|Fig. 1: A natural gas drilling rig on the Pinedale Anticline, just west of Wyoming's Wind River Range. (Source: Wikimedia Commons)|
We are still reliant on fossil fuels although a lot less than we were a decade ago, and while the decreasing trend will continue, it is impractical to think that fossil fuels can go away completely at least not yet. Renewables are more and more competitive every day and there is an incredible amount of research going into not just the technology and science, but the policy and finance. For example, PTCs have been a major driver of utility- scale renewable energy development. Wind capacity has declined every time a PTC expired hence the boom and bust cycle of development that is seen in wind power generation data. Federal PTCs provide the financial incentive for more wind production and allows wind to be more cost competitive. 
We have also found that no one source can provide all of our energy needs. As we continue to shift to renewable energy sources, it is important that we in the meantime have access to cleaner fossil fuels. That fossil fuel is natural gas accounting for nearly two thirds less CO2 emissions than coal. Natural gas is also a more efficient fuel. Advanced drilling technologies have helped immensely to capture natural gas. In the past decade, coal has dropped to a third of our electricity generation and natural gas has increased to a third.
We are currently aiming for the nearly complete removal of coal from our energy infrastructure. We are at the same time working towards being fossil fuel independent totally opting for only carbon neutral sources. We will get there but until the economics of renewables such wind and solar improve, we need a less harmful alternative that works within our current infrastructure which is why natural gas serves as a "bridge fuel." Natural gas is affordable relative to renewable sources, and we can use it to cut carbon emissions now in the short term.  Natural gas is also available due to advanced drilling methods. Drilling sites as the one pictured in Fig. 1 are now more efficient than ever before. Additionally, renewables tend to be intermittent and location specific which bring in energy storage issues which is also extremely expensive and difficult to tackle again requiring a placeholder fuel while we work on energy storage technologies for our intermittent sources.
The one thing that could potentially hurt us with this solution is not focusing on the end goal, which is to move to one hundred percent renewables. Many would argue that using natural gas as a bridge fuel is taking our focus away from our goal and could even cause us to stay with fossil fuels even longer. That is definitely one potential downside, so the policy has to be in place to prevent this outcome. So while this is an effective solution short term, it could potentially cause more harm if we plan on it long term.
© Florence Adewale. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 D. Cusick, "Renewables Boom Expected Thanks to Tax Credit," Scientific American, 21 Dec 15.
 J. Kirkland, "Natural Gas Could Serve as 'Bridge' Fuel to Low-Carbon Future," Scientific American, 25 Jun 10.