Energy and utility stocks generally showed little reaction to the Obama administration’s sweeping rules, proposed on Monday, that aim to slash power plants’ carbon dioxide emissions 30 percent by 2030 to slow global warming.

“This rule was expected, the proposed rule wasn’t as harsh as it could have been, and we don’t have all the details about how states will approach the change,” Edward Jones energy analyst Andy Pusateri said.

The Environmental Protection Agency’s 645-page proposal is expected to be final next year. Political, legal and policy pushback could mean states will have until 2018 to draft their own plans to comply with the final rule, and the bulk of the cuts in emissions won't occur until 2024.

Power plants are the single-largest source of man-made carbon emissions in the U.S, according to the EPA. The U.S. utility sector accounts for about 6.4 percent of global carbon emissions, according to a Wall Street Journal analysis.

The Dow Jones U.S. Coal Index, which primarily tracks coal producers, was up a modest 0.8 percent and holding steady in late Monday trading.

Sixteen of the top 40 performing stocks of the S&P 500 last month were utility companies, and the Utilities Select Sector SPDR fund was the top category for mutual fund inflows in mid-May, reported. The SPDR fund is up about 14 percent year to date.

“I would assume nothing has changed because it’s already priced into the market because it was expected,” Doug Vine, senior energy fellow at the Center for Climate and Energy Solutions, said. “A lot of the utilities are adjusting their business models accordingly.”

Earlier EPA rules limiting mercury and other air toxics emissions from power plants have pressured some coal-fired power plants to close in recent years.

The EPA’s latest proposed rules would force more coal plants to retire, but coal plants are already retiring, so the power plant industry has already been reducing emissions.

“Switching from coal to natural gas is a fairly cost-effective way to reach the targets,” Kyle Aarons, senior energy fellow at the Center for Climate and Energy Solutions, said.

Greenhouse gas emissions peaked in 2007 and have since declined by about 10 percent, due mainly to an economic slowdown and an unexpected, sudden boom in shale gas used for power generation.

“If they can make [the rule] stick it will be positive for [natural] gas, but not maybe in a big way as people are expecting,” Macquarie global commodities analyst Vikas Dwivedi said. “By our numbers, you’re going to get 4 bcf [billion cubic feet] a day of natural gas [demand], and this rule would raise it by 6 bcf a day by 2020, so it’s helpful to gas, but it’s really an incremental increase.”

In other words, natural gas prices and stocks probably won’t change much due to the EPA's proposed rules.

“You’re going to get a lot of help from renewables over the decade,” Dwivedi added.

“We still believe that most companies will focus on growing renewables, but that it will be a long while before renewables ever surpass coal or gas generation,” Pusateri said.