As global leaders prepare for December's Climate Change Conference in Copenhagen, CNBC is speaking to heads of business from around the world to reflect on the summit, discuss plans for reducing emissions and investment opportunities.

Can you cash in on climate change? Barely a day passes it seems without a new green fund launch, or another ETF bundling together a collection of stocks in companies that have green credentials.

Green investing has grown well beyond niche status, as the number of mutual funds and ETFs has increased enormously in recent years. Here's a list of the major ones.

Green or sustainability is now such a broad and deep subject, so multi-dimensional, that even the most aware and informed have trouble keeping up. At the same time, some still don't get it, and in that way green is a bit fuzzy. There's nothing fuzzy about carbon, however. It's as old as the world as we know it and the core of our energy supply.

Ahead-of-the-curve retail investors looking to play carbon as a commodity may want to bone up on the facts while they are waiting to for the nascent market to scale up.

Carbon may be the next great investment opportunity but private capital is still trying to get its arms around around it. The ideal carbon investment structure may be a hybrid of private equity and hedge funds models.

In addition to the usual specialized brokerage and accounting services any commodity needs, carbon markets also require established standards to ensure credits are reliably similar and registries to track those credits from birth to retirement

With emissions rules looking inevitable, companies are taking steps to prepare for a number of different  government  scenarios.

With carbon cap-and-trade legislation before Congress and increasing pressure from shareholders, US companies know they’ll have to deal with their greenhouse gas emissions, or carbon footprint, and many are jumping the gun to change their carbon liability into an asset.

The decision of several major companies to quit the Chamber of Commerce over carbon emission regulation underscores the concern—and confusion—within Corporate America about how it will impact the bottom line.

“I’m estimating carbon markets could be worth $2 trillion in transaction value – money changing hands – within five years of trading (starting),” says one federal regulator.

The potential economic impact of a carbon market seems to divide American industry as much as talk about healthcare reform may divide a family at Sunday dinner.

As the National Energy Summit kicks off in Washington, CEOs shared their insights on the future of energy and what it means for business on Wednesday.

As the Markey-Waxman bill on carbon emissions cap-and-trade makes it way through the Senate, a new carbon-counting reality may soon be here for American businesses.