NEW STUDY: GLOBAL SEA-LEVEL RISE SIGNIFICANTLY LOWER THAN THOUGHT

Discussing: Woeppelmann, G., Miguez, B.M., Bouin, M.-N. and Altamimi, Z. 2007. Geocentric sea-level trend estimates from GPS analyses at relevant tide gauges world-wide. Global and Planetary Change 57: 396-406.

What was done

The authors describe a technique they developed for utilizing Global Positioning System (GPS) data, which they obtained from numerous GPS stations situated in close proximity to various tide gauges around the world, to correct the tide gauge records and thus obtain what they call a "set of 'absolute' or geocentric sea-level trends." Based on a number of criteria that had to be met by both the tide gauge and GPS stations, they ultimately used paired data sets from 28 locations that covered a time span of 5.9 years (1999.0-2005.7) to derive their final mean global result, after which they compared it with what they call the "most quoted" tide-gauge results of Douglas (1991, 1997, 2001), which had been corrected for the most common form of vertical land motion by means of theoretical models of Glacial-Isostatic Adjustment (GIA).

What was learned

Whereas the data of Douglas yielded a mean global sea-level rate-of-rise of 1.84 ~ 0.35 mm/year after correction for the GIA effect (Peltier, 2001), Woeppelmann et al. obtained a much lower mean value of 1.35 ~ 0.34 mm/year when employing their correction for measured GPS vertical velocities. The sizable difference between these two results raises the question of how they compare with results obtained from other ways of estimating global sea level trends. In this regard, the four researchers note that Mitrovica et al. (2006) recently indicated there is a 1 mm/year contribution to sea-level rise from the melting of global land ice reservoirs, as well as a 0.4 mm/year contribution from thermal expansion of the global ocean (Antonov et al., 2005). Together, these two numbers yield a value of 1.40 mm/year for the global ocean's total sea-level mean rate-of-rise, which is much closer to the 1.35 mm/year result of Woppelmann et al. than to the Douglas-Peltier result of 1.84 mm/year.

What it means

The mean global sea-level rate-of-rise calculated by Woppelmann et al. appears to resolve the "sea-level enigma" noted by Munk (2002), who called attention to the sizable discrepancy that existed at the time of his writing between estimates of climate-related contributions to sea-level change and what the observed value was thought to be. Now, there is no longer any discrepancy between these two numbers. What is more, the global ocean's mean rate-of-rise is now seen to be much slower than what was previously believed to be the case.

Source

Original journal abstract follows:

Geocentric sea-level trend estimates from GPS analyses at relevant tide gauges world-wide

By G. Woeppelmann et al.

Abstract

The problem of correcting the tide gauge records for the vertical land motion upon which the gauges are settled has only been partially solved. At best, the analyses so far have included model corrections for one of the many processes that can affect the land stability, namely the Glacial-Isostatic Adjustment (GIA). An alternative approach is to measure (rather than to model) the rates of vertical land motion at the tide gauges by means of space geodesy. A dedicated GPS processing strategy is implemented to correct the tide gauges records, and thus to obtain a GPS-corrected set of 'absolute' or geocentric sea-level trends. The results show a reduced dispersion of the estimated sea-level trends after application of the GPS corrections. They reveal that the reference frame implementation is now achieved within the millimetre accuracy on a weekly basis. Regardless of the application, whether local or global, we have shown that GPS data analysis has reached the maturity to provide useful information to separate land motion from oceanic processes recorded by the tide gauges or to correct these latter. For comparison purposes, we computed the global average of sea-level change according to Douglas [Douglas, B.C., 2001. Sea level change in the era of the recording tide gauge. Int. Geophys. Ser., 75, pp. 37-64.] rules, whose estimate is 1.84 ~ 0.35 mm/yr after correction for the GIA effect [Peltier, W.R., 2001. Global glacial isostatic adjustment and modern instrumental records of relative sea level history. Int. Geophys. Ser., 75, pp. 65-95.]. We obtain a value of 1.31 ~ 0.30 mm/yr, a value which appears to resolve the 'sea level enigma' [Munk, W., 2002. Twentieth century sea level: an enigma. Proc. Natl. Acad. Sci. U.S.A., 99(10), pp. 6550-6555].

Global and Planetary Change, Volume 57, Issues 3-4, June 2007, Pages 396-406





Organic farming farts lots of greenhouse gases into the air

Genetically modified crops are better!

As the world's policymakers and business elites look to curb greenhouse gas emissions, one economic sector due for a closer look is agriculture. What many people presently view as a 'green' agriculture choice is, upon closer examination, deeply environmentally suspect.

