You can put it into perspective by identifying what would actually happen. The article says
"tens of millions of coastal refugees would have to flee inland, potentially straining societies to the breaking point"
First, that's the worst case, not the expected case and even if it did happen, it's not the end of the world. In WWII, we murdered tens of millions of people and strained societies to the breaking point. But the survivors picked themselves up and now we're fine.
Mao did it again in China, but they're back on their feet now too. We've already had several equivalent worst case scenarios happen in the last century.
"tens of millions of coastal refugees would have to flee inland, potentially straining societies to the breaking point"
First, that's the worst case, not the expected case and even if it did happen, it's not the end of the world. In WWII, we murdered tens of millions of people and strained societies to the breaking point. But the survivors picked themselves up and now we're fine.
Mao did it again in China, but they're back on their feet now too. We've already had several equivalent worst case scenarios happen in the last century.