The size of the blockchain is 178 GB as hugeblack has pointed out. This is not very large by today's standards, even my phone has enough storage space to hold the full Bitcoin blockchain. Yes the blockchain will continue to grow in size, but there is a fixed amount it can grow yearly, it cannot continue to grow exponentially, so there is no reason not to think that this aspect of Bitcoin can't scale.
There are a certain amount of blocks per year, and those blocks can only hold so much space. So with 52,560 blocks per year (avg 144 blocks/day * 365 days/year), and with each of those blocks having 100% segwit tx usage, that would put the block size at about 4 MBs (some say 1.6MB - 2 MB). 4 MB/block * 52,560 blocks/year is a maximum of 205 GBs of data added to the blockchain per year. This is not an exponential number. We aren't even close to the blocks being this full/large, but we already have the storage to meet this demand. Once we are seeing 100% full blocks at 4 MB/block I'm sure 205 GBs of data per year will be nothing in terms of storage space.
Nice phone. Haha! I also got a 200 GB SD card last year, it's very nice. I don't come anywhere close to filling it up though, of course.
I don't understand that much about how the blocks work, so thanks for your explanation. I read on another thread that people were concerned that the blockchain size is doubling every year. It's nice to know that that's not possible. I found a graph of the current blockchain size. (
https://www.blockchain.com/charts/blocks-size?timespan=all). It seems a bit alarming, but judging by what you said, I guess it'll become more linear in the near future. I think Bitcoin has a bunch of problems, but storage space shouldn't be one of them. In 2016 Seagate shows off a 60TB SSD. Storage space is growing extremely quickly, much faster than blockchain.