Before the close of the decade, the United States could become the world’s top producer of oil and natural gas. According to the International Energy Agency (IEA), increasing domestic production combined with domestic energy efficiency could leave the country “all but [energy] self-sufficient.” The U.S. could even become a net oil exporter by 2030, shifting a trend that has been a hallmark in the energy debate for decades.

Last year, about 60% of crude oil processed in U.S. oil refineries was imported from other countries. While a significant amount of crude oil and refined petroleum is also exported, in 2011 America still faced a 45% net import level.

But, this 45% level was actually the lowest seen in the U.S. since 1995. Thanks in large part to the shale oil boom, the country has been able to increase its total oil production since 2008, a fact cited several times by President Obama during his re-election campaign. Coupled with the Administration's successful bid for increased vehicle efficiency standards, the nation's dependence on oil from the Middle East could be drastically diminished. According to the IEA's World Energy Outlook 2012 report, "by around 2020, the United States is projected to become the largest global oil producer," over-taking Saudi Arabia and allowing the country to become a net oil exporter by 2030.

U.S. natural gas production is a similar story, though with an ever shorter timeline. Hydraulic fracturing, despite concerns regarding groundwater contamination, has caused a surge in domestic natural gas production. As a result, the country could surpass Russia and become the world's largest natural gas producer in just 5 years.

According to Fatih Bitol, IEA's chief-economist "[the] foundations of the global energy systems are shifting." But, the orgaization is quick to say that this shift is mixed news with respect to growing environmental concerns surrounding global climate change.

Easier access to more oil and gas could cause a surge in global greenhouse gas emission levels, which could trump recent reductions seen in the U.S. and Europe. While natural gas is less greenhouse gas-intensive than the coal it would likely replace, the net impact could still be higher global emissions.

This possibility is already becoming a reality in the coal industry. As the fossil-fuel has become increasingly unpopular in the face of cheap natural gas in the United States and environmental concerns, American coal producers haven't stopped mining. But, this resource is increasingly being shipped overseas where Chinese and Indian markets are happy to absorb the excess.

In turn, this global rebound effect could result in an even larger challenge to those working to reduce global greenhouse gas emissions. According to the IEA, this could hinder the world's ability to achieve the "2 degree scenario." Further, as exported fuels could be burned in countries without stringent environmental regulations, a geographic shift in coal consumption could lead to increasing public health concerns.

Regardless of these concerns, one message is clear - this "steadily changing [role] of North America in global energy trade" as projected by the IEA would have significant implications for world energy markets.

To read more about the International Energy Agency's latest "World Energy Outlook" report - go here.