For the boutique environmentalists the Keystone pipeline is bad no matter how many suffer.

Report Finds Higher Risks if Oil Line Is Not Built

WASHINGTON — If the Keystone XL pipeline is not built — and more oil from the Canadian oil sands is moved by rail — there could be hundreds more deaths and thousands more injuries than expected over the course of a decade, according to an updated State Department analysis of the contested project that was released Friday.

The report is the latest twist in the long fight over the proposed 1,700-mile pipeline, which would carry crude oil from Alberta to Gulf Coast refineries. The findings are significant: The State Department has the authority to approve the pipeline because it would cross international borders, although President Obama is expected to make the ultimate call.

The initial study noted that without the pipeline, companies would simply move the oil by rail, and an addendum concluded that the alternative could contribute to 700 injuries and 92 deaths over 10 years. Friday’s updated report raised those numbers more than fourfold, concluding that rail transport could lead to 2,947 injuries and 434 deaths over a decade.

The State Department said the initial report was based on an erroneous database search.

There is growing concern nationwide about the risks of moving oil by rail. In April, a train carrying oil derailedin Lynchburg, Va., caught fire and spilled 30,000 gallons into the James River, forcing the evacuation of 350 people. It was the latest in a series of accidents — starting with a 2013 oil train explosion in Lac-Mégantic, Quebec, that killed 47 people — that have caught industry regulators and railroad officials off guard.

Both supporters and opponents of the pipeline project seized on Friday’s news. Keystone proponents said that the risk of more deaths strengthens the case in favor of the project. Environmental groups said that the report highlighted the danger inherent in developing the oil sands at all.

State Department officials said the updated information was not likely to influence any decision. Secretary of State John Kerry has sought opinions from several cabinet officials in his deliberations, and State Department officials say he will consider the pipeline’s impact on the environment, economy and national security, among other issues, before making a recommendation to Mr. Obama.

Shawn Howard, a spokesman for TransCanada, the company that hopes to build the pipeline, said the updated report “reaffirms what we have been saying for years: The safest, most environmentally responsible and affordable way to move oil to the markets where they are needed is a pipeline.”

But Jim Murphy, senior counsel at the National Wildlife Federation, linked the findings to the wider issue of whether the oil sands should be developed at all.

“Today’s correction by State Department further highlights the extreme dangers to people and wildlife posed by climate-disrupting tar sands oil,” he said. “Doubt over Keystone XL has already likely caused the cancellation of major new tar sands projects, which means less tar sands coming out of the ground. It is only by keeping tar sands in the ground and quickly moving to clean, responsible sources of energy that we can avoid severe harm to America’s public health, wildlife habitat and communities.”

It is unlikely that the administration will reach a decision about the project until after the November election. In April, the State Department said it would delay its calls until it has a clearer idea of how legal challenges to the pipeline’s route would be settled. Those issues are not expected to be resolved before the end of this year.

The pipeline is shaping up as a major issue this fall — as it was in the 2012 presidential election — with supporters saying it is important to economic growth and opponents calling on Mr. Obama to reject the project as a symbol of his commitment to fighting climate change.