Is this finally proof we're NOT causing global warming? The whole of
the Earth heated up in medieval times without human CO2 emissions, says
new study

• 
  Evidence was found in a rare mineral that records global temperatures
• Warming was global and NOT limited to Europe
• Throws doubt on orthodoxies around 'global warming'
  

By
Ted Thornhill


PUBLISHED:

07:21 EST, 26 March 2012




UPDATED:

07:55 EST, 26 March 2012


Current theories of the causes
and impact of global warming have been thrown into question by a new
study which shows that during medieval times the whole of the planet
heated up.It then cooled down naturally and there was even a 'mini ice age'.


A team of scientists led by geochemist Zunli Lu from Syracuse University
in New York state, has found that contrary to the ‘consensus’, the
‘Medieval Warm Period’ approximately 500 to 1,000 years ago wasn’t just
confined to Europe.In
fact, it extended all the way down to Antarctica – which means that the
Earth has already experience global warming without the aid of human CO2
emissions.


Cold facts: Antarctica actually warmed up during medieval times, contrary to what climate scientists believe


At present the Intergovernmental
Panel on Climate Change (IPCC) argues that the Medieval Warm Period was
confined to Europe – therefore that the warming we’re experiencing now
is a man-made phenomenon.

However, Professor Lu has
shown that this isn’t true – and the evidence lies with a rare mineral
called ikaite, which forms in cold waters.‘Ikaite
is an icy version of limestone,’ said Lu. ‘The crystals are only stable
under cold conditions and actually melt at room temperature.’It
turns out the water that holds the crystal structure together - called
the hydration water - traps information about temperatures present when
the crystals formed. This finding by Lu's research team establishes, for the first time, ikaite as a reliable way to study past climate conditions.




Evidence that the Earth heated up over a 1,000 years ago was found in a rare mineral called ikaite


The scientists studied ikaite crystals
from sediment cores drilled off the coast of Antarctica. The sediment
layers were deposited over 2,000 years. The
scientists were particularly interested in crystals found in layers
deposited during the ‘Little Ice Age,’ approximately 300 to 500 years
ago, and during the Medieval Warm Period before it.
Both
climate events have been documented in Northern Europe, but studies
have been inconclusive as to whether the conditions in Northern Europe
extended to Antarctica.Lu’s team found that in fact, they did.

They were able to deduce this by studying the amount of heavy oxygen isotopes found in the crystals.

During cool periods there are lots, during warm periods there aren’t.

‘We
showed that the Northern European climate events influenced climate
conditions in Antarctica,’ Lu says. ‘More importantly, we are extremely
happy to figure out how to get a climate signal out of this peculiar
mineral. A new proxy is always welcome when studying past climate
changes.’The research was
recently published online in the journal Earth And Planetary Science
Letters and will appear in print on April 1.
Read more: http://www.dailymail.co.uk/sciencetech/article-2120512/Global-warming-Earth-heated-medieval-times-human-CO2-emissions.html#ixzz1qLX9PpAN

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