While the natural gas boom has generated dramatic benefits across America's energy, jobs, and national security landscape, that ground is far from solid. Several factors could compromise the shale gas miracle. Exposed companies will either benefit or suffer, depending on the choices they're making today.

If it seems too good to be true...
A report out today from the nongovernmental Environmental Integrity Project, or EIP, finds that a multiindustry clamor for cheap, domestic natural gas has paved the way for a massive increase in domestic greenhouse gas emissions. Given that one of the big arguments in favor of natural gas is that it helps to reduce those emissions, this is not a happy development.

To be clear, the EIP's "Gas Rush" report doesn't dispute the fact that natural gas burns more cleanly than coal. Rather, it highlights the "tidal wave" of new projects at oil, gas, and petrochemical plants that depend on natural gas as a feedstock or fuel.

As the natural gas infrastructure expands and matures, and the Environmental Protection Agency approves permits for new chemical, fertilizer, and petrochemical plants, the impact on the climate is considerable. The EIP calculated that based on permits that have already been approved, these new developments will pump as much greenhouse gas into the atmosphere as would 20 large-baseload, coal-fired power plants. Annually.

In natural gas' defense, that's a lot less than it would have been if the same projects were developed on the basis of coal, but it's still a huge net increase in greenhouse gas emissions at a time when the whole world is struggling to put a lid on climate change. While the outcome of the recent climate change talks in Warsaw was pathetically tepid, the world is still inching closer to a stronger climate accord.

Modeling a carbon price
Don't believe me? Maybe you'll find BP (NYSE:BP), ExxonMobil (NYSE:XOM), and General Electric (NYSE:GE) more convincing. Those companies are among a group of at least 29 major corporations that have begun assuming a carbon price in their forecasting models.

A new report from the Carbon Disclosure Project, or CDP, finds that some of the biggest companies on the planet, including all five oil majors, are integrating a carbon price into their long-term financial plans and growth strategies. This is because they assume eventual government action on climate change, plain and simple. While carbon is only one of the greenhouse gases, and not even the most important one where natural gas is concerned, a carbon price would likely be just a first step toward broader regulation.

The CDP report is based entirely on these companies' voluntary disclosures. Consider BP's statement:

We factor a carbon cost into our investment appraisals and engineering designs for some new projects. We do this by requiring larger projects, and those for which emissions costs would be a material part of the project, to apply a standard carbon cost to the projected GHG emissions over the life of the project.

BP estimates its carbon price at $40 per ton. General Electric, for its part, doesn't disclose its estimated carbon price, but the company is deeply analyzing the broader factors that could threaten the natural gas infrastructure expansion in which GE is investing heavily. In a GE report published this October, the industrial giant acknowledged leakage and emissions in the existing natural gas infrastructure as "legitimate concerns," adding:

...with a focus on reduction technologies, and appropriate regulatory policies, many of these negative externalities can likely be mitigated. Actions that can improve emissions monitoring and ensure greater adoption of technologies that can cost-effectively reduce methane leakage, while maintaining safety and reliability of the network, should be pursued. More broadly, natural gas is more likely to reach its potential if it is accepted as a safe, sustainable, efficient, and reliable energy source.

But perhaps the biggest surprise in the CDP report came from ExxonMobil. Not even 10 years ago, that company was running an aggressive campaign to deny climate change. Today, ExxonMobil publicly acknowledges the fact that fossil fuels contribute to climate change. Notably, shareholder pressure contributed to that evolution.

ExxonMobil's CDP disclosure assumes the highest carbon price per ton -- $60 -- of any of the reporting companies. Considering that the company is now the U.S.' biggest natural gas producer -- indeed, many of its projects are among those highlighted in the Environmental Integrity Project report -- ExxonMobil actually stands to benefit from a future in which carbon costs.

But again, it's about more than carbon. Natural gas presents far greater problems when it comes to methane and nitrous oxide, which are both significantly more potent greenhouse gases than carbon dioxide. The EIP report notes that the EPA has thus far failed to act on a Supreme Court decision requiring it to implement industry-wide standards under the Clean Air Act that would set consistent and enforceable emission limits for large sources of those gases. Much like a carbon price, this is a matter of when, not if. Whenever regulation happens, it will be a rude awakening for natural gas-dependent companies that haven't prepared.

What should a long-term investor consider?
If you are considering a long-term investment in a natural gas company, or one that depends heavily on natural gas as a feedstock or fuel, look for signs that the company is preparing itself for a greenhouse gas-constrained future.

Is the company assuming a carbon price in its financial models? Is it taking steps to reduce its other greenhouse gas emissions? Is the company reporting on its emissions and efforts to reduce them, whether through the CDP or other mechanisms? If it's not, that company's stock could be destined for a tumble.

Sara Murphy has no position in any stocks mentioned. Follow her on Twitter @SMurphSmiles. The Motley Fool owns shares of General Electric Company. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.