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

This paper contains many interesting graphics and provides a good short summary of natural variation and the evidence for such variation.  The author does not find any evidence of influence by carbon dioxide emissions.  In fact, the author debunks some of the supposed evidence used to support the greenhouse effect.

The abstract reads:

A number of published papers and openly available data on sea level changes, glacier retreat, freezing/break-up dates of rivers, sea ice retreat, tree-ring observations, ice cores and changes of the cosmic-ray intensity, from the year 1000 to the present, are studied to examine how the Earth has recovered from the Little Ice Age (LIA). We learn that the recovery from the LIA has proceeded continuously, roughly in a linear manner, from 1800-1850 to the present. The rate of the recovery in terms of temperature is about 0.5°C/100 years and thus it has important implications for understanding the present global warming. It is suggested on the basis of a much longer period covering that the Earth is still in the process of recovery from the LIA; there is no sign to indicate the end of the recovery before 1900. Cosmic-ray intensity data show that solar activity was related to both the LIA and its recovery. The multi-decadal oscillation of a period of 50 to 60 years was superposed on the linear change; it peaked in 1940 and 2000, causing the halting of warming temporarily after 2000. These changes are  natural  changes, and in order to determine the contribution of the manmade greenhouse effect, there is an urgent need to identify them correctly and accurately and remove them from the present global warming/cooling trend.

Reference:

Akasofu, S.-I. 2010. On the recovery from the Little Ice Age. Natural Science 2: 1211-1224.

[Link to full paper, click on Full Text]

The paper’s abstract reads:

At around 2040-2050 we will be in a new major Solar Minimum. It is to be expected that we will then have a new “Little Ice Age” over the Arctic and NW Europe. The past Solar Minima were linked to a general speeding-up of the Earth’s rate of rotation. This affected the surface currents and southward penetration of Arctic water in the North Atlantic causing “Little Ice Ages” over northwestern Europe and the Arctic.

The contention of the paper is that solar cycles affect ocean circulation in the Arctic and that during solar minima, this change in circulation causes cooling. “Variations in Solar activity lead to changes in the Solar Wind and in Solar irradiance, both of which may affect Earth’s climate. The variations in irradiance are known to be small or even minute. The variations in Solar Wind are large and strong, via the interaction with the Earth’s magnetosphere, it affects Earth’s rate of rotation, by that forcing several different terrestrial variables like the Gulf Stream beat in the North Atlantic.”

Read the 13-page paper here.

(PhysOrg.com) — Sunspot formation is triggered by a magnetic field, which scientists say is steadily declining. They predict that by 2016 there may be no remaining sunspots, and the sun may stay spotless for several decades. The last time the sunspots disappeared altogether was in the 17th and 18th century, and coincided with a lengthy cool period on the planet known as the Little Ice Age.

Sunspots are regions of electrically charged, superheated gas (plasma) on the surface of the sun, formed when upwellings of the magnetic field trap the ionized plasma. The magnetic field prevents the gas from releasing the heat and sinking back below the sun’s surface. These areas are somewhat cooler than the surrounding sun surface and so appear to us as dark spots.

Sunspots have been observed at least since the early 17th century, and they are known to follow an 11 year cycle from solar maximum to solar minimum. The solar minimum usually lasts around 16 months, but the current minimum has already lasted 26 months, which is the longest minimum in a hundred years.

Since 1990, Matthew Penn and William Livingston, solar astronomers with the National Solar Observatory (NSO) in Tucson, Arizona, have been using a measurement known as Zeeman splitting to study the magnetic strength of sunspots. The Zeeman splitting is the distance between a pair of infrared spectral lines in a spectrograph taken of the light emitted by iron atoms in the atmosphere of the sun. The wider the distance, the greater is the intensity of the magnetic field.

Penn and Livingston examined 1500 sunspots and found that the average strength of the magnetic field of the sunspots has dropped from around 2700 gauss to 2000 gauss. (In comparison, the Earth’s magnetic field is below one gauss.) The reasons for the decline are unknown, but Livingston said that if the strength continues to decrease at the same rate it will drop to 1500 gauss by 2016, and below this strength the formation of sunspots appears to be impossible.

During the period from 1645 to 1715, a time known as the Maunder Minimum, there were almost no sunspots. This period coincided with the Little Ice Age, which produced lower than average temperatures in Europe. Livingston said their results should be treated with caution as their techniques are relatively new and it is not yet known if the decline in magnetic field strength will continue, and that “only the passage of time will tell whether the solar cycle will pick up.”

David Hathaway, a solar physicist with the Marshall Space Flight Center in Huntsville, Alabama, also cautioned the calculations do not take into account that many small sunspots with relatively weak magnetic fields appeared during the last solar maximum, and if these are not included in the calculations the average magnetic field strength would seem higher than it actually was.

Penn and Livingston’s paper has been submitted to the online colloquium, International Astronomical Union Symposium No. 273.

Maybe, instead of trying to reduce carbon dioxide emissions, we should follow my modest proposal to triple our carbon footprints.