Most people do not realize that agriculture is a major contributor to atmospheric CO2. Further, different types of agriculture have very different CO2 emission profiles. The widespread adoption of modern agricultural biotechnology products have allowed farmers to maintain yields while reducing CO2 emissions.

Like all animals, soil micro-organisms "breathe out" CO2. In fact soil respiration contributes approximately 20 percent of all land-based CO2 emissions. The United Nations estimates a 2-5 degree C increase in global temperature in the next hundred years. Couple this with research that showed a 5 degree C increase doubles CO2 emission from soil and it becomes clear agriculture must be included in future CO2 reduction strategies.

Soil management by farmers is important. Tillage practices can have a major effect on the levels of soil CO2 emissions. Organic agriculture controls weeds primarily by ploughing. The microbial respiration rate is increased every time a plough churns up the soil. When compared to no-tillage, mould-board ploughing doubles CO2 emissions from the soil.

Along with microbial production of CO2, tractors burn huge amounts of diesel fuel pulling metal ploughs through the soil. Research has shown that a conversion to no-tillage practices can save up to 32 litres/hectare. With no-tillage farming practiced over millions of hectares, there is a huge reduction in the amount of CO2 produced by tractors.

The UN estimates that the conversion from conventional ploughing to no-tillage agriculture would store carbon in the soil at 300 kg/hectare/year. The US and Canada are world leaders in no-tillage agriculture. The advent of genetically modified (GM) herbicide tolerant (HT) crops has allowed farmers to use highly effective, low environmental impact herbicides instead of the plough for weed control.

Over the past ten years US farmers have eagerly adopted GM crops with 84 percent of corn, 90 percent of soy and 85 percent of cotton now planted with GM varieties. In Canada, farmers have increased no-tillage canola from 0.8 million hectares to 2.6 million hectares. Ninety five percent of this acreage is planted with GM herbicide tolerant canola.

Like tillage practices, the type of fertilizer used can have a large effect on CO2 emissions. Conventional agriculture relies on synthetic fertilizers while organic farms primarily use manure. Synthetic nitrogenous fertilizers depress soil respiration rates. Conversely, research has shown that the use of manure fertilizer increases soil respiration rates and therefore CO2 emissions by 2-3 fold.

Some have suggested a complete conversion to organic agriculture. But, on average, organic agriculture produces 30 percent less per hectare than conventional farms. If we were to convert entirely to organic agriculture, we would need at least 30 percent more farmland. Significant amounts of the remaining wilderness would have to be ploughed under to maintain current food production levels.

The conversion to organic farming would also require a tremendous increase in animals to generate manure fertilizer. Anyone who has ever been near the back end of a cow knows this would significantly increase a different greenhouse gas.

The organic food industry proudly states double digit increases in sales each of the last few years. However the world is not black and white and research has demonstrated there are significant environmental consequences of this success.

Organic farming practices generate significantly greater CO2 emissions while producing less than conventional agriculture. On the other hand, growing genetically modified crops allow the farmer to reduce CO2 emissions while maintaining yields.

Research has demonstrated soil and water conservation benefits of genetically modified HT crops. It is now clear that these products of modern biotechnology can also help farmers reduce agriculture based CO2 emissions. The public is calling for "greener" options in every industry. But when it comes to agricultural CO2 emissions, the "greener" option may not be what people think.

Source






Irresponsible journalism burns global warming debate

I am surprised to see that on July 31, the Missourian published a letter smearing The Heartland Institute as global warming "deniers" and spreading falsehoods about renewable energy costs. The writer asserts it is cheaper to produce energy from wind, solar, geothermal, and biomass than from conventional sources. Such an assertion is downright laughable. Indeed, in states where renewable power is mandated, consumers pay 42 percent more for electricity than in states without such mandates (see http://www.cei.org/pdf/5982.pdf). If renewable power were cheaper to produce, then why does the government have to subsidize and mandate it to get people to produce and buy it?

Moreover, if presenting sound science rather than irresponsible alarmism makes someone a global warming "denier," then count me in. For example, when environmental extremists irresponsibly claimed the Gulf Stream was on the verge of shutting down, The Heartland Institute reported the truth (see http://www.heartland.org/Article.cfm?artId=20505 and http://www.sciencemag.org/cgi/content/summary/314/5802/1064a).

When environmental extremists irresponsibly claimed global warming was melting the glacier atop Mt. Kilimanjaro, The Heartland Institute reported the truth (see http://www.heartland.org/Article.cfm?artId=14287 and http://www.americanscientist.org/template/AssetDetail/assetid/55553/page/1).

