The iron CLAW

Mike Harvey

doi:10.1071/EN07066

RESEARCH FRONT

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The iron CLAW

Mike Harvey

+ Author Affiliations

- Author Affiliations

National Institute of Water and Atmospheric Research, PO Box 14-901, Kilbirnie, Wellington, New Zealand. Email: m.harvey@niwa.co.nz

Environmental Chemistry 4(6) 396-399 https://doi.org/10.1071/EN07066
Submitted: 14 September 2007 Accepted: 28 October 2007 Published: 6 December 2007

Environmental context. A ‘climate stabilising’ feedback system known as the CLAW hypothesis, which involves the phytoplankton driven influence on cloud reflectivity through the cycling of sulfur was proposed ~20 years ago, and because of its complexity, it remains unproven today. Since the CLAW proposal, experiments that have added iron to the ocean have proven that iron can significantly limit phytoplankton productivity and can also affect the marine sulfur cycle in a complex manner. Because of a range of possible feedbacks between iron, sulfur and climate, it is likely that future advances in understanding the CLAW hypothesis will require a comprehensive process-based description that can be tested in fully coupled earth-system models.

Acknowledgements

The work is supported by the New Zealand Foundation for Research, Science and Technology contract CO1X0703 – Drivers and Mitigation of Global Change. The author thanks reviewers for helpful suggestions.

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The iron CLAW

Acknowledgements

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