Maria-Krystyna Duval is ClientEarth’s Head of Climate.


Before joining ClientEarth, she advised the New Zealand government on the economic, fiscal and wellbeing impacts of climate change policy. She advised on the Zero Carbon Act, reforms to the Emissions Trading Scheme and the Resource Management Act as well as aspects of the world’s first Wellbeing Budget. She also helped to design the Climate Implications of Policy Assessment tool, which requires all government decisions to take impacts on emissions into account. Prior to working in New Zealand, Maria-Krystyna worked on environmental policy issues in Hong Kong with a focus on water security and urban wellbeing. Before that, she was in private practice specialising in international public and private law in Hong Kong, London and Paris for many years.


She is a native English and French speaker and fluent in Italian, German and Russian with intermediate Spanish and Mandarin. Aside from her law degree, she holds two Masters’ degrees in political science and economics and two Bachelors’ degrees in English and French literature.

I feel immensely proud and humbled to join an organisation such as ClientEarth whose work is so critical to the wellbeing of our planet and its many diverse inhabitants. I became a lawyer because I have a strong belief in the importance of the rule of law as a transformative tool and look forward to working with ClientEarth's immensely talented team to use the law to combat the ills of climate change.