After years of protests and lobbying, the Obama administration is expected to decide within months on the fate of the 1,200-mile Keystone XL oil pipeline.

The State Department is finalizing a supplemental environmental impact statement (SEIS) for the project, which would ship tar sands oil from Canada, through America's heartland, and to the Gulf Coast via other pipelines.

The agency will use the SEIS—expected any day now—to help determine whether the project is in the "national interest," a term that includes economic, energy security and climate change considerations. Due to the pipeline's high profile, President Obama will play an important role in the decision.

Uncertainty and rumors are rife, partly because Hurricane Sandy reignited concern about human-caused climate change and fossil fuels, but largely because the two top officials who bear main responsibility for the decision will soon be replaced. Secretary of State Hillary Clinton and Environmental Protection Agency Administrator Lisa Jackson will step down this month.

Recognizing the impact of global warming—or perhaps just looking for a little positive press—large corporations are adopting internal greenhouse gas reduction and renewable energy goals.

Noticeably underrepresented? Oil and gas companies.

A report released last month by the World Wildlife Fund (WWF) showed that 58 of the country's Fortune 100 companies set goals in 2012 to either use more renewable energy for their operations or reduce their greenhouse gas emissions. Globally, the number of participating companies was even higher—68 of the world's 100 largest companies have set some sort of greenhouse or renewable energy goal.

But energy companies lagged behind on both lists. Eight of the 11 domestic energy companies on the Fortune 100 haven't set internal energy goals. The exceptions are Hess and Chevron, which both set renewable energy and greenhouse gas targets, and ExxonMobil, which set a greenhouse gas target. (Hess was accidentally omitted from the report, according to a WWF spokesman.)

Eleven of the 20 energy companies on the global list hadn't set targets, the lowest participation rate of any industry.

This was the year climate change vanished from the political agenda—and then suddenly reappeared, after Hurricane Sandy shook the country.

It was just a few years ago that Pres. Obama flew to Copenhagen to rescue faltering climate treaty talks amid bipartisan calls for global warming action. But in 2012, there wasn't a single Congressional proposal or hearing on climate legislation. Neither was there mention of climate change on the presidential campaign trail, or in the debates for the first time in decades.

In the rare instances that climate change surfaced in national discussions, politicians were fixated on the one aspect of warming scientists aren't debating: whether it's occurring. 

Republican-affiliated climate researchers told InsideClimate News that attempts to educate their party leaders on the science were rebuffed. Meanwhile, many U.S. scientists fended off attacks of global warming skeptics, while Canadian scientists had to deal with budget cuts and muzzling by the government.

Amid the silence and skepticism, the Earth sent its own message.

This was the year "dilbit" registered on the U.S. political and public radar in a major way.

Previously just a technical industry term, dilbit—short for diluted bitumen—became the center of citizens' concerns about the controversial Keystone XL oil pipeline.

Bitumen is a heavy crude oil mined from Canada's oil sands region. The bitumen is so thick that it must be diluted with liquid chemicals before it can flow through pipelines—hence the term dilbit.

Environmental groups have long opposed oil sands production due to its climate change impacts. But dilbit is also significant because it doesn't behave like conventional crude oil when it spills into water. Those risks became apparent in July 2010, when a ruptured pipeline spewed more than a million gallons of dilbit into Michigan's Kalamazoo River.