The focus of Hannover Re's efforts to conserve the environment is on reducing CO2 emissions associated with the supply of electricity and heat to its premises as well as those caused by its business travel. The goal of operating on a carbon-neutral basis at the Hannover location was achieved in the 2016 financial year. The changeover to renewable energy in 2012 and the offsetting of greenhouse gas emissions resulting from air travel through the climate protection organisation atmosfair were key factors in this achievement. Additional CO2 emissions deriving from the use of district heating and from paper consumption were offset not only by making payments to the climate protection organisation atmosfair but also by purchasing climate certificates for the moorland project of Friends of the Earth Germany (BUND – Bund für Umwelt und Naturschutz Deutschland).

Having already converted the power supply at the Hannover location to renewables, this measure is now to be extended progressively to Hannover Re's international offices as well. In addition, the company makes every effort to ensure the economical and resource-saving use of materials and raw materials such as paper and water at its offices. The Group records central consumption and emissions data for its Home Office in Hannover. Furthermore, the company is engaged in a number of environmental conservation projects, including for example the local initiative Climate Alliance Hannover and the "Extreme Events and Climate Risks" working group of the Geneva Association, and it also participates in the CDP (Carbon Disclosure Project).