Global warming - a misnomer?

Question

Global warming is a misnomer - the ice caps melt due to the rise in sea temperature, in turn the ice water cools the sea and the gulf stream - bringing on an ice age.

Answer 1

To provide a detailed and accurate answer to your question would take a lot of explaining, the reason being that this issue is far more complicated than it may appear. I'll provide a short answer but do feel free to e-mail me if you require clarification or further details about anything.

The Gulf Stream is an offshoot of a much larger system of ocean currents that circulate the planet and distribute warm and cold water. The entire sytem is known as the Thermohaline Circulation and derives it's name from Thermo meaning density and Haline meaning salinity.

It's the density and salinity of the water that are the two driving factors of the circulation, changes to either of these could cause changes to the ocean currents.

The Gulf Stream or North Atlantic Conveyor, is probably the section of the system which is most vulnerable to change. In fact, it's always changing of it's own accord and tends to move east and west within the North Atlantic. Currently the flow is directed more towards Great Britian but not so long back (geologically speaking) it was Greenland that was the major beneficiary of the warm water current.

It's worth pointing out that the potential consequences of global warming on thermohaline circulation isn't something that is particularly well understood. Many future predictions are based on guesswork and speculation. It seems likely that any effects will be minimal but there is a possibility, a small one, that there could be somewhat dramatic changes, most notably to the Gulf Stream.

Also worth pointing out, there have been massive amounts of fresh water entering the North Atlantic from the melthing of the Arctic and Greenland ice for many years now and so far the behaviour of the Gulf Stream has been entirely within expected natural tolerances. That doesn't necessarily mean that there hasn't been any change at all, just that whatever change there have been (if any) have been small.

Here's what could happen...

The Arctic ice is melting faster than ever before, so too is the Greenland ice cap. Each year melting from these two locations introduces nearly one trillion tons of fresh meltwater into the North Atlantic - it's about the same amount of water as would be contained in an Olympic sized swimming pool for every citizen in the US.

Water has an unusual property, most substances are at their densest when they're in their solid state but not water, it's most dense in it's liquid state and when it's at 4°C. Because the seas surrounding the ice packs are usually just below freezing (the salt lowers the freezing point) the meltwater from the ice is actually warmer than the sea into which it runs but because the meltwater is below 4°C it's more dense than the sea water. You would expect the meltwater to be colder and less dense but this isn't the case.

The melting ice introduces fresh water into the seas and oceans. As mentioned earlier, it's density and salinity that are the drivers of the ocean currents and the meltwater is different from the sea water on both counts.

What may be happening, we don't know for sure, is that the differnce in salinity is balancing out the effects of the difference in density. If these two are in equilibrium, and remain so, then it's unlikely to have any impact on the Gulf Stream.

There's another conflict which is self-balancing in that the fresh water is more dense than the sea water so it should sink but it's also warmer than the sea water so should float. Again, the two may be in equilibrium and be cancelling each other out.

If the Gulf Stream were to be affected it could happen in one of several ways. It could be nudged off course, if it were nudged eastward the UK and parts of northern Europe and Scandinavia would warm up whilst Iceland and parts of Greenland would cool down. If it were nudged westward then the reverse would happen, Greenland and Iceland would warm up and the European countries would cool down.

Another possibility is that the Gulf Stream would truncate short of it's current position, depending where it truncated would determing how much cooling there would be in northern Europe.

Another option would be the divergence of the Gulf Stream with one fork branching east and one branching west.

A final scenario would be the complete shutting down of the Gulf Stream, this is the one that would have the greatest impact. The climate of the UK is some 7°C warmer than it would be were it not for the Gulf Stream. Similarly, the other countries mentioned benefit from the arrival of warm Carribean water although to a lesser extent. If this flow of warm water were to stop then there would be an advance of glaciers in parts of Northern Europe with Scotland being the most seriously affected in the early stages.

Permenant ice would first return to the Cairngorm Plateau in Scotland and extend outwards, other ice sheets would start to form on the higher ground, in time they would merge into one and the glaciers would advance southwards through Scotland and into England, Wales and Ireland.

A similar scene would be played out in Norway, the frozen Hardanger Plateau would extend outwards into ice free areas whilst at the same time the glaciers, more typically found in the North of the country, would advance southward. In Greenland and Iceland, much of the ice free coastal regions would reglaciate.

In total about 80 million people, mostly in England, would be displaced by the advancing glaciers. There wouldn't be any need to panic as the process would take hundreds of years.

Elsewhere in the world, it seems highly unlikely that the thermohaline circulation would be noticably affected, it's not a possibility that can be completely ruled out but it is an unlikely one.

The above information should hold true for the next 40 years after which time the Arctic ice cap is expected to melt completely, a consequence of which could be the establishing of new ocean currents flowing where the Artic ice once existed. This also seems unlikely but again, can't be completely ruled out.

