The transition to renewable energyrenewable energyEnergy derived from resources that are not depleted on timescales relevant to the economy, i.e. not geological timescales. is vital if we are to tackle climate change. Yet, with existing technologies, that transition would only tackle 55% of the emissions that cause the climate to change. It would tackle the emissions that come from the electricity and heat we use in buildings, from our energy system more broadly, and from transport. To tackle the remaining 45% of emissions, which come from industry, agriculture, and land use, we need to transition to a circular economycircular economyA systems solution framework that tackles global challenges like climate change, biodiversity loss, waste, and pollution. It is based on three principles, driven by design: eliminate waste and pollution, circulate products and materials (at their highest value), and regenerate nature..