Ian Simm, chief executive of environmental asset manager Impax, tries to avoid labels such as socially responsible investing. In his view, the objective of the firm, which has £1.8bn in assets under management, is to invest in opportunities arising from resource scarcity – and that does not require a particular ethical or moral view.

Simm admits that now is not the best time for asset management firms like his that are focused on environmental investments because investors remain cautious and future government investments in infrastructure appear uncertain. Indeed, Impax has seen its share price fall more than 20% over the past year.