Former Vice President Al Gore took aim at skeptics who doubt the reality of human-caused climate change, saying he wished it were an illusion but that the problem is real and urgent.

Gore, who has made the fight against climate change his signature issue since leaving the White House in 2001, specifically addressed challenges to the accuracy of findings by the U.N. Intergovernmental Panel on Climate Change.

"I, for one, genuinely wish that the climate crisis were an illusion," Gore wrote in an op-ed piece in The New York Times.

"But unfortunately, the reality of the danger we are courting has not been changed by the discovery of at least two mistakes" in reports by the U.N. Intergovernmental Panel on Climate Change.

Climate change skeptics have pointed to errors in the panel's landmark 2007 report -- an overestimate of how fast Himalayan glaciers would melt in a warming world and incorrect information on how much of the Netherlands is below sea level -- as signs that the report's basic conclusions are flawed.

The panel's report said that climate change is "unequivocal" and that human activities contribute to it.

Gore's defense of the panel's findings came two days after the United Nations announced that an independent scientific board would review the panel's work in light of the errors.

The intergovernmental panel shared a 2007 Nobel Peace Prize with Gore and has driven political momentum to agree on a global climate treaty to replace the carbon-capping Kyoto Protocol.

A December meeting in Copenhagen that aimed to bring about a global agreement failed to reach this goal, and Gore blamed inaction in the U.S. Senate.

"Because the world still relies on leadership from the United States, the failure by the Senate to pass legislation intended to cap American emissions before the Copenhagen meeting guaranteed that the outcome would fall far short of even the minimum needed to build momentum toward a meaningful solution," Gore wrote.

Three U.S. senators -- Democrat John Kerry, Republican Lindsey Graham and Independent Joe Lieberman -- have proposed to restart the process by dumping across-the-board cap-and-trade provisions in favor of sectoral approaches to cutting greenhouse gas provisions.

The new bipartisan bill could target individual sectors and move away from a system used in Europe in which companies would buy and sell the right to pollute, a process that caps and eventually reduces emissions blamed for heating the Earth.