ClimateWire: When the Department of Transportation doled out $1.5 billion in infrastructure grants last week, one of the largest checks went to a rail overhaul in the Chicago area. Almost all of the country’s freight railroads converge there. The region handles so much cargo that only three cities outrank it: Hong Kong, Singapore and Shanghai. And like O’Hare, Chicago’s infamous airport, it’s reviled for its traffic. “When there’s delays at O’Hare, it impacts the whole nation’s air …