Oliver was criticized last week for seemingly casting doubt on climate change science, saying in an interview with La Presse that "people aren't as worried as they were before about global warming of two degrees."
"Scientists have recently told us that our fears (on climate change) are exaggerated," Oliver told the Montreal daily newspaper.
In the interview, Oliver also said he was unaware of a recent warning from the International Energy Agency, a partnership of governments including Canada, that two-thirds of the existing known fossil fuel reserves must remain in the ground to prevent average global warming of more than 2 C above pre-industrial levels.
The two-degree threshold is considered to be a dangerous tipping point of irreversible damage to the planet's ecosystems and economy.
On Tuesday, Oliver said the Conservative government believes climate change is an urgent issue and insisted he expressed that view in last week's interview.
"I consider this to be an urgent matter," Oliver told reporters following the grilling at committee. "I believe and the government believes it's a serious issue and we're going to continue to act on that belief going forward."
The minister does not think his comments will have any impact on the Obama administration's decision on whether to approve the Keystone XL oil-sands pipeline that would run from Alberta to the U.S. Gulf Coast.
Oliver is planning to travel to Washington, D.C. and New York next week to further sell the importance of the pipeline to the United States.
U.S. President Barack Obama is expected to make a final decision on the pipeline sometime in 2013, but it could come as early as the spring or summer.
"We respect that process but we want to make sure they understand what we're doing and the economic benefits and national security benefits to them," Oliver said.
But NDP natural resources critic Peter Julian called on Oliver to retract his initial comments on climate change.
He said the Conservative government is a bit of a laughing stock internationally because of its refusal to take climate change seriously, and "the Keystone project is in jeopardy because of that."
"What he was trying to do was insinuate that somehow (climate change) is not urgent and that it's exaggerated and that Canadians aren't concerned about this," Julian added. "Canadians are very concerned about the impacts of climate change."
The minister was also questioned about recent changes to public participation rules for pipeline hearings.
The Conservative government stuffed hundreds of pages of changes to environmental protection laws in budget implementation legislation in 2012, including restricting public participation in pipeline hearings to people directly affected or those with relevant expertise.
The National Energy Board recently announced it is using the government's omnibus legislation to require Canadians to fill in a 10-page form and, when applicable, submit a resume of their credentials in order to participate in public hearings or write a letter on the Enbridge pipeline reversal project.
The Line 9 pipeline reversal would allow Alberta oil-sands and other crude to flow east into Central Canada.
"It is a way of ensuring that the public is not consulted on this pipeline reversal and on future projects," Julian said about the NEB rules.
Oliver, however, said there was an attempt by some groups to "game the system" during the Northern Gateway pipeline hearings in an effort to delay the process and defeat the project. ILLUS: Darryl Dyck, The Canadian Press / Natural Resources Minister Joe Oliver says despite comments he made to La Presse that some climate change fears are 'exaggerated,' he considers the issue 'an urgent matter.'