Four years ago, the backdrop for energy and environmental debates in the United States was quite different than it is today. Oil prices had just hit $140 per barrel, a spectacular new record. Climate change was a pressing concern for both parties. The resurgence of domestic oil and gas drilling, in places like North Dakota, had yet to reveal itself fully.

Seen in a new light. (Matt Strasen/AP)

Since then, however, things have changed. The country is gradually (and sometimes painfully) adjusting to higher oil prices. Both Canada and the United States appear to have sizable resources of unconventional oil. For many politicians, getting off crude altogether has become less of a priority. Meanwhile, the still-struggling U.S. economy has pushed global warming down the list of voter concerns.

Last week, we looked at how Republicans have adjusted to this changed landscape in their party platform — by heavily emphasizing domestic oil and gas drilling and ignoring climate change altogether. The Democratic platform, meanwhile, tries awkwardly to juggle these competing concerns. Here's a look at how the Democrats' 2012 platform differs from their 2008 platform on energy and environmental issues:

1) A less-apocalyptic take on climate change. Unlike the GOP, Democrats haven't quite forgotten about this warming planet of ours. But the party's assessment of the problem has grown less dire. Back in 2008, the Democratic platform had this to say:

We will lead to defeat the epochal, man-made threat to the planet: climate change. Without dramatic changes, rising sea levels will flood coastal regions around the world. Warmer temperatures and declining rainfall will reduce crop yields, increasing conflict, famine, disease, and poverty. By 2050, famine could displace more than 250 million people worldwide. That means increased instability in some of the most volatile parts of the world.

In the 2012 platform, the language is vaguer and a bit more perfunctory:

We know that global climate change is one of the biggest threats of this generation – an economic, environmental, and national security catastrophe in the making. We affirm the science of climate change, commit to significantly reducing the pollution that causes climate change, and know we have to meet this challenge by driving smart policies that lead to greater growth in clean energy generation and result in a range of economic and social benefits.

Why the muted tone? The scientific evidence that the climate is changing significantly has only solidified in the past four years. But, on the other hand, the economy is hurting, and environmental issues have dropped on the list of voter concerns.

2) Less-ambitious plans to reduce carbon emissions. In 2008, the Democratic platform vowed to enact an "economy-wide cap and trade system" that would "dramatically reduce our greenhouse gas emissions and jumpstart billions in private capital investment in a new energy economy." That cap-and-trade proposal passed the House but eventually died in the Senate. Republicans in Congress are now firmly against the idea.

As such, this year's Democratic platform is left touting (and proposing) smaller-scale efforts—mostly things that can be done without Congress's approval. There's one big boast here: The Obama administration has, indeed, put in place new fuel-economy standards that will require the auto fleet to average 54.5 miles per gallon by 2025. That's a significant step. But the other accomplishments listed in the platform are more modest: The EPA's "first-ever carbon pollution limits for new fossil-fuel-fired power plants," for instance, will mainly just affect future coal plants—and few utilities were building new coal plants anyway.

It's true that U.S. energy-related emissions have dropped to their lowest level since 1992, but that's owed a lot to the recession, the warm winter, and to the fact that cheap natural gas is displacing dirtier coal, rather than to any particular Obama administration efforts. Tellingly, Democrats are offering up few explicit proposals this time around for tackling global warming—not even a pledge to expand EPA regulations on carbon dioxide further.

3) Still sounding upbeat on clean energy. The 2008 Democratic platform made specific promises about transforming the U.S. energy landscape. "We are committed to getting at least 25 percent of our electricity from renewable sources by 2025," it said. There was also a pledge to "make America 50 percent more energy efficient by 2030."

Democrats have made some headway here. Renewable sources like wind and solar have made significant advances during the Obama years—the United States now gets 5.75 percent of its energy from renewables, nearly doubling from four years ago. (Some of those gains, though, are due to state-level policies.) But it's unclear how long this will last: Many of the key tax credits for wind and solar are slated to expire this year, and it's unclear whether Congress will pass further policies to prop up renewable energy.

The platform does, however, make a new promise: "President Obama has encouraged innovation to reach his goal of generating 80 percent of our electricity from clean energy sources by 2035." This is a reference to the Clean Energy Standard that would require utilities to get more of their electricity from low-carbon sources, whether it's renewables or nuclear or even natural gas. (Here's a breakdown of the bill.)

4) A warmer embrace of fossil fuels. The 2008 Democratic platform promised to free the country from "the tyranny of oil." There was a promise to reduce oil consumption 35 percent by 2030. There was a pledge to direct the Justice Department to "vigorously investigate and prosecute market manipulation in oil futures." And there was no mention of domestic U.S. oil or gas production whatsoever.

What a difference four years makes. Domestic oil and gas production has been booming thanks to new shale drilling techniques. And, in response, this year's Democratic platform is a lot more ambivalent about oil, gas, and even coal:

We can move towards a sustainable energy-independent future if we harness all of America’s great natural resources. That means an all-of-the-above approach to developing America’s many energy resources, including wind, solar, biofuels, geothermal, hydropower, nuclear, oil, clean coal, and natural gas. ...  We can further cut our reliance on oil with increased energy efficiency in buildings, industry, and homes, and through the promotion of advanced vehicles, fuel economy standards, and the greater use of natural gas in transportation.

Harnessing our natural gas resources needs to be done in a safe and responsible manner, which is why the Obama administration has proposed a number of safeguards to protect against water contamination and air pollution. We will continue to advocate for the use of this clean fossil fuel, while ensuring that public and environmental health and workers’ safety are protected. We support more infrastructure investment to speed the transition to cleaner fuels in the transportation sector. And we are expediting the approval process to build out critical oil and gas lines essential to transporting our energy for consumers.

The platform tries to balance talk about clean energy and efficiency with a nod toward the boom in oil and gas drilling. ("Our dependence on foreign oil is now at a 16-year low, and a new era of cheap, abundant natural gas is helping to bring jobs and industry back to the United States.") Environmental concerns haven't vanished. But in an era in which oil and gas companies are adding thousands of jobs in the United States, those green concerns are now being tempered with a big nod toward America's fossil-fuel resources.

Related: GOP platform highlights the party's abrupt shift on energy, climate