November 5, 2007

Greenland Climate: Now vs. Then, Part II. Record Greenland Melt Area?

Filed under: Arctic, Climate History, Polar

Recently the press was more ablaze than California with NASA proclamations that the surface area of Greenland had melted in 2007 at a record-high rate. This is true, if the record only extends back only 20 years or so—which is the case of the NASA dataset. If you could peer back a bit further into the past, say back into the 1950s, it is quite likely that the melt area in Greenland then was about the same as it is now, effectively rendering the 2007 melt area hardly newsworthy. Just another NASA climate-change exaggeration?

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October 24, 2007

Tropical Cyclones of China

Recently, former Vice President Al Gore won a share of the Nobel Peace Prize for his contributions to our understanding of the global warming problem. His film was seen as a masterpiece that certainly sealed the deal on his Nobel Prize. However, on the same day the Nobel committee honored Gore, world renowned hurricane specialist Dr. William Gray told a packed lecture hall at the University of North Carolina that humans were not responsible for the warming of the Earth and not responsible for alter hurricane patterns, as strongly suggested in the Gore film. Gray told the crowd “They’re going to the Gore movie and being fed all this,” and “It’s ridiculous. The human impact on the atmosphere is simply too small to have a major effect on global temperatures.” Dr. Gray said there were 101 hurricanes from 1900 to 1949 in a period of cooler global temperatures compared to 83 hurricanes between 1957 and 2006. Don’t look for Dr. Gray to receive a Nobel Prize anytime soon.

As we sit through a ho-hum year in terms of hurricanes (a.k.a., tropical cyclones) in the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea, another article has appeared in the professional literature with results that call into question any prediction about more tropical cyclones in the future. The latest work comes from a team of scientists with China’s Shanghai Typhoon Institute and is published in the Chinese journal Acta Oceanologica Sinica (you may notice a few misspelled words and odd phrases in some quotes from the article). The work was funded by the National Natural Science Foundation of China and the Special Climate Project of China’s Meteorological Administration.

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October 22, 2007

A million square miles of open water

A couple of weeks ago, New York Times science writer Andrew Revkin wrote a piece titled “Arctic Melt Unnerves the Experts” in which he described this year’s record low Arctic summer sea ice extent and the how the dramatic decline over last year had caught many sea-ice scientists by surprise. Revkin goes on to interview a variety of experts on the topic of sea ice, most of which realize that some (most) of the sea ice decline observed over the past several decades is likely related to anthropogenic changes to the earth’s climate, while admitting that undoubtedly, some natural (non-human-influenced) processes likely contributed to the decline as well.

Revkin starts out by noting “astonished by the summer’s changes [in ice extent], scientists are studying forces that exposed one million square miles of open water—six Californias—beyond the average since satellites started measurements in 1979.”

And then he continues:

Proponents of cuts in greenhouse gases cited the meltdown as proof that human activities are propelling a slide toward climate calamity.

Arctic experts say things are not that simple. More than a dozen experts said in interviews that the extreme summer ice retreat had revealed at least as much about what remains unknown in the Arctic as what is clear. Still, many of those scientists said they were becoming convinced that the system is heading toward a new, more watery state, and that human-caused global warming is playing a significant role.

For one thing, experts are having trouble finding any records from Russia, Alaska or elsewhere pointing to such a widespread Arctic ice retreat in recent times, adding credence to the idea that humans may have tipped the balance. Many scientists say the last substantial warming in the region, peaking in the 1930s, mainly affected areas near Greenland and Scandinavia.

Depending on what Revkin meant by “recent times,” perhaps we could help him out as to where he may look in order to find out some information indicating that “widespread Arctic ice retreat” has occurred without any human help. If Revkin meant “since satellites started measurements in 1979” then, he probably has that covered, but if by “recent” he meant within the past 100 years or so, then maybe we could suggest a few other avenues to investigate.

