Ice shed from the giant sheets covering Antarctica and Greenland is responsible for just 12% of the current rate of global sea level rise, according to a new review. The authors emphasise that it is now clear that the ice caps are losing ice faster than it is being replenished by snowfall. But exactly why this is happening remains unknown, making it difficult to predict the extent of future sea level rises.
The remaining 88% of the current rise is due to the expansion of water as it warms, and melting from mountain glaciers and ice caps outside Greenland and Antarctica. Yet the shrinking of Greenland and Antarctica remains crucial because together they hold enough water to make sea levels rise by 70 metres, submerging vast swathes of land and displacing millions.
Over the past 10 years, satellite measurements have vastly improved the quality of data detailing changes in the ice sheets, say Duncan Wingham from University College London and Andrew Shepherd from the University of Edinburgh, both in the UK. Having reviewed the latest data, the pair conclude that losses from the ice sheets of Greenland and Antarctica contribute 0.35 millimetres per year to the total rate of sea level rise, estimated at 3 mm per year. This contribution is close to the Intergovernmental Panel on Climate Change's latest estimate of 0.41 mm from the Greenland and Antarctic ice sheets. According to the IPCC, measurements since 1993 show that the thermal expansion of water is responsible for 1.6 mm of the annual rise and other melting glaciers and ice caps for 0.77 mm.
Ice flow
The satellite data have revealed how the ice sheets are losing mass. "It has become very clear over the past five years that these sheets are not losing most of their mass through melting, they are losing it because the ice is flowing into the ocean faster than the snow is replacing it," Wingham told New Scientist (see Greenland's glaciers are speeding to the ocean). The bases of the glaciers appear to be able to slip more easily at their base than in the past, so they slide into the sea faster.
And this is where uncertainties arise. In Greenland, it is possible that water from melting ice at the surface of the glaciers is boring holes through the ice sheets and lubricating their base. "It is at least possible," says Wingham, that global warming is causing this to happen now more than before. But Antarctica is much colder than Greenland, so there is no such melt-water to travel down to the base of the glaciers. "Most people don't realise that Antarctica is so cold there isn't much melting going on," Wingham told New Scientist. Whatever is causing Antarctic glaciers to flow faster than before, he says, it is not melting of their surfaces.
Increased snowfall
Wingham and Shepherd's review of recent research on Antarctica did find that four Antarctic glaciers that are retreating in unison share a common feature: they are all in direct contact with the sea. "Our assessment confirms that just one type of glacier in Antarctica is retreating today - those that are seated in deep submarine basins and flow directly into the oceans," says Shepherd. "These glaciers are vulnerable to small changes in ocean temperature, such as those that have occurred over the 20th century and those predicted for the 21st century. A rise of less than 0.5 oC could have triggered the present imbalance."
Climate modelling predicts that snowfall on the ice caps will increase over the 21st century. But the researchers warn that the processes that are causing ice sheets to shrink - with surface melting in Greenland and changes in sea temperatures in Antarctica as possible candidates - could in the 21st century rapidly counteract the ice gained from increased snowfall.
They say continued observations by satellite and on the ground in both regions are essential to improve predictions of sea-level rises. In a separate review paper, also in Science on 15 March, David Vaughan and Robert Arthern of the British Antarctic Survey agree that there are two main obstacles to predicting the future of ice sheets: more needs to be known about what is going on underneath the ice sheets, and what happens at their edges where they meet ocean waters.
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THE COMING GLOBAL COOLING?
An article has appeared in a recent issue of Meteorology and Atmospheric Physics with a curious title "Multi-scale analysis of global temperature changes and trend of a drop in temperature in the next 20 years."
Wow, that's a mouthful! Imagine publishing a paper in a respected, peer-reviewed scientific journal in which you predict global cooling over the next few decades? Apparently, the authors were not moved by the 46.6 million websites found when doing a quick search of the internet for "global warming." The article was produced by Lin Zhen-Shan and Sun Xian of the Nanjing Normal University in China (obviously, English is not their first language, if you couldn't tell from the title, and some of the following quotes from their article are a bit awkward).
The work was funded by the Chinese National Science Foundation, and not by coal interests in China. We have no reason to suspect that Zhen-Shan and Xian are puppets of any group with any interest in denying global warming in the coming decades.
