can have a pretty outsized  carbon footprint and I'm wondering how   you reconcile the vast amount of computational  power necessary to accomplish this work and its   negative impact on the environment and whether  or not this is something you all are considering

You throw away computing power as fast as possible to show you deserve the bitcoins. Your chance of winning the bitcoin lottery is in direct proportion to how much you waste. Bitcoin mining now uses over 0.5% of all the electricity in the world — for the same seven transactions per second it managed to do in 2009. Bitcoin is the most inefficient payment system in human history.

Proof-of-work is not the only technology we have on which to build consensus protocols. Today, many forward-looking networks are deploying proof-of-stake (PoS) for their consensus. In these systems, your “voting power” in the network is determined by your ownership stake in some valuable on-chain asset, such as a new or existing electronic token. Since cryptocurrency has coincidentally spent a lot of time distributing tokens, this means that new protocols can essentially “cut out the middleman” and simply use coin ownership directly as a proxy for voting power, rather than requiring operators to sell their coins to buy electricity and mining hardware. Proof-of-stake systems are not perfect: they still lead to some centralization of power, since in this paradigm the rich tend to get richer. However it’s hard to claim that the result will be worse than the semi-centralized mess that proof-of-work mining has turned into.