Is cryptocurrency environmentally friendly?

Is it true that cryptocurrency is environmentally friendly, or are there hidden costs to its production and use that we should be aware of? With the surge in popularity of digital currencies like Bitcoin and Ethereum, there have been growing concerns about the environmental impact of their mining processes. What are the main factors that contribute to their carbon footprint, and what steps are being taken to mitigate these impacts? As an investor or consumer of cryptocurrency, how can I ensure that my actions are sustainable and environmentally responsible?