This story was originally published by Yale E360  and is reproduced here as part of the Climate Desk  collaboration. Justin Smarsh and his family used to kayak a few times a year on the rivers and creeks near their home in Cherry Tree, Pennsylvania. High on the Appalachian Plateau, northeast of Pittsburgh, he spent hours in the woods and taught his two sons to hunt. Today, Smarsh said, he gets “suffocated just walking.” He has a constant dry cough, and he loses his breath if he bends down to tie his shoes.  A few years after he graduated from high school and got married, Smarsh went to work in a coal mine in his home county, just as his father and grandfather had. “It was the best-paying job around,” he said. “It still is.” Now Smarsh, 42, has progressive massive fibrosis — the most severe form of coal workers’ pneumoconiosis, or black lung. There is no cure for Smarsh’s condition.…