PSI investigators have been analyzing different ways of mitigating climate change with coworkers from the US, China, Ireland, Finland, and Sweden, using a comprehensive computer simulation of the climate, the global economy, and the global energy system.
Human activities account for approximately 42 billion tons of CO2 emissions per year. The Intergovernmental Panel on Climate Change (IPCC) estimates that only another 300 to 600 billion tons can be added starting in 2020, or the goal of restricting global warming to 1.5 ºC will be nearly impossible to achieve.
It could be a close shave, because 70% of our scenarios predict that the world will exceed the 1.5 °C mark in the next five years.
Evangelos Panos, Laboratory for Energy Systems Analysis, Paul Scherrer Institute
Which Climate Measures Are Most Successful?
Combating climate change requires various political, economic, and social decisions. These decisions, however, are uncertain. Decision-makers seek strong evidence, for instance, in answering one of the central questions: Which measures have the greatest impact while also being economically advantageous as a process of attaining the net-zero emissions target set by Switzerland, for instance?
A large computer simulation working on this issue is now offering some answers. It integrates climate models with economic models and 1200 energy-supply and-use technologies, all while reducing greenhouse gas emissions. A supercomputer calculated 4,000 scenarios for 15 regions of the world as part of the study, taking into consideration potential developments in 10-year steps up to the year 2100.
“This calls for sophisticated data analysis and visualization techniques,” notes co-author James Glynn, Head of the Energy Systems Modelling Program at Columbia University in the US. The final file includes 700 gigabytes of data. The study was published in the academic journal Energy Policy.
What distinguishes Evangelos Panos and his colleagues’ work is that, for the first time, their integrated assessment models account for many of the uncertainties inherent in the models. Earlier scenarios have normally assumed that all future parameters, like which technologies will be available and when, how much they will cost, and how huge the possibility for expanding renewable energies is, are known.
Furthermore, the IPCC calculations are completely focused on technology options, i.e., the impact of choosing certain technologies on the climate. Uncertainties inherent in climate models and how the climate responds to economic growth, as well as several other uncertainties, like population trends and policy measures, are excluded from the equation.
The most important contribution of our research is that it allows policymakers to make concrete decisions about climate action based on a full understanding of the existing uncertainties.
Brian Ó Gallachóir, Study Co-Author, University College Cork
18 Uncertainty Factors and 72,000 Variables
When researchers want to calculate scenarios that contain a large number of variables and uncertainties, they often resort to what is known as the Monte Carlo method. The Monte Carlo method does not predict the future.
“Instead, it creates a kind of data map made up of what-if decision pathways,” details Evangelos Panos. In the present study, the group adjusted 72,000 variables for each scenario.
We considered 18 uncertainty factors, including population and economic growth, climate sensitivity, resource potential, the impact of changes in agriculture and forestry, the cost of energy technologies, and the decoupling of energy demand from economic development.
James Glynn, Columbia University
Sound Basis for National Pathways to an Energy System Transformation
Additional parameters particular to each country must be considered to break down individual scenarios concentrating on political and economic issues into separate national pathways to an energy system transformation.
“An energy system that enables the transition to a zero-carbon economy is capital-intensive and requires the mobilization of resources from all stakeholders,” Panos states. This urges for tailored analyses to be conducted at the national level: “Our study provides a sound basis for these.”
Panos, E., et al. (2023). Deep decarbonisation pathways of the energy system in times of unprecedented uncertainty in the energy sector. Energy Policy. doi.org/10.1016/j.enpol.2023.113642.