That's not enough? Most major cities are coastal. We'd lose Hong Kong, New York, most of Holland. We'd also see more extreme weather in the form of powerful hurricanes and droughts. Water and food supplies start to disappear which will inevitably lead to conflict and war over resources. Then you've got the medium-term horizon of about 1000 years when the ocean can no longer sustain phytoplankton and oxygen levels drop to the point that most air-breathing animals will die off.
Which potentially includes lots of coastal areas, like, say, New York, large portions of Bangladesh, and a few entire island nations. That's a pretty high cost.
But the linked post is politics, so I'm flagging it in any case.
