Computational resources are all resources of energy and material that are involved in any given task that requires computing.

These are finite and do not double every new generation. [...] On the other hand, the demand for computational resources is set to increase considerably. [...] Therefore, as a society we need to start treating computational resources as finite and precious, to be utilized only when necessary, and as frugally as possible.

As detailed in the paper, we cannot count on renewables to eliminate CO2 emissions from electricity in time to meet the climate targets. Reducing the energy consumption is the only option.

The projections at the current rate are also alarming for 2040. Also

The production of this next generation of devices will create more emissions than any operational gains can offset.

Based on https://eeb.org/library/coolproducts-report/ the devices should last 25 years

The vision for zero-carbon compting is then to improve purely through better computing science. The computational capacity will in effect increase without any increase in energy consumption. Meanwhile, technologies for the next generation of devices, designed for energy efficiency as well as long life will be developed.

The author details multiple research challenges in cloud computing, Ultra-HD video &VR/AR (really?), IoT, and mobile devices.

HCI can make users aware of the energy/carbon costs of their actions, nudge users towards more sustainable practices and interfaces can both influence energy consumption and the useful life of devices.