Intergovernmental Panel on Climate Change

Scenarios for Climate
An international body for assessing the science related to climate change, widely recognised for its comprehensive and authoritative assessment reports, using scenarios in an attempt to lay the ground for action


Climate denialism and disavowal are rife. In the face of irrefutable scientific evidence of anthropogenic climate change, governments and corporations find increasingly inventive strategies to talk themselves out of acting, or indeed to keep worsening the situation. Approximately 40% of global emissions and 50% of global energy consumption can be attributed to the built environment sector, which has been identified as “lagging behind” others in taking action to mitigate the effects of climate breakdown.1Paolo Bertoldi, Jacob M. Kihila, André F.P. Lucena, Érika Mata, Sebastian Mirasgedis, Aleksandra Novikova, and Yamina Saheb, ‘Buildings’, in Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, ed. by Priyadarshi R. Shukla and Jim Skea et al. (Cambridge, UK: Cambridge University Press, 2022), pp. 953-1048 <> [accessed 13 February 2023]. Still, action on climate change at all levels tends to focus on short-term solutions, siloed within disciplinary niches, and on what can be controlled technologically—despite the obvious fact that climate breakdown is well beyond control and requires much broader approaches. 

Many attempts have been made by activists, scientists, politicians, and others to create a sense of urgency around carbon emissions in particular. In 1988, NASA’s James Hansen told reporters outside a US Senate Hearing to which he had just testified, that “it is time to stop waffling”, to accept the greenhouse effect, and to take action. Yet throughout the ensuing decades, human activity emitted more greenhouse gases than during several millennia of civilisation. There was no great mobilisation, only increasing inequality and exclusion. 

But who is responsible for making the argument? Who assembles data and scientific knowledge, and how open and transparent is the reporting process? In the same year, 1988, the Intergovernmental Panel on Climate Change (IPCC)—an independent body of scientists from 195 countries—was established by the United Nations Environment Programme and the World Meteorological Organization, with the remit to produce reports providing guidance to policymakers on the state of knowledge around climate change, as well as strategies for reducing greenhouse gas emissions and adapting to the impacts of climate breakdown. 


At the core of Hansen’s senate testimony were a set of scenarios: possible futures that might arise from different actions, presented in terms of the effects that different levels of emissions might have on the earth’s climate, and the resulting environmental, social, and economic consequences. This process followed a lineage of prediction going back to the 19th century, which has also been fundamental to the IPCC’s operations. The IPCC’s use of scenarios has evolved, however, to accommodate increasing levels of uncertainty around climate futures (notably, that recent predictions are coming true much quicker than expected), as well as to open up the process to a wider public. The IPCC’s reports are based on a comprehensive review of scientific literature and undergo a rigorous peer-review process. Their assessments are policy relevant, but they don’t dictate specific policies or actions. In recent decades, the IPCC has explicitly moved from “predictions to projections to storylines and now pathways”—the latter being illustrations of possible futures, consequences, and responses in order to enable informed decision-making.2Renata Tyszczuk and Joe Smith, “Culture and Climate Change Scenarios: The Role and Potential of the Arts and Humanities in Responding to the ‘1.5 Degrees Target’”, Current Opinion in Environmental Sustainability, 31 (2018), pp. 56-64 <> The point is not to frustrate or paralyse but to “open the future” by exploring the agency of real-world choices.3Mason Inman, ‘Opening the Future’, Nature Climate Change, 1 (2011), pp. 7-9 <> 

“The goal of working with scenarios is not to predict the future but to better understand uncertainties and alternative futures, in order to consider how robust different decisions or options may be under a wide range of possible futures.”4IPCC, ’Scenario Process for AR5’, Socio-Economic Data and Scenarios, [n.d.] <> [accessed 1 August 2023].

IPCC has a unique structure with stakeholders from governments, the scientific community, and other organisations. It is divided into Working Groups, a Task Force on National Greenhouse Gas Inventories, Technical Support Units, and the Secretariat which manages the organisation’s operations. The interdisciplinary structure aims to ensure scientific rigour, transparency, and inclusivity while making assessments accessible and relevant to policy-makers worldwide. The IPCC’s latest report cycle, AR6, concluded in March 2023 with the release of the AR6 Synthesis Report. Following the format of previous reporting cycles, the synthesis report was preceded by working group reports covering the The Physical Science Basis (ie. what is happening); Impacts, Adaptation and Vulnerability (ie. what the consequences will be); and Mitigation (ie. what we can do about it). 

The IPCC’s 35-year long practice of insistence—of securing and bringing up to date the state of knowledge, and of relentlessly pointing out the potential consequences of climate change—seemed to shift in this latest reporting round. The tone moved from future to current, placing the now very much inside climate change whilst maintaining its projective, scenario-based format. Such scenarios become increasingly propositional now that the IPCC is a generation old, and whilst its reports cannot yet be said to have been successful, it can be said to stand for a form of scientifically-driven practice which does not limit itself to technological solutions. As well as offering a reliable source of scientific data around climate and built environment, it is propositional: in its combination of evidence, insistence, and playing out the ramifications of climate breakdown in interdisciplinary settings and through long-term, scenario-based thinking. 


External links

Global Change Research Program (USGCRP)—a US interagency programme that coordinates and integrates federal research on changes in the global environment and their implications for society 

European Environment Agency (EEA)—an EU agency that provides independent information on the environment to support policy development and implementation 

Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)an independent intergovernmental body that assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision-makers