The answer is yes, since Satoshi's paper back in 2008 a whole subset of CS research has propped up just on consensus algorithms. Other alternatives are simply to switch to a PoS style of consensus, which without a doubt has it's own set of tradeoffs. Currently Ethereum is planning to switch to PoW/PoS system where the amount of computation on the PoW is drastically reduced from the current level of difficulty i.e. There essentially having a PoW/PoS model where the PoW is just like HashCash it's purpose isn't to do consensus but stop "spam".