The Global Warming Megathread

[Greybeard]

The question that never seems to get answered is whether we have already passed the point of no return regarding global warming.

 

i.e. if cutting back on emissions now will make any difference at all

 

Anyone have an idea ?

 

Certainly one of the reprecussions, even during out lifetimes will be the 'Water Wars'...

 

Z

 

Probably because there is insufficient data and it's not a calculation scientists have had to make before.

 

Contrarily cutting back on one type of emission could seriously accelerate global warming. A study on the effects of aircraft contrails on atmospheric temperatures found that these block a significant amount of sunlight and so reduce the warming effect of CO2 etc.

 

These findings were reinforced by a detailed study undertaken during the grounding of all commercial aircraft over North America in the days following 9/11.

 

As someone has already mentioned the greatest threat to northern Europe is the stopping of the NAD caused by the meltdown of the Greenland ice-cap. Scientists don't yet seem at all certain about how drastically this might affect our climate or even if some other compensatory circulation might arise in the north Atlantic. I'm not inclined to believe Hollywood's take on it

[Crayfish]

Global dimming is caused by aerosols... the scary thing about that one isn't so much that it's going to cool us all into extinction, but that it might be hiding the warming effect we've already produced and is far less stable, so could disappear, we all get hotter, things start melting, thermohaline circulation goes to pot... if this happens, the northern hemisphere could stop recieving warm water from the equator and the whole hemisphere would be about 6 degrees cooler. The gulf stream is a smaller offshoot which would primarily affect britain and some of Europe if it disappeared - if you look across the world on the same latitude as Britain, you'll find a few much colder countries. Only difference between us and them is the gulf stream. On the bright side for me, buying a first house would become a lot easier as the country emptied.

 

Global warming is the most debated issue in science ever, and it's difficult to study and draw definite conclusions on - the world climate is a complex system. A picture is building up though and most scenarios now predict change of some sort or another though as a direct result of anthropogenic emissions. The world climate isn't constant anyway over geological time - we're actually in a relatively cool period at the moment - but humans are pushing things out of balance and accelerating the process.

 

There are quite a lot of more radical theories involving various things that could kill us as things warm up, too. (e.g. icecaps melt, redistribution of pressure opens magma chambers and sets off mass volcanism).

 

Safest place to live is probably southern hemisphere, try central Australia.

 

Be on the safe side and keep emissions as low as possible - reducing energy consumption would also reduce the need for nuclear energy in this country and limit air pollution as well as reducing global warming.

[Greybeard]

if you look across the world on the same latitude as Britain, you'll find a few much colder countries. Only difference between us and them is the gulf stream.

 

Practically all the countries between 50 and 60° latitude enjoy a 'continental' climate but even without the NAD our climate would remain 'maritime'. I think what would be critical for UK would be the source of the prevailing airflow, particularly in the winter months.

 

Are there any projections of how a failure of the NAD would affect Atlantic SSTs and weather patterns ?

[Cliff Clavin]

Apparently there's this thoery that if we cut back we'd make things worse because all the toxics in the air are bouncing back the Global Warming effects.

 

There is also the theory that if we continue using fossil fuels as we are then our surface temperature will be hot enough to melt lead by the year 2100, if we begin using coal to make up for Oil and Gas deficit - which we already have begun to do so, then it could be as early as 2050 - 2080

[Crayfish]

Practically all the countries between 50 and 60° latitude enjoy a 'continental' climate but even without the NAD our climate would remain 'maritime'. I think what would be critical for UK would be the source of the prevailing airflow, particularly in the winter months.

 

Are there any projections of how a failure of the NAD would affect Atlantic SSTs and weather patterns ?

 

I was thinking of Norway, Denmark and Sweden. Suppose they're not that much colder though... although they are also slightly impacted by the gulf stream.

 

Apologies, 6 degrees over the whole of Europe was incorrect. Be about 2 degrees for most of Europe, with specific areas such as Greenland being hit harder (about 8 degrees).

 

There are projections for weather patterns, but none of them in agreement. I've heard it quoted that there might be more floods and storms in Europe but can't remember why or even if there was a reason given. Sea surface temperatures would definitely be reduced and this would have consequences for marine life, plankton stocks could easily crash.

[Crayfish]

Apparently there's this thoery that if we cut back we'd make things worse because all the toxics in the air are bouncing back the Global Warming effects.

 

There is also the theory that if we continue using fossil fuels as we are then our surface temperature will be hot enough to melt lead by the year 2100, if we begin using coal to make up for Oil and Gas deficit - which we already have begun to do so, then it could be as early as 2050 - 2080

 

Cutting back on fossil fuel use would certainly make things better. As I mentioned there is a cooling effect due to aerosol compounds. Many of these substances have been banned or fallen out of use, so in effect we already have cut back on them.

 

The IPCC projected a range of possible scenarios for the year 2100... none of them were lead melting, though there is a wide range due to uncertainties about future emissions from sources such as fossil fuel use.

 

Most agree the most probable prediction is a rise of 5.5-6 degrees in the next 100 years globally.

[Mathom]

Norway, Sweden and Denmark do benefit from the Gulf Stream too, in the southern regions of the former two nations. I would say the best comparison might be Newfoundland in Canada, which is on the same latitude but does not get the Gulf Stream, and it's damn cold there in Winter. Even the Northern States in the US suffer from immense snowfall.

 

The other effect of the Gulf Stream is the Azores Ridge, which keeps our weather milder in Winter; when this is not present we are affected by Continental and Arctic weather patterns - this was predicted to break down this past Winter, but it didn't happen as the forecasters said it might.

 

I've read that just a 2 degree rise in temperature would be enough to melt enough of the polar ice cap that London and most of our low lying land would be wiped out. If Greenland goes, then it's curtains.

 

Mathom-please excuse my ignorance but where in the world(if anywhere) would be deemed as the safest place to live?

*rushes off to pack suitcases*

 

I'd be tempted to stay put on top of one of Sheffield's hills - I always say that if this place gets flooded then everyone's stuffed. But it might be a bit too cold for most.

[Greybeard]

 

Most agree the most probable prediction is a rise of 5.5-6 degrees in the next 100 years globally.

 

But for us this could be modified downwards by the cooling effect of a failure of the NAD. It's no wonder climatologists have sleepless nights.

 

I've seen several discussions about GW and have been amazed how many people seem to think the result will just be increasing global temperatures and overlook the effect this will have on climate. In many areas of the world inundation and increasing drought will have a serious impact on food production and the availability of fresh water. Not to mention the large increase in both frequency and intensity of tropical storm activity.

 

I'm sure Zafar is correct in his prediction of 'water wars', - and 'food wars' will not be far behind. It will be a testing time for humanity which thankfully I'll not be here to witness.

[Tony]

And then there is the idea that it's all part of natures long term plan and that nothing we have done or can do has / will make a blind bit of difference.

 

Forget emissions, it's just the next ice age on its way.

 

The magnetic field flipping might be more scary TBH.

[Phanerothyme]

As I understand it, the chief danger from global warming is an increase in the total overall energy of the global climate system. This leads to the degradation of stable weather systems, and an increase in random extreme weather everywhere. As you pump more energy in to the system it becomes increasingly difficult for weather systems to settle into stable, seasonal or even daily rhythms.

 

I'm fairly convinced that radical climate change is on the menu. Warming or dimming, I don't know. Ice core data seems to indicate and enormous increase in the rate of change of temperature correlating well with human CO2 emissions.

 

Daisyworld it's not.