Climate change isn't going to be free. A report by Point Carbon, an independent consulting company that tracks global carbon and energy markets, estimates that U.S. climate legislation could push the price at the pump 13 cents a gallon higher. The increase would result from the cost to oil companies for carbon permits, which they can pass along to consumers.

This is a much rosier view than that of the oil industry, however, which believes a U.S. cap-and-trade system would thrash demand for gasoline and lead to the shuttering of many refineries.

The U.S. Chamber of Commerce is fighting back. The organization has filed a civil lawsuit against the Yes Men, an activist group that announced that the chamber had changed its position on climate change.

The Yes Men told the National Press Club on October 19, 2009 that the Chamber of Commerce would give up lobbying against the Senate's 800-page climate change bill. Reuters, CNBC and Fox Business Network all reported on the story, with the anchors correcting themselves midstream, when they learned that it was false.

Wall Street watchers can be excused for feeling a little whipsawed this week. After watching stocks lose ground early in the week, they roared back Thursday, riding high on a bevy of upbeat earnings reports. That enthusiasm remains partially on display this morning with two of the three major U.S. stock indexes showing a positive opening ahead of the morning bell.

At about 7 a.m. ET, the Nasdaq Composite Index and S&P 500 were slightly higher, while the Dow Jones industrial average was down by about 4 points. The Dow gained 1.3% Thursday to close the session at 10,081.31, led by the strong earnings reports from five of the benchmark index's 30 component stocks.

Apple just bailed on the U.S. Chamber of Commerce, citing the business organization's view on climate change. The Chamber of Commerce doesn't accept the notion that people are the force behind global warming and has called for public hearings to question the evidence that many accept. But, this has led several companies to leave the group, with Apple (NASDAQ: AAPL) only the latest.

The technology company stated through Catherine Novelli, a vice president of government affairs, that it would "prefer that the chamber take a more progressive stance on this critical issue and play a constructive role in addressing the climate crisis." Apple resigned its membership "effective immediately."

The dealmaking is heating up in the nuclear sector. Today, Exelon Corp (NYSE: EXC) upped its hostile bid by 12% for NRG Energy (NYSE: NRG). This new price tag translates into a valuation of $7.45 billion.

The wrangling between the companies has gone on for roughly eight months. In fact, hostile deals can be time-consuming (in some cases, lasting a couple years).

Something else: Exelon has indicated that this is the "best and final offer." Apparently, the company has realized new cost savings, which justifies the higher valuation.

Exelon (NYSE: EXC) offered to buy NRG Energy (NYSE: NRG) for $6.2 billion or 0.485 of an EXC share for each NRG shares, which is worth about $26.43 for each NRG share. EXC, the biggest U.S. operator of nuclear power plants, closed at $54.50. EXC November option implied volatility of 75 is above its 26-week average of 75 according to Track Data, suggesting larger price movement.

NRG, a generation company with annual revenues of $5.9 billion, closed at $19.33. NRG November option implied volatility of 133 is above its 26-week average of 42 according to Track Data, suggesting larger price movement.

Volatility Index S&P 500 Options-VIX at 70.33; 10-day moving average is 61.44.

Option Update is provided by Stock Specialist Paul Foster of theflyonthewall.com

MOST NOTEWORTHY: Northrop Grumman, Groupe Danone and MercadoLibre were today's noteworthy upgrades:

• Oppenheimer upgraded shares of Northrop Grumman (NYSE: NOC) to Outperform from Perform after the Pentagon selected the company over Boeing (NYSE: BA) for the newly designated KC-45A Aerial Refueling Tanker with a potential value of $35B.
  
• Citigroup upgraded shares of Groupe Danone (OTC: GDNNY) to Buy from Hold on valuation, as they believe the sell-off on commodity cost concerns is overdone.
  
• MercadoLibre (NASDAQ: MELI) was raised to Outperform from Sector Perform at RBC Capital, as they believe MELI's long-term thesis is more compelling now vs. six months ago and notes favorable reaction to Mercado Pago v2.0.

OTHER UPGRADES:

• Goldman upgraded Societe Generale (OTC: SCGLY) to Neutral from Sell.
  
• Jefferies upgraded Exelon (NYSE: EXC) to Buy from Hold.
  
• Deutsche Telekom (NYSE: DT) was raised to Neutral from Underweight at JP Morgan.

MOST NOTEWORTHY: Alltel (AT), Exelon (EXC) and STMicroelectronics (STM) top today's extensive list of downgrades.

• Alltel Corp. (NYSE:AT) was downgraded at Robert W. Baird to Neutral from Outperform, citing lower EBITDA and valuation.
• Exelon Corp. (NYSE:EXC) was downgraded to Hold from Buy at Citigroup. The move came on lower expectations for growth at their ComEd unit.
• STMicroelectronics (NYSE:STM) was downgraded at Robert W. Baird to Neutral from Outperform citing weak NOR flash trends.

OTHER DOWNGRADES:

• Whole Foods Markets, Inc. (NYSE:WFMI) was downgraded to Sector Perform from Outperform at RBC Capital Markets on valuation.
• Finally, Prudential downgraded Timberland Co. (NYSE:TBL) to Underweight from Neutral citing management comments of continued earnings pressure.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).