HARRISBURG, Pa. - Republican Gov. Tom Corbett and his Democratic challenger, Tom Wolf, will appear in the same place for the first time in the campaign Wednesday night when they deliver remarks at an environmental group's dinner in Philadelphia.

The men will speak after a 6:30 p.m. Pennsylvania Environmental Council award ceremony at the Crystal Tea Room.

Environmental policy is at the forefront with President Barack Obama announcing a plan last week to address global warming. He wants to put into a motion a 30-percent reduction in the nation's carbon dioxide emissions over 25 years by ordering cuts in the pollution discharged by America's power plants, primarily those fueled by coal.

There is also considerable discussion in the Legislature over whether to increase taxes on Pennsylvania's booming natural gas industry to help make up a $1 billion-plus gap in Corbett's budget plan for the fiscal year beginning July 1.

Corbett and Wolf are effectively on opposite sides of the issues.

Corbett's campaign has heaped scorn on Obama's plan as a "war on coal" that would damage Pennsylvania's coal industry, while Wolf's campaign has signaled support for it, saying health impacts are important and "clean coal" is part of the future of energy.

On climate change, Corbett's campaign has said the governor understands that climate change is happening and that scientific literature points to a human role in it. But Corbett maintains there is a scientific debate over whether there is an immediate impact of climate change on human health and the environment.

Wolf's campaign said he believes global warming is already affecting human health and environment and has promised that his administration would set "meaningful" emission-reduction targets for greenhouse gases. Corbett has not set such targets.

On a severance tax on natural gas extraction, Wolf favors imposing one while Corbett does not.

In an excerpt of Wolf's speech to the council provided in advance by the campaign, he will promise to launch a third round of the "Growing Greener" program. The first two rounds have provided more than $1 billion since 1999 for a grab-bag of environmental cleanup and land improvement projects, including preserving farmland, protecting waterways from polluting drainage and improving public parks and forests.

He did not say in the excerpt how he would pay for it. The last round, a $625 million bond approved by Pennsylvania voters in 2005, is winding down.

Many members of the Pennsylvania Environmental Council board are from the business world, and its chairman was one of four environmental advocates on Corbett's 30-member Marcellus Shale Advisory Commission, a group criticized for its heavy complement of business and gas industry advocates.

This year, however, the council has sided with other environmental groups on several high-profile issues that put it into conflict with business associations.