Between 1988 and 1990, Frérot worked at Credit National as finance operations manager for major transport, aerospace and heavy machinery enterprises.

[9] Frérot's strategy encompasses progressive disengagement from transport activities, in favor of the French Deposits and Consignments Fund, as well as decreased international expansion, limited to approximately forty countries.

[11] On 26 February 2014 Veolia's administrative council decided to renew Frérot's mandate until 2018 in order to finalize the process of restructuring of the Group.

In the spirit of his tagline, "modern mankind is living on ecological credit," he called on the participating enterprises and organizations to support projects favoring a sound and stable price of CO2.

According to Frérot, the carbon price should be the core of environmental politics, and a way to tackle climate change that would simultaneously enable economic growth.

Quoting European Resource Efficiency Platform, Frérot advocated circular economy both as a means to reduce consumption of raw materials by 20%, and a source of 1.4 to 2.8 million potential jobs.

More than half of this growth is the result of new activities identified as strategic, such as the circular economy, energy efficiency, the treatment of difficult pollution, the management of end-of-life industrial equipment.