Geoengineering our future Climate Blue = http://royalsociety.org/uploadedFiles/Royal_Society_Content/policy/publications/ 2009/8693.pdf What is Geoengineering? What points in the system should we intervene in? Fossil energy system CO2 emission to biosphere Mitigation of energy use Industrial Carbon management Climate system Geoengineering Impact of climate on human welfare Adaptation Do we use less fossil fuel energy by less energy demands? Or just use less fossil fuel energy by less greenhouse gases? Emit less CO2 by carbon capture and storage? Pump it below ground Plan B to carry on burning fossil fuel by geoengineering? Or do we just adapt to the effect that it is going to happen? Geoengineering ... the intentional large-scale manipulation of the environment, particularly manipulation that is intended to reduce undesired anthropogenic climate change. But must be: - Large scale (not just modify the weather e.g. cloud seeding (localized) - Intentional (by humans). It is a very recent science of comes to prominence in the last decade, so may be immature science. Types of Geoengineering: SRM (Solar Radiation Management) To try to reduce the amount of sunlight coming into the Earth surface, by either increasing the reflectivity of the surface or increasing the amount reflected by the atmosphere. Effects the environmental impacts itself rather than the effects on the climate, it operates directly on the radiative fluxes in the Earth's energy balance and so are rapid relatively to action so can be used on short notice' but has environmental manipulation. And is measured on the climate sensitivity to the amount of radiative forcing attainable. These technologies are relatively feasible at a direct financial cost of implementation which is small compared to the costs of Climate Change. It can be deployed and produce rapid reductions in global temperatures at a rate and level that couldn't be achieved by mitigation. But the reductions wouldn't be in the locations as the warming (explained more further down).
CDR (Carbon Dioxide Removal) Try to remove CO2 in the atmosphere (not by reducing emissions) by taking it directly from the atmosphere. 'Operate on the atmospheric stocks of CO2 and require the draw-down of a significant fraction of this before affecting the energy balance so they augment efforts to reduce emissions and can delay it by decades before having a significant effect on the earth.' And is measured by the mass of CO2 removed. So, they are technically feasible but slow acting and relatively expensive as they act slowly at removing CO2 concentrations as mitigation for Climate Change. The most desirable CDR remove carbon from the atmosphere without perturbing other Earth systems processes and without deleterious land use change requirements. But emissions are still needed to be reduced for them to as well. SRM: Stratospheric Sulphate Aerosols (its been the most looked at as it is very cost efficient) 1.0 Some of the cooling coincide with major volcanic eruptions as Mount Pinatubo's eruption in 1991 cooled the world about 0.3 degrees. 0.5 Temperature anomaly (?) 0.0 -0.5 Santa Maria -1.0 1900 1920 Agung Pinatubo El Chichon 1940 1960 1980