The fund seeks to achieve sustainable, above market returns over the longer term by investing globally in companies active in the growing resource efficiency and environmental markets. These markets address a number of long term macro-economic themes: growing populations, rising living standards, increasing urbanisation, rising consumption and depletion of limited natural resources. Investments are made in companies which have >20% of their underlying revenue generated by sales of environmental products or services in the energy efficiency, renewable energy, water, waste and sustainable food and agriculture markets.