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October 5, 2007

Big Apple Hurricanes

Imagine if a large hurricane struck New York City during this tropical cyclone season – the devastation would be incredible and during and following the disastrous event, global warming would undoubtedly be blamed for the all that happened to the Big Apple. Believe it or not, this will happen sometime in the not-so-distant future, it’s a virtual lock! New York City has been struck many times in the past by tropical cyclones, and it is just a matter of time before another hurricane passes directly over the city. Officials there are fully aware of the threat, as this brochure attests, providing plenty of information about hurricane evacuation zones located throughout the metropolitan area.

As we have detailed many times in the past, there is a considerable debate in the climate community regarding the future of hurricane activity. There are several prominent scientists arguing that recent global warming has increased tropical sea surface temperatures (SSTs) that can support more hurricanes, stronger events with much higher destructive powers, and hurricanes that simply last longer. These scientists and their many followers have suggested that Katrina and other recent hurricanes have been made more destructive given the ongoing buildup of greenhouse gases. Many others have raised substantial doubts about the proposed link between greenhouse gases and hurricane activity (we have covered many of their research papers, for the latest, see here). Nonetheless, should a large hurricane pass over downtown Manhattan, scientists promoting the greenhouse link would breathlessly appear on our televisions 24 hours a day.

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September 14, 2007

Sea-Level Slowdown?

We have heard a million times that if we don’t stop emitting greenhouse gases, our inexcusable actions will result in a warmer earth, and the warming of the planet will cause icecaps and mountain glaciers to melt and sea level to rise. Island nations will be drowned, coastlines around the world will go underwater, Florida will cease to exist, and the World Trade Center Memorial could someday be a sight seen only by scuba enthusiasts. The United Nations Intergovernmental Panel on Climate Change says very clearly in the Summary for Policymakers “Global average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961 to 2003. The rate was faster over 1993 to 2003: about 3.1 [2.4 to 3.8] mm per year. Whether the faster rate for 1993 to 2003 reflects decadal variability or an increase in the longer-term trend is unclear. There is high confidence that the rate of observed sea level rise increased from the 19th to the 20th century.” The IPCC crew reminds us that “Global average sea level in the last interglacial period (about 125,000 years ago) was likely 4 to 6 m higher than during the 20th century, mainly due to the retreat of polar ice.” It seems that sea levels fell and rose many times in the past and long before humans had any chance interfere with the natural order of things. There is no reason whatsoever to expect sea level to remain constant – it never has and it never will.

We have covered this sea-level rise issue many times in the past at World Climate Report and we fully agree that sea level is rising – sea level has been somewhat steadily rising for the past 10,000 years. During the last glacial advance, a large amount of fresh water was tied up in ice, and as the glaciation ended, that water returned to the oceans. Furthermore, as the earth warmed up following the last glacial advance, thermal expansion of the ocean water occurred, and sea level rose even more. There is little doubt that the sea-level rise will continue into the future, but the rate of rise is the focus of an interesting paper published recently in Global and Planetary Change by a team of scientists from France and Spain.

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August 23, 2007

Taming the Hurricane

On September 28, 1955, a Category 5 hurricane named Janet slammed into Chetumal, on Mexico’s Yucatan Peninsula, killing over 600 people.

Hurricane Dean, another Category 5, and the third-strongest storm ever measured at landfall, hit in exactly the same place earlier this week (Tuesday, August 21,2007) and killed no one. Maximum winds in both storms were indistinguishable. The hurricane-hunter pilot who flew through the eyewall of the storm Tuesday reported severe turbulence, which is a temporary loss of aircraft control. Probably for the first time in human history, a Category 5 storm hit a populated area and everyone lived.

Because of its peculiar location, the Yucatan takes more big hurricane hits than just about anywhere else in the western hemisphere. When Mexico was dirt-poor, as it was in 1955, hurricanes could kill hundreds. They were warned, then, too. Hurricane-hunter planes also monitored Janet. Only one of these has ever been lost, and it as Janet was making landfall.

