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.

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.

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

A federal wildlife biologist whose observation that polar bears likely drowned in the Arctic helped galvanize the global warming movement during the last decade was placed on administrative leave while officials investigate scientific misconduct allegations.

While it wasn't clear what the exact allegations are, a government watchdog group representing Anchorage-based scientist Charles Monnett said investigators have focused on his 2006 journal article about the bears that garnered worldwide attention.

The group, Public Employees for Environmental Responsibility, filed a complaint on Monnett's behalf Thursday with the agency, the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement.

NASA satellite data from the years 2000 through 2011 show the Earth's atmosphere is allowing far more heat to be released into space than alarmist computer models have predicted, reports a new study in the peer-reviewed science journal Remote Sensing. The study indicates far less future global warming will occur than United Nations computer models have predicted, and supports prior studies indicating increases in atmospheric carbon dioxide trap far less heat than alarmists have claimed.

Study co-author Dr. Roy Spencer, a principal research scientist at the University of Alabama in Huntsville and U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer flying on NASA's Aqua satellite, reports that real-world data from NASA's Terra satellite contradict multiple assumptions fed into alarmist computer models.

This isn’t the endorsement Mitt Romney needs right now.

Liberal Al Gore took to his blog Wednesday to applaud the former Massachusetts governor for his stance on climate change.

“Good for Mitt Romney,” Gore, the former Democratic vice president, wrote about the Republican seeking the White House in 2012.

He continued: “While other Republicans are running from the truth, he is sticking to his guns in the face of the anti-science wing of the Republican Party.”

Gore went on to reference a Washington Post story that said Romney during a town hall meeting last week “stuck to the position he has held for many years — that he believes the world is getting warmer and that humans are contributing to it.”

Virginia Attorney General Kenneth T. Cuccinelli II says a judge’s order compelling the University of Virginia to turn over thousands of pages of climate-change research will likely alter his own battle for the long-sought documents.

The Republican attorney general and state Delegate Robert G. Marshall have battled the university for more than a year over the release of documents related to the work of former professor Michael Mann. Mr. Mann had been involved in a leaked email exchange with colleagues that climate-change skeptics claimed showed scientific misconduct.

Mr. Marshall, Prince William Republican, requested the documents through the Freedom of Information Act, while Mr. Cuccinelli subpoenaed them. Mr. Cuccinelli said an order issued Tuesday in Prince William County Circuit Court that grants Mr. Marshall’s request could affect his own appeal to the state Supreme Court to reverse a previous ruling in favor of the university.

The Polar Bear Specialist Group of the International Union for the Conservation of Nature (IUCN), the organization of scientists that has attempted to monitor the global polar bear population since the 1960s, has issued a report indicating that there was no change in the overall global polar bear population in the most recent four-year period studied.

“The total number of polar bears is still thought to be between 20,000 and 25,000,” the group said in a press release published together with a report on the proceedings of its 15th meeting

20,000 to 25,000 polar bears worldwide is exactly the same population estimate the group made following its 14th international meeting.

Newt Gingrich, the former Republican Speaker, Tim Pawlenty, the former governor of Minnesota, and Mitt Romney, have all been put on the defensive for past assertions that climate change was real. Each candidate is handling it differently, at least so far.

Gingrich formally announced he was running for president in 2012 on Wednesday.

Following the devastating fires in Southern California, the Select Committee on Energy Independence and Global Warming will hold a hearing examining the scientific link between a changing climate and the frequency and intensity of wildfires. Witnesses wil

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