EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Underestimated Role of Fires in Providing Nutrients for Biogeochemical Cycles

Douglas Hamilton1, Anne Barkley2, J. Keith Moore3, Almut Arneth4, Tami Bond5, Kenneth Carslaw6, Cassandra Gaston2, Stijn Hantson7, Akinori Ito8, Jed Kaplan9, Keith Lindsay10, Lars Nieradzik11, Joseph Prospero2, Sagar Rathod12, Rachel Scanza13, and Natalie Mahowald1
Douglas Hamilton et al.
  • 1Department of Earth and Atmospheric Science, Cornell University, Ithaca, NY, USA
  • 2Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149
  • 3Department of Earth System Science, University of California Irvine, Irvine, CA, USA
  • 4Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research/Atmospheric Environmental Research, 82467 Garmisch-Partenkirchen, Germany
  • 5Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA
  • 6School of Earth and Environment, University of Leeds, Leeds,
  • 7Geospatial Data Solutions Centre, University of California Irvine, Irvine, CA, USA
  • 8Yokohama Institute for Earth Sciences, JAMSTEC, Yokohama, Kanagawa 236-0001, Japan
  • 9Department of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China
  • 10National Centre for Atmospheric Research, Boulder, CO, USA
  • 11Institute for Physical Geography and Ecosystem Sciences, Lund University, Lund, Sweden
  • 12Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
  • 13Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA

Fire regimes respond to both climate and human land management practice changes, in turn modifying land cover distributions, surface albedo, carbon storage, and emissions. Much attention has recently been given to the health and climate impacts of fires, but fires are also an important source of nutrients, such as iron and phosphorus, to both land and ocean biospheres. Fires therefore create important feedbacks within the Earth system. Here we discuss recent developments showing how fires are a previously underestimated source of limiting nutrients, providing up to half the annual deposited amount of soluble iron and soluble phosphorus to southern oceans and the Amazon, respectively. Fire can therefore stimulate ocean productivity by providing long range transport of essential nutrients, released from the vegetation burned and entrained with dust from the surrounding environment, to remote regions. We considered the impact of human activity on soluble iron deposition for the past (c.1750 CE), present (c.2010 CE), and future (c.2100 CE). We find that the global carbon cycle and climate response is dominated by changes to primary productivity within the Southern Ocean (>30ºS) and that the carbon export efficiency (gram of carbon sequestered per gram of soluble iron added) for this region is 43% larger when altering fire emissions compared to altering dust emissions. Results suggest that modelling past and future changes in biogeochemical cycles should incorporate information on how fires, and the nutrients carried within their plumes, respond to changes in climate.

How to cite: Hamilton, D., Barkley, A., Moore, J. K., Arneth, A., Bond, T., Carslaw, K., Gaston, C., Hantson, S., Ito, A., Kaplan, J., Lindsay, K., Nieradzik, L., Prospero, J., Rathod, S., Scanza, R., and Mahowald, N.: Underestimated Role of Fires in Providing Nutrients for Biogeochemical Cycles, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10650,, 2020

Comments on the presentation

AC: Author Comment | CC: Community Comment | Report abuse

Presentation version 1 – uploaded on 29 Apr 2020
  • CC1: Comment on EGU2020-10650, Joan Llort, 06 May 2020

    Hi @Douglas, thanks for your presentation. Looking forward to reading the paper. Did you consider in your study a third scenario where both high dust and high fire emission co-exist?