
396 Engineering Response to Climate Change
the decades to come (USGCRP 2000, 2009; IPCC 2007a). Assessments of the
potential vulnerabilities under a range of possible futures are an important
means to understand the possible vulnerabilities and how those vulnerabili-
ties may be affected under different levels of climate change.
The higher-emissions scenarios described in Chapter 2 do not represent
a ceiling for the changes the world may experience. At the same time, the
lower-emissions scenario discussed there does not represent a oor. As
an example, the lower-emissions scenario in Chapter 2 describes a world
in which atmospheric concentrat