Answer 2

Global Warming Misnomer

Answer 3

You forgot to mention that ocean temperatures are rising, glaciers are melting, ocean levels are rising, there is more flooding, and more hurricanes and typhoons are forming- and much evidence points toward global warming as being the cause. Have you ever seen the documentary by Al Gore called "An Inconvenient Truth"? If not, you should. It's very disturbing. However, there is a message of hope in it as well. There are things we can do to slow down the global warming process...maybe even stop it, before we destroy the earth and it's inhabitants. The U.S. is far behind many other countries that are less advanced than we are, in the fight to stop global warming and reduce CO2 emissions. Yet we lead the world in these emissions. It's time this country did it's part to help stop the effects of global warming before it's too late. I can't believe some of the answers I'm reading here that say "mankind hasn't had an impact on our environment." How tragically ignorant! What about the 200,000 year old ice core samples that say differently? Yes, temperatures have fluxuated up and down, with more or less a very steady rhythm over hundreds of thousands of years. However, in the last 50 years or so, the temperatures have far exceeded anything that has been reached in all of that thousands of years of time. Coincidence? I don't think so. There is too much scientific evidence that suggests otherwise. And to the answerer that said that we've set off nuclear bombs with no ill effects on the environment: that's crap. For all we know, the effects of those bombs have only added to the global warming problem. Why do you think we don't do it anymore??? And let's just suppose for a minute that the scientists are wrong about the causes of global warming. We still have an issue to deal with: the temperatures are still rising, the effects of temperatures rising are still causing problems (potentially catastrophic)- so shouldn't we still be concerned with finding ways to slow down or stop this process from continuing? People can fight all they want to about the causes, but the issue still remains. And it's clear that it's in our own best interests to do whatever we can to help solve the problem. Jeez. Some people's kids.

Answer 4

I think it is a misnomer as the ambient temperature in different parts of the world may not increase initially, although the total average air temperature of the world is increasing. "Climate change" is a better descriptor.

But the scenario you describe, Naboo, is a theory (that was the plot line of "Day After Tomorrow"). That is yet to be proved.

And before all the denialists and tree-huggers start fighting: Yes, there have been periods in pre-history, of increased CO2 concentrations in the atmosphere. Yes, there have been periods where there were no ice-caps. Yes we are still coming out of an ice-age, but there is indisputable evidence that climate change is happenning, the argument is how much is man made CO2 causing it to accellerate.

And it's not sun-spots as the sun is currently in a cycle of reduced sun spot activity. And for those who say it can't be man, how long have we had industry... well not that long actually, significant industrialisation has only been around for 200 years. Climate cycles are measured in thousands of years.

You're great in the Mighty Boosh, by the way, Naboo :)

Answer 5

Wrong. That scenario had to do with ice sheet melt water changing the salinity of the Gulf Stream, but the theoretical "shut down" scenario is not viewed as the most likely outcome at this time.

By the way, why not disclose your source?

Here's some information that may be a bit more reliable.

'Antarctica lost much more ice to the sea than it gained from snowfall according to a NASA survey done between 1992 and 2002. It also had a corresponding rise in sea level. The survey documented for the first time extensive thinning of the West Antarctic ice shelves. "
http://www.giss.nasa.gov/research/news/20070530/

Scientists Warn on 8 Climate Tipping Points
http://www.guardian.co.uk/environment/2007/aug/16/climatechange.greenland

Excerpts:

Some tipping points for climate change could be closer than previously thought. Scientists are predicting that the loss of the massive Greenland ice sheet may now be unstoppable and lead to catastrophic sea-level rises around the world.

Professor Lenton said: "We know that ice sheets in the last ice age collapsed faster than any current models can capture, so our models are known to be too sluggish."

Prof Lenton said the IPCC way of working, including multiple reviews, caused it to issue more conservative reports than his team's studies. He added that the inevitable collapse of the Greenland ice sheet was closer than thought because of the latency in the Earth's climate system. "If you could stabilise the greenhouse gas levels to today's level, you'll still get some further warming [by 2100]."

A global average temperature rise of just 1C would be enough to slip the Greenland ice over the edge. The IPCC's prediction for 2100 is a rise of 1.1C-6.4C.

Heightened concern about ice sheet stability and sea level rise derives from:
(1) increasingly clear paleoclimate evidence showing how sensitive climate and sea level are to even weak climate forcings, summarized in our paper in Phil. Trans. Royal Soc.
http://pubs.giss.nasa.gov/abstracts/2007/Hansen_etal_2.html
(2) precise data on changes occurring in the past few years on Antarctica and Greenland.

"Paleoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the "albedo flip" property of water substance, provides a powerful trigger mechanism. A climate forcing that "flips" the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Ice sheet and ocean inertia provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures. Carbon dioxide (CO2) is the largest human-made climate forcing, but other trace constituents are important. Only intense simultaneous efforts to slow CO2 emissions and reduce non-CO2 forcings can keep climate within or near the range of the past million years."

Answer 6

Global warming is indeed a misnomer when you talk about the gulf stream cooling.
But the gulf stream is only a very small part of the globe. When taken as a whole, the globe is warming.at an alarming rate.

Answer 7

Very possible that the rise in sea temperature is due to under water volcanos. check out http://www.iceagenow.com

Also Nasa has recently found that the circulation of the oceans current has changed direction which will bring cooler weather. And the current solar minimum which we are in seems to be ongoing. Many things are suggesting cooler weather to come.

Answer 8

Yes it is a misnomer. It should be clarified with this statement: The Average Global Temperature has increased slightly. (Also realize the temperatures they are averaging together are from select locations.)

The other thing they try to sweep under the rug is that CO2 levels have increased and fallen before, even before Humans came into the picture.

Answer 9

WAKE UP!
we are responsible, its about time mankind woke up, to what is happening right in front of are eyes, you can choose a blinkered view but the truth is out there for all to see .
We effect every part of this planet & everything ,the ice caps are melting for sure, its a proven fact,thats just the tip of the iceburg.

Answer 10

Why this spamming with hundreds of new global warming questions? Read the thousands of facts added in this forum ...