LITTLE ROCK — The Keystone XL pipeline project should be canceled, former Vice President Al Gore said Monday in a talk at the Clinton Presidential Center.

Gore also defended his decision to sell Current TV to Al Jazeera, saying the news network owned by the Qatar government has a reputation for outstanding professionalism and objectivity.

Gore spoke to an audience of about 350 people as part of the distinguished lecture series of the University of Arkansas Clinton School for Public Service. He is currently on a tour promoting his latest book, “The Future: Six Drivers of Global Change.”

Responding to a question about the Keystone project, Gore said, “I think it ought to be canceled and vetoed. I think it’s ridiculous.”

If it receives government approval, the pipeline would carry oil from Alberta, Canada, to refineries in the U.S. as far south as the Gulf Coast of Texas. Every member of Arkansas’ congressional delegation supports approval of the project, which is opposed by environmentalists.

“It’s the dirtiest source of energy that you can imagine. It’s not oil, it’s tar embedded in the sand,” Gore said. “The pollution that results is way more than from any other kind of oil.”

Regarding the sale of Current TV, Gore said the network won most of the major awards in journalism and was profitable, but it was difficult for an independent network to compete with networks owned by conglomerates. After nine years it was clearly time to make a change, he said.

“When this offer came in and I started due diligence on it, I knew full well that I’d have to face questions and some criticism,” he said. “I get it. I understand it totally. But it was completely clear that this was the right decision in spite of the criticism that would come my way.”

Gore said it was the right decision not only because of his responsibility to the shareholders but also because of his responsibility to do business in a way that makes the country and the world a better place.

“Al Jazeera has established a reputation globally, particularly Al Jazeera English, for being an outstanding objective, professional newsgathering organization,” he said.

In response to a question about fracking, the practice of injecting water, sand and chemicals into rock to fracture it and release natural gas, Gore said there are several problems with the practice, including the large amount of water required and the question of whether leaks are causing underground pollution. An even greater concern, he said, is the contribution that natural gas processing makes to climate change.

“Our challenge is to shift as quickly as we can to a non-carbon-based economy,” he said.

Gore also talked about his new book, in which he identifies six things he believes are driving global change: The emergence of a global economy; the emergence of a global communications grid; a shifting balance in political, economic and military power; rapid, unsustainable growth; breakthroughs in areas such as molecular science and genetics; and climate change.

Discussing climate change, the subject of his movie “An Inconvenient Truth,” Gore said nothing less than the survival of civilization is at stake, yet no questions on the subject were asked during any of last year’s presidential debates.

“Who are we as human beings?” he said. “Are we destined to prove the proposition that the combination of an opposable thumb and a neocortex was just a big mistake? Are we destined to be creatures that destroy our own future? I refuse to believe that. I refuse to accept that.”