The incoming head of America's Environmental Protection Agency, climate skeptic Scott Pruitt, said Thursday he believes that carbon dioxide is not a primary contributor to global warming.

A known fossil-fuel ally, Pruitt's appointment to head the EPA - a department he repeatedly sued as a state attorney general - was deeply contentious.

'I think that measuring with precision human activity on the climate is something very challenging to do and there's tremendous disagreement about the degree of impact, so no, I would not agree that it's a primary contributor to the global warming that we see,' Pruitt told CNBC's Squawk Box Thursday.

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At odds: New EPA boss Scott Pruitt's stance is at odds with the international scientific consensus that underpins the landmark Paris Agreement

Emissions: Scott Pruitt said that carbon dioxide emissions were not 'a primary contributor' to global warming. His words suggest he believes it climate change is not man made

This past January was the third warmest on record, a new analysis of global temperatures has revealed. The data show January was .92 degrees Celsius warmer than the average January temperature from 1951-1980

'We need to continue the debate and continue the review and the analysis,' he added.

Pruitt's stance is at odds with the international scientific consensus that underpins the landmark Paris Agreement, which saw more than 190 world leaders agree to lower emissions that lead to global warming.

President Donald Trump's team is reportedly divided over whether the United States should withdraw from the Paris climate accord, negotiated under Barack Obama.

Pruitt - whose agency is tasked with implementing US commitments to lower emissions - described the Paris accord as a 'bad deal.'

'I happen to think the Paris accord, the Paris treaty, or the Paris Agreement, if you will, should have been treated as a treaty, should have gone through Senate confirmation. That's a concern,' he told CNBC's Joe Kernen.

As attorney general for the state of Oklahoma, the 48-year-old Republican filed or joined in more than a dozen law suits to block key EPA rules, siding with industry executives and activists seeking to roll back various regulations on pollution, clean air and clean water.

His position jars with the positions of both NASA and the National Oceanographic and Atmospheric Administration, which jointly concluded in January that global warming was driven largely by increased carbon dioxide and other man-made emissions.

NASA and NOAA reported in January that Earth's 2016 temperatures were the warmest ever recorded.

The planet's average surface temperature has risen about 2 degrees Fahrenheit since the late 19th century, 'a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere,' the agencies said in a joint statement.

The EPA says on its website that 'carbon dioxide is the primary greenhouse gas that is contributing to recent climate change.' The agency notes that human activities, such as the burning of fossil fuels, 'release large amounts of CO2, causing concentrations in the atmosphere to rise.'

Ben Santer, climate researcher at Lawrence Livermore National Laboratory, said in a statement: 'We can´t afford to reject this clear and compelling scientific evidence when we make public policy. Embracing ignorance is not an option.'

Kerry Emanuel, professor of atmospheric science at the Massachusetts Institute of Technology, said Thursday that 'Scott Pruitt is just plain wrong on this.'

Emanuel, co-director of the Lorenz Center at MIT, said the most authoritative compilation of scientific research has shown that increasing carbon dioxide has been the dominant source of global warming, followed by methane and other gases.

Environmental groups and Democrats seized on Pruitt's comments as evidence he is unfit for the office he holds.

Skeptic: Scott Pruitt told CNBC's Joe Kernen that the Senate should have been given a vote on the Paris accord.

RISING GLOBAL TEMPERATURES Year Temperature increase (°C relative to average temperature 1961-1990) 2016 0.77 2015 0.76 2014 0.58 2013 0.51 2012 0.47 2011 0.42 2010 0.56 2009 0.51 2008 0.39 2007 0.49 2006 0.51 2005 0.54 2004 0.45 2003 0.51 2002 0.5 2001 0.44 2000 0.29

'The arsonist is now in charge of the fire department, and he seems happy to let the climate crisis burn out of control,' said Sierra Club executive director Michael Brune.

Pruitt 'is spewing corporate polluter talking points rather than fulfilling the EPA's mission of protecting our air, our water and our communities,' Brune said, noting that EPA has a legal responsibility to address carbon pollution.

Sen. Brian Schatz, D-Hawaii, said the comments underscore that Pruitt is a 'climate denier' and insisted lawmakers will stand up to him.

'Anyone who denies over a century's worth of established science and basic facts is unqualified to be the administrator of the EPA,' Schatz said in a statement.

Pruitt previously served as Oklahoma attorney general, where he rose to prominence as a leader in coordinated efforts by Republican attorneys general to challenge former President Barack Obama's regulatory agenda. He sued or took part in legal actions against the EPA 14 times.

Pruitt said during his confirmation hearing in January that climate change is real - breaking with President Donald Trump and his own past statements.

Pruitt told Democratic senators that he disagreed with Trump's earlier claims that global warming is a hoax created by the Chinese to harm the economic competitiveness of the United States.

'I do not believe climate change is a hoax,' Pruitt said.

The Republican has previously cast doubt on the extensive body of scientific evidence showing that the planet is warming and man-made carbon emissions are to blame.

In a 2016 opinion article, Pruitt suggested that the debate over global warming 'is far from settled' and he said 'scientists continue to disagree about the degree and extent of global warming and its connection to the actions of mankind.'