For example, we are seeing the development of new regulations in countries such as China and Trinidad & Tobago.
We monitor our air emissions and put measures in place to reduce the potential impact of our activities on the surrounding community.
As one example, in our unconventional gas operations in the US, we use lower sulphur fuels in the engines of our drilling rigs and hydraulic stimulation equipment which reduces sulphur dioxide emissions.
And in shipping, we are introducing six liquefied natural gas (LNG) carriers with energy efficiency enhancements. They are designed to use approximately 25% less fuel and emit less nitrogen oxides than our older LNG ships.
The decrease in emissions of nitrogen oxide in 2017 is primarily due to reduced diesel usage at our offshore drilling activities. We saw decreases in emissions of non-methane hydrocarbon primarily due to replacing pneumatic gas pumps at our Wamsutter operations in the US. Emissions of sulphur oxide have also decreased due to planned shutdowns for maintenance at some of our refineries.