Karl had a long and illustrious career as a European Union official, including top positions as Director-General for Environment and Deputy Director-General for Trade. Upon retiring from the European Commission in 2017 he became an independent policy adviser and university lecturer.

Widely recognised as one the best trade negotiators Europe has ever had, Karl began his career in the Commission in 1977 as a textiles negotiator. He moved to the broader multilateral trade negotiations area, and represented the EU in the Uruguay Round negotiations that established the WTO. He negotiated the major multilateral services sector liberalisation in Telecommunications, Financial Services, Audiovisual Services and Maritime Transport.

After the fall of the Berlin Wall he served as an adviser on international relations and German reunification to then Commission President Jacques Delors, before being appointed in 2004 as Deputy Director-General for Trade, covering all EU bilateral trade relations.

From 2009 to 2015 he was Director-General for Environment, dealing with Climate Change negotiations and all domestic and international environmental policies. He was the EU lead negotiator for Climate, Biodiversity and a range of other international agreements. He launched the EU’s circular economy policies and negotiated the Sustainable Development Goals of the UN. In 2016 he wrote a report on the EU’s implementation of the UN’s Sustainable Development Goals, called Sustainability Now, addressed to the previous European Commission President Jean-Claude Juncker.

In 2017 he joined Oxford University as a Senior Fellow, and has lectured at the London School of Economics, Aberdeen, Parma, the College of Europe and the Colegio de México. He has also worked as an adviser to the European Aluminium Federation, and has worked on training trade negotiators in the UK government. He is also a Senior Adviser to the German city of Hamburg on waste policies.