During July, the prices of oil exploration and coal stocks mentioned in my newsletter tumbled precipitously. For example, Arch Coal (NYSE: ACI) and Peabody Energy (NYSE: BTU) lost roughly a quarter of their value by the end of July and Ultra Petroleum (NYSE: UPL) and Southwestern Energy (NYSE: SWN) which had been up over 40% through June ended July up a relatively paltry 4% and 11% respectively.

I find this interesting because it violates one of the basic theories I have about what moves stock prices. This beat-and-raise theory says that if a company beats earnings estimates and raises its guidance, then the stock will rise. Otherwise it will fall. In the case of these four companies, each of them with the exception of Ultra which did not report, reported doubling or tripling of earnings and raised their guidance.

So why did their stocks fall? In the case of the oil and gas companies, it could be because of declining oil prices. Those peaked at $146 a barrel and recently traded at $127. But I am not aware of any diminution in the price of coal for which demand is strong due to Chinese and Indian infrastructure investment among other factors. Coal is used to make steel and to fire up power plants.

The Washington Post reports that pension fund managers representing $1 trillion have petitioned the Securities and Exchange Commission (SEC) to required public companies to disclose the impact of global warming on their business prospects. If the SEC agrees, the change could threaten investors in utility stocks -- which are among the biggest private sources of carbon dioxide emissions that cause global warming.

Here's a list of utility stocks which could be most affected:

• American Electric Power (NYSE: AEP). AEP produced 145.4 million tons of carbon dioxide in 2006. In Europe, where legislation already limits carbon dioxide emissions, allowances for a ton of carbon dioxide sell or 20.5 euros, or about $28.50. So if its 2006 carbon dioxide had been emitted in Europe, AEP would have had to pay over $4 billion.
• Dominion Resources (NYSE: D)
• Dynegy (NYSE: DYN)
• Xcel Energy (NYSE: XEL)

Coal producer, Peabody Energy Corp. (NYSE: BTU) could also be among those companies affected.