Climate Change

I have just been reading an article in New Scientist which is warning of a posssible mini-ice age. This is based upon oceanographic data obtained from the Gulf Stream. The link is below. I am slightly sceptical since the Montreal follow up to the Kyoto Meeting on climate change is happening this week. In my line of work I often find that appropriate research is given the "Press" treatment to create a stir.

The Ice Age is coming!

I'm sure you are right about the timing of this report but it does simply pick up on existing theory - indeed the film "The Day after Tomorrow" was based on it.

The worrying thing is that if the theory is correct it is quite possible that we have already reached a point of no return - I am hoping the theory is wrong!!!

Can you explain in lay man terms how global warming can lead to an ice age?

Sorry for being thick be I just don't get it

May be, all the gases causing so called global warming, block out the suns rays ?
I think it's something to do with the Gulf Streams,failing to warm the seas,it would not be a worldwide ice age but, just like it was millions of years ago.
What goes around comes around.

I've started sitting in the fridge for two hours a night just to get acclimatised.


Okay Fred, you can start shouting at me.........NOW.

I wouldn't do that to you Merv,your one of the funny ones.
err....yes,well, you know what I mean?

Fred
Have I got this right
THe polar ice cap melts due to global warming this causes colder water than normal to flow into the gulf stream and so causes a mini ice age?

My understanding is that a warming of the climate melts a lot of the ice held in the arctic circle. Melted ice ends up going into the seas as freshwater in such volumns that it desalinates the oceans. Because salt water is heavy, the diluting effect somehow effects the ocean currents (scientists think that the deep ocean currents are probably the single most important factor in determining global weather patterns).
There will come a point when the gulf stream stops progressing to the north pole, stopping at more southerly latitudes. When that happens most of the northern hemisphere plaunges into a new ice age as the polar icecap gets bigger.
Kind of thing.....

There you go,Mort.

I understand more of what's said here so the southern hemisphere will bet warmer and the Northern hemishpere colder

Chub King has summarised the article quite well. Now as to the impact upon our beloved sport...
"The last shutdown, which prompted a temperature drop of 5?C to 10?C in western Europe, was probably at the end of the last ice age, 12,000 years ago. There may also have been a slowing of Atlantic circulation during the Little Ice Age, which lasted sporadically from 1300 to about 1850 and created temperatures low enough to freeze the River Thames in London."

Ice fishing anyone?

I suppose the new barbel section will have to shut down if that happens, oh! dear.?

Chub kings explanation is mainly right about how the ?Atlantic Conveyor? (AC) works and the impact ice melt/freshwater input will have. However, what he should have added is warm salt seawater is lighter, due to less salinity, than cold saltwater which has more salinity. The lighter seawater is driven northwards by the currents of the Gulf Stream. When it reaches the Atlantic Ice Sheet it cools and sinks (The salinity increases) to the ocean floor and is retuned to the Gulf of Mexico where it warms up, becomes lighter and starts the process of northward travel again.

For the system to work as we know, there has to be enough of an ice sheet to cool it. The Atlantic Ice Sheet has been melting at an alarming rate over the last 30 years. There will be a point through climate change, where there isn?t an ice sheet sufficiently large enough to cool it. At that point in time the conveyor will stop. The temperate climate we enjoy which comes from the Gulf Stream and the south-westerly winds it bring, will give way to Artic North winds plunging the UK into a mini Ice Age.

There are other impacts to the shrinkage of the Ice Sheets that have a knock on effect on Climate Change - one being the Albido Effect.

Colsmiff of course the timing was done to coincide with this conference, BUT it was done for the best of reasons. To convince that thick Texan to take Climate Change seriously AND to do something about it, rather than stick his head up his a*** and his oil profit bank balance.

Libido effect (sounds good)

I said Albido Effect Monk!
And as you know what this effect is, you can explain it to the FM masses.

