In this first worldwide synthesis of in situ and satellite‐derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade−1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice‐covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade−1) to ice‐free lakes experiencing increases in air temperature and solar radiation (0.53°C decade−1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes.

Low‐elevation land areas and their populations are at risk globally from rising sea level. Global sea level has risen by about 2 millimeters per year over the past century. About half of this rise may be attributed to thermal expansion of the ocean and the melting of temperate‐latitude glaciers [Dyurgerov and Meier, 1997]. The remainder of the rise is believed to come from a net loss of mass from the Antarctic and Greenland ice sheets, although the exact contribution is unknown.

Increased attention to global climate change in recent years has resulted in a wide array of maps and geovisualizations that forecast various scenarios. Since many consequences of climate change are inherently geographic in nature, effective cartographic representations that depict these risks are valuable for planning and mitigation purposes. In particular, sea-level rise resulting from climate change calls attention to the numerous representation issues that warrant consideration for hazard and risk mapping in general, including categorizing and representing risk, selecting an appropriate level of realism, and displaying potential impacts of a hazard on human populations as well as on the natural and built environments. Using examples of potential inundation from sea-level rise at global, regional, and local scales, the authors propose a conceptual framework of key cartographic considerations for maps, Web-based mashups, and geovisualizations that depict risk. The cartographic framework presented here may be extended to other risks of an ambiguous or fuzzy nature and may be used to organize key future research areas for hazard or risk mapping in general.

Future sea level rise caused by climate change would disrupt the physical processes, economic activities, and social systems in coastal regions. Based on a hypothetical global sea level increase of one to six meters, we developed GIS methods to assess and visualize the global impacts of potential inundation using the best available global datasets. After susceptible areas were delineated, we estimated that the size of the areas is between 1.055 (one meter) to 2.193 million km 2 (six meters). Population in the susceptible areas was estimated to range from 108 (one meter) to 431 million (six meters) people. Among the seven land-cover types in the susceptible areas, forest and grassland account for more than 60 percent for all the increments of sea level rise. A suite of interactive visualization products was also developed to understand and communicate the ramifications of potential sea level rise.