[1] In 1975 he returned to Greece to take up the post of deputy governor of the Hellenic Industrial Development Bank (ETVA), while also being a member of the committee preparing Greek accession to the EEC.

In a speech to a committee of the European Parliament Dimas announced four main priorities for his term in office: climate change, biodiversity, public health, and sustainability.

He emphasised the importance of the Kyoto Protocol, the Natura 2000 project, the REACH directive, and the need to better enforce existing EU environmental legislation.

Concerns were raised in advance by MEPs and many NGOs that by appointing a former Wall Street lawyer and industry minister to the environment post the EU had signalled a decreased commitment to environmental issues in favour of promoting economic competitiveness.

However, after some months time, the environment unions quickly endorsed his programme and publicly congratulated him for being able to support the positions of the environmental organizations with great success within the commission.

Dimas' role was vital especially since the President, Mr Barroso, was ready to disregard the effects on the environment due to the need to improve economic development.

At UN talks on climate change in Buenos Aires in December 2004 he attempted to negotiate a new system of mandatory emissions reductions to follow the expiration of the initial Kyoto targets in 2012.

The Italian environment minister Altero Matteoli broke EU ranks on the issue, proposing voluntary targets after 2012, and saying that it was, "unthinkable to go ahead without the US, China and India."