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Climatologists Retrench As Climate Refuses To Warm

Doug Hoffman, The Resilient Earth

Once again we see that the predictions of those who expect the worst are most likely wrong. The lack of sea-level rise over the last half century, the missing spread of drought, the stubborn refusal of major storm frequency to rise, and, most noticeably, the lack of increasing temperatures have conspired to force the climate alarmists back to their models.

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Prognosticating Earth gazers are suddenly revising their estimates of global warming downward.

A newly released study from the Research Council of Norway has climate change alarmists abuzz. One of the things the alarmists have been pushing for is to halt warming at a 2°C increase at any cost (and they mean that literally). In the Norwegian study, much to the alarmists’ dismay, researchers have arrived at an estimate of 1.9°C as the most likely level of future warming. The report also recognizes that temperatures have stabilized at 2000 levels for the past decade even though CO2 levels have continued to rise.

Meanwhile, a reconstruction of the Eemian interglacial from the new NEEM ice core, published in the journal Nature, shows that in spite of a climate 8°C warmer than that of the past millennium, the ice in Northern Greenland  was only a few hundred meters lower than its present level. This finding casts doubt on the projected melting of ice sheets and resulting sea-level rise.

After rising sharply through the 1990s, Earth’s mean surface temperature has leveled off nearly completely at its 2000 level. Ocean warming also appears to have stabilized, despite the fact that CO2 emissions and other anthropogenic factors claimed to contribute to global warming are still on the rise. Clearly, a number of factors affect climate development, not just the usual suspects cited by the Intergovernmental Panel on Climate Change (IPCC).

The complexity of the climate system is further compounded by feedback mechanisms—how factors such as clouds, evaporation, snow and ice interact with one another. Uncertainties about the impact of feedback mechanisms make it very difficult to predict future climate change. Moreover, predicting how much of the rise in Earth’s mean surface temperature is due to manmade emissions is nearly impossible in the face of our lack of knowledge.

That has not stopped some groups from prognosticating, predicting that catastrophic climate change is just around the corner and we, humanity, are to blame. One hotbed of blame-humanity-first climate science has been the UK’s Met Office. But strange things are happening at the Met. Their latest long-term forecast basically says that temperatures will stay the same for the next five years. If this comes to pass we will have experienced a full two decades—twenty years—of flat temperatures, supposedly in the midst of killer global warming.

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The Met Office says temperatures will remain flat until 2017.

“Global average temperature is expected to remain between 0.28 °C and 0.59 °C (90% confidence range) above the long-term (1971-2000) average during the period 2013-2017, with values most likely to be about 0.43 °C higher than average,” they state, intentionally obfuscating the fact that temperatures have been in that same range for 16 years. That range is only higher than average based on an arbitrarily choice of reference that includes the cold decades between 1970 and 1990. Some people have a hard time speaking the simple truth when it contradicts their personal beliefs.

One way to predict temperature rise is to use computer models that have at their heart a simple metric called climate sensitivity. Climate sensitivity is a measure of how much global mean temperature will rise if the level of greenhouse gases in the atmosphere double. The baseline used is the world’s preindustrial level from the year 1750. Since CO2 is the primary greenhouse gas emitted by human activity, and its level is easily measured, a simplistic way to predict temperature will rise is to link it to a doubling of  CO2.

According to the IPCC, the climate’s sensitivity to doubled atmospheric CO2 levels is probably between 2°C and 4.5°C, with the most probable being 3°C of warming. In the new Norwegian study, however, researchers have arrived at an estimate of 1.9°C as most likely. According to the official news release:

The figure of 1.9°C as a prediction of global warming from a doubling of atmospheric CO2 concentration is an average. When researchers instead calculate a probability interval of what will occur, including observations and data up to 2010, they determine with 90% probability that global warming from a doubling of CO2 concentration would lie between 1.2°C and 2.9°C.

This maximum of 2.9°C global warming is substantially lower than many previous calculations have estimated. Thus, when the researchers factor in the observations of temperature trends from 2000 to 2010, they significantly reduce the probability of our experiencing the most dramatic climate change forecast up to now.

A reasonable question would be how this new study differs from those in the past. “In our project we have worked on finding out the overall effect of all known feedback mechanisms,” says project manager Terje Berntsen, who is a professor at the University of Oslo’s Department of Geosciences and a senior research fellow at the Center for International Climate and Environmental Research – Oslo (CICERO).  “We used a method that enables us to view the entire earth as one giant ‘laboratory’ where humankind has been conducting a collective experiment through our emissions of greenhouse gases and particulates, deforestation, and other activities that affect climate.”

