Bitcoin was started as an alternative to present monetary system. Now compare the resources used in Bitcoin development (mining and other expenses) to Monetary System (banks, ATM, running costs). Bitcoin hardly utilize 1-2% as what utilized by present banking and monetary structure. And what about presence of 2 AC in 10x6 feet ATM room? Do these ACs contribute nothing to Green House gases?
Re-think!

Let's compare bitcoin to what they usually like to usually compare it to - gold. How is gold mined and what are the costs? Aside from all the energy used to mine it, it usually comes with an environmental cost, with landscapes destroyed and chemicals from digging as well as processing the gold can also escape into the environment. Cryptocurrencies only become damaging to the environment if the electricity used was from polluting plants like coal and oil.