you look closely at the graph it is not a straight line. It goes up and down every single year. It goes up in the Winter and down in the Summer. Only it always goes up more than it goes down.

Going off "An Inconvenient Truth," this is due to the fact that the northern hemisphere has a lot more landmass (and, therefore, vegetation) than the southern hemisphere. So when it's winter for the north, more CO2 is given out than when it's winter for the south. And then global warming causes the difference in increase/decrease. Or something.

Anyway, you probably knew this, but I still think it's fascinating People should watch this film/lecture - it is entertaining, if nothing else.

I am the kind of person that tends towards the "I don't care, where's my local cinema?" attitude, but even I have recently started to worry about global warming. So it must be important

I wish that America (its policies, not necessarily its population) would start to actually do something about its emissions. At least some countries are paving the way, and the UK is getting better, too

[Green]

Originally Posted by jackokent

a tidal convector

As a process/physics modeller (and someone with zero professional experience in climatology), I'm not going to dismiss someone's well-crafted model out of hand, but it does make me wonder what evidence there is to back this model up.

Is there evidence of this process happening in the past? I've only heard of global-warming/ice-age cycles happening over long time periods. Which is not to say it won't happen, but I was just thinking that our biggest worry was the warming part, not the freezing part. There's the stuff about global dimming that came into view after 9/11, but as far as I understand it, that just means we're warming the planet even faster than we thought.

[jackokent]

Originally Posted by Green

As a process/physics modeller (and someone with zero professional experience in climatology), I'm not going to dismiss someone's well-crafted model out of hand, but it does make me wonder what evidence there is to back this model up.

Is there evidence of this process happening in the past? I've only heard of global-warming/ice-age cycles happening over long time periods. Which is not to say it won't happen, but I was just thinking that our biggest worry was the warming part, not the freezing part. There's the stuff about global dimming that came into view after 9/11, but as far as I understand it, that just means we're warming the planet even faster than we thought.

Well it's funny you mentioning about evidence of this process happenning in the past as apparantly (according to Horizon) it has. They studdied these bubbles in the ice rods and they concluded it has happenned a few times. As for evidence, to someone like me, they wouldn't have to put much effort into making it compelling, but it did look quite compelling when they showed how the salinity was falling so dramatically.

I am the same as you, I tend not to worry about these things. I am not really young and I don't have children myself so I always think it won't really effect me. But when they start mentioning timescales of 20 years I start sitting up and taking notice.

[mosaix]

Originally Posted by jackokent

Well it's funny you mentioning about evidence of this process happenning in the past as apparantly (according to Horizon) it has. They studdied these bubbles in the ice rods and they concluded it has happenned a few times. As for evidence, to someone like me, they wouldn't have to put much effort into making it compelling, but it did look quite compelling when they showed how the salinity was falling so dramatically.

I am the same as you, I tend not to worry about these things. I am not really young and I don't have children myself so I always think it won't really effect me. But when they start mentioning timescales of 20 years I start sitting up and taking notice.

Yes Jacko, that's the thing that to me seems different this time - it's all happening so quickly.

[Green]

That's the scary part. Twenty years ago, nobody even cared about global warming. Now they're thinking that in twenty years from today they may not even have a home above water, and twenty years after that, all life on the planet might be dead. Or made of fish.

[jackokent]

Originally Posted by Green

That's the scary part. Twenty years ago, nobody even cared about global warming. Now they're thinking that in twenty years from today they may not even have a home above water, and twenty years after that, all life on the planet might be dead.

Well there was a bit of a silver lining, as it wasn't all life. Fish would be quite chuffed apparantly with the changes.

[Green]

You quoted me about 30 seconds before my edit

[Spartan27]

Originally Posted by chrispenycate

I believe the methane reserves are beneath icecaps or permafrost layers; methane's not very soluble) And a warm winter could precipitate a positive feedback effect (at least no-one has a mathematical model which proves that it couldn't) If methane is released at an acceptbly low rate (ie, those reserves released over decades) it will disappear; methane only exists in our oxygen-rich atmosphere because it's continuously replenished by biological processes, it "burns" relatively fast (yes, giving carbon dioxide, but that's another side of the question) If jt were released fast, from the Siberian tundra because of one warm winter following several years of permafrost reduction, it could trigger a feedback effect (over a few years, maximum) There again, it might not - climate models just aren't good enough, and information about reserves of methane not accurate enough, for anything better than "interpolation of data" (that's gobbledegook for "a guess").
While looking at rising sea levels, take a glance at a relief map of Bangladesh. How many bengali refugees?

Crispy...Methane has 2 to 3 times the GHG effect than CO2 does. The largest methane concentrations are located beneath our oceans. And there is evidence that fissures are releasing methane into the oceans and into the atmosphere at greater rates than the past 500 years or so. From studies which now are starting to be discussed, Methane and not CO2 is the leading reason for the green house effect. Scary stuff.....

[Lenny]

Add the fact that millions of cows are dispelling methane all day every day, and the whole thing suddenly becomes a lot more serious.

[Spartan27]

Originally Posted by Lenny

Add the fact that millions of cows are dispelling methane all day every day, and the whole thing suddenly becomes a lot more serious.

Absolutely correct.

[Urien]

Hmm could it be methane causing the warming?
Could it be solar activity?
Could it be part of a natural cycle?
Could it be us?

Will it be bad?
Can our climate models predict accurately?
What did the climate models say the weather would be like today, in their predictions ten years ago?
Can our models predict what it will be like next week?
Did the earth manage without icecaps in the past?
Why is the total ice mass in Antarctica increasing?


Is there a self-corrective mechanism?
What happens if we try to manage carbon output towards an unknown target?
Is it safe to try to manage a chaotic system that might be going through a natural cycle?

Have we panicked prematurely before about an ice age, natural resources running out, overpopulation leading to starvation?
Is it in our nature to be doom mongers?
Have we always found some new end of the world?
Are we prone to hysteria, panic and dread?

Is the human race naively credulous?

Do we honestly have the answers?