If you're of a certain age - OK, if you can remember '70s television - then you probably remember the little old man character that comedian Tim Conway would play on

The Carol Burnett Show

.

It always took an interminable amount of time for the geezer to walk across the stage, bringing to mind just how long it has taken for President Bush to move forward on global warming.

For most of his first term, the president refused to acknowledge that human activity might be causing climate change. The subject was never deemed important enough for one of Bush's State of the Union speeches until the one last year.

Finally, Thursday, with nine months left in his presidency, Bush announced a plan to limit greenhouse-gas emissions. Not only does the plan come late, but experts say its goals would not be enough to stop global warming from hurting the planet.

Bush's plan wouldn't stabilize U.S. carbon dioxide emissions until the year 2025, with reductions occurring only after that date.

The Intergovernmental Panel on Climate Change says the worst effects of global warming - a massive rise in sea levels, maybe even the extinction of species worldwide - likely cannot be avoided unless the growth in emissions is stopped by 2015.

The IPCC, which with Al Gore was awarded the 2007 Nobel Peace Prize, wants industrialized countries to cut their carbon dioxide emissions to 40 percent of what they were in the 1990s by 2015 and to 95 percent of 1990s levels by 2050.

"The science is clear on what is necessary to tackle global warming, and the Bush administration's plan doesn't come close in getting the job done," says PennEnvironment field organizer Adam Garber.

"Since Pennsylvania is the third-highest emitter of global- warming pollution, we need Gov. Rendell to introduce a state-level global-warming plan that follows the science," Garber said.

Perhaps the states should take more action. But the federal government can do better. In fact, the Senate has before it a plan that would stop the growth in greenhouse emissions by 2012 and cut them to 66 percent of 2005 levels by 2050.

It's a good sign that each of the remaining viable presidential candidates - Hillary Clinton, Barack Obama and John McCain - has promised to do more to reduce carbon dioxide emissions.

Bush has expressed a justifiable caution against crippling American industry to fight global warming. Developing nations such as China and India don't want their economic growth stunted either. But it's time to pick up the pace.