I?m off to a meeting to draw up a tree strategy for Manchester?..Boy does it need it! So I?ll leave it in your capable hands! :0)

sneaky things trees, thats why manchester needs a strategy to deal with em. wheres my last post gone about how the gulf stream works.

Phil, I couldn't agree with you more about the US's total lack of action over the Kyoto accord. I wasn't complaining about the reporting of the research, nor the inevitable "sexing-up" it will receive once the BBC news editors read New Scientist this week (their only source of information about the world of Science, by past endeavours).
Rather I was actually trying to start a thread about the fact that such a change in climate would impact severely upon fishing as we have come to know it.

I said Albido Effect Monk!
And as you know what this effect is, you can explain it to the FM masses.


Nope, sorry mate, cant remember what I copied from you at Uni???

Oh OK, Err off the top of me head
The albedo is a measure of reflectivity of a surface or body. It is the ratio of electromagnetic radiation (EM radiation) reflected to the amount incident upon it. The fraction, usually expressed as a percentage from 0% to 100%, is an important concept in climatology and astronomy. This ratio depends on the frequency of the radiation considered: unqualified, it refers to an average across the spectrum of visible light. It also depends on the angle of incidence of the radiation: unqualified, normal incidence. Fresh snow albedos are high: up to 90%. The ocean surface has a low albedo. Earth has an average albedo of 31% whereas the albedo of the Moon is about 12%. In astronomy, the albedo of satellites and asteroids can be used to infer surface composition, most notably ice content. Enceladus, a moon of Saturn, has the highest known albedo of any body in the solar system, with 99% of EM radiation reflected.

Human activities have changed the albedo (via forest clearance and farming, for example) of various areas around the globe. However, quantification of this effect is difficult on the global scale: it is not clear whether the changes have tended to increase or decrease global warming.

The "classical" example of albedo effect is the snow-temperature feedback. If a snow covered area warms and the snow melts, the albedo decreases, more sunlight is absorbed, and the temperature tends to increase. The converse is true: if snow forms, a cooling cycle happens. The intensity of the albedo effect depends on the size of the change in albedo and the amount of insolation; for this reason it can be potentially very large in the tropics.

think thats what it means anyway?

to elaborate, off the top of me head

Fairbanks, Alaska
According to the National Climatic Data Center's GHCN 2 data, which is composed of 30-year smoothed climatic means for thousands of weather stations across the world, the college weather station at Fairbanks, Alaska, is about 3 ?C (5 ?F) warmer than the airport at Fairbanks, partly because of drainage patterns but also largely because of the lower albedo at the college resulting from a higher concentration of pine trees and therefore less open snowy ground to reflect the heat back into space. Neunke and Kukla have shown that this difference is especially marked during the late winter months, when solar radiation is greater.

The tropics
Although the albedo-temperature effect is most famous in colder regions of Earth, because more snow falls there, it is actually much stronger in tropical regions because in the tropics there is consistently more sunlight. When Brazilian ranchers cut down dark, tropical rainforest trees to replace them with even darker soil in order to grow crops, the average temperature of the area appears to increase by an average of about 3 ?C (5 ?F) year-round.

Small scale effects
Albedo works on a smaller scale, too. People who wear dark clothes in the summertime put themselves at a greater risk of heatstroke than those who wear white clothes.

Pine forests
The albedo of a pine forest at 45?N in the winter in which the trees cover the land surface completely is only about 9%, among the lowest of any naturally occurring land environment. This is partly due to the color of the pines, and partly due to multiple scattering of sunlight within the trees which lowers the overall reflected light level. Due to light penetration, the ocean's albedo is even lower at about 3.5%, though this depends strongly on the angle of the incident radiation. Dense swampland averages between 9% and 14%. Deciduous trees average about 13%. A grassy field usually comes in at about 20%. A barren field will depend on the color of the soil, and can be as low as 5% or as high as 40%, with 15% being about the average for farmland. A desert or large beach usually averages around 25% but varies depending on the color of the sand. [Reference: Edward Walker's study in the Great Plains in the winter around 45?N].