Table 4.
Impacts of Control, SRM and CDR scenarios on ecosystem services
| Control | CDR examples | SRM examples | ||||
|---|---|---|---|---|---|---|
| Doubled atmospheric CO2 | Afforestation (land) | Engineered carbon capture and storage (underground) | Ocean fertilization (ocean) | Stratospheric aerosol injection (land/ocean) | Cloud albedo enhancement (ocean) | |
| Supporting (net primary productivity, soil, nutrient cycling) | Mixed effects on ocean and land net primary productivity; indirect effects on soils; positive effects from high CO2; mixed effects from increased temperature; negative effects from drought; reduced ocean nutrient supply but could be offset in some regions by enhanced atmospheric nitrogen deposition (Duce et al. 2008) | Increased forest causes higher net primary productivity | Depends on materials needed for specific carbon capture technology | Ocean nutrient robbing—localized increases in primary production but potential decreases far afield (Gnanadesikan and Marinov 2008) | Changes for the “Control” case would be same for CO2, and productivity would be enhanced by increased diffuse radiation | Changes similar to the “Control” case are expected for land net primary productivity; enhanced upwelling and nutrient supply may increase ocean net primary productivity |
| Provisioning (fuel, fiber, food) | Food supply is reduced by temperature increase and drought, but partially offset by high CO2; ocean impacts are unclear but probably negative for fisheries and shellfish (e.g., altered distribution of ‘fish food’ zooplankton in Atlantic,Richardson and Schoeman 2004) | Competition with food for arable land | Energy cost for capturing and storing CO2 | Possible enhancement of some fisheries due to increased phytoplankton, but such carbon cycling through food web would reduce carbon sequestration | Energy will be required for aerosol delivery; otherwise fuel and fiber likely improved relative to “Control” case | Energy is required; potential changes to fishery production in some regions (e.g., Peruvian tuna fishery); possible increased productivity for upwelling-based fisheries |
| Regulating (climate regulation, water quality) | Diminished capacity for carbon sequestration; terrestrial biosphere is likely to become net carbon source; tundra source of methane; change in water vapor distribution; freshwater supply redistributed; higher O3 exposure of plants; warming reduces ocean biological (Bopp et al. 2002) and solubility pumps | Increased water use and changes to water availability; trace gas emissions reduced | Water will be required for capturing and storing CO2 | Possible albedo increases from enhanced DMS emissions; enhanced ocean capacity of CO2; potential production of N2O during re-mineralization (Law 2008); altered water quality (less nutrients, less O2 and more acid) in mid and deep water as well as column | Cooler temperatures may increase water availability due to lower temperature and less drought; increased ozone hole formation from aerosol heterogeneous chemistry, causing increased UV radiation damage to land-based biota | May be better climate regulation than base case if global temperature is reduced, but intense cooling over small ocean regions could change circulation (e.g., El Nino and monsoon cycles), which could impede climate regulation; enhanced ocean upwelling could increase outgassing of CO2 |
| Cultural (esthetics, educational, spiritual) | Changes in biome distributions; loss of biodiversity and ecosystems, especially at high altitudes and latitudes; negative impacts on coral and other ecosystem-related tourism | Reduced visual diversity | Factories will be visually unappealing but likely to impact small, unpopulated areas | Impacts on coastal fishing communities; possible H2S production due to increased anoxic zones; increased acidification of deep ocean biota (Cao and Caldeira 2010) | No blue sky; impeded astronomical observations | Increased man-made structures in ocean regions; possible reduced visibility at sea; similar to arguments against offshore wind turbines |