35 years after Earth Day was first celebrated in 1970 the world population has doubled to 7 billion people. The combined effect of population growth and industrial processes on our planet is now so great that it has been proposed that our age should be regarded as a new geological epoch - the Anthropocene. Changes to the atmosphere and the effects of mining, manufacturing and agriculture are affecting Earth systems and increasing rates of extinction to levels that will be as visible in geological strata as the Cretaceous–Tertiary (K–T) boundary that marks the end of the age of the dinosaurs. Even if the putative need for continual economic growth can be sustained by renewable energy sources and/or the long-awaited realisation of thermonuclear electricity generation, the journey to a world population of 16 billion by the end of this Century will cause us to question attempts to preserve even small areas of nature in an unaltered state. New forms of art are required to help us to think about what is natural, essential, desirable or beautiful.