We address this question by investigating how Google users’ search on global warming is associated with the trading activeness of Ethereum, the second largest cryptocurrency in the world. Exploiting Ethereum’s transition to a green blockchain (i.e., “The Merge”), we find that before the transition, Google search on global warming is negatively associated with the transaction volumes of Ethereum, but the relationship turns significantly positive after The Merge, suggesting online users’ green orientation towards energy-efficient cryptocurrencies. Our analysis sheds light upon an emerging research on the environmental issues in crypto markets.