The city's proposed $5.3 billion rail system could increase greenhouse gas emissions in Hawaii by as much as 28,000 tons by 2030, according to a study commissioned by rail opponents.

City officials criticized the report as a last-ditch effort to sabotage the project, which aims to break ground by the end of next month.

“;It's a little bit like hearing that the Grinch is analyzing Christmas,”; said Kirk Caldwell, city managing director. “;This, I believe, is a last-minute effort to try to derail rail. They basically are saying that taking 30,000 cars off the road is somehow bad for the environment. It doesn't make sense.”;

The report, “;The Honolulu Rail Line Greenhouse Gas Emissions Evaluation,”; was commissioned by the Small Business Hawaii Education Foundation, a nonprofit research arm of Smart Business Hawaii, a trade group that opposes rail.

Sen. Sam Slom (R, Diamond Head-Hawaii Kai), president of Smart Business Hawaii, formerly Small Business Hawaii, said the research group spent $5,000 to have mainland consultant Wendell Cox perform the analysis based on the project's draft environmental impact statement. Cox has consulted for the U.S. Department of Transportation as well as for public agencies in Canada, Australia and New Zealand.

Under a worst-case scenario, Honolulu's greenhouse gas emissions in 2030 would be about 1.36 million tons annually with the rail system, an increase of about 28,000 tons compared with emissions without rail, according to the study.

The worst-case scenario assumes a more gradual decline in the use of fossil fuels for transportation.

In the best-case scenario, in which 70 percent of Hawaii's energy is derived from renewable sources by 2030, greenhouse gas emissions would decrease 12,000 tons by 2030, the study said.

“;In the best case, rail would marginally reduce greenhouse gas emissions at an extremely high cost per ton,”; the study said. “;As a strategy for reducing greenhouse gas emissions, the Honolulu rail line is exorbitantly expensive.”;

Slom presented the study yesterday at the steps of City Hall along with Panos Prevedouros, a University of Hawaii transportation engineering professor who unsuccessfully challenged Mayor Mufi Hannemann in the 2008 election.

Both contend that the draft impact statement for the rail does not address concern over greenhouse gas emissions and their impact on climate change.

Caldwell said the city has complied with a request from the Environmental Protection Agency that an emissions analysis be included in the final environmental impact statement, which is being reviewed by the Federal Transit Administration.