I wonder what Global average temperature would reflect if we had thermometers in every mile and in all directions? ... and we had measurements for thousands of years and at every hour on the hour? I think science is silly when they make the simple claim of AGW (anthropogenic global warming) when they haven't accurately measured the whole planet at any time. Satellite temperature readings seem to be the way to go nowadays, but there are problems with accurately measuring temperatures through satellites also. A less than 1C average temperature change in 150 years is nothing to be concerned about.
I think what eddie means to say is 'so even though the UK is closer to the North Pole then Michigan the UK has a less harsh winter because of the gulf stream'.
It's not as he states that these current bring heat, they are in fact created by the heat difference between the poles and the equator, the Sun's energy drives the worlds currents of which the Gulf stream is just one.
http://en.wikipedia.org/wiki/File:Corrie...
Red warm currents usually (but not always) are associated with wetter regions, like Brazil or Eastern U.S. or Eastern Australia. Blue currents with dryer conditions like California or Western Australia.
On the above you will notice cold currents usually are moving away from the poles and warm move towards the poles water losses heat and sinks at the poles and is warmed at the equator this drives the cycles. Land masses affect the flow of these currents and where they go as well.
It is thought that millions of years ago what is now the Gulf stream did not exist and it flowed instead between North & South America which would have (at the time) made Northern Europe much more like Canada where harbors freeze in Winter at much the same latitude as London. When geologic action closed this gap, the warm waters where directed North up the coast warming much of coastal Western Europe.
Antarctica is another example, it is surrounded by the circumpolar current, that act to isolate it (to some degree) from the warmer currents, this also has not always been the case long ago it was attached to South America and go back a little further to Australia as well. At this point in time with no circumpolar current it was warmer, it still would have had long periods without Sun, but the vast glaciers it has now, could not form. This only happened after the separation of the other two land masses allowing the current to form. This eventually cooled the entire planet, and is thought to be linked to the start of the glacial cycle, which started only about 2.5 million years ago.
Go back even further say 500 million years and it all very different, you have the continents of Gondwana and Laurasia and very different currents which would have had a marked effect on climate.
http://en.wikipedia.org/wiki/Gondwanalan...
This is a time in Earths history when there was no real life on land, it was all rocky desert, no animals, no plants, this is also the point where that started to change altering the very albedo of the planet.
The climate here on the Oregon coast, and north of here is fairly mild due to tropical storms and 58 degree ocean water. South West storms push this coastal climate into the mid 70s F. during the winter months, and it is very seldom that even a skim of snow sticks. It is said that the "Japanese Current" makes this region so pleasant in the winter as compared with eastern regions of the country. Of course, this is a rainforest area and it often gets much rain and darkness. So, there you have it; the ocean currents here keep this region nice in the winter.
Oceans can bring warm water to cold countries leaving there climate warmer. For example, the gulfstream, which runs north on the east side of the us, brings warm water to the UK, so even though the UK is closer to the equator then Michigan the UK has a less harsh winter because of the gulf stream. The warm water heats the air and makes a warmer climate.
In so many ways, water covers 70% of Earths surface and receives most of the suns heat, we have a thermohaline circulation, see image http://ts1.mm.bing.net/th?id=H.476463174... which spreads heat all over the world and generally moderates our climate.
We also have ocean phenomenon like EL nino's and La nina's which also change the climate from cool to warm and wet to dry, and then there are the Pacific decadal oscillation (PDO) and the Atlantic multi decadal oscillation (AMO) which can have long term effects on temperatures.
Also the cold Arctic and Antarctic waters that sink down into the oceans bringing oxygenated waters into the ocean depths allowing life to flourish.
a scientific encyclopedia could answer your question you should have consulted that before asking the question.
just see this link to get more about it
www.aip.org/history/climate/oceans.htm
