Figure 19-7: Impacts of
or risks from climate change, by reason for concern. Each row corresponds to a
reason for concern; shades correspond to severity of impact or risk. White means
no or virtually neutral impact or risk, light gray means somewhat negative impacts
or low risks, and dark gray means more negative impacts or higher risks. Global
average temperatures in the 20th century increased by 0.6°C and led to some
impacts. Impacts are plotted against increases in global mean temperature after
1990. This figure addresses only how impacts or risks change as thresholds of
increase in global mean temperature are crossed, not how impacts or risks change
at different rates of change in climate. Temperatures should be taken as approximate
indications of impacts, not as absolute thresholds.
