30
Chapter 5
The Effect of Climate Change on Human Activities
ญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญ
There are at least six very different ways in which cli-
degradation, open water, loss of multi-year ice, late
mate change may lead to an alteration of contaminant
freeze-up (see, for example, Fast and Berkes, 1998; Ried-
pathways through a modification of human activities.
linger, 2001)). Because the manner in which contami-
First, people on the margins of the Arctic Ocean will
nants enter and concentrate in these two food webs is so
make dietary choices, as they have always done, based
different, the balance between terrestrial and aquatic
on the availability of traditional country foods including
food items in the food basket will be a pivotal point of
terrestrial and marine animals (Krupnik, 2000; McGhee,
change in exposure to biomagnifying contaminants.
1996; Vibe, 1967). Second, a marginal sea that clears of
With marginal seas clear of ice for long periods of the
ice for large portions of the year will encourage ship-
year, it is inevitable that the Arctic will become a fa-
ping, tourism, oil exploration and other industrial activ-
voured shipping route between Europe, Asia and North
ities each of which brings with it associated contami-
America either via the Northern Sea Route (Russia) or
nants. Furthermore, enhanced shipping increases the
the Canadian Arctic Archipelago. Shipping brings with
risk of introducing exotic species or diseases which then
it specific, well-known contaminants such as hydrocar-
affect indigenous species. Third, the encroachment of
bons and marine antifoulants (e.g., tributyltin) and, po-
commercial fisheries into the Arctic could alter the food
tentially, non-indigenous species in ballast water. The
web structure in oceans (Bockstoce, 1986; Parsons, 1992;
major concern, however, is likely to come from acceler-
Pauly et al., 1998, 2001) and lakes (AMAP 2003b; de
ated oil exploration and development on the Arctic con-
Graff and Mychasiw, 1994). Fourth, climate change may
tinental shelves of North America and Eurasia (Bakke et
promote the spread of insect pests globally forcing some
al., 1998).
countries to re-introduce or increase the use of pesti-
Outside the Arctic, global warming and alteration of
cides. Fifth, climate change toward conditions suitable
hydrological cycles will probably cause insects and other
for domestic crops may encourage further expansion of
pests to flourish in some locations. Many of the Arctic's
agriculture or silviculture within the Arctic drainage
problematic pesticides (toxaphene, DDT, hexachloro-
basin along with increased industry. Lastly, the various
hexane (HCH)) continue to be used in central America,
changes listed above will probably contribute to demo-
Africa and Asia, particularly by developing countries,
graphic shifts and population increases in northern re-
and it is these countries that may be forced to rely more
gions, which will in turn lead to increased local re-
heavily on pesticides in coming decades (Harner, 1997).
leases of contaminants (for example from burning,
Within Arctic drainage basins, warming may expand
power and fuel consumption, use of industrial or agri-
the area suitable for agriculture. Much of the southern
cultural products).
portion of the Mackenzie Basin in North America is
It is well known that the dietary composition of the
presently cultivated; under a global warming scenario
human `food basket' (e.g., marine versus terrestrial foods,
this region is projected to contribute an additional 10
fat versus protein, older fish or seals versus younger fish
million hectares of land suitable for small grain crops
or seals) controls the amounts and kinds of contami-
(Cohen, 1997b), an area that might be further expanded
nants ingested (AMAP, 1998; Kinloch et al., 1992; Van
with the development of new `climate' resistant crops. In
Oostdam et al., 1999). Dietary changes can be forced by
Russia, most of the major Arctic river basins contain
fluctuations in the populations of target species as dis-
agricultural land, particularly within the river valleys
cussed in chapter 4 (e.g., beluga (Delphinapterus leucas),
and as far north as 65ฐN (including the Severnaya
bowhead whales (Balaena mysticetus), walrus (Odobe-
Dvina, Ob, Yenisey and Lena River basins). Agriculture
nus rosmarus), seals, bears, birds, fish, caribou/reindeer
brings with it pesticides and other chemicals and, should
(Rangifer tarandus), muskox (Ovibos moschatus)) or by
pests thrive in a warmer Arctic climate, farmers may re-
changes in access to the species (early melt, permafrost
sort to increased reliance on pesticides to protect crops.

---