Fig. 2: Change in regional energy system costs and commodity trade costs under 1.75 and 2 °C HDI-based redistributed cases relative to optimal cases, 2020–2060.

Panels a–d represent the change in energy system costs by HDI group, compared with the cost-optimal case. Negative values show a reduction in costs, while the black trend line shows the net change in global costs. Cost estimates do not include tax revenues raised by the production tax, with the focus on the techno-economic costs of the system. Source data are provided as a Source data file.