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The controversy swirling around the leaked e-mails of climate scientists apparently trying to downplay data and exclude dissenting opinions has led to calls for President Obama to skip this month's climate summit in Denmark until the e-mails can be investigated.

Instead, the White House announced Friday that Obama was doubling down on his commitment to the summit's goals and moving his visit later in the month, hoping it will secure a "meaningful" agreement.

The scandal being referred to as "Climate-gate" has rallied global warming skeptics, who say the threat is exaggerated -- let alone caused by humans. In some of the e-mails stolen by hackers and posted online, scientists at Britain's University of East Anglia's Climatic Research Unit appear to discuss hiding or deleting data that may contradicts global warming claims. Others discuss ways of keeping competing research out of peer-reviewed journals.

Former Republican vice presidential candidate Sarah Palin is the most prominent figure to call on Obama to boycott the conference in Copenhagen in the wake of the e-mails' release.

"The president's decision to attend the international climate conference in Copenhagen needs to be reconsidered in light of the unfolding Climategate scandal," she said in a posting on her Facebook page. "Boycotting Copenhagen while this scandal is thoroughly investigated would send a strong message that the United States government will not be a party to fraudulent scientific practices."

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But on Friday, Obama abruptly delayed his arrival at the summit until Dec. 18, the last scheduled day and considered a crucial period when more leaders will be in attendance. Obama is hoping to capitalize on steps by India and China and build a more meaningful political accord, the White House said.

The U.S., India, and China all have specific proposals on the table for the first time, and world leaders are aiming for a deal that includes commitments on reducing emissions and financing for developing countries. They no longer expect to reach a legally binding agreement, as had long been the goal.

The White House is shrugging off the Climate-gate e-mails.

"I think there's no real scientific basis for the dispute of (global warming)," White House Press Secretary Robert Gibbs said this week.

And Obama's top science adviser, John Holdren, downplayed the e-mails Friday, telling Congress that the controversy involves a small group of scientists and how they have interpreted and shared global warming data.

"It's important to understand that these kinds of controversies and even accusations of bias and improper manipulation are not all that uncommon in science, in all branches of science," he said at a congressional hearing.

"The strength of science is that these kinds of controversies get sorted out over time as to who is wrong, who is right, and how much it matters, by the process of peer-review and continued critical scrutiny by the knowledgeable community of scientists," he said.

Rep. Darrell Issa, the top Republican on the House Oversight and Government Reform Commmittee, on Friday joined Sen. James Inhofe, R-Okla., in calling on the Obama administration and Congress to investigate the Climate-gate e-mails.

"The very integrity of the report that the Obama administration has predicated much of its climate change policy upon has been called into question and it is unconscionable that this administration and Congress is willing to abdicate responsibility of uncovering the truth to the United Nations,"   the California Republican said in a written statement.

"The administration's Climate-gate denials and refusal to acknowledge the need for a congressional investigation are a sad abdication of their responsibility to ensure that U.S. policies are not driven by corrupted science and data," he said.

Some climate change analysts say the e-mails undermine the entire Denmark conference.

"This raises questions about some of the very U.N. science that forms the basis of what's going to be discussed in Copenhagen," said Ben Lieberman, a senior policy analyst at the conservative Heritage Foundation and an expert on energy and environmental issues.

"There's a lot to be concerned about here," he told Fox News. "At the very least the president shouldn't agree to anything in Copenhagen until we get to the bottom of Climate-gate and find out just how much there is to global warming that we can still trust."

Despite a recent decline in global temperatures, the trend over the past 150 years has shown temperatures rising -- but the timing of the e-mail scandal is perfect for skeptics, said Heather Conley, senior fellow with the Center for Strategic and International Studies.

"It doesn't negate the fact that the global community does need to address its rate of emitting carbon and it needs to develop clean and greener technologies, but it does continue to throw this debate out there," she said.

The president's climate czar, former Environmental Protection Agency administrator Carol Browner, said she's sticking with scientists who believe in man's impact on global warming.

Fox News' Wendell Goler and The Associated Press contributed to this report.