As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts. Even with evidence of these broad trends, scientists cautioned in the past that individual weather events couldn't be attributed to climate change. Now, with advances in understanding the climate science behind extreme events and the science of extreme event attribution, such blanket statements may not be accurate. The relatively young science of extreme event attribution seeks to tease out the influence of human-cause climate change from other factors, such as natural sources of variability like El Niño, as contributors to individual extreme events. Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.

The Erice International Seminars are multidisciplinary seminars attended by over 100 eminent participants from all fields of science. Each year, a few scientific issues are selected and experts are invited to present contrasting views during the plenary multidisciplinary sessions of the seminar. General debates soon follow. These sessions offer a unique opportunity for specialists to broaden their perspectives after being confronted with ideas and suggestions from high level scientists in complementary domains of science. Associated workshops allow the experts to further refine and process the ideas evoked during the seminar. This year's topics are focused on the World Energy Crisis and more specifically on the future of nuclear power, the sustainability of biofuels and nuclear waste. On Global Monitoring of the Planet we have focused on the climate change issue and specifically on the theoretical basis for model calculations, on vector-borne and air-borne particulates disseminating diseases and the crisis in internet security. A full day session was devoted to the Disarmament and Proliferation Regime, in collaboration with the Government of Italy and international institutions.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 173. The ocean's meridional overturning circulation (MOC) is a key factor in climate change. The Atlantic MOC, in particular, is believed to play an active role in the regional and global climate variability. It is associated with the recent debate on rapid climate change, the Atlantic Multi-Decadal Oscillation (AMO), global warming, and Atlantic hurricanes. This is the first book to deal with all aspects of the ocean's large-scale meridional overturning circulation, and is a coherent presentation, from a mechanistic point of view, of our current understanding of paleo, present-day, and future variability and change. It presents the current state of the science by bringing together the world's leading experts in physical, chemical, and biological oceanography, marine geology, geochemistry, paleoceanography, and climate modeling. A mix of overview and research papers makes this volume suitable not only for experts in the field, but also for students and anyone interested in climate change and the oceans.