To ensure that as our business grows, our carbon footprint does not, we'll offset any increase in our operational greenhouse gas (GHG) emissions above 2015 levels that's not covered by our sustainable reductions activity. Our operating businesses aim to deliver this through improved energy efficiency, fewer methane emissions and reduced flaring - all leading to permanent, quantifiable GHG emissions reductions. We only count a sustainable emissions reduction in the year it occurs, but we expect the benefit of the reduction to continue in later years too.