And they could be large:
In January, the Department of Housing and Urban Development announced grants totaling $1 billion in 13 states to help communities adapt to climate change, by building stronger levees, dams and drainage systems.
One of those grants, $48 million for Isle de Jean Charles, is something new: the first allocation of federal tax dollars to move an entire community struggling with the impacts of climate change. The divisions the effort has exposed and the logistical and moral dilemmas it has presented point up in microcosm the massive problems the world could face in the coming decades as it confronts a new category of displaced people who have become known as climate refugees. ...
Around the globe, governments are confronting the reality that as human-caused climate change warms the planet, rising sea levels, stronger storms, increased flooding, harsher droughts and dwindling freshwater supplies could drive the world’s most vulnerable people from their homes. Between 50 million and 200 million people — mainly subsistence farmers and fishermen — could be displaced by 2050 because of climate change, according to estimates by the United Nations Institute for Environment and Human Security and the International Organization for Migration. ...
“This is not just a simple matter of writing a check and moving happily to a place where they are embraced by their new neighbors,” said Mark Davis, the director of the Tulane Institute on Water Resources Law and Policy.
“If you have a hard time moving dozens of people,” he continued, “it becomes impossible in any kind of organized or fair way to move thousands, or hundreds of thousands, or, if you look at the forecast for South Florida, maybe even millions.”
via www.nytimes.com
Climate change adaptation proponents (i.e., "serious economists") suggest that "the market" will reduce these costs. My thinking is that these potential costs should be part of the conversation instead of assumed to be mitigated to a large extent as a result of market forces.
