Want to be kind to the planet and your portfolio at the same time? The Fool shows you how in our special series on Earth-friendly investing.

Concerns about global warming are constantly hitting the headlines these days, and if you've seen An Inconvenient Truth, you're aware of the scientific data that suggest the Earth is heating up rather quickly. The consumption of fossil fuels is largely to blame; they spew carbon dioxide and other pollutants, contributing to unwanted climate changes.

Climatecrisis.net stems from Al Gore's insightful documentary and offers a number of helpful ways for consumers to reduce carbon emissions. Among them is an emphasis on using alternative energy. Fellow Fool Mike Norman recently shined a light on solar energy, including ways for enterprising Fools to invest in burgeoning companies in the space, such as SunPower (NASDAQ:SPWR), First Solar (NASDAQ:FSLR), and Rule Breaker SunTech Power (NYSE:STP).

Solar's little brother: Wind
Solar power is far from the only source of renewable energy, though. Meet wind power, solar's less-exciting fellow renewable and alternative energy source. Wind power doesn't attract as much attention from investors because pure-play investment options are scarce. Investors do have some options, though, and you might be surprised to learn who the major players are.

Across the big pond, renewable energy has received much more emphasis and is further down the development path. Danish firm Vestas is a leader in providing "wind power systems," including the windmill blades and turbines that turn wind power into electricity. Vestas likely will benefit the most from the rapid growth in wind energy. Unfortunately for us Yankees, the shares trade in Copenhagen.

German engineering giant Siemens AG (NYSE:SI) provides a variety of wind power services, including routine turbine maintenance, upgrades, and other technical support and staff training. But don't get your hopes up too high, because wind-related revenue was only a drop in the bucket of the firm's revenues.

Industrial titan General Electric (NYSE:GE) entered the wind power industry in a big way back in 2002 when it acquired Enron Wind during the Houston energy company's fall from grace. It now is one of the leaders in offering wind turbines through GE Wind Energy. Again, though, wind-related businesses accounted for a minuscule part of last year's $161 billion in sales.

To further burst your bubble, Siemens and GE operate in a wide array of energy businesses and likely work with dirtier fossil fuel providers on a much larger scale. But at least you now know the major players and can take solace in the fact that there are many firms that have identified wind-related renewable energy sources as a way to both make money and a difference.

A final option may be to check out just how committed the major integrated oil companies are to non-oil based energy and corporate responsibility. Big Oil, including BP (NYSE:BP) and ExxonMobil (NYSE:XOM), is well aware of the changing social, political, economic, and environmental tides, and you can count on it to try to maximize long-run profits to the best of its abilities. The key question is how its commitment to renewable energy fits into its long-run plans.

Fortunately, we as consumers and investors have an opportunity to continue making waves and turn the tide to more convenient environmental truths.

A free trial to Rule Breakers gives you a chance to chat with other investors and our analysts about the technologies that will change our lives and help our portfolios.  

Fool contributor Ryan Fuhrmann has no financial interest in any company mentioned. The Fool has an ironclad disclosure policy. Feel free to email him with feedback or to discuss any companies mentioned further.