Attributing Extreme Weather Events to Climate Change

11/24/20223 min read

Probabilistic event attribution (“PEA”) is the science of understanding whether (and the extent to which) historical anthropogenic emissions of greenhouse gases have contributed to the likelihood of the occurrence of an extreme weather event (Otto et al 2014).

Attributable risk is assessed by analysing massive numbers (“ensembles”) of climate model experiments, in order to calculate the frequency of extreme weather events, and changes in this frequency (Otto et al 2014). Essentially, this involves comparing the frequency of such an event in model experiments representing, on one hand, real-world situations (with anthropogenic forcing), and on the other hand, the “world that might have been” (sans human influence) (Otto et al 2014).

The usefulness of PEA in the international context lies in the value it can provide in the assessment of loss and damage under the Warsaw international mechanism for Loss and Damage associated with Climate Change Impacts (“WIM”).

The WIM was established at COP19 in 2013 to “address loss and damage associated with impacts of climate change… in developing countries that are particularly vulnerable to the adverse effects of climate change” (UNFCCC), and has the responsibility of “promoting implementation of approaches to address loss and damage associated with the adverse effects of climate change” (UNFCCC).

There are limits to our abilities to predict or prevent extreme climate events and their effects, thus hampering our ability to adapt fully to climate impacts. Loss and damage arose as part of UNFCCC negotiations “where adaptation actions are unaffordable, not physically or technically possible, socially difficult or simply not sufficient to prevent some harm to humans, the environment and assets” (Byrnes and Surminski 2019). Notably, developing countries request compensation for losses and damage suffered by reason of climate change, developed countries prefer to frame loss and damage to be treated as an element of adaptation (Byrnes and Surminski 2019).

By assessing specific observed events, PEA can shed light on ways to enhance resilience to those events as they occur more or less frequently; by studying long-term changes in the climate system, PEA can inform adaptive measures in a broader sense (Otto et al 2015).

Despite the fact Africa is one of the continents most vulnerable to climate change (Boko et al 2007), very limited research has been conducted in Africa on attribution of weather events (Otto et al 2015). There is a clear need for more PEA studies in order to attain a comprehensive understanding of the range of adaptation options available and the extent of loss and damage to be addressed.

Dialogues and co-production of knowledge are key to the productive and effective application of PEA (Otto et al 2015). The scientific and policy communities must act together in determining the questions to be asked in PEA studies – what is the counterfactual “world that might have been”, what climate drivers are to be removed to generate that simulation, how are decisions made in removing drivers, and how is the extreme event in question to be defined (Otto et 2015). The process must amalgamate scientific and local knowledge, and take account of various factors including space, time, socio-politics, and lived experience of members of affected social groups.

A proper understanding of the links between environmental hazards, climate change, and vulnerability, will prevent any misapplication of public funds and potential injustice and inequity to future generations (Otto et 2015).

References:

  • Otto, F., R. James, and M. Allen. (2014). ‘The science of attributing extreme weather events and its potential contribution to assessing loss and damage associated with climate change impacts’. Environmental Change Institute, University of Oxford.

  • United Nations Framework For Climate Change. (‘UNFCCC’). ‘Warsaw International Mechanism for Loss and Damage associated with Climate Change Impacts (WIM)’. https://unfccc.int/topics/adaptation-and-resilience/workstreams/loss-and-damage/warsaw-international-mechanism

  • Byrnes, R., and Surminski, S. (2019). ‘Addressing the impacts of climate change through an effective Warsaw International Mechanism on Loss and Damage: Submission to the second review of the Warsaw International Mechanism on Loss and Damage under the UNFCCC’. London: Grantham Research Institute on Climate Change and the Environment and Centre for Climate Change Economics and Policy, London School of Economics and Political Science. https://www.lse.ac.uk/granthaminstitute/wp-content/uploads/2019/10/GRI_Addressing-the-impacts-of-climate-change-through-an-effective-Warsaw-International-Mechanism-on-Loss-and-Damage-1.pdf

  • Otto, F.E., E. Boyd, R.G. Jones, R.J. Cornforth, R. James, H.R. Parker, and M.R. Allen. (2015). ‘Attribution of extreme weather events in Africa: a preliminary exploration of the science and policy implications’. Climatic Change 132(4) 2015, pp.531–543.

  • Boko, M., I. Niang, A. Nyong, C. Vogel, A. Githeko, M. Medany, B. Osman-Elasha, R. Tabo, and P. Yanda. (2007). ‘Africa’. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge UK, 433-467. https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter9-1.pdf