RUTHFULLY YOURS

Earlier this year the Obama administration again delayed a decision about the Keystone XL pipeline. The 1,200 mile, $5.2 billion pipeline could increase North American energy security and create more than 15,000 jobs. But behind the White House’s unwillingness to move forward are environmental groups that vehemently oppose the project. Groups like the Sierra Club warn that Keystone “poses a health risk to our communities” and is a “climate disaster in the making.”

We’ve lived through these scare tactics before. Exhibit A is the 800-mile Trans-Alaska Pipeline. Since its completion in 1977, this technological marvel has conveyed more than 17 billion barrels of oil, worth more than $1.5 trillion in today’s dollars, from Alaska’s North Slope to the Port of Valdez for shipment to the lower 48 states. Yet the pipeline was almost not built, thanks to a propaganda campaign by environmental groups beginning in 1969. Most of their dire warnings have proved inaccurate.

The Wilderness Society, for example, issued a resolution warning that the pipeline threatened “imminent, grave and irreparable damage to the ecology, wilderness values, natural resources, recreational potential, and total environment of Alaska.” James Moorman, counsel to the Environmental Defense Fund, predicted that “disastrous massive oil spills along literally thousands of miles of the Pacific Coast” were “inevitable.” David Bower, then president of Friends of the Earth, said that, “If, as many scientists fear, we are approaching the point of no return in a race to oblivion, then we urge that all the checks and balances of Government be used, not superficially, to ensure a tenable future for us all.”

In March 1970 the Wilderness Society, Friends of the Earth and the Environmental Defense Fund sued to block the pipeline. The lawsuit claimed the pipeline would “have a substantial adverse environmental impact on a significant portion of the Alaska wilderness.” The complaint also warned it would “interfere with the natural and migratory movements of wildlife, primarily caribou and moose.”

The resulting court injunction and other legal hurdles delayed the project until Congress passed the Trans-Alaska Pipeline Authorization Act in November 1973. Debate in Congress was fierce. Opponents of the pipeline such as Rep. John Dingell (D., Mich.) warned of earthquake risks, an “extreme” hazard to wildlife, and “an enormous threat to the way of life” of native American tribes.

However, aside from the 1989 Exxon Valdez oil spill—which was a tanker accident, not a pipeline leak—the Trans-Alaska Pipeline System, or TAPS, has had an exemplary environmental record.

The fear of earthquake-related ecological disaster proved overblown when a magnitude 7.9 earthquake struck along the Denali Fault on Nov. 3, 2002. Structures holding the pipeline above ground were damaged, but the pipeline itself did not buckle.

And what of the pipeline’s impact on the ecosystem? A study delivered in 2002 to the American Society of Civil Engineers found that “the ecosystems affected by the operation of TAPS and associated activity for almost 25 years are healthy.” The pipeline system, it said, “is simply another feature on the landscape, to which the flora and fauna have habituated.”

Meanwhile, the ecosystem of Prince William Sound has in large part recovered from the damage inflicted by the 1989 tanker spill (in which an estimated 11 million gallons of crude leaked when the ship ran aground). According to the National Oceanic and Atmospheric Association’s 25th anniversary report, the “measurable impacts have diminished over the last two decades. In 2013, even two vertebrate species that had shown consistent and lengthy signs of exposure and effects—harlequin ducks and sea otters—appeared to have recovered.”

The oil-field structures, according to an environmental report prepared for TAPS in 2001, were used by birds “for nesting, perching, and foraging.” In 2011, a census (the most recent) conducted by the Alaska Department of Fish and Game, Division of Wildlife Conservation, showed that the Western Arctic caribou herd (Alaska’s largest) numbered about 325,000—four times the pre-pipeline count of 75,000 in 1976.

The lesson of the Trans-Alaska pipeline is that we can build pipelines in ways that protect the environment while yielding large economic benefits. The naysayers were wrong 40 years ago, and policy makers should give scant credence to their arguments against Keystone today.

Mr. Moore is chief economist at the Heritage Foundation, where Mr. Griffith is a senior research associate.