First of all, welcome to the blog, Brett.

Now, onto climate. Judging by how winter showed up in 2006/07, a weakening gulf stream wouldn't be a problem. On the contrary, if this ever happens, may be snow will fall again in some parts of Europe. I mean, I spent January 2007 in England and France, and it was quite a mild Winter! I could actually go for some Ocean Cooling!

Not quite today's topic, but did you happen to read this Brett? http://www.noaanews.noaa.gov/stories2007/s2876.htm

It's an article I've just read. It says, amongst other things that "WIDESPREAD WARMTH LEADS TO THE FIFTH WARMEST SPRING FOR UNITED STATES,
DRIEST SPRING ON RECORD ACROSS THE SOUTHEAST WORSENS DROUGHT" and that "The global land-surface temperature was the highest for the month of May, as well as for boreal spring. The combined global land- and ocean-surface temperature was fourth warmest for May, and tied with 1998 as the warmest January-May period". If there still are doubts about this Spring being a particularly warm one, the article adds: "For spring 2007 (March-May), the average temperature for the continental United States was 54.38 degrees F (12.43 degrees C), which was 2.49 degrees F (1.38 degrees C) above the 20th century mean and the fifth warmest spring on record, based on preliminary data. The four warmest springs in order are 1910, 2004, 2000 and 1934". These are all statistics that, I believe, reflect the fact that "During the past century, global surface temperatures have increased at a rate near 0.11 degrees F (0.06 degrees C) per decade, but the rate of increase has been three times larger since 1976, or 0.32 degrees F (0.18 degrees C) per decade"

The Gulf Stream has slowed down by 30% over the last fifteen years, and is considerably wider and lower in salinity. This is a significant effect of AGW as the ocean is no longer getting the circulation that pulls up nutrients from deep water. This has caused a lack of food in the system as well as a decline in co2 absorbing plankton blooms which has already affected the carbon sink and fisheries causing sea food prices to increase.
The climate effect can already be seen in delayed seasons due to the slower rate that the body of warm water passes toward its Arctic turning point. This trend will establish milder winters and severe summer drought until the decrease in speed reaches 60% in around another decades. By then European climates will have little heat to absorb as the stream stagnates at some point after it passes the equator. At that time surrounding sea will dissipate the warming effect from the southern hemisphere and the northern hemisphere will enter into a period of long term Ice Age.
At such a time the sceptics will still say its just cyclical and natural while we all crank up the heat to stop shivering and clear cut a carbon credit forest to put fuel in the pot belly stove.
The demand for heating will force co2 emissions to increase along with climate refugee numbers.

Hi Guys,

Here is a little set of charts and graphs that illustrate the PDO and AMO or ocean oscillations.

http://icecap.us/images/uploads/Ocean_Multidecadal_Cycles.pdf

"The four warmest springs in order are 1910, 2004, 2000 and 1934". These are all statistics that, I believe, reflect the fact that "During the past century, global surface temperatures have increased at a rate near 0.11 degrees F (0.06 degrees C) per decade, but the rate of increase has been three times larger since 1976, or 0.32 degrees F (0.18 degrees C) per decade"

Emiliano, How does the person making this quote believe that this supports the thesis? It's fifth warmest and there's no trend at all here. It was REALLY warm both a long time ago and more recently and this warming doesn't correspond to CO2 increases at all...what am I missing?

Also, an interesting study was recently published where people are actually finally double checking the on-ground weather stations for accuracy and finding them in poorly placed locations that slant the data towards being warmer...http://www.pittsburghlive.com/x/pittsburghtrib/opinion/columnists/steigerwald/s_513013.html

Simon,

Western Europe is influenced in large part by the North Atlantic Oscillation (NAO). When the NAO is in positive mode, westerlies prevail, which in turn bring mild maritime polar airmasses into Western Europe. When the NAO is in negative mode, the westerlies are cut off, and continental air masses prevail. During an NAO negative phase, Europe will see seasonal extremes (dry, blistering summers, and frigid, snowy winters).

There is no evidence that changes in the Gulfstream in recent years (which have been small) have any affect on the NAO.

If you wish to look for the genesis of our ocean currents go to the Pacific. The Pacific Decadal Oscillation mirrors the efficiency of how the atmosphere transports equatorial air masses northward. It is in the Pacific where the great ocean conveyor begins.

JP, as the NAO generates cold air from its arctic cold water it is logical to state that a warming effect is generated during its negative phase because it is influenced by the Gulf stream as warm water enters the north atlantic which is felt over the entire continent in summer or in winter over land and indeed in the water that carries the NAO.

Therefore a 30% decrees in Gulf Stream currents does have a significant effect in the region by actually heating the currents of the NAO causing the negertive effect. We should not be surprised that .there is no evidence of this from observations of the Pacific Decadal Oscillation as the Gulf Stream is propelled north to south by the cooling waters sinking. However as salinity in the Arctic leg of the jorney drops the stream will disapate further as we observe greater loses in speed.

Simon,
I think you are little confused concerning terminology; the NAO doesn't produce cold air masses -the artic and polar source regions do. For Western Europe this is the Russian sub polar and polar regions as well as the interior of Greenland and points north. The NAO, when in negative mode, high pressure -mainly from Russia- builds westward, or a large dome of high pressure builds from the Northwest; the prevailing Westerlies are forced Southward, driving the Atlantic's maritime polar air south over the Med. In this case, atmosphereic conditions prevail over maritime. My point is that the Gulfstream doesn't have an effect on the NAO, but the NAO can drive the Gulfstream generated mild maritime air masses southward.

The Pacific ocean is by far the largest body of water, and its efficiency vis-a-vis heat absorbtion and transfer has a profound effect on global climate. The PDO greatly influences the timing, extent, and strength of ENSO, and the global ocean conveyor belt. Since 1976 (the year of the Great Climate Shift), the PDO has been positive; coincidentally the NAO has been more positive than negative, ENSO events have been at record levels (1983,1988, 1998), and it is ENSO that has been driving most of the climate patterns. Like I stated earlier, look to the Pacifc for most of our climate answers.

JP,
Thanks JP there is a lot for me to think about from your post. Nevertheless, why is it, in your opinion, that the Gulf Stream gets all the attention?
Are you saying that the pacific has more of an effect on global temps, if that's the case, could you name a current or stream that circulates temps through both hemispheres? Is it wind that provides the oceans current power or the drag/ push on effects of currents sinking once salinity dilutes in the polar seas?