In 2005, annual emissions of CO2 in the US reached an all-time high of just under six billion tons. By 2016, emissions had declined by 14% from that peak and by 18% when adjusted for growth in population and economic activity.
How have we done it?
- Energy Efficiency: Reduced consumption of electricity and of fuels in the home, industrial, transportation, and business sectors is responsible for 45% of the reduction.
- Generating Electricity from Natural Gas Rather Than Coal accounts for one-third of the savings.
- New Renewable Energy From Wind and Solar accounts for the remaining 22% of savings.
Challenges going forward
We must do better in transportation
The transportation sector recently surpassed the electricity generation sector as the largest single emitter of carbon. However, it did so even though transportation emissions declined between 2005 and 2016. They just didn’t decline as rapidly as emissions in other sectors. And, since 2012, transportation emissions have begun climbing again, which suggests the need for improved policy.
Natural Gas is a contributor to savings today, but will be a barrier going forward
Compared to coal, natural gas looks good. Of course, just about anything looks good compared to coal. Burning natural gas to generate electricity produces half or more of the carbon emissions that come from coal, which means that, although it’s better, natural gas is still a major polluter raising the question of how heavily it should be used, under what circumstances, and for how long?