For some, melting polar ice caps may not provide unimpeachable proof of global warming. Nor will an 80-degree March day in Minnesota. Even the accumulation of effects can be ignored by those so inclined. But a list of them would be downright depressing, even for the deniers.
Yesterday I read the observations of a University of Colorado biologist who described how cottonwoods are budding earlier, and how the change has forced naturalists to move their field trips from the first Saturday in May to early April.
Maybe these kind of observable local examples will help turn the tide of public opinion. One of my old posts that gets a surprising number of hits is about possums moving north.