Natural gas is abundant and produces far less greenhouse gas emissions (GHGs) - other than the potent GHG methane (a notable caveat) - when it's burned for energy as compared to coal. Natural gas reservoirs in vast shale rock formations underground have been discovered and developed. How much lower are GHGs from natural gas than coal? The difference is dramatic, making natural gas a much cleaner-burning energy alternative compared to coal (although compared to renewable energy generation for electricity, natural gas is still not really optimally "clean").

According to the Worldwatch Institute, natural gas energy generation emits about half the amount of GHGs as coal (although natural gas combustion produces the much more potent GHG methane in higher amounts than coal). This stat includes taking a variety of factors into account, such as methane flares and methane leaks associated with natural gas vs. the quantity of GHGs associated with coal. Another upside of energy from natural gas is that, like solar and wind, natural gas is less expensive than coal in every stage of energy production of the fuel source.

The countries that produce the most gas are the United States and Russia; with the natural gas-producing countries China, Canada, Saudi Arabia, Norway, and Australia, combined, not producing as much gas as the U.S. and Russia each do individually. The countries and regions that consume the most natural gas, after the United States (which consumes over 20% of the world's gas), are the EU nations and Russia, with Germany individually being the highest gas-consuming EU nation. However, Germany still consumes less natural gas energy than Canada, Saudi Arabia, Japan, and Mexico.

Greenhouse gas reductions with natural gas

The United States actually reduced its GHGs back to 1996 levels a decade ago; by more than 12% (as of 2013), largely due to a focus on natural gas energy generation. Much of the credit for the GHG reduction in the United States in the 21st-century has been attributed to a significant shift from coal to natural gas to power major U.S. electrical utilities.

Coal has fallen from supplying over 50% of U.S. total energy output at the turn of the century, to less than 20%. Natural gas has increased from 15% to around 40% of overall United States energy production in that same time period. Because natural gas burns cleaner than coal, this shift to more gas than coal combustion for U.S. energy has without a doubt been a factor in the reduction of GHGs being pumped into the atmosphere.

Note - other factors have reduced the overall production of GHGs in the U.S. as well;  increased fuel efficiency in vehicles, use of sustainable public mass transit, fewer vehicles on the road due to increased use of public transit and ride-sharing services, and increased use of green building and energy efficiency technologies. Still, the reduction of coal usage and the increase of natural gas is a significant influence on the reduction of GHGs.

Methane from natural gas stays in the atmosphere for a shorter duration than carbon dioxide (CO2), and other GHGs from coal combustion (CO2 is the most significant GHG associated with coal). Methane is a more destructive GHG to the earth's atmosphere (methane is far more potent than carbon dioxide). However, the quantity of CO2 and other GHGs produced with burning coal is significantly higher with coal, than with natural gas.

Natural Gas is Cleaner and more efficient than coal

In addition to burning cleaner than coal, natural gas (along with renewable energy from wind and solar) has been determined to be less expensive overall than all other forms of energy generation when looking at the levelized cost of energy (LCOE); as seen in this study by the University of Texas at Austin Energy Institute. Natural gas also integrates seamlessly when paired with renewable energy and energy storage.

Natural gas power plants can use integrated gas combined cycle (IGCC) technologies, and even emerging CCS technologies to produce cleaner energy. Gas plants can combine to work in synergy with solar and solar thermal and energy storage in power plants. When natural gas is used in these capacities, it is certainly a clean(er) energy technology (although burning natural gas still produces GHG emissions). Natural gas "peaker" power plants provide back-up energy to renewable power plants during peak times of energy demand, or provide energy from the hybrid plant to the grid in lieu of energy storage.

In the United States, over 30% of natural gas is generated using advanced combined-cycle gas generation; and that share of the U.S. gas market for the lower cost, higher efficiency advanced gas combined-cycle plants is increasing.

In addition to having a lower LCOE, natural gas also represents a significant source of employment, income, and revenue to the U.S. economy. Although natural gas is still a fossil fuel, natural gas can be part of a clean energy project by efficiently integrating with renewable energy and energy storage (see the hybrid Martin County power plant pictured above). Such hybrid power plants certainly exemplify clean energy technologies creating jobs in the US economy. Clean energy jobs provide a needed boost to the economy.

Another advantage of gas is that natural gas rigs tend to be less obtrusive within the environment when compared to mountaintop removal coal mining, strip mining, and the large-scale terraced pits of major coal operations. Coal is still an abundant form of energy; and it’s still relatively cheap to burn when the energy distribution remains close to the coal power plant (although, burning coal does become more and more expensive as GHG reducing technologies like carbon capture and storage (CCS) are employed in the burning of coal - and 'clean coal' technologies like CCS are certainly necessary in order to even consider burning coal for energy). Technologies like CCS and IGCC significantly reduce GHG emissions from the production of energy when applied to the burning of coal for energy.

The biggest of the MANY significant drawbacks of coal is that, while being abundant, it is also among the dirtiest forms of energy (only tar-sand crude oil is dirtier). Coal emits a tremendous amount of GHGs, and also emits fine particulates, which cause public health hazards and are a danger to wildlife and the environment.

In order to mitigate anthropogenic climate change, the energy generation sector must be focused on ways to reduce pollutants; such as 'clean coal' technologies like CCS and IGCC. Although these technologies don't actually turn coal plants into clean power plants, they do become considerably cleaner than plants without these technologies.

In burning coal for energy, the many negative externalities of coal (such as: contributing significantly to climate change, damage to public health, damage to plant and animal ecosystems, and other damage to the environment from coal pollution) must be considered; external costs which add dramatically to the economic and social cost of coal.

Controversies with natural gas   

Of course, the boom in natural gas production has not been without controversy. The process of hydraulic fracturing (fracking - the process of extracting natural gas from shale rock) has spawned widespread protest, especially from environmental groups, because the process is tremendously damaging to the environment.  Fracking requires enormous amounts of water, which is mixed with huge quantities of silica, and a large variety of toxic chemicals, to be injected deep underground; causing minor earthquakes, frequent leaks of methane from natural gas rigs, and leaks of other toxic chemicals from fracking operations that get into freshwater supplies, causing damage to ecosystems, animal, and human health. Here's a list of 20 negative impacts of fracking on the environment. It must be noted that coal is worse for the environment.

Please see: Energy Storage

and Power to Gas - renewable energy storage, and fuel for the grid