Frequent and severe heat waves lead to increases in heat-related illness and death, especially in urban areas and among the elderly, the young, the ill, and the poor. Hotspots in this category illustrate notably warm periods or heat waves within the last few years. Candidate events were initially gathered from news reports and climate bulletins. We avoided using one-day records because of the inherent probability that a maximum temperature record could be broken on any given day due to internal climate variability. Only those events that were notable either in duration or geographic extent were included.
Warmer temperatures increase melting of mountain glaciers and cause ocean water to expand.
Largely as a result of these effects, global sea level has risen 4 to 10 inches over the past 100 years. With additional warming, sea level is projected to rise from half a foot to 3 feet more during the next 100 years. Although the inundation records for the South Pacific islands are based on anecdotal evidence from local residents, we included them because these accounts are often the best and only evidence available in these very vulnerable small island nations. Glaciers melting Over the past 150 years, the majority of mountain glaciers monitored have been shrinking. Many glaciers at lower latitudes are now disappearing, and scientists predict that, under some plausible warming scenarios, the majority of glaciers will be gone by the year 2100.