S ince 2000, progress is visible in emissions of traditional air pollutants, transport fuel efficiency, energy intensity, renewable energy, water use, sewage treatment, and biodiversity protection. This is partly explained by the slowdown in economic activity following the economic crisis, but also by increased uptake by OECD countries of instruments to address environmental pressures, including taxation to influence consumer behaviour and internalise environmental costs. Environmental considerations are also increasingly being mainstreamed in development co-operation and in research and development.