220.127.116.11. Recreation and Tourism
Climate creates opportunities and limitations for outdoor recreation. It is
a major influence on the economic viability of some recreation enterprises.
Several studies have projected shorter North American skiing seasons as a result
of climate change. In a study of the implications of an effective CO2 doubling
on tourism and recreation in Ontario, Canada, Wall (1988) projected that the
downhill ski season in the South Georgian Bay region could be eliminated. This
outcome assumed a temperature rise of 3.5-5.7°C and a 9% increase in annual
precipitation levels. Some of these losses would be offset by an extended summer
recreational season. Lamothe and Périard (1988) examined the implications of
a 4-5°C temperature rise throughout the downhill skiing season in Quebec. They
projected a 50-70% decrease in the number of ski days in southern Quebec; ski
resorts equipped with snowmaking devices probably would experience a 40-50%
reduction in the number of ski days. This change in winter recreational traffic
would have direct implications for road traffic (down) and requirements for
snow-removal and road repair (also probably down). On the other hand, Masterton
et al. (1976) have noted that low temperatures are a limiting factor on recreation
activity in the northern part of the prairie provinces. The summer recreation
season in many areas may be extended (Masterton et al., 1976; Staple and Wall,
1994). Warmer temperatures may offset some of the costs of sea-level rise for
recreational barrier islands.
18.104.22.168. Extreme Weather Events
Human settlements and infrastructure are especially vulnerable to several
types of extreme weather events, including droughts, intense precipitation,
extreme temperature episodes, high winds, and severe storms. Hence, there could
be impacts should the frequency or intensity of these extreme events increase
or decrease with climate warming.
Weather-related natural disasters (wildfires, hurricanes, severe storms, ice,
snow, flooding, drought, tornadoes, and other extreme weather events) are estimated
to have caused damages in the United States averaging about $39 billion per
year during the years 1992-96 (FEMA, 1997). Those losses included damages to
structures (buildings, bridges, roads, etc.) and losses of income, property,
and other indirect consequences.
As indicated in Section 8.2.3 and IPCC (1996, WG I, Section
6.5), the ability to predict changes in the frequency or intensity of extreme
weather events using global and regional models has been limited by their lack
of small-scale spatial and temporal resolution and uncertainties about representation
of some processes.3 Historical changes in
frequencies of extreme events also provide some insights on possible changes,
but there is debate about which changes are significant and which are unambiguously
attributable to climate warming. However, some indications of directions of
change have been inferred from observations and model simulations for North
America, particularly regarding increased variability of precipitation. Beyond
those inferences, a number of vulnerabilities of resources to extreme events
have been identified should such events increase in frequency or magnitude.
Conversely, decreases in extreme events could reduce levels of damages currently
experienced. Additional research is needed to better understand the sensitivity
and vulnerabilities of North American human settlements and infrastructure to
extreme events, including factors beyond climate that are changing those vulnerabilities.
Flooding may be a very important impact because of the large amount of property
and human life potentially at risk in North America, as is evident from historical
disasters. There have been relatively few studies addressing the change in risk
directly because of the lack of credible climate change scenarios at the level
of detail necessary to predict flooding.
The evidence for an increasing trend in warm-period rainfall intensities in
the United States (discussed in Section 8.2.2) suggests
the potential for a shift in the periodicity of the flood regime in North America.
More frequent or more extreme flooding could cause considerable disruption of
transportation and water supply systems.
Increases in heavy rainfall events (e.g., suggested changes in frequency of
intense subtropical cyclones) (Lambert, 1995) and interactions with changes
in snowmelt-generated runoff could increase the potential for flooding of human
settlements in many water basins. Changes in snowmelt runoff may add to or subtract
from rainfall events, depending on basin characteristics and climate changes
for a basin. Extreme rainfall events can have widespread impacts on roads, railways,
and other transportation links. As long as rainfall does not become more intense,
impacts on urban roads and railways in temperate, tropical, and subtropical
zones are likely to be modest.
Some areas in North America may experience changed risks of wildfire, land
slippage, and severe weather events in a changed climate regime. Although this
increase in risk is predicated on changes in the frequency or intensity of extreme
weather events-about which there is controversy-considering these risks in the
design of long-lived infrastructure may prove cost-effective in some circumstances.
Human settlement infrastructure has increasingly concentrated in areas vulnerable
to wildfire, such as the chaparral hillsides in California. Settlements in forested
regions in many areas are vulnerable to seasonal wildfires. Areas of potentially
increased fire danger include broad regions of Canada (Street, 1989; Forestry
Canada, 1991) and seasonally dry Mediterranean climates like the state of California
in the United States. It is possible that fuel buildup under drought conditions
would decrease, decreasing fire intensities. Although generally less destructive
of life than in many developing world locations, landslides triggered by periodic
heavy rainfall events threaten property and infrastructure in steep lands of
the western United States and Canada. Relict landslides occur in much of northern
Europe and North America (Johnson and Vaughan, 1989). Although stable under
present natural conditions, these landslides are reactivated by urban construction
activities and are triggered by heavy rains (Caine, 1980). Lands denuded of
vegetation by wildfire or urban development also are vulnerable.
Although there has been an apparent downward trend in Atlantic hurricanes in
recent years (e.g., Landsea et al., 1996), not all authors agree (Karl et al.,
1995b). What is certain is that the amount of property and the number of people
in areas known to be vulnerable to hurricanes is large and increasing in low-lying
coastal areas in much of the United States Atlantic and Gulf coasts. For example,
although data on the amount or proportion of national physical assets exposed
to climate hazards are not readily available, it is known that in the United
States about $2 trillion in insured property value lies within 30 km of coasts
exposed to Atlantic hurricanes (IRC, 1995).
Most authors have found increases in seasonal minimum temperatures in North
America, but not in seasonal maximums (IPCC 1996, WG I, Chapter 3). These results
would suggest reduced incidence of cold-related problems without a concomitant
increase in heat-related problems. However, increases in regional cold outbreaks
occurred from the late 1970s to the mid-1980s. There has been little evidence
of an increase in danger from tornadoes in the region (Grazulis, 1993; Ostby,
Offshore oil and gas exploration and production would be influenced by change
in extreme events. In the south, an increase in extreme storm events in the
Gulf of Mexico may mean increasing fixed and floating platform engineering standards
(i.e., more expensive platforms) and more frequent and longer storm interruptions.
In terms of interruptions, weather-related production shutdowns result in losses
to production companies in the range of $1 million dollars per day-$10,000-50,000
per facility where evacuation is necessary. The industry defers millions of
dollars annually in royalties (approximately $7 million each day for offshore
Gulf of Mexico facilities) paid for hydrocarbon produced from fields owned by