This episode of the Physics World Weekly podcast looks at two very different and very difficult challenges — how to build a quantum computer that can overcome the debilitating noise that plagues current processors; and how to ensure that the UK meets its target for net-zero greenhouse gas emissions by 2050.

Our first guest is the nuclear physicist and sustainable energy expert, Martin Freer, who coordinated the writing of a report from the Institute of Physics (IOP) called Physics Powering the Green Economy. Freer, who is at the University of Birmingham, explains why more investment and support will be needed to ensure that the UK meets its target to achieve net-zero greenhouse gas emission by 2050.

Meanwhile in Paris, the quantum-computer maker Alice & Bob is developing “cat qubits” that promise to reduce the amount of hardware required to do quantum error correction. The company’s co-founder and CEO Théau Peronnin explains how the technology works and how it could be used to build quantum computers that could solve practical problems. He also explains why the company chose its quirky name.