Showing posts with label global temperature. Show all posts
Showing posts with label global temperature. Show all posts

Friday, August 24, 2007

Margin of Error anf Global Warming

Margin of Error and Global Warming

How do we obtain an accurate measure of the several forces at work affecting our climate? We have just been reminded that cloud cover is impossible to properly model at all. This means that whatever factor or function is assigned to its effect, its statistical error range will be huge.

For any given point of earth, the local temperature can already be safely written as T + or – 50 degrees F. Ocean temperature is very consistent but its volumetric flow rate is anyone’s guess. Remember that we measured the apparent volume of the Gulf Stream recently and found it had apparently declined by around forty percent since 1957. With two data points, we have no clue if it is significant. More recent work suggests that the effect is much more variable than we ever guessed.

See: http://www.realclimate.org/index.php?p=159

I think that the important conclusion that we can draw is that the globe has several mechanisms whose variation within their natural range are quite capable of shifting global temperature around in the order of magnitudes that we are experiencing and have experienced historically. These same mechanisms also must move to moderate any such temperature variation. The sense is that if a trend goes too far in one direction, counter balancing triggers kick in and a lot sooner than is obvious.

We recap the mechanisms:

We have the man made direct impact of particulate production that is allowing more heat to be absorbed by the atmosphere.

We have the warming of the North Pole if sustained will eventually induce a warmer and perhaps wetter arctic.

We have agriculture, which has historically been a releaser of carbon, perhaps now about to become the major collector of all the carbon ever produced and perhaps a much larger absorber of solar energy through expansion into the deserts..

We have the speculation that cold water from the South Atlantic has periodically been injected into the Atlantic with major chilling effects on Europe and North America. The south polar sea is the primary engine of cooling on this planet because of the unusual location of Antarctica and the related circum polar current. Recall that all the cold water available for cooling in the Pacific comes from Antarctia.

Last but not least we may have the possible impact of the greenhouse mechanism.

Those are a lot of levers to juggle in any atmospheric model. And we truly need a thousand years of data to secure any knowledge that we can trust. What we have now is the knowledge that it has been hotter and it has been colder.

In the meantime, the best that we can hope to do is to regulate our global society to eliminate non carbon atmospheric pollution and to sequester carbon in all agricultural croplands as an economic bonus. And as an extra bonus, we want to grow forests on all the dry lands which will nicely double the amount of land under tree cover, absorbing solar energy and using it to sequester carbon.

Wednesday, August 8, 2007

The Global Temperatrure Trend

I am reposting this post by Roger Coppock from the news groups.

July tied for 8th warmest of the 128 year NASA global land record.

Lately, fossil fools fondly repeat a lie about global warming slowing down. "Global warming ended in 1998," they say. The truth is published here every month in this section of these reports:

The month of July in the year 2007, is linearly projected to be 14.397, yet it was 14.57 above projected.

Using the line of regression, the temperature is projected. If global warming reversed, the actual measured temperatures would have to fall below the line of regression temperature, and do so for a year or more. So far this has not happened, not for even two months in a row.

Measured temperatures which are nearly always above projected temperatures mean that the temperature rise is accelerating. This is simple geometry. Each above the line measured global temperature raises the slope of the regression line when that new point joins the data. This pattern is now 5 decades old.


Please see:
http://members.cox.net/rcoppock/Slope1952-2006.jpg

Clearly therefore, the fossil fools lie, and global mean
surface temperatures continue to rise.

These globally averaged temperature data come from NASA:


http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt

They represent the results of tens of millions of readings taken at thousands of stations covering all the lands of the Earth over the last 128 years. Yes, the data are corrected for the urban heat island effect.

The Mean July temperature over the last 128 years is 14.024 C.
The Variance is 0.08871.
The Standard Deviation is 0.2978.

Rxy 0.72910 Rxy^2 0.53159
TEMP = 13.644595 + (0.005877 * (YEAR-1879))
Degrees of Freedom = 126 F = 142.99616
Confidence of nonzero correlation = approximately
0.999999999999999999999 (21 nines), which is darn close to 100%!

The month of July in the year 2007, is linearly projected to be 14.397, yet it was 14.57. <- Above projected. The sum of the residuals is 21.14880

Exponential least squares fit: TEMP = 13.647507 * e^(.0004181 * (YEAR-1879))
The sum of the residuals is 21.10617

Rank of the months of July
Year Temp C Anomaly Z score
1998 14.90 0.876 2.94
2002 14.73 0.706 2.37
1990 14.66 0.636 2.14
2005 14.66 0.636 2.14
1995 14.60 0.576 1.94
1991 14.59 0.566 1.90
2006 14.59 0.566 1.90
2007 14.57 0.546 1.83 <-- 2001 14.57 0.546 1.83 2003 14.54 0.516 1.73 1981 14.51 0.486 1.63 1999 14.51 0.486 1.63 1987 14.50 0.476 1.60 MEAN 14.024 0.000 0.00 1892 13.68 -0.344 -1.15 1902 13.68 -0.344 -1.15 1889 13.66 -0.364 -1.22 1899 13.66 -0.364 -1.22 1888 13.64 -0.384 -1.29 1923 13.64 -0.384 -1.29 1912 13.59 -0.434 -1.46 1918 13.59 -0.434 -1.46 1890 13.55 -0.474 -1.59 1882 13.45 -0.574 -1.93 1884 13.44 -0.584 -1.96 1904 13.43 -0.594 -1.99 1895 13.37 -0.654 -2.19 1891 13.19 -0.834 -2.80

The most recent 176 continuous months, or 14 years and 8 months, on this GLB.Ts.txt data set are all above the 1951-1980 data set norm of 14 C.

There are 1531 months of data on this data set:
-- 744 of them are at or above the norm.
-- 787 of them are below the norm.

This run of 176 months above the norm is the result of a warming world. It is too large to occur by chance at any reasonable level of confidence. A major volcano eruption, thermonuclear war, or meteor impact could stop this warming trend for a couple of years,
otherwise expect it to continue.

What he is showing us is that the curve fits a linear up trend since 1960. The actual curve was below the line for the last several years, but this year has jumped above the trend line. Ouch!

I also have a sense that this year the land temperatures are everywhere warmer leaving absolutely no room for argument.

From a larger perspective, we are continuing to recover from the little ice age that abruptly began in the late 15th century that sent Europe reeling and also likely crashed the populations of North America. Corn is very vulnerable.

This ice age is posited as been caused by a reduction in solar activity attested by the lack of sunspot activity.

There is one other mechanism of global warming and cooling that I think we should at least contemplate. Is Antarctica capable of sending periodic ice surges into the south Atlantic, thereby abruptly dropping global surface temperatures by a degree or so?

It is clear to me that the Northern hemisphere will normally stabilize around a regime in which winter sea ice is created and destroyed annually comfortably offsetting the heat pump of the gulf stream. We are watching it happen rapidly now.

So why did we get a little ice age?