In the wake of Super Typhoon Haiyan, climate scientists have reiterated earlier warnings that the average tropical cyclone maximum wind speed is likely to increase, even though the global frequency of tropical cyclones could decrease, or remain unchanged. In its fifth assessment report, the United Nations’ Intergovernmental Panel on Climate Change indicated that human influence on the climate was now “unequivocal” and had been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise and in changes in some climate extremes.