Zhen-Shan and Xian gathered temperature data for the globe, the Northern Hemisphere, and 10 regions in China from 1881 to 2002; the datasets they chose are the same ones used by the Intergovernmental Panel on Climate Change (IPCC). They also gathered data for atmospheric carbon dioxide (CO2) concentrations over the same 1881 to 2002 period, and again, they selected the data commonly used by climate scientists throughout the world. Anyone criticizing their conclusions would be hard-pressed to argue that Zhen-Shan and Xian used inappropriate data sets.
Any long time series of data can be statistically decomposed into various components - the time series may have some underlying linear trend up or down, the trend could be highly non-linear, there could be breakpoints in the time series, there could be high or low frequency periodicities in the data, the record could change its variability during various periods - you name it. These patterns underlying the data can be clearly identified so that when they are all added together, the original time series is reproduced.
Climatologists have been decomposing time series for many decades using statistical techniques that carry fancy names like Fourier analysis, harmonic analysis, spectral analysis, empirical orthogonal function analysis, and classical factor analysis. Each statistical technique has its own strengths and weaknesses, and each technique has its loyal fan base as well as groups of highly critical scientists. The various techniques make assumptions about the time series being analyzed, they handle missing data in differing ways, and they produce various outputs that can be useful in some investigations but rather useless in others.
In our world of celebrating statistical diversity, Zhen-Shan and Xian roll-out something developed in 1998 called Empirical Mode Decomposition (EMD) that identifies the Intrinsic Mode Function (IMF) components underlying a time series. They show the basic equations for the technique, they argue the advantages of using the technique in analyzing climate data, and they obviously convinced the reviewers and editors of Meteorology and Atmospheric Physics that their work was credible and of potential interest to the atmospheric science community at large.
Figure 1 is a decomposition of the global temperature record since 1881 and it indicates that global temperature variation contains "four quasi-period oscillations on various timescales and a trend of larger timescale in the last century." They note that "IMF3 with quasi 20-year periodicity oscillation and IMF4 with quasi 60-year periodicity oscillation in global" temperature "have been decreasing since the year 2000. Hence, we consider that global temperature will witness a drop on 20-60-year timescales in the following 20 years." They reproduced the analyses for the Northern Hemisphere and the 10 regions in China and find much of the same, and in fact, they argue that the cooling in China is already well underway since 2000.
The global mean temperature is decomposed into four intrinsic mode functions (IMF) and a trend by EMD method. The first IMF is 3-4-year period. The second IMF has 6-8-year period. The third IMF corresponds to 20-year period. The fourth IMF contains 60-year cycles. The Res indicates larger timescale oscillation (from Zhen-Shan and Xian, 2007)
Recall that the pair of scientists also decomposed the annual CO2 since 1881 and compared those IMFs with the global temperature reconstruction. Not very surprisingly, they discovered that "the greenhouse effect of CO2 in the atmosphere on global temperature variation is mainly the century scale trend. And CO2 concentration in the atmosphere has little effect on periodical variation on the rest of the timescale."
That makes perfect sense - the ongoing buildup of greenhouse gases should explain the upward trend in the data but could hardly explain periodicities in the record.
Through more statistical wizardry, they found "the contribution of CO2 concentration to global temperature variation is no more than 40.19%, or in other words, 59.81% of the weight of global temperature variation is caused by non-greenhouse effect."
They report that "Despite the increasing trend of atmospheric CO2 concentration, the components IMF2, IMF3 and IMF4 of global temperature changes are all in falling" and that "the effect of greenhouse warming is deficient in counterchecking the natural cooling of global climate change in the coming 20 years. Consequently, we believe global climate changes will be in a trend of falling in the following 20 years."
They were on a roll and they continued stating "The global climate warming is not solely affected by the CO2 greenhouse effect. The best example is temperature obviously cooling however atmospheric CO2 concentration is ascending from 1940s to 1970s. Although the CO2 greenhouse effect on global climate changes is unsuspicious, it could have been excessively exaggerated. It is high time to re-consider the global climate changes."
Quite a conclusion! Whether this paper falls into the "if you torture the data long enough it will confess" category or not will be determined by the temperature trend in the coming years. As for us, we're not taking any bets on this one.
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Global Warming Is Not a Crisis
From the Babylon of Gilgamesh to the post-Eden of Noah, every age has viewed climate change cataclysmically, as retribution for human greed and sinfulness. In the 1970s, the fear was "global cooling." The Christian Science Monitor then declaimed, "Warning: Earth's climate is changing faster than even experts expect," while The New York Times announced, "A major cooling of the climate is widely considered inevitable." Sound familiar? Global warming represents the latest doom-laden "crisis," one demanding sacrifice to Gaia for our wicked fossil-fuel-driven ways. But neither history nor science bolsters such an apocalyptic faith.
