Bitcoin or the blockchain is not a magic wand which will save the environment. On the flip side, crypto currency mining requires hell lot of power to operate that is actually harmful to the environment. I too have came across few such ICOs who are trying to build decentralized waste management and recycling  service, decentralized hydro power mining operations and solar powered mining and electrification initiatives. But these ICOs are at a very nascent stage and didn't show any result yet.

If they start their operations, they probably won't add to the existing environmental burden around us but won't reduce it as well to any significant extent. So saving the environment is out of question. Blockchain is only being used as an operational method by these companies. As more research will happen in the crypto space, we will probably see more new ideas on how effectively we can use blockchain for the betterment of our environment, but it's too early to comment now.

I don't think that Bitcoin can save the environment but Blockchain tech can definitely have a positive effect on things. It has been well documented the negative effects that Bitcoin mining and other forms of coins using a Proof Of Work consensus algorithm have had on the environment, in terms of energy consumption, when it comes to mining those coins in certain countries. This effect has been noticed by governments such as the Chinese government which is looking to totally cut out mining in their country since cities like Shenzhen have been feeling the effect of this physical form of mining. Bitcoin won't really have a positive effect on the environment unless there is a change to greener solutions such as Proof Of Stake models which entail potential beneficial impacts of models like Proof Of Ambassador within position papers I've read, ie. Bitcoin Origin, which has more of a view to the sustainability of the project in the long term without a negative effect on the environment that brute force mining has.

Have a look: https://cointelegraph.com/news/bitcoin-minings-electricity-bill-is-it-worth-it
https://www.bitcoinorigin.io/pdf/BitcoinOrigin-PositionPaper.pdf

Too early to give substantial information since the blockchain technology is still on its embryonic stage. The idea of eliminating fiat by replacing it with currency that exists electronically may have benefits in the community and in the environment (as fiats are composed of mixed metals and paper) but the trade-off might be worse. Like what others mentioned, mining bitcoin requires tremendous power and energy in order to sustain and power CPUs. Even if some ICOs are proclaiming that their project may be beneficial to the environment, it will inevitably harm the environment on a different aspect.

Like what I mentioned, the blockchain is still on its early stages and further developments must be introduced in order to embrace this idea. Who knows, maybe in the future, people would develop a system wherein it both benefits the environment and the community- making it a win-win situation.

I don´t see the possitive causality between bitcoin and the environment - on contrary confirming and validating transactions in the proof of work scheme consume a lot of electrical power, which is not good for the environment at all. But changing to the proof of stake or using alternative sources of energy could definitely make a change.

I don't know if it could help or detrimental to the environment. But in my opinion the consumable number of electric supply could sum up in to a large amount of demand. And this is could be a bad news for the environment.

Any production leads to an external environment. So we will not stop making cars, plastic, rubber. The main thing in this problem is to create conditions for minimal impact. A better program to restore damaged eco-systems.

Bitcoin mining needed that much energy so what do you is the impact of that to the environment?

But if those mining hardware are placed to the suitable places where the climate is very cold and I think there's no impact that it will bring to the environment. Can't say a thing about the environmental effect of blockchain but we'll see about it in the near future.

of course could save the environment because of the bitcoin safe and care about environtment.

I think it is impossible
The environment that exists or is destroyed is due to human consciousness

When we say environment it means we are talking about external work, and that's the need of a manual people's work around, i dont think that bitcoin or blockchain can saved our envirenment.