The National Academy of Sciences (NAS) – the nation’s most prestigious scientific group – has dropped its go-slow approach to stopping global warming.

The group now calls for immediate action to raise the price of carbon in any fuel, preferably through a mix of carbon taxes and a national cap-and-trade program. NAS says the goal of any U.S. energy policy must be to make fossil fuels much more expensive now so that alternative and renewable fuels will become economically viable.

Lesson to business: Find ways to significantly improve energy efficiency, because if the NAS advice is followed, energy and fuel prices should be rising dramatically. One solution: Shop for clean energy suppliers — solar, wind, and nuclear.

Companies may also want to start planning to move inland and away from the coasts. The NAS 860-page analysis predicts that sea levels will rise by two to four feet by 2050 and by five feet by 2100. And don’t move to the Southwest. Water shortage problems in this area will intensify there due to changing weather patterns.

Jacking up energy prices is the only way to wean America off reliance on coal and imported petroleum fuels, NAS says in one of three reports, Advancing the Science of Climate Change, released last week.

Forcing America to reduce GHG emissions by 80% by 2050 would just be the start of the climate change campaign and the sooner, the better. NAS notes that the longer it takes to adopt a GHG reduction plan for America, the more expensive it will be in later years.

The elite scientists releasing their report say that without a doubt, “climate change is occurring, the Earth is warming … and there are very clear fingerprints” that human activities are the leading cause of the overloading of carbon dioxide (CO2) in the atmosphere. It’s the CO2 buildup that’s causing most of the climate change.

Meanwhile, both the national weather and space agencies reported last week that 2009 was the warmest year in human history.