US crosses milestone for CO2 emissions

In 2016 – for the first time ever – carbon dioxide (CO₂) emissions from natural gas burning are set to surpass those released from burning coal in the United States (US).  Driven by the hydraulic fracturing revolution and cheaper access to natural gas, the next challenge for producers will be to ensure that methane emissions from fugitive emissions and leaks do not counteract the positive effects of the switch. 

CO₂ is released when natural gas or coal is burned to generate electricity.  In 2016 emissions from natural gas burning are expected to be 10 per cent higher than emissions from coal.  While historically CO₂ emissions from coal electricity have been the leading climate polluting agent globally, an increasing number of US companies are relying on natural gas to power electricity plants.

In 2015, the US used around 81 percent more natural gas than coal for electricity.  Coal contains more carbon than natural gas, so carbon emissions from burning both were relatively equal.  The rise in natural gas consumption in the US is expected to continue.  The US Energy Information Administration (EIA) estimates that burning natural gas will release around 1.5 billion metric tons of carbon dioxide in 2016 compared to around 1.4 billion metric tons from coal.

The increased supply of low-cost natural gas is largely the result of the US shale gas revolution.  With hydraulic fracturing operations increasing, the decline of coal production will likely continue.  This is supported by climate change policies in the US, including President Obama’s Clean Power Plan.  The plan is being implemented in line with the US commitment to the Paris Climate Agreement, which aims to limit emissions to prevent global warming from exceeding 2°C above pre-industrial levels.

While burning natural gas releases less CO₂ than coal, extracting and transporting processes are prone to leaks and fugitive emissions.  Before natural gas is burned to release CO_2, the primary component is methane, which is roughly 30 times more potent as a greenhouse gas.  When leaks occur, it is methane entering the atmosphere, not CO₂.

Burning natural gas compares relatively favourably to coal in terms of emissions.  The question now is how will the industry focus on minimising fugitive emissions and leaks to ensure the benefits are realised over the long term?