The consensus-estimate of 1.5°C to 4.5°C for climate sensitivity has remained unchanged for two decades. Nevertheless, during these years scientific knowledge regarding climate has changed dramatically—new factors have been discovered, theories refactored and old data refined. This study is important not just for what it says about warming levels but because climate scientists, after over a decade of denial, are finally coming to grips with the lack of recent global temperature rise. In other words, they are finally taking a more balanced look at what is for them a very inconvenient truth. Naturally, the climate change establishment (i.e. the IPCC and its supporters) are skeptical of the new results. Still, those who have reviewed the study are reported as “enthusiastic.”

“These results are truly sensational,” says Dr Caroline Leck, an internationally renowned climate researcher at Stockholm University. “If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate.”

As heartening as the Norwegian study is, there was more good news on the climate catastrophe front. Previous efforts to extract a Greenland ice core with a complete record of the Eemian interglacial have been unsuccessful. Now, in an article published in Nature, “Eemian interglacial reconstructed from a Greenland folded ice core,” by researchers known collectively as the NEEM community, new information has come to light regarding Greenland ice melt during the previous interglacial.

From all indications, the Eemian interglacial (130,000 to 115,000 years ago) was significantly warmer than our own Holocene. A new North Greenland Eemian Ice Drilling (‘NEEM’) ice core shows just how warm, and surprisingly indicates only modest ice-sheet melting in response to the strong warming. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the present-day annual average of roughly −25 °C. This early peak was followed by a gradual cooling that was probably driven by decreasing summer insolation. These findings are summarized in the figure below, which is followed by a description from the article.

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Reconstruction of the temperature and elevation history through the Eemian based on the stable water isotopes (δ18Oice) and the air content records. The zone with surface melt (127–118.3 kyr bp) is shaded in light grey. a, The measured δ18Oice record (black) on the constructed timescale. The average of the recent millennium (−33.60‰) is marked with a thin black line. It is seen that the δ18Oice values at the depositional locations in the melt zone are above −33.0‰ (grey horizontal line). The fixed-elevation change of temperature—constructed from the observed δ18Oice, the elevation changes determined from the air content and the upstream corrections (curves below)—is shown as a red curve using the red axis. The standard error range (orange shading) is a sum of the error of the δ18Oice and the elevation change correction. b, Air content (black) is plotted and guided by the two stable levels on each side of the melt zone. A dot-dashed line connecting these levels has been suggested with an error range as the dark grey shaded area. The standard error range is a sum of the error assumed in the zone with surface melt (127–118.3 kyr bp) and the 1% error on the air content measurements. In addition, the average level 107–105 kyr bp is marked with a horizontal black bar. The changes in the air content are caused by pressure changes due to changing surface elevation at the depositional sites and changes to the air trapping processes in the firn assumed to be controlled by the changing summer insolation. c, When corrected for upstream flow (cyan) and summer insolation changes (green), the air content curve can be ‘translated’ to elevation changes (blue, dashed) with the shaded zone indicating the uncertainty range introduced by this translation. Blue bars mark the air content of the ‘translated’ air content black bars.

Ice core analysis shows that the ice sheet at the NEEM site did not get much thinner than its present 2.5 kilometers. This was indicated by the air content in the core, which the team correlated with elevation. Before the Eemian warming began, the Greenland ice sheet was some 200 meters thicker than it is today. But after six millennia of strong warming the ice sheet lost just over one-tenth of its thickness, dropping to 130 meters below its present height. It then remained steady until the end of the Eemian. The NEEM core implies that Greenland’s ice sheet lost at most one-quarter of its volume, and contributed no more than 2 meters of sea-level rise.

The bottom line on this report is that Greenland’s ice sheet, even when subjected to significantly warmer temperatures than today, did not melt rapidly and disappear as some alarmists would have us believe. Those who point to Greenland’s melting ice and predict massive sea-level rise are in for some disappointment. And need I point out that those higher Eemian temperatures occurred when what few humans existed had only campfires to contribute to their carbon footprints.

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Not likely to disappear quite as fast as they thought.

“We are in a similar climate regime as the world was in the early Eemian,” says Eric Steig, a researcher who studies ice cores at the University of Washington in Seattle. “It’s illuminating to see just how strongly Greenland had warmed at the time. That the warming seemingly caused only relatively modest melting is of course also remarkable.”

Once again we see that the predictions of those who expect the worst are most likely wrong. The lack of sea-level rise over the last half century, the missing spread of drought, the stubborn refusal of major storm frequency to rise, and, most noticeably, the lack of increasing temperatures have conspired to force the climate alarmists back to their models. Granted, the Norwegian study is only a minor retrenchment, but it is a start. After all, one of the great things about the scientific method is that it is self-correcting. Climate crystal ball gazers can predict anything they want, but physical reality will not be denied. True science is about reality, not computer models.

Be safe, enjoy the interglacial and stay skeptical.

The Resilient Earth, 28 January 2013