Climate experts are raising new questions about the Obama administration's reliance on Environmental Protection Agency rules to cut carbon emissions ahead of a global climate deal being reached in Paris next month.

"If you add them up, we are way, way, way short to what we committed to in Paris," said David Bookbinder, former counsel for environmental group Sierra Club and a leading figure on environmental law in Washington. He was referring to the emission rules for vehicles and power plants the administration says will meet its obligations.

Many scientists blame greenhouse gas emissions, principally carbon dioxide, that the EPA rules seek to reduce for raising the Earth's temperature through the burning of fossil fuels. The warming has been blamed for increased flooding, droughts and acidification of the oceans.

Bookbinder made the statement while making a presentation at an all-day conference at the Cato Institute Friday on the upcoming Paris conference, which will start negotiations on a global climate change deal Nov. 30.

Bookbinder's comments came just hours after the U.N. climate chief, Christiana Figueres, said the commitments made by the nations ahead of the climate conference are "not enough" to succeed, though progress had been made. A new U.N. report issued Friday added up the commitments made by the U.S. and more than 150 other countries to curb emissions to stave off the worst effects of climate change.

The U.S. made commitments to the U.N. earlier this year to reduce its emissions 26-28 percent by 2025. Bookbinder said the report the administration sent to the U.N. "is in some ways a fantasy document … [that] will not be reducing emission by 26 percent."

One of the reasons for his pessimism is that the Clean Power Plan, the centerpiece of Obama's climate agenda, is being contested in court and will likely go to the Supreme Court. Also, the plan's power plant rules are expected to be killed if a Republican moves into the White House in 2017. Much won't be sorted out for years, pushing back the emissions goals. But problems exist with other emission-reduction programs.

Economists at the nonpartisan Resources for the Future think tank in Washington issued a report raising questions about the emission-reducing benefits of the Environmental Protection Agency's ethanol mandate, and others like it around the world, which could have repercussions for the Paris talks. The think tank focuses on the economics of energy and environmental policy.

The study's modeling shows that the ethanol mandate, called the Renewable Fuel Standard, will encourage countries to use more oil and other fossil fuels, increasing emissions through 2022. Vehicle rules are part of how the U.S. says it will meet its climate obligations.

"An aggressive renewable fuels mandate may not lower global carbon emissions, because oil prices go down and [oil] consumption increases in other nations," the study says, placing into question the policy.

The report, when combined with recent government data issued by the Commerce Department, shows environmental regulations for vehicles are beginning to backfire when it comes to combating the emissions blamed for causing climate change. That is mainly due to the low cost of oil and market factors the EPA has not accounted for in designing its regulations, according to the study.

Brent Erickson, executive vice president for the environment at the Biotechnology Industry Organization trade group, refuted the study's claims. "This is a bit of a stretch and does not recognize that fuel prices are affected by a number of more potent factors," not biofuels. "World oil prices do not seem to fluctuate based on biofuels use even on a large scale as in Brazil." His trade group has been both a defender and critic of the EPA's biofuel policy.

The study's scenario doesn't account for increasing oil supplies from Russia, the U.S. and Iran, which could keep the world in a global oil glut for the foreseeable future, keeping the price of oil low.

That scenario has the net effect of lowering biofuel consumption in the rest of the world by 20 percent, according to the economists' study. Therefore, "oil use in the rest of the world goes up by 1 percent," not lower as the policies were designed to do.

At the same time, the Commerce Department and the Energy Information Administration say the market is pushing EPA regulations meant to reduce gasoline consumption in the wrong direction.

The agencies say consumers are turning their spending to larger sport utility vehicles and light-duty trucks that consume more fuel since oil and gasoline prices are so cheap. The increase in purchases of the larger, less fuel-efficient vehicles rose to record highs in the first half of the year.

Sales of light-duty trucks such as sport utility vehicles, pickup trucks and vans outpaced sales of passenger cars by a record 28 percent through August, the Bureau of Economic Analysis said.

The trend is so staggering that it could up-end the goals of EPA's clean-vehicle programs, which require automakers to increase the average fuel economy of their cars and trucks to 54.5 miles per gallon by 2025. The federal regulations also place restrictions on the amount of greenhouse gas emissions their fleets can emit, driving them to market more hybrid-electric and electric cars.

Mark Cooper, long-time consumer advocate and a clean vehicle policy expert, said the low price of oil may be reducing the number of electric cars the public is willing to buy, but that the interest in the vehicles has skyrocketed.

Cooper, with the Consumer Federation of America, issued a study Thursday that showed 31 percent of U.S. consumers would consider purchasing an electric car, compared with the 60 percent said they would not.