Posties converting to pedal power and trials of electric vans are how Australia Post intends to continue reducing its carbon emissions.

The company has already reduced emissions by 20 per cent since 2000, but plans to make that 25 per cent by 2020 under a new environmental action plan.

Chief financial officer Janelle Hopkins says the plan, released as part of World Environment Day on Tuesday, will ensure long-term sustainability and save $10 million a year.

The plan includes 34 actions, from setting post-2020 carbon and environmental sustainability targets, to maintaining five star energy across corporate offices and other sites where feasible, and testing innovative building and transport technologies.