Now tell me again: Who is the reality "denier?"

Source




ISRAELI RESEARCHERS CLAIM SOLAR ENERGY BREAKTHROUGH

The afternoon Negev sun shone brightly on the solar panels at the National Center for Solar Energy near Sde Boker. The center's director, physicist Prof. David Feiman, squinted into the light. "After 30 years of research on solar energy, my life's work of experiments in how to produce electricity from the sun, I can say this year that I know how to manufacture solar energy that will compete with conventional energy," he says.

A few months ago, the center's scientists managed to develop a new technology of solar, or photovoltaic cells, that Feiman says will make the production of solar energy so efficient that the cost of the photovoltaic cells that convert solar energy into electricity will be negligible.

In an ordinary solar panel of the type in use today, the silicon that makes up the cells is very expensive, making it a costly product. According to Feiman, photovoltaic cells carry out two functions: First, they change the light into electricity, their essential task; second, they store the light. "The principle is to focus the light using little material," Feiman says. "We constructed a large, parabola-shaped glass plate. It not only absorbs the light, it also focuses it on one point, a thousand times more than regular sunlight."

According to Feiman, "an ordinary photovoltaic cell, which is 10 by 10 centimeters, normally produces one watt of electricity. We managed to extract more than a thousand times more - 1,500 watts. In this way, the cost of a cell is 1,500 less, becoming almost nothing." "No one has ever produced so much electricity from a solar cell at this strength," he says.

The Solar Energy Center is now collaborating with an Israeli start-up company, Zenith Solar, to create a home system of solar cells based on this technology within about a year. "What is good for the home is also good for the country," Feiman says.

Israeli solar energy technology is already used extensively in power stations throughout the world. At the center at Sde Boker, which belongs to the Jacob Blaustein Institutes for Desert Research of Ben-Gurion University of the Negev, two solar panels are installed, each one about 100 meters long, moving in synch with the sun. An oil pipe is at the center.

The panels, built by Sollel, a Beit Shemesh company, are not based on photovoltaic cells, but rather focus the light on the pipe, causing it to heat up. Heat produced by panels of this type turn into steam, which moves turbines. Last month, Sollel signed a contract with the U.S. company PG&E, to build the largest [solar] power station in the world, in the Mojave desert in California, which will have about 7,000 such panels and will cover about 14 square kilometers. It is due to go into service in about four years, providing 553 megawatts of electricity.

The British-born Feiman has lived at Midreshet Sde Boker since 1976, when he began researching solar energy. A world expert in the field, he says the economic model he has built will allow a significant part of Israel's energy to go solar within the decade. "We're paying about 10 cents per kilowatt/hour. If the government taxes the Electric Corporation one cent per kilowatt/hour, it will amount to about a half billion dollars a year. In a decade, we won't need any outside funding. If we want to solve Israel's energy problems, we should stop building conventional power stations and build a solar power station every year of one gigawatt - equal to two of the type of station Sollel is building in California."

The National Infrastructure Ministry said it would "soon be determining electricity rates for home photovoltaic systems. At present, the parties are working on removing obstacles that have to do with land use."

Source

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The Lockwood paper was designed to rebut Durkin's "Great Global Warming Swindle" film but it is in fact an absolute gift to climate atheists. What the paper says was of course all well-known already but the concession from a Greenie source that fluctuations in the output of the sun have driven climate change for all but the last 20 years really is invaluable. And the one fact that the paper documents so well -- that solar output is on the downturn -- is also hilarious, given its source. Surely even a crazed Greenie mind must see that the sun's influence has not stopped and that reduced solar output will soon start COOLING the earth! Unprecedented July 2007 cold weather throughout the Southern hemisphere might even be the first sign that the cooling is happening. And the fact that warming plateaued in 1998 is also a good sign that we are moving into a cooling phase. As is so often the case, the Greenies have got the danger exactly backwards. See my post of 7.14.07 for more detail on the Lockwood paper

For more postings from me, see TONGUE-TIED, EDUCATION WATCH INTERNATIONAL, POLITICAL CORRECTNESS WATCH, FOOD & HEALTH SKEPTIC, GUN WATCH, SOCIALIZED MEDICINE, AUSTRALIAN POLITICS, DISSECTING LEFTISM, IMMIGRATION WATCH INTERNATIONAL and EYE ON BRITAIN. My Home Pages are here or here or here. Email me (John Ray) here. For times when blogger.com is playing up, there are mirrors of this site here and here.

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