Jens Terhaar

OS Ocean Sciences

The 2025 Division Outstanding Early Career Scientist Award is awarded to Jens Terhaar for outstanding research on the biogeochemistry of the ocean carbon cycle and its feedbacks on climate.

The 2025 OS Division Outstanding Early Career Scientist Award is awarded to Jens Terhaar for outstanding research on the biogeochemistry of the ocean carbon cycle and its feedbacks on climate.

Since completing his PhD in 2019, Terhaar rapidly established himself as an outstanding scientist, with a prolific record of publications, communications, and outreach activities, a sharp mind and deep and wide-ranging knowledge of the outstanding issues in his field. The breadth and quality of his research contributions are evidenced by a large number of peer-reviewed publications, as well as by the impact of his studies.

Terhaar’s work is characterised by a thorough and critical assessment of ocean biogeochemical models and observational data and their uncertainties, as well as by insightful and novel approaches. For example, he demonstrated for the first time the importance of the land-ocean aquatic continuum for Arctic Ocean primary production. Furthermore, his work has contributed to improve modelled estimates of the past and future ocean carbon sink using sea surface salinity observations, resolving one of the long-standing questions in the carbon cycle field, namely how much human-made CO2 can be absorbed by the Southern Ocean in the future. Terhaar further developed a new algorithm for improved climate projections, which is now applied by various Earth system modeling centers.

Terhaar’s excellence is not limited to his publications but extends to his funding record, international experience, engagement in community efforts (e.g., RECCAP2 and IPCC reports), and involvement in community work such as reviewing, mentoring, teaching and outreach, as well as being a PhD representative at the Laboratory for Climate and Environmental Sciences (LSCE). In these roles he excels in his dedication to promote an open, diverse, and inclusive academy, and in the kindness and altruism displayed towards his peers. These achievements are even more extraordinary given that Terhaar is a father of three children, currently working 80% of full time equivalent to share parenting duties.

In summary, Jens Terhaar is an outstanding scientist in ocean biogeochemistry, with outstanding contributions at all levels, even when compared to more senior scientists in the field.