It should be other way , effect of climate change on eutrophication.... Recent research suggests that climate change will reinforce the negative consequences of man-made eutrophication and make it more difficult to improve water quality in lakes and estuaries . The direct effects of nutrients are thus also tangled with the structure of food webs, and in turn the nature of food webs is influenced by climate. Some interesting PDFs enclosed..

Eutrophication in our waters leads to increased algal biodiversity and consequent gene pool and hence increased productivity. Basic role of the primary algal species fix the Co2 in quantum thus reducing atmospheric carbon accumulation as a means of mitigation. This is further enhanced by the extensive water coverage in our biosphere which also increase this carbon sinking.

i agree with Abubakar

Please have a look at these useful ResearchGate links.

Chapter Eutrophication and Climate Change: Present Situation and Fut...

Chapter Interaction of climate change and eutrophication

Hi all and thank you for the answers.

I am well aware of the fact that there is another discussion about the effect of global warming on eutrophication.

BUT!

Here I try to ask about the oposite issue, can, will, and to what extent eutrophication can lead to slow down of the anthropogenic global warming.

One thing I do want to correct, as far as I know, eutrophication does not lead to "increased algal biodiversity" It leads to increased algal concentrations but usually reduce biodiversity.

Even if not covering all aspects, please think on the following issues. Eutrophication increases nutrient availability, and, as such, would primarily enhance primary production, this is, carbon fixation, and part of this fixed carbon could be sequestered in less accessible compartments (e.g. sediments). However, the excess of organic matter produced as a consequence of this increase in nutrient availability would, in turn, generate more organic matter to be released, which means more organic matter to be respired. When there is enough oxygen, this respiration would be aerobic, which would release part of the CO2 already fixed by the primary producers, but just a part of it. Still, some carbon can be sequestered. But, what happens when this excess of aerobic respiration creates anoxic zones in part of the aquatic environments? That respiration turns into anaerobic processes, and bot denitrification and methanogenesis generate greenhouse gases (GHG) which much higher greenhouse effect than CO2, such as nitrogen oxides and methane. Thus, the warming effect of these releases, which are allowed by the excess of respiration creating anoxic zones is much higher than that of the CO2. At the end, the positive or negative effects on carbon sequestration and GHG release of eutrophication would primarily depend on the balances of these processes.

Antonio, thank you for your comment.

The processe you mentioned are exactly those that were observed during the IRONEX experiment.

I think the heart of my question is, do we have the tools to e evaluate the effect?

Yes, Yair, you can make an evaluation of those processes. See a partial example on it in our attached paper

Paerl, H. W., & Paul, V. J. (2012). Climate change: links to global expansion of harmful cyanobacteria. Water research, 46(5), 1349-1363.

Charlton, M. B., Bowes, M. J., Hutchins, M. G., Orr, H. G., Soley, R., & Davison, P. (2018). Mapping eutrophication risk from climate change: Future phosphorus concentrations in English rivers. Science of the Total Environment, 613, 1510-1526.

Hillebrand, H., Brey, T., Gutt, J., Hagen, W., Metfies, K., Meyer, B., & Lewandowska, A. (2018). Climate Change: Warming Impacts on Marine Biodiversity. In Handbook on Marine Environment Protection (pp. 353-373). Springer, Cham.

Pesce, M., Critto, A., Torresan, S., Giubilato, E., Santini, M., Zirino, A., ... & Marcomini, A. (2018). Modelling climate change impacts on nutrients and primary production in coastal waters. Science of The Total Environment, 628, 919-937.

Hello Yair,

Your first hypothesis is correct in the condition when there is more oxygen with the evolution of more carbon dioxide. But, in your second hypothesis, under circumstances, if there is less oxygen dissolved as a result of high water temperature, then less carbon dioxide will evolve and without being decomposed rest of the carbon (not carbon dioxide) will be deposited on the sea bottom as sea sediment and may take thousands of years for decomposition.

This is what I meant. I probablg didnt write it correctly.