Extreme weather events are ever present, and there is no evidence of systematic increases. Outside the tropics, variability should decrease in a warmer world. If this is a "crisis," then the world is in permanent "crisis," but will be less prone to "crisis" with warming.
Sea levels have been rising since the end of the last ice age, most rapidly about 12,000 years ago. In recent centuries, the average rate has been relatively uniform. The rate was higher during the first half of the 20th century than during the second. At around a couple of millimeters per year, it is a residual of much larger positive and negative changes locally. The risk from global warming is less than that from other factors (primarily geological).
The impact on agriculture is equivocal. India warmed during the second half of the 20th century, yet agricultural output increased markedly. The impact on disease is dubious. Infectious diseases, like malaria, are not so much a matter of temperature as of poverty and public health. Malaria remains endemic in Siberia, and was once so in Michigan and Europe. Exposure to cold is generally more dangerous.
So, does the claim that humans are the primary cause of recent warming imply "crisis"? The impact on temperature per unit CO2 goes down, not up, with increasing CO2. The role of human-induced greenhouse gases does not relate directly to emission rate, nor even to CO2 levels, but rather to the radiative (or greenhouse) impact. Doubling CO2 is a convenient benchmark. It is claimed, on the basis of computer models, that this should lead to 1.1 - 6.4 C warming.
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THE BIODIESL/PALM OIL CONUNDRUM: GREENIE VERSUS GREENIE
America's drive for energy independence and clean air could threaten orangutans, Sumatran tigers, elephants, rhinoceroses and the world's largest butterflies. All could be hurt as the rainforests of Southeast Asia are cleared to produce palm oil for use in biodiesel. It's the downside of the crash effort to rein in global warming.
And the owners of what will be the largest biodiesel plant in the nation - at a deepwater port on Washington state's coast - are well aware of the environmental consequences of logging and burning some of the most biologically diverse forests in the world to provide the prime ingredient for a much-in-demand clean fuel. "We recognize there are serious deforestation issues," said John Plaza, the founder of Imperium Renewables, which is building the plant in the Port of Grays Harbor. "It's not OK to clear rainforest to put palm down. But to demonize an entire industry doesn't do anyone any good. We need to solve these issues." Besides palm, the Grays Harbor plant will convert soy, canola and other feedstocks directly into biodiesel without blending it with any petroleum products.
Oil palm growers, processors, traders, users and several environmental groups have formed the Roundtable for Sustainable Palm Oil, which is developing regulations to ensure an eco-friendly supply of palm oil. Imperium and other U.S. biodiesel manufacturers have joined the roundtable. But some remain wary of the roundtable, and even Plaza is frustrated by how long it's taking to develop sustainable standards. An earlier report prepared for Friends of the Earth, a member of the roundtable, found that the "actual on-the-ground impact of these private-sector initiatives remains negligible at present." The report went on to warn that the palm-oil industry may be incapable of self-regulation.
Efforts to police the palm industry come at a time when worldwide demand for palm oil is soaring, driven mostly by what's expected to be a doubling in biodiesel production by the end of next year.
Billions of people around the world use palm oil for cooking, and it's found in thousands of products including soaps, shampoos, cosmetics and detergents, along with such foods as margarine, mayonnaise, salad oil, potato chips and other snacks, confectionaries, cakes, pastry, bread and ice cream.
Existing biodiesel plants and those on the drawing boards will easily "soak up" all of the palm oil currently available, according to a January report from the financial company Credit Suisse.
More than 85 percent of the world's supply of palm oil comes from two nations - Indonesia and Malaysia. The rainforests on the islands of Borneo and Sumatra are ground zero in the dispute over expanding palm plantations. The forests are logged and burned to make way for the plantations, at times producing a thick blanket of smog that can cover parts of Southeast Asia for weeks and release millions of tons of greenhouse gases. The plantations also are moving into peat swamps, which are drained. As the peat dries, it also releases tons of carbon dioxide. The trend is accelerating. Indonesia is already the third-largest producer of carbon dioxide in the world, behind the United States and China. By 2015, an area of Indonesia the size of West Virginia is expected to be covered with palm plantations. "It's absolutely disingenuous to suggest that biodiesel made from palm oil is green or sustainable," said David Waskow, international program director for Friends of the Earth.
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Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is generally to promote themselves as wiser and better than everyone else, truth regardless.
Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists
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Jim Hansen and his twin
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