Crypto-asset markets are rapidly developing and reached USD 3tn in late 2021, yet the infrastructure supporting mainstream crypto-assets, such as the Bitcoin, use an enormous amount of energy. This paper explores the growing environmental impact of crypto-assets due to increasing institutional and retail investors participation in these markets. The use of energy-intensive transaction validation through Proof-of-Work consensus mechanisms and the corresponding carbon footprint create climate transition risks for market participants. Policy considerations and action are necessary given the carbon footprint and associated climate transition risks of certain digital assets when combined with negative externalities extending to the wider society.