evidence: Individuals and groups committed to opposing action on climate change persistently tried to discredit the evidence of warming, and failed. Painstaking historical studies, using everything from ship logs to ice caps to ocean sediments to tree rings, proved that nothing like the recent rise had been seen for millennia. As for the cause, the specific patterns of temperature change acted as"fingerprints" that unambiguously matched the predicted effects of humanity’s greenhouse gas emissions.