You should own global-warming stocks. Even if you think that global warming is based on bad statistics and unconvincing computer models. Or that it's a plot by the tree huggers and the United Nations to institute some kind of world government.

I'm not one of the skeptics. I find the science compelling. Human activities ranging from burning coal for electricity to driving gasoline-fueled vehicles have increased levels of carbon dioxide in the atmosphere.

These changes are about to shift the world's climate into a new state that will dramatically alter rainfall patterns, ocean currents, sea levels and the acidity of the world's oceans. And we've got only a relatively small window, maybe as few as 50 years, before these changes to global climate take on an irreversible momentum.

I'm not here to argue the science. There are lots of books that do a good job of that. My current favorite is Tim Flannery's The Weather Makers. I accept your skepticism. Doubters and scoffers welcome.

So let's say you don't buy it. I still think you ought to invest in global-warming stocks. At worst, you'll make a profit. At best, you'll make a profit and help save the world. That sound OK to you? Then let me explain my logic. At the end of this column, I'll give you five kinds of global-warming stocks to consider for your portfolio. Not Just an Environmental Issue The deck is stacked at the moment in favor of action on global warming. Even if global warming winds up on the rubbish heap of discredited scientific theories, entities such as the European Union, Japan, China, India and even the U.S. are going to adopt a program that looks a whole lot like one designed to stop global warming because it fits each nation's need to increase its energy security as well.

It's not just coincidence that politicians on both sides of the Atlantic are talking simultaneously about stopping global warming and ending their nations' addiction to oil.

This program of action, whether under the guise of national security or stopping global warming, couldn't come at a better time for what I'll have to call alternative-energy stocks, for lack of a better term. The subsidies and market incentives in this program will be more than enough to push maturing, but still not fully commercialized, technologies into the market on an equal footing with other energy technologies.

Come what may after that, these alternative-energy technologies -- and I'm thinking here primarily, though not exclusively, of wind and solar power -- will have received enough of a boost to be able to compete with the rest of the energy sector. You can get a good sense of what the coming global-warming combat orders are going to look like from the plan unveiled Jan. 10 by the European Union.

The plan calls for:

• Making a 20% reduction, from 1990 levels, in carbon emissions in the European Union by 2020.

• Getting 20% of electricity supply in the European Union from renewable sources by 2020. That's more than a doubling from current targets.

• Constructing a new generation of safer nuclear reactors to keep nuclear power at a 30% share of supply.

• Keeping coal at 30% of electricity supply but ensuring that all new and existing plants include systems for capturing carbon and storing it out of the atmosphere.

• Having biofuels provide 10% of fuel for transportation by 2020, up from 2% now.

Global warming or no global warming, it's pretty clear that these changes are critical for the future health of the European economy. Europe is desperately worried about its reliance on Russian energy supplies. In the most recent example to Europeans of why they have to do something to reduce their dependence on Russian natural gas and oil, Russia cut off oil supplies to Western Europe through the pipeline that crosses Belarus for three days during a dispute with Belarus.

Even in Washington, the ice is thawing because of this conjunction of global-warming science and national energy security. The "Advanced Energy Initiative" in last year's State of the Union address promised a 22% increase in research for "clean" coal, "safe" nuclear power, "revolutionary" wind and solar energy, "cutting-edge" biofuels, hybrids and hydrogen fuels.

This year I expect more research money to be thrown at the same sectors, with the possibility that the Bush administration will actually apply more federal cash to the big job: building unit volume in order to drive down costs for wind and solar, the most commercially developed of these technologies.

What does all this amount to from an investor's perspective? I'd break down the opportunities into two groups. Group 1: Saving the World These stocks maximize your long-term potential returns, since they really can play a role in solving the global-warming problem.

Wind and solar: These technologies are set to go over the top and into the commercial market. There are several factors putting a breeze at the back of wind technology:

• More cost-efficient turbines have driven down the cost of using the wind to produce electricity by about 50% over the past 15 years.

• The European Union's carbon-trading systems put a price on pollution, making it more costly for utilities to do business the old way.

• Big utilities are able to raise capital at extremely low costs.

• Government funding for global-warming programs will be enough to finance the construction of manufacturing facilities that will remove the current solar-cell bottleneck. It's hard to grow a solar-energy market when no one can get enough raw material to build solar cells.

Stocks to watch: I'd look to add global-warming positions in European market leaders such as Gamesa, which trades over-the-counter, and Vestas, which trades on the Copenhagen Exchange); Indian market leader Suzlon Energy, which trades on the Mumbai stock exchange; and U.S. market leader GE Wind, a subsidiary of General Electric (GE - news - Cramer's Take - Rating).

Or you can buy up-and-coming suppliers of key technologies to the wind industry, such as carbon-fiber supplier Zoltek Cos. (ZOLT - news - Cramer's Take - Rating) and ultracapacitor maker Maxwell Technologies (MXWL - news - Cramer's Take - Rating).

Jim Jubak is senior markets editor for MSN Money. He is a former senior financial editor at Worth magazine and editor of Venture magazine. Jubak was a Bagehot Business Journalism Fellow at Columbia University and has written two books: "The Worth Guide to Electronic Investing" and "In the Image of the Brain: Breaking the Barrier Between the Human Mind and Intelligent Machines." As an investor, he says he believes the conventional wisdom is always wrong -- but that he will nonetheless go with the herd if he believes there's a profit to be made. He lives in New York.