When the Powering Past Coal Alliance was first announced at the end of 2017, an astute New York Times’ headline caught my attention : "19 Countries Vowed to Phase Out Coal. But They Don’t Use Much Coal". This sparked a lot of questions. Is the Alliance just a symbolic gesture or might it really help the climate? Are these countries breaking past trends or just retiring old plants? How likely is it that the Alliance would expand, which countries may join next, and would the major coal consumers such as the US, China and India ever become members? 

Answering these questions meant drawing theories and methods from different disciplines. This was a challenge but also an opportunity.

In our paper Prospects for powering past coal, published in Nature Climate Change, we tackle the first and second questions by calculating the CO₂ emissions under a business as usual scenario when coal power plants are retired at the end of the average lifetimes and compare these to the emissions in a scenario with coal phase-out pledges. We show that the Alliance will avoid about 1/150th of the emissions expected from currently operating power plants worldwide, a small fraction of what is needed for climate change mitigation. This is because major coal consumers are not members of the Alliance. This analysis relied on ideas, data and methods commonly used in energy modeling and climate policy research, but it did not answer whether the impact of the Alliance could expand in the future if other countries join.

To tackle this problem, we looked at what makes the Powering Past Coal members similar to each other and different from other countries. We started by exploring the data with descriptive statistics and then ran a logistic regression analysis to work out which variables best explain the difference between those countries which join the Alliance and those which don't. This is a method commonly used in political science. We found that members of the Alliance are wealthy countries with independent and transparent governments where electricity demand does not grow, power plants are older and there is little mining and use of coal.

Using methods and data from two different disciplines gave us the opportunity to bridge  knowledge from different fields. It was interesting to observe contrasting reactions of different research communities to our methods and findings. Political scientists were generally familiar with climate pathways from the IPCC report and basic energy modeling concepts such as a business as usual and a least cost climate stabilisation scenario. In contrast, we often received questions from energy modellers about fundamental political science concepts. For example, they felt that one of our key explanatory variables, an index of transparency and independence of governments, should be replaced by a "more objective" variable, not realizing that political scientists have spent decades conceptualizing governance and how to measure its different components.

The asymmetrical knowledge of our audiences means that social scientists are becoming increasingly familiar not only with the findings of the IPCC reports but also with their methods. It also indicates that energy and climate modellers need to learn more about political process. While the IPCC pathways articulate the scale of the problem and technically feasible solutions, whether these solutions can be forged in the real world largely depends on their political feasibility, which can only be evaluated by bringing in knowledge from political and other social sciences.

In the most recent example of how useful such an interaction might be, an article published the same day as ours in Nature showed that the 1.5 degree target can only be achieved if existing energy infrastructure, particularly power plants, is retired before the end of its lifetime. Our analysis empirically shows that such pre-mature retirement is extremely rare even among PPCA members (with the exception of the Netherlands and possibly Germany). Our research thus supports the call from that article to pay more attention to carbon capture and storage and negative emission technologies as potential solutions to the climate crisis.

This work was supported by the Research Council Norway under grant agreement 267528 Analyzing past and future energy industry contractions: Towards a better understanding of the flip-side of energy transitions. A. Cherp received support from the Central European University’s Intellectual Themes Initiative Political Economy of Energy Transitions Project.