Relationship between increases in global mean temperature and impacts on ecosystems, food production, water and socio-economic systems

This paper attempts to associate different levels of global mean surface temperature increase and/or sea level rise with specific impacts and risks for species, ecosystems, agriculture, water and socio-economic damages compared to pre-industrial global mean temperature. It is found that that the risks arising from projected human induced climate change increase significantly and systematically with increasing temperature. Below a 1oC increase the level of risks are generally low but in some case not insignificant, particularly for highly vulnerable ecosystems and/or species. Above a 1oC increase risks increase significantly, often rapidly for highly vulnerable ecosystems and species. In the 1-2oC-increase range risks across the board increase significantly and at a regional level are often substantial. Above 2oC the risks increase very substantially involving potentially large numbers of extinctions or even ecosystem collapses, major increases in hunger and water shortage risks as well as socio-economic damages, particularly in developing countries.