Researchers have discovered the rare mineral Ikaite in sediment cores from Antarctica.  Ikaite is a hexahydrate of calcium carbonate, CaCO₃·6H₂O, that exists in nature only at temperatures cooler than about 44° F.  At warmer temperatures is decomposes or recrystallizes into a form of calcite called glendonite (see photo).

The significance of the discovery is that the water within the ikaite crystal lattice contains oxygen-18 (d18O) isotopes which are a proxy for temperature.  Therefore, analysis of the ikaite can give a record of the ambient temperature at the time the mineral formed.

According to a press release from Syracuse University:

Ikaite crystals incorporate ocean bottom water into their structure as they form. During cooling periods, when ice sheets are expanding, ocean bottom water accumulates heavy oxygen isotopes (oxygen 18). When glaciers melt, fresh water, enriched in light oxygen isotopes (oxygen 16), mixes with the bottom water. The scientists analyzed the ratio of the oxygen isotopes in the hydration water and in the calcium carbonate. They compared the results with climate conditions established in Northern Europe across a 2,000-year time frame. They found a direct correlation between the rise and fall of oxygen 18 in the crystals and the documented warming and cooling periods.

The abstract from the research paper reads:

Calcium carbonate can crystallize in a hydrated form as ikaite at low temperatures. The hydration water in ikaite grown in laboratory experiments records the d18O of ambient water, a feature potentially useful for reconstructing d18O of local seawater. We report the first downcore d18O record of natural ikaite hydration waters and crystals collected from the Antarctic Peninsula (AP), a region sensitive to climate fluctuations. We are able to establish the zone of ikaite formation within shallow sediments, based on porewater chemical and isotopic data. Having constrained the depth of ikaite formation and d18O of ikaite crystals and hydration waters, we are able to infer local changes in fjord d18O versus time during the late Holocene. This ikaite record qualitatively supports that both the Medieval Warm Period and Little Ice Age extended to the Antarctic Peninsula.

Note that the Medieval Warm Period and Little Ice Age disappeared in Michael Mann’s infamous hockey stick graph and from IPCC reports.  This discovery is another piece of physical evidence that the Medieval Warm Period, a time when global temperatures were as warm or warmer than today, was indeed a worldwide phenomena.  It is also another piece of evidence that recent warming is nothing unusual.

See also:

Norwegian research shows that current warming is not unusual

More evidence that current warming is not unusual

We keep hearing in the press that the year 2010 has been the hottest ever, or at least hottest since 1880, or at least hottest since it’s been cooler. That claim is partially the result of cherry-picking data and even manufacturing data with sophisticated computer programs that “invented” weather stations where none exist.

Here is some real data, from NOAA High Plains Regional Climate Center, of temperature departure from normal for January 1, 2010 through July 31, 2010. It shows that the northeast U.S. has been warmer than normal, but about 60% of the U.S. has had temperatures below normal.

Source: http://www.hprcc.unl.edu/products/maps/acis/YearTDeptUS.png

In the Arctic, spring sea ice melting got a late start, then melted faster than normal, and now has returned to a normal rate (see red line in graph below).

Source: http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

From Dr. Roy Spencer at UAH: “Sea Surface Temperatures (SSTs) measured by the AMSR-E instrument on NASA’s Aqua satellite continue the fall which began several months ago. The following plot, updated through July 29, 2010 shows that the cooling in the Nino34 region in the tropical east Pacific continue to be well ahead of the cooling in the global average SST, something we did not see during the 2007-08 La Nina event.

Spencer’s graph of atmospheric temperatures, based on satellite readings, show that 2010, an El Nino year, is warmer than the 1979-2001 average, but still cooler than 1998, also an El Nino year:

Abundant research shows that the Medieval Warm Period, ca. 1100 to 1300 A.D. was about 6 degrees F warmer than now (see one example here.)

Meanwhile, in the southern hemisphere:

Peru declared state of emergency amid plunging temperatures. Hundreds die from extreme cold in remote mountain villages also struggling with severe poverty. Source UK.Guardian. Brazil, Argentina, and Uruguay experience extreme cold. In Bolivia, tropical areas temperatures plummeted to zero causing “millions of dead fish” in rivers that normally flow in an environment of 20 Celsius.

Antarctic sea ice extent is greater than normal (Data from National Snow and Ice Data Center in Boulder, Colorado.)

When put into perspective, 2010 is not so hot. Last winter when much of the U.S. experienced very cold weather, climate alarmists dismissed that saying short term weather is not climate. In that they were right. But now since we’ve had a hot June, those same people are using a short-term weather phenomenon to claim that the climate is heating up. The climate has cycles of many different periods from years to centuries to millennia to hundreds of millions of years. Where we are now in these cycles seems to depend on who is doing the measuring and data compilation. Lost in the prognostications and press releases is evidence of causation. In the case of those who say we are experiencing unprecedented warming is the implication that humans are the main cause, but those same people are unable to present any compelling physical evidence to support that contention. Personally, I find the physical geological evidence of natural climate cycles both compelling and sufficient to explain the trends. The contention that this year or this decade is warmer or cooler than some time in the past proves nothing.

Dr. Ross McKitrick has just published “A Critical Review of Global Surface Temperature Data Products,” which goes into great detail about problems with our temperature data sets (73 pages). That paper documents a major reduction in world-wide weather stations since 1970. The remaining stations are skewed toward airport sites, lower latitudes, and lower elevations; each of which produces a warming bias in the data. McKitrick concludes, “The overall conclusion of this report is that there are serious quality problems in the surface temperature data sets that call into question whether the global temperature history, especially over land, can be considered both continuous and precise. Users should be aware of these limitations, especially in policy-sensitive applications.”

For some further perspective see a recent report of a drilling project in Greenland. This project drilled more than 1.5 miles into the ice to investigate “the Eemian interglacial period from about 115,000 to 130,000 years ago, a time when temperatures were 3.6 to 5.4 degrees Fahrenheit above today’s temperatures.” “Ice cores from previous drilling efforts revealed temperature spikes of more than 20 degrees Fahrenheit in just 50 years in the Northern Hemisphere.” So what if the last decade was the warmest since whenever?