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Ocean acidification in a geoengineering context.

Williamson P, Turley C - Philos Trans A Math Phys Eng Sci (2012)

Bottom Line: Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO(2)) in the atmosphere.There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100.The future magnitude of such effects will be very closely linked to atmospheric CO(2); they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques.

View Article: PubMed Central - PubMed

Affiliation: School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. p.williamson@uea.ac.uk

ABSTRACT
Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO(2)) in the atmosphere. Ocean acidity (H(+) concentration) and bicarbonate ion concentrations are increasing, whereas carbonate ion concentrations are decreasing. There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100. Laboratory experiments, observations and projections indicate that such ocean acidification may have ecological and biogeochemical impacts that last for many thousands of years. The future magnitude of such effects will be very closely linked to atmospheric CO(2); they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques. However, some ocean-based CDR approaches would (if deployed on a climatically significant scale) re-locate acidification from the upper ocean to the seafloor or elsewhere in the ocean interior. If solar radiation management were to be the main policy response to counteract global warming, ocean acidification would continue to be driven by increases in atmospheric CO(2), although with additional temperature-related effects on CO(2) and CaCO(3) solubility and terrestrial carbon sequestration.

No MeSH data available.


Related in: MedlinePlus

(a) The relationship between changes in global annual carbon emissions over the period 1800–2500 and (b) global mean surface pH. The pH stabilization levels of 8.10, 8.01, 7.94, 7.87, 7.82 and 7.70 correspond to atmospheric CO2 levels of 350, 450, 550, 650, 750 and 1000 ppm. Dotted lines labelled OSP (overshoot stabilization profile) show pathways requiring negative CO2 emissions (i.e. carbon dioxide removal geoengineering) to achieve atmospheric CO2 stabilization at 350 and 450 ppm; dashed lines labelled DSP (delayed stabilization profile) show delayed approach to emissions reductions to achieve stabilization at 450 and 550 ppm; solid lines labelled SP represent stabilization profiles. From Joos et al. [34], modified by permission of Oxford University Press.
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RSTA20120167F4: (a) The relationship between changes in global annual carbon emissions over the period 1800–2500 and (b) global mean surface pH. The pH stabilization levels of 8.10, 8.01, 7.94, 7.87, 7.82 and 7.70 correspond to atmospheric CO2 levels of 350, 450, 550, 650, 750 and 1000 ppm. Dotted lines labelled OSP (overshoot stabilization profile) show pathways requiring negative CO2 emissions (i.e. carbon dioxide removal geoengineering) to achieve atmospheric CO2 stabilization at 350 and 450 ppm; dashed lines labelled DSP (delayed stabilization profile) show delayed approach to emissions reductions to achieve stabilization at 450 and 550 ppm; solid lines labelled SP represent stabilization profiles. From Joos et al. [34], modified by permission of Oxford University Press.

Mentions: The tight relationship between atmospheric CO2 and surface ocean chemistry means that emission reduction measures that stabilize the former, e.g. at 450, 550, 650, 750 or 1000 ppm, will also stabilize surface ocean pH, at approximately 8.01, 7.94, 7.87, 7.82 and 7.71, respectively (figure 4) [34]. The predicted consequences of a pH fall of 0.4 (to 7.7, discussed earlier as the ‘business as usual’ scenario) are therefore avoidable, if strong mitigation measures are taken.Figure 4.


Ocean acidification in a geoengineering context.

Williamson P, Turley C - Philos Trans A Math Phys Eng Sci (2012)

(a) The relationship between changes in global annual carbon emissions over the period 1800–2500 and (b) global mean surface pH. The pH stabilization levels of 8.10, 8.01, 7.94, 7.87, 7.82 and 7.70 correspond to atmospheric CO2 levels of 350, 450, 550, 650, 750 and 1000 ppm. Dotted lines labelled OSP (overshoot stabilization profile) show pathways requiring negative CO2 emissions (i.e. carbon dioxide removal geoengineering) to achieve atmospheric CO2 stabilization at 350 and 450 ppm; dashed lines labelled DSP (delayed stabilization profile) show delayed approach to emissions reductions to achieve stabilization at 450 and 550 ppm; solid lines labelled SP represent stabilization profiles. From Joos et al. [34], modified by permission of Oxford University Press.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3405667&req=5

RSTA20120167F4: (a) The relationship between changes in global annual carbon emissions over the period 1800–2500 and (b) global mean surface pH. The pH stabilization levels of 8.10, 8.01, 7.94, 7.87, 7.82 and 7.70 correspond to atmospheric CO2 levels of 350, 450, 550, 650, 750 and 1000 ppm. Dotted lines labelled OSP (overshoot stabilization profile) show pathways requiring negative CO2 emissions (i.e. carbon dioxide removal geoengineering) to achieve atmospheric CO2 stabilization at 350 and 450 ppm; dashed lines labelled DSP (delayed stabilization profile) show delayed approach to emissions reductions to achieve stabilization at 450 and 550 ppm; solid lines labelled SP represent stabilization profiles. From Joos et al. [34], modified by permission of Oxford University Press.
Mentions: The tight relationship between atmospheric CO2 and surface ocean chemistry means that emission reduction measures that stabilize the former, e.g. at 450, 550, 650, 750 or 1000 ppm, will also stabilize surface ocean pH, at approximately 8.01, 7.94, 7.87, 7.82 and 7.71, respectively (figure 4) [34]. The predicted consequences of a pH fall of 0.4 (to 7.7, discussed earlier as the ‘business as usual’ scenario) are therefore avoidable, if strong mitigation measures are taken.Figure 4.

Bottom Line: Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO(2)) in the atmosphere.There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100.The future magnitude of such effects will be very closely linked to atmospheric CO(2); they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques.

View Article: PubMed Central - PubMed

Affiliation: School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. p.williamson@uea.ac.uk

ABSTRACT
Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO(2)) in the atmosphere. Ocean acidity (H(+) concentration) and bicarbonate ion concentrations are increasing, whereas carbonate ion concentrations are decreasing. There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100. Laboratory experiments, observations and projections indicate that such ocean acidification may have ecological and biogeochemical impacts that last for many thousands of years. The future magnitude of such effects will be very closely linked to atmospheric CO(2); they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques. However, some ocean-based CDR approaches would (if deployed on a climatically significant scale) re-locate acidification from the upper ocean to the seafloor or elsewhere in the ocean interior. If solar radiation management were to be the main policy response to counteract global warming, ocean acidification would continue to be driven by increases in atmospheric CO(2), although with additional temperature-related effects on CO(2) and CaCO(3) solubility and terrestrial carbon sequestration.

No MeSH data available.


Related in: MedlinePlus