Minal PATHAK
Associate Professor at the Global Centre for Environment and Energy (Ahmedabad University, India)
The use of models and emission scenarios are pillars of the reports on climate change mitigation by the Intergovernmental Panel on Climate Change (IPCC), while elements of earth system tipping points are reflected in WG1 reports and impacts, vulnerability, and adaptation fall under WG2 methodology (e.g., ISIMIP).
Unfortunately, IPCC mitigation reports rely almost exclusively on global scenarios built in Integrated Assessment Models (IAMs) with the arguments that these scenarios are the only ones to integrate the interrelationship between the economy and the environment in the long-term. Several scholars pointed to flawed foundations of IAMs methodology, especially regarding risks, equity and justice challenges raised by climate change. Scenarios developed using IAMs also fail in answering the question of the speed and the nature of the climate action needed to avoid the announced climate breakdown in IAMs scenarios.
Criticism of IAMs is growing. However, they do not question the underlying normative IAM framework, which is driven by largely exogenous socio-economic growth trajectories and utility maximization, nor do they question IAMs description of structural change, markets, technologies, North/South equity, and distributional issues. Instead, the most progressive critics of IAMs propose considering damage functions and altering the current underlying IAM framework to include a better description of structural and systemic changes needed to avoid the climate breakdown.
The latest IPCC workshop on scenarios suggests a continuation of the use of IAMs for the next assessment report by considering few improvements such as equity and distribution. The proposed changes are unlikely to make IAMs valuable tools to provide policy guidance regarding climate targets and justice because IAM bias is within the underlying modeling framework.
This workshop aims at debunking what does not work with existing dominant modeling framework and to develop an outline for a new modeling approach that include a wider set of parameters to build momentum and push for alternative methods and models, which allows assessing in an open manner by all users i) the magnitudes of risks in different countries/regions associated with different concentrations of greenhouse gasses and the announced climate neutrality targets as well as ii) how these risks could be distributed across countries and generations considering the known deep uncertainties.
The aim is to i) feed the next IPCC cycle by providing scenarios that reflect better the identified climate risks and their regional and intergenerational impacts and to allow for an open and realistic public debate about climate action, and to ii) identify researchers and institutions in the global South to build collaborations and capacity to empower IPCC focal points.