The problem of equity in IPCC reports
What underpins mitigation action in assessment reports by the UN Intergovernmental Panel on Climate Change? What are Integrated Assessment Models? Do these models follow the principle of equity? What did the latest study find with respect to over 500 futu
The story so far:
In a study published on March 4, researchers analysed more than 500 future emissions scenarios the UN Intergovernmental Panel on Climate Change (IPCC) assessed in its latest reports. These scenarios relate to mitigation actions like reducing carbon dioxide emissions from burning fossil fuels and increasing carbon sequestration through forestry. It found that across all 556 scenarios, income, energyuse, and emissions disparities between developed and developing countries are projected to continue up to 2050.
What are IPCC assessment reports?
Typically, IPCC reports comprise three Working Group reports: one on physical science, one on climate adaptation, and one on mitigation action. One synthesis report consolidates findings from the three Working Group reports. Then there are thematic special reports. Each report assesses climaterelated scientific literature to capture the state of scientific, technical, and socioeconomic knowledge on climate change. The IPCC is currently in its Seventh Assessment cycle (AR7).
How does it assess future scenarios?
The IPCC uses ‘modelled pathways’ to estimate what it will take to limit the warming of the earth’s surface. These pathways are drawn using Integrated Assessment Models (IAMs) that describe human and earth systems. IAMs are complex models that examine possible futures of the energy and climate system and economies. Its macroeconomic models can point to future growth levels in terms of GDP; its energy models can project future consumption; vegetation models can examine landuse changes; and earthsystem models use the laws of physics to understand how climate evolves. With such integration across disciplines, IAMs are meant to provide policyrelevant guidelines on climate action. However, these models also have shortcomings. They prioritise leastcost assessments — for example, the absolute cost of setting up a solar plant or undertaking afforestation in India is lower than in the U.S. However, experts have said they could exercise the option of enabling countries to equitably share the burden of action, where the richest undertake more drastic mitigation action more immediately.
What did the new study find?
The study was conducted by Tejal Kanitkar and Akhil Mythri from the National Institute of Advanced Studies, Bengaluru, and T. Jayaraman from M.S. Swaminathan Research Foundation, Chennai. They assessed 556 scenarios in
IPCC’s AR6 report and found they project that percapita GDP across SubSaharan Africa, South Asia, West Asia and the rest of Asia, which together constitute 60% of the world’s population, will be below the global average even in 2050. They spotted similar inequities between the Global North and the Global South visàvis the consumption of goods and services and both energy and fossil fuel consumption.
The scenarios were also found to project higher carbon sequestration from landbased carbon sinks (like forests) and higher deployment of carbon capture and storage (CCS) technologies in developing countries compared to developed ones. Thus, poorer countries, they concluded, would bear the burden of both mitigation action and carbon dioxide removal and CCS. “Our analysis of the regional trends underlying the global modelled scenarios in the IPCC’s [AR6] indicates that the scenarios disregard the notion of historical responsibility of the Global North,” the authors wrote in their paper, adding the scenarios also “disregard” the future energy needs of the Global South to meet development goals.
Why does equity matter?
The principles of equity and common but differentiated responsibilities are enshrined in the UN Framework Convention on Climate Change
(UNFCCC). Article 3 of the Convention states countries “should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof.”
These principles recognise that while tackling climate change requires global action, richer countries are better placed to shoulder bigger climate action responsibilities than poorer ones. By viewing climate action solely through the lens of globallevel technical and economic feasibility, mitigation pathways modelled using IAMs often run counter to equity principles, researchers say.
“Equity in this sense would imply that developed regions need to accelerate towards net negative emissions and make the remaining carbon budget available to other less developed regions. However, the scenarios project precisely the opposite,” they wrote in their paper.
In the study, the authors conclude that construction of IPCC scenarios will need to be both equitable and environmentally sound. “This is currently a major gap in the emissions modelling domain and we need to move towards model and scenario building techniques where questions of equity and climate justice come to the foreground,” they wrote.
Rishika Pardikar is a freelance environment reporter based in Bengaluru