Other reports in this collection
Exploration, production, transportation, and associated construction of processing
facilities are likely to be affected by climatic change (Maxwell, 1997). Changes
in a large number of climate and related variables will affect on- and offshore
oil and gas operations. Use of oil drilling structures or ice-strengthened drillships
designed to resist ice, use of the ice itself as a drilling platform, and construction
of artificial islands are likely to give way to more conventional drilling techniques
employed in ice-free waters (Maxwell, 1997). These likely changes are not without
concerns. Although the use of regular drillships may reduce operating costs
by as much as 50% (Croasdale, 1993), increased wave action, storm surges, and
coastal erosion may necessitate design changes to conventional offshore and
coastal facilities (McGillivray et al., 1993; Anderson and DiFrancesco, 1997).
This may increase the costs of pipeline construction because extensive trenching
may be needed to combat the effects of coastal instability and erosion, especially
that caused by permafrost melting (Croasdale, 1993; Maxwell, 1997). Design needs
for onshore oil and gas facilities and winter roads are strongly linked to accelerated
permafrost instability and flooding. The impact of climate change is likely
to lead to increased costs in the industry associated with design and operational
changes (Maxwell, 1997).
The capacity of permafrost to support buildings, pipelines, and roads has decreased
with atmospheric warming, so pilings fail to support even insulated structures
(Weller and Lange, 1999). The problem is particularly severe in the Russian
Federation, where a large number of five-story buildings constructed in the
permanent permafrost zone between 1950 and 1990 already are weakened or damaged,
probably as a result of climate change (Khroustalev, 1999). For example, a 2°C
rise in soil temperature in the Yakutsk region has led to a decrease of 50%
in the bearing capacity of frozen ground under buildings. Khroustalev (1999)
has predicted that by 2030, most buildings in cities such as Tiksi and Yakutsk
will be lost, unless protective measures are taken. The impact of warming is
likely to lead to increased building costs, at least in the short term, as new
designs are produced that cope with permafrost instability. Snow loads and wind
strengths may increase, which also would require modifications to existing building
codes (Maxwell, 1997). There will be reduced demand for heating energy with
warmer climate (Anisimov, 1999).
The impact of climate warming on transportation and communications in Arctic
regions is likely to be considerable. Within and between most polar countries,
air transport by major commercial carriers is widely used to move people and
freight. Irrespective of climate warming, the number of scheduled flights in
polar regions is likely to increase. This will require an adequate infrastructure
over designated routes, including establishment of suitable runways, roads,
buildings, and weather stations. These installations will require improved engineering
designs to cope with permafrost instability. Because paved and snow-plowed roads
and airfield runways tend to absorb heat, the mean annual surface temperature
may rise by 1-6°C, and this warming may exacerbate climate-driven permafrost
instability (Maxwell, 1997). Cloud cover, wind speeds and direction, and patterns
of precipitation may be expected to change at the regional level in response
to global warming. At present, the density of weather stations is relatively
low in Arctic regions. Increased air (and shipping) travel under a changing
climate will require a more extensive weather recording network and navigational
aids than now exists.
The impact of climate warming on marine systems is predicted to lead to loss
of sea ice and opening of sea routes such as the Northeast and Northwest passages.
Ships will be able to use these routes without strengthened hulls. There will
be new opportunities for shipping associated with movement of resources (oil,
gas, minerals, timber), freight, and people (tourists). However, improved navigational
aids will be needed, and harbor facilities probably will have to be developed.
The increase in shipping raises questions of maritime law that will need to
be resolved quickly. These issues include accident and collision insurance,
which authority is responsible for removal of oil or toxic material in the event
of a spill, and which authority or agency pays expenses incurred in an environmental
cleanup. These questions are important because sovereignty over Arctic waters
is disputed among polar nations, and increased ship access could raise many
destabilizing international issues. Increased storm surges are predicted that
will affect transport schedules.
There already are a large number of case studies in the Arctic that indicate the effects of different pollutants on terrestrial, freshwater, and marine ecosystems (Crawford, 1997). In the event of increased industrial activity (e.g., mining, oil and gas extraction) under climate warming, new codes will be needed for retention of toxic wastes and to limit emissions of pollutants from processing plants. In the oil industry, considerable progress has been made in revegetating disturbed and polluted sites (McKendrick, 1997), often with plant species that can survive at northern sites under climatic warming. Changes in hydrology, possible increases in catchment rates, and melting of ice may result in wider dispersion of pollutants from accidents. Current ice cover and the low productivity of Arctic lakes restrict sequestration of contaminants (Barrie et al., 1997; Gregor et al., 1998). Projected changes to ice cover and the hydrology of these lakes may cause them to become greater sinks for river-borne contaminants, similar to those in more temperate regions. In the Arctic Ocean, many persistent organic pollutants (e.g., hexachlorocyclohexane) are trapped under ice as "ghosts of the past" (de March et al., 1998). Reductions in sea-ice cover may speed their introduction to the Arctic food chain and pose risks for the human population. Long-lived apex consumers with high lipid content have a high potential for long-term accumulation of contaminants (Alexander, 1995; Tynan and DeMaster, 1997), and not all of these pollutants are derived within the Arctic. Development of Arctic haze is thought to result from aerosol loading (primarily sulfate particles) of the atmosphere in mid-latitude regions. These particles are then carried northward to the Arctic. The haze is most pronounced in the winter because the particles have a longer residence time in the stable Arctic air masses at that time of year. The increased presence of sulfate particles in the atmosphere is of concern because of their ability to reduce the flow of energy through the atmosphere to the Earth's surface (Shaw, 1987).
|
Other reports in this collection |
|