CHICAGO — Jim Anderson winced as he said opportunity. He paused on the word for a moment as about 20 weather-industry professionals sat in folding chairs before him. Anderson didn’t want to sound mercenary or, worse, cheerful. But climate change, he repeated, is an opportunity for them, albeit one they may “wish they could forgo.” Yet here they were, a gathering of data miners, weather instrument manufacturers and climate scientists, at the recent Meteorological Technology World Expo in Rosemont, Ilinois, hoping to mitigate that pain. After all, Anderson said, not just “philosophical ambition…