Part 3 Temperature

At the Eemain’s peak the northern hemisphere were generally warmer and wetter than now, although some areas were cooler, with by some odd fact that the northern Alps were 1-2ºC warmer than present, and the area south of the Alps was 1-2ºC cooler than today. Keep in mind during these periods of warming (labeled “interglacial) as the ice melted the sea levels rose about 130 meters (426.5 feet), this between 19,000 and 11,000 years ago over a period of 8,000 years at about a rate of 0.63 inches per year, not a speedy event. Looking at it from a perspective of 65 years (about 42 inches) now that would shake a few people up, unless you’re living on hi-bank property somewhere next to a large body of water. During this time the global temperature was a bit higher than they are today, in studying this period of time I first read about the term “recurring upper bound” to the Earth’s natural temperature, and that we reached the long-term projection about 8,000 years ago and we’re due to cool off.

Then there are measurement available

from

measurements

of

satellite the

lower

atmosphere, (green line) with a corrected line (red line) by the ground observation factor, this I have grouped together with the surface

temperature

record,

showing the effects of El Nino / La Nina

and

the

Mount

Pinatubo

emissions between 1990 and 1995.

The one thing I am learning is that on this Blue Planet there are so many different variables to consider when examining the temperature change across its face – so many. I have read too many headlines and watched way too many news stories about how we have increased the CO2 levels in our atmosphere by 50 ppm during the last 37 years, that is about 1.35 ppm per year – and during that time we have increased the temperature by at least 0.15ºC during these past few years – some scientist maintain they even if we doubled the CO2 level above us the temp would increase by 0.8ºC, and yet we rush abut screaming the “end is near” for life as we know it. Some scientist (guess what side of the equation they’re on) are worried that our instruments today need to be more accurate to overcome “possible” uncertainties in our existing records, especially those taken on board sailing ships of old as they sailed the world’s oceans and maybe some now are below standard at some locations on the earth today…the next step I imagine will be a digital thermometer coupled to a satellite whereas it will calibrated hourly with a feed, back to a national center located somewhere near Al Gore’s habitat. One other variation I have

discussed

is

the

oceans

and

the

world’s

effect they have on our climate,

other

than

a

mention about El Nino and La Nina, this too has been making Mostly

headlines they

currents

that

country’s

lately.

discuss

the

effect

the

around

the

Atlantic, touching on the Pacific from time to time, but

mostly

they

worry

about the effect of the Gulf Stream on Greenland.

The overwhelming fear is that the Gulf Stream will shut down or be affected to such a degree that it will no longer provide the warming current to the North Atlantic. This stream which originates in the Gulf of Mexico, and exits

into

the

Atlantic

through the Strait of Florida is a powerful, swift and very warm current that follows the United States eastern coastline

north.

East

of

Newfoundland it head east for a bit, where it splits in two with one part heading towards and

northern the

other

Europe leg

recirculating off the West Coast of Africa. It receives it easterly drift with the help of the wind, and is considered as one of the main reasons for Europe’s mild climate. This current is important, but another current that carries equal importance is the North Atlantic Drift which is by in large driven by the thermohaline circulation. The thermohaline circulation (“THC”) is a global density-driven current of all the earth’s oceans, created by the difference of heat and “haline” (salt), which together form the density of the sea water. In a nutshell, as the Gulf Stream heads north, cooling during its journey, where eventually

it

sinks

forming

the

North

Atlantic Deep Water (“NADW”). Cool water sinks, remember?

This dense water then

flows into the ocean basins, while the bulk of it “upwells” in the Southern Ocean, the

older waters with a “transit time” of at least 1,600 years “upwell” in the Pacific Ocean (talk about a slow boat to China). The important section of the previous paragraph is the NADW that is formed in the North Atlantic Ocean, being largely formed in the Labrador Sea and in the Greenland Sea, is a creation of water that is high in saline and very dense (being cold). This water mass has been traced flowing around the end of Greenland and then at depths of 2000-4000 meters (6,561 feet to 13,123 feet), down the coast of Canada and the United States where it turns east. Eventually ending up past the eastern tip of South America and across the South Atlantic.

In this “conveyor belt” model of the thermohaline circulation, the sinking of the NADW pulls the waters of the “North Atlantic drift” northward, however, this is very simplified in its presentation and its affect on the Gulf Stream – in reality it is much more complicated and slow moving.

Imagine, the waters from the North

Atlantic may arrive sometime in the neighborhood of 1,600 years later in the Pacific. Although it is admitted that it has a large impact on the climate of the earth, there is a large debate going on when and for how long. Rest assured the current has changed over the past million or so years many times. Well there you have it – some of my notes in my lame attempt to find out what everyone is talking about, there is a wealth of information out there floating over the Internet – none of it untrue, and yet most of it based on what they label “proxy evidence”, not quite circumstantial but at best a calculated guess.

Makes you wonder doesn’t it?