The radiative forcing potential of different climate geoengineering options

Lenton, T. M. and Vaughan, N. E. ORCID: https://orcid.org/0000-0002-4532-2084 (2009) The radiative forcing potential of different climate geoengineering options. Atmospheric Chemistry and Physics, 9 (15). pp. 5539-5561.

Preview

PDF (Lenton-Vaughan-2009) - Published Version Available under License Creative Commons Attribution. Download (708kB) | Preview

Abstract

Climate geoengineering proposals seek to rectify the Earth's current and potential future radiative imbalance, either by reducing the absorption of incoming solar (shortwave) radiation, or by removing CO2 from the atmosphere and transferring it to long-lived reservoirs, thus increasing outgoing longwave radiation. A fundamental criterion for evaluating geoengineering options is their climate cooling effectiveness, which we quantify here in terms of radiative forcing potential. We use a simple analytical approach, based on energy balance considerations and pulse response functions for the decay of CO2 perturbations. This aids transparency compared to calculations with complex numerical models, but is not intended to be definitive. It allows us to compare the relative effectiveness of a range of proposals. We consider geoengineering options as additional to large reductions in CO2 emissions. By 2050, some land carbon cycle geoengineering options could be of comparable magnitude to mitigation "wedges", but only stratospheric aerosol injections, albedo enhancement of marine stratocumulus clouds, or sunshades in space have the potential to cool the climate back toward its pre-industrial state. Strong mitigation, combined with global-scale air capture and storage, afforestation, and bio-char production, i.e. enhanced CO2 sinks, might be able to bring CO2 back to its pre-industrial level by 2100, thus removing the need for other geoengineering. Alternatively, strong mitigation stabilising CO2 at 500 ppm, combined with geoengineered increases in the albedo of marine stratiform clouds, grasslands, croplands and human settlements might achieve a patchy cancellation of radiative forcing. Ocean fertilisation options are only worthwhile if sustained on a millennial timescale and phosphorus addition may have greater long-term potential than iron or nitrogen fertilisation. Enhancing ocean upwelling or downwelling have trivial effects on any meaningful timescale. Our approach provides a common framework for the evaluation of climate geoengineering proposals, and our results should help inform the prioritisation of further research into them.

Item Type:	Article
Additional Information:	Gold Open Access
Uncontrolled Keywords:	sdg 3 - good health and well-being,sdg 13 - climate action,sdg 15 - life on land ,/dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_being
Faculty \ School:	Faculty of Science > School of Environmental Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Depositing User:	Rosie Cullington
Date Deposited:	23 Feb 2011 10:27
Last Modified:	20 Mar 2024 11:31
URI:	https://ueaeprints.uea.ac.uk/id/eprint/24298
DOI:	10.5194/acp-9-5539-2009

Downloads

Actions (login required)

View Item