"Four years ago, the IPCC forecast that sea levels could rise by half a metre in this century and by a maximum of between 1.5 and 3 metres over the coming 500 years. The new assessment suggests an eventual rise of 7 to 13 metres is more likely. This is enough to drown immense areas of land and many major cities. These rises will occur even if governments succeed in halting global warming within the next few decades, the report says."
"...the disintegration of the Greenland ice sheet would be "irreversible this side of a new ice age".
There are some scientists who think there will be another mini ice age within the next century or so. I think I will need a time machine to satisfy my curiosity.
I don't know. Despite whether it is natural or caused by humans, it is without a doubt happening. My personal theory is that humans are accelerating an already natural process.
If there is another mini ice age, half of Britain would be covered in ice. :)
A decade ago, one could argue that the increase in "global" temperature observations was the result of natural variation or inconsistent measurement practices. By now, though, the planet's temperature history has been determined in a consistent manner from ice cores, tree rings, etc., and you can judge for yourself whether the recent changes are natural:
This graph is from the PBS television documentary What's Up with the Weather?, which I highly recommend to anyone interested in global warming.
Now that we know the phenomenon is real, the magnitude of the problem is mind-numbing. Only by abandoning fossil fuels almost entirely can we expect bring the greenhouse effect under control, but we won't do that in the foreseeable future. Instead, fossil-fuel consumption can be expected to rise dramatically as prosperity spreads to previously under-developed parts of the world. So whatever we're doing to the climate, we WILL have to ride it out.
Do we have to "fiddle" to minimize global warming? Well, the problems discussed in the article Naomi linked to -- the melting of the Greenland ice cap and possibly the West Antarctic ice sheet -- will be disastrous for people living on coastlines, which is a LOT of people. It's distressing to read that there's now a consensus that Greenland's ice sheet will melt. But the article concerns itself only with what can be predicted safely. Lurking in the less certain global warming scenarios are dangers so great that they deserve even more attention than gradual sea level rise.
Notice that the article says the West Antarctic Ice Sheet "is perched on submerged islands". If that ice sheet disintegrates, the sea level rise will occur not as the ice melts, but when the sheet collapses into the ocean. (Once the ice is afloat, the water displacement has already occurred and is unaffected by subsequent melting.) Needless to say, such a sudden sea level rise will be more disastrous than a gradual one.
The scariest thing of all is that we're modifying not only the planet's air and surface temperatures, but also the thermal structure of the oceans. If ocean currents change as a result, the climate could change so drastically that entire economies could collapse. Europe might start to resemble Alaska, for example, because at present the only thing keeping Europe warm is the Gulf Stream crossing the Atlantic from Florida. The speed of such changes might amaze people, because there is now evidence that past ice ages began much more quickly than scientists has previously imagined -- well within a human lifetime, in fact. I'm offering a worst-case scenario in this last paragraph, of course, and no, I can't give you the odds on ocean circulation being affected. But as far as anyone knows, global warming could have this outcome, and it would be so devastating that to increase the chance of it by even 1 percent is unacceptable.
What a grim post, eh? I don't know what to do about any of this, except try to make more people aware, and try to encourage development of renewable energy sources as alternatives to fossil fuels. Of course we ought to be taxing fossil-fuel users to help in relocating people who'll lose their homes to sea-level rise, but first we'd need governments capable of administering such a plan. That would be a discussion for another day, I guess.
Not really all that grim.
But is there any proof this isn't some 10,000 year cycle? or 100,000 year? Or maybe it's something all planets similar to Earth eventually go through? Maybe our Sun is getting hotter?
Yes, it's very likely that fossil fuels contribute tremendously to it, but if you think people are going to give up their cars just for the environment, well, you're wrong. People are dumb. They are sheep. As long as there is money to be made on fossil fuels you can expect them to be around and in heavy use. Now *that's* grim.
There are 100,000-year cycles in CO2 levels, and the changes since the Industrial Revolution are a break from that pattern:
Anyway, we know we're pumping CO2 into the atmosphere, so the question is whether temperatures are rising as a result. I'd say it's safe to conclude that they are, unless there's something wrong with the temperature data used by PBS to make that first graph. The temperature rise was a predicted result of the CO2 rise, and the timing is right. If there were another likely explanation for a global temperature change this sudden and this large, it would be big news. Whether a connection is proven can always be debated, so I'll just say the evidence is convincing.
Did I sound like I think people will give up their cars (not to mention plane travel and most of their electricity) for the environment? Not at all. We'll keep on doing what we're doing, until (a) renewable energy becomes cheaper than fossil fuels, or (b) most of us get killed off somehow. I wouldn't know which outcome to bet on.
Quit proving me wrong, do you have any idea how bad that is for my self esteem? *sobs*
It looks like we were due for another increase anyway, judging by the graph, except we're just ampliphying the increase beyond what it was 'intended' to be.
