A Changing Environment for Human Security

3    Climate change and security

Jon Barnett

Introduction

It seems increasingly likely that efforts to slow the rate of greenhouse gas emissions will fail to prevent mean global warming in excess of 4ºC above pre-industrial levels by the end of this century (Anderson and Bows, 2008). When warming reaches 2ºC above pre-industrial levels, the security of supply of freshwater from many of the world’s major river basins will diminish, many coral reefs will bleach on an annual basis, crop productivity in lower latitudes will decline, the frequency and severity of coastal flooding will increase, extreme hydroclimatic events will increase in intensity, and the risk of infectious diseases will increase (IPCC, 2007). These changes in environmental conditions ...