15.1. The North American Region
15.1.1. Previous Work
This chapter offers an assessment for Canada, the United States, and three
border regionsthe Arctic, U.S.-Mexican, and U.S.-Caribbean borders. More
detailed assessments for the Arctic, Mexico, and the Caribbean appear in Chapters
16, 14, and 17, respectively.
The IPCC's Special Report on Regional Impacts of Climate Change
(IPCC, 1998) provides a review of more than 450 research publications concerned
with impacts in North America, generally covering work done during 1975-1997.
That review focused on six key sectors:
- Hydrology and water resources.
- Nonforest terrestrial and forested ecosystems.
- Food and fiber, including agriculture, production forestry, and fisheries.
- Coastal systems.
- Human settlements and industry.
- Human health.
Our update of key regional concerns (see Section 15.2)
uses similar categories, with a couple of modifications. First, we consider
coastal and marine ecosystems together with terrestrial ecosystems, within the
review of natural resources (Section 15.2.2). Second,
human settlements are reviewed as a separate category, with extended discussion
of infrastructure (Section 15.2.5). Impacts on tourism
and insurance are treated separately (Sections 15.2.6
and 15.2.7, respectively). We also include a series of
subregional cases that highlight adaptation challenges and opportunities (see
This categorization of key regional concerns in North America reflects growing
interest in higher order impacts. Recent increases in financial losses from
extreme weather events (hurricanes, winter storms, floods) have raised new questions
about changing frequencies of atmospheric events superimposed on changing development
and investment patterns. In the United States, there were 28 such events during
the 1980-1997 period with losses exceeding US$1 billion. The most costly
were the droughts and heat waves of 1988 and 1990, Hurricane Andrew in 1992,
and the 1993 Mississippi River flood, with combined costs exceeding US$100 billion.
In Canada, the 1996 Saguenay flood and 1998 ice storm in Ontario and Quebec
each cost more than US$0.7 billion (CDN$ 1 billion) (Etkin, 1998). It is important
to understand the extent to which these loss trends hinge on changes in climate
or changes in vulnerability that may be independent of any changes in climate.
In recent years, the North American nations have undertaken intensive region-specific
assessments of impacts and vulnerability (Canada Country Study, U.S. National
Assessment, regional case studies). Although some of these assessments are still
in progress at this writing, several themes have emerged. The involvement of
stakeholders (commercial entities, local and regional governments, natural resource
managers, and citizens) has brought new perspectives and refocused the definition
of research questions. In nearly all regions, stakeholders perceive changes
in variability to be far more threatening than decadal-scale gradual change.
Many stakeholders see limited problems in adaptation and possible benefits to
slow predictable change. However, there may be appreciable changes in ecosystem
distributions and water resources, with significant economic impacts, leading
to requirements for substantial changes in infrastructure (e.g., in coastal
and permafrost regions, major urban centers). There clearly will be winners
Overall, available information suggests that if projected levels of climate
changes occur, North America will become quite a different place.
15.1.2. What is Different about the North American Region?
North America includes economies and resources that might be comparable to
those in developed countries and the more developed of the developing countries.
Areas within highly urbanized and industrial zones or intensively managed agriculture,
forests, and nonrenewable resource extraction all represent large-scale, highly
managed resources and human-dominated ecosystems. Within this context, however,
there continues to be a great deal of "extensive" land management.
Many Canadian and U.S. forests are managed in relatively large tracts compared
to other regions and are rather lightly managed aside from harvest schedules.
Some are more intensively managed, including post-harvest site preparation for
Table 15-1 shows a range of development indicators
for Canada and the United States and compares these indicators to Mexico and
the rest of the world. Higher levels of resource consumption, urbanization,
life expectancy, and gross domestic product (GDP) are obvious, as are the higher
rates of CO2 emissions. At the same time, the two countries also
are unusual in preserving extensive rangelands and other landscapes, so a unique
feature is the juxtaposition of intensive management with "extensive" management
of huge and sparsely populated areas. Some of these areas remain very much a
part of the national economy, but other areas are used for subsistence. Areas
that are undeveloped or are under aboriginal land claims that support traditional
subsistence lifestyles include features that are found in developing country
rural economies. These include low levels of built infrastructure, informal
barter systems, close ties to the land, and strong historical and cultural attachments
to subsistence-based communities, even in the face of opportunities in the modern
In wage and nonwage circumstances, climate change scenarios become scenarios
of changing opportunities and risks. Given the multi-objective and multi-stakeholder
aspects of North American regions, a climate-related change in potential (e.g.,
longer growing season, higher fire risk, altered hydrological cycle) may not
lead to an immediate, linear response by stakeholders (see Section
15.3). An important factor that must be considered is the extent to which
individual rights are valued relative to community interests in the management
of landscapes. Changing vulnerabilities may occur as a result of coupling of
management to current climatic variability (e.g., watersheds developed for hydroelectric
production and flood control must continue to adjust to seasonal and yearly
variations in natural streamflow, as well as changing management objectives).