Overview of climate change impacts

Climate change is a fundamental change in the Earth’s physical systems; it has a range of effects on many systems and sectors that rely on climate, such as water resources, terrestrial and marine ecosystems, food production, natural disasters, coastal zones, industries and human health. These effects have apparently been occurring because climate change accelerated in the last decades of the twentieth century. Sea ice and permafrost areas have significantly shrunken in the Arctic, where the largest rise in atmospheric temperature is observed. Many species and ecosystems have started moving towards the poles and higher elevations in mountains. Several extreme events causing serious damage to human society have occurred in the twenty-first century, such as the heatwave in Europe in 2003, Hurricane Katrina in 2005, recent droughts in Australia and floods and droughts in Asia and Africa. Although the causal relationship between individual extreme events and global warming cannot be identified, the increase in the intensity of natural disasters resulting in further threats to human society has been a major concern.