Similar storms, huge storms, very different results. What’s happening here?

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August 22, 2007

Ocean Circulation Slowdown: False Alarm

We are sure many of you remember headlines similar to these: “Global Warming to Cause Next Ice Age!” or “Global Warming to Send Europe into a Deep Freeze!” In fact, next time New England or Europe has a cold winter, we’ll guarantee that you’ll see them again. The idea behind this scare story (and the premise of the climatefright film The Day After Tomorrow) is that the ocean’s thermohaline circulation (which among other things modestly warms the winter climate of western Europe) slows down, or even worse stops, sending the climate into disarray—all because of anthropogenic global warming. In the case of The Day After Tomorrow, this circulation shut down led to a flash freeze of the planet, while more “reasonable” climate alarmists at least give it a couple of decades to turn Europe into the icebox. But, in reality, things just don’t seem to be headed that way at all.

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August 8, 2007

Clouding Asian Warming

In 1998, Balling et al. published an article in Climate Research dealing with summer and winter warming rates in several widely-used gridded temperature time series. As seen in Figure 1 below, the Balling crew (which includes several World Climate Report team members) found that winters were warming far more than summers, based on near-surface thermometer records, for a large part of northern and central Asia over the period 1946-1995. We repeated the analyses for the satellite-based lower-tropospheric temperature measurements over the period 1979-1995 and found the same red blob (wamer temperatures) over northern and central Asia. We suggested in the article that the build-up of greenhouse gases would most impact the coldest and driest air masses of the world, which just happen to be the air masses that cover northern and central Asia in the winter. Elevated greenhouse gas concentrations in warm and moist air masses would have less of an effect given the overwhelming greenhouse effect of naturally occurring water vapor. We had produced what appeared to be a smoking gun – the greenhouse “fingerprint” looked rather obvious in our analyses. Of course, finding that the coldest and driest air masses of the planet were warming slightly is seen by some as a blessing and not a great cause for concern – are residents of northern Siberia really worried about their winters being a bit warmer?


Figure 1. Seasonal difference (winter minus summer) in temperature trends (°C per decade) for the thermometer-based near-surface data over the period 1946-1995 (from Balling et al., 1998).

Well, the smoking gun has become a bit cloudier given a recent article in Nature entitled “Warming trends in Asia amplified by brown cloud solar absorption.”

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June 26, 2007

Mont Blanc Glaciers Refuse to Shrink?

If you have an interest in global warming and its effect on mountain glaciers, you will be thrilled to know that there are over one million websites on the subject. Even before you get to the first site, you already know what you will find. Burning fossil fuels increases atmospheric concentrations of greenhouse gases, the Earth is warming, mountain glaciers are in full retreat all over the planet, delicate ecosystems are in peril, and humans who rely on the freshwater from mountain glaciers better get creative fast. Recall that in the Gore film, a great deal of attention was paid to the diminishing “snows of Kilimanjaro” – Gore has made hay in Glacier National Park as well pointing to shrinking glaciers. Retreating mountain glaciers have become a poster-child of the global warming alarmists – no presentation on the subject is complete without one.

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June 12, 2007

A Kilimanjaro We-told-you-so

File this one under “we been telling you this for years.”

The headline of the University of Washington press release reads “The woes of Kilimanjaro: Don’t blame global warming.” The press release was prepared to announce an article in an upcoming issue of American Scientist magazine (linked to by the press release), by Phil Mote (University of Washington research scientist and State Climatologist of Washington) and Georg Kaser (glaciologist at the University of Insbruck, Austria)

The press release begins:

The “snows” of Africa’s Mount Kilimanjaro inspired the title of an iconic American short story, but now its dwindling icecap is being cited as proof for human-induced global warming.

However, two researchers writing in the July-August edition of American Scientist magazine say global warming has nothing to do with the decline of Kilimanjaro’s ice, and using the mountain in northern Tanzania as a “poster child” for climate change is simply inaccurate.

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