this is a trending topic and almost all the crypto platforms are discussing it. Crypto currencies are going viral, day-in and day-out a lot of people are adopting crypto currencies. Some use it for the sake of business, some for investment, others to work on campaing bounties and earn tokens, many others to mine crpyto and the rest.
So this implies that crypto transactions are increasing, so the question is, will crypto replace fiat money?
What are your suggestions

This cannot be overlooked as crypto adoption is increasing and so as its mining. Countries who accept Crypto and is determined to use crypto to expand its economy would have to increase it electricity supply. However, some countries already have systems in place to cater for the increase in technology use, therefore those countries wouldn't suffer a great deal.

Popularity and stability in crypto is hardly gained so I applaud ethereum for being able to come this far. I'll base its popularity on factor such like the smart contract that it offers. Moreover, ethereum has proven to be very promising and continues to be. Its market cap now makes it even more preferred to other coins

Both currencies have been seen to have highs and lows which usually happens concurrently. Comparing the percentage rise and fall in both coins in the year 2018, Ethereum will definitely have the highest. But you may not see this because of the high market capitalization of Bitcoin. So I'll choose to hold my ethereum.