Resumen de Editorial
Few of those with any understanding of the scientific evidence have any doubt that the Earth's climate is warming at an accelerating pace. A recent study of European climate since Roman times has underlined how exceptional the last 30 years have been, with average summer temperatures significantly higher than at any time in the previous two millennia. The cause, too, seems now (at last) to be generally agreed: that human activity, and sheer human numbers, are so great that they are affecting the planet's climate system. For some, that is, of course, an inconvenient truth, obliging us to change behaviours in ways that might be costly and troublesome. For archaeologists, versed in the effects of previous climate shifts both large and small, it should provide a golden opportunity to demonstrate the relevance of our discipline, and to cast present problems in the perspective of past events. The Maya drought, the Moche floods, and the low Niles, which may have put an end to the Egyptian Old Kingdom, all offer examples of what can happen to human societies. And of course, at the larger scale, there are the successive �Ice Ages� that characterised the Pleistocene. There is an argument that we are all, in a sense, a product of the Ice Ages, and it is certainly remarkable how successful our ancestors became at exploiting sub-Arctic habitats. A 45 000-year-old butchered mammoth in Siberia, 72°N, provides the most vivid recent testimony.