Well, you did at least vaguely hint at everyone needing to jump the fossil fuel ship if we want to have a hope of correcting this...
Everyone seems to know that Global Warming is a reality except for the Republican Party. Did you hear Bush in the debates? He just grinned and said something along the lines of, "the juries still out."
*sigh* I sure hope Bush doesn't get into the White House. Gore's not perfect, but at least he's not in total denial when it comes to the environment.
I used to know a PhD of Climatology who was an advisor to the UN. He was one of the people who believed it was a natural course of events and that nobody should worry about it too much because there was nothing to do to stop it. Sadly for every scientist who points to the apparently obvious conclusion that even if it is natural, we're accelerating it, there's another one willing to deny that.
Of course the Doctor of Climatology held some other rather odd ideas which bring his overall level of intelligence into question. On a not unentirely unrelated note, he was a dyed in the wool Republican.
Yeah, I remember Bush saying something like that. He pretty much got away with it.
Bush's performance in the debates was underrated, I think. Even though he didn't make a great impression, he displayed an amazing ability to seem sincere regardless of what he was saying.
My strongest impression of the debates was that Gore accurately described his positions in response to every question, whereas Bush avoided answering a lot of questions and often misrepresented his positions when he did answer. Bush's voice and demeanor, though, NEVER suggested that he was saying something he didn't believe, in spite of some tough questioning.
A survey later showed that people watching the debates thought Gore to be more knowledgeable but Bush to be more honest. The inaccuracies in some of Gore's supporting factual details may have had something to do with that, but it's a frustrating result, because if honesty means telling people who you are, Gore won hands down.
I see your *sigh* and raise you.
Wow. You put it much more eloquently and detailed than I could have.
Here is a link about the "possible mini ice age."
I have a few more links on it elsewhere, but this was the first I found.. funnily enough from New Scientist also.
Of course, it's just a theory, but one worth some thought.
There are some people who are still in denial that it is happening at all, despite all the overwhelming evidence. I don't have a lot of patience for that kind of ignorance.
I agree that Nature will do what it pleases.. for the most part. However, our actions are affecting the Earth, there isn't any way that they could not be. The question is, to what degree are we affecting it? Maybe it is "Nature's Plan", but I have a hard time swallowing that one. I'm not saying it's impossible, and I'm not saying we're "outside the realm of the natural path." I just believe that we may be quickening the pace of that possible destiny.
Whatever the cause, I'd still rather not live in or leave a world to future generations that is falling apart at the seams. If it can be helped, I'm all for doing so.
I'm not suggesting that people give up their cars, etc, either. If fossil fuel were taken away abruptly, much of the world would come to a standstill. I don't think any of The Hague meetings currently in progress, or any future actions, will ever make a big enough difference to halt or reverse the process of global warming. However, due to the possible shortages of fossil fuel in the future, a lot of big oil corporations are investing good amounts of money into alternative energy sources. It is too bad it takes greed and a need to continue their livelihood to make them do so, but they want to make sure they have their asses covered for the future.
The thing I find interesting about the ozone hole at the South Pole is that it is indeed growing. At least by "recent history" standards. It has now spread as far as South America. Whether we're causing it or not, if it grows further we are going to have some problems.
I have a hard time just shrugging all this off like many people do. There isn't much I personally can do about it, but I will still remain interested. Granted, there could be any number of possible causes, but what harm can be done by countries lowering their pollution output? If it is done gradually it would hardly be devastating to world industry and economy.
I'm not entirely sure what you're getting at, because you've basically just elaborated on what I already said I believe in my previous comment.
Or maybe that was your intention.
Like I said, I do believe Nature will take its course regardless of what we do.
Personally, I'd be very sad if all the current coastal areas of the world disappeared. Is that selfish of me?
I don't think we're the most important creature to have ever walked the planet, but I'd say we're certainly the most unusual. And industrialized society doesn't fit into the balance terribly well.
I never suggested that we "chop off our proverbial arm," but exactly what you said about getting the Earth back in balance gradually, and in any way possible. Maybe that's terribly idealistic of me.
And we do recycle, as much as we can. :)
I believe size does matter. *g*
Then, as more efficient and friendly fuels become available, we can transition.
I agree with that.. but "friendly fuels" are already becoming available, it's just a question of when they will be affordable.
I wonder if anyone has created a map that estimates which areas are at high risk from being flooded in the future, be quite a scary map if your area of the world is under water.
The US govenment has an agency called F.E.M.A setup for this sort of thing, thats if you believe stuff like that ;)
I agree with you in that we're exacerbating an already existing event. My guess is we're closing on an interglacial, but due to human intervention, the problem got worse.
Same thing happened to a lot of the world's megafauna. Climatic change was wiping them out.. then along comes Homo sapiens, and it's bye bye to diprotodontids, moas, and many others :/