Marine Ecosystems under Toxic Pressure - Vulnerability of Coastal Ecosystems and Adaptation - page 34

Climate (GIEC), on the subject of changes for the end of this century,
concern a wide range of environmental conditions: raised temperature,
changes in precipitation regimes, an increase in the acidity of the
oceans and a reduction in ice covering the seas [INT 07] (see also the
[MON 14a, b and c] also from the Seas and Oceans set). These
projections include significant uncertainties in regional variations but
agree on an increase in the frequency of extreme meteorological
phenomena such as heat waves, droughts and storms. The transfer, the
arrival and then the exposure to contaminants will also be impacted by
GCC [VER 08], although there is already great uncertainty associated
with the effects of GCC on future concentrations of contaminants in
the environment [NOY 09].
1.5.1. Impact on the future of contaminants
It is at the level of the highest latitudes that the increase in
temperature is the most pronounced. Reports from IPCC indicate that
the average of temperatures in the Arctic has increased by almost
twice more than the global average in the last hundred years [IPC 07].
POPs are, mostly, semi-volatile compounds that can be found
thousands of kilometers from the place where they were emitted. In
effect, they are transported, in the form of gas and/or adsorbed to
aerosols, by global atmospheric circulation into higher latitudes. As
the gradients in temperature between high and low latitudes will be
less pronounced, the presence of persistent organic pollutants in high
latitudes could diminish [BEY 03, BRA 05, BRE 04, WAN 96].
Moreover, this increase in temperature will also have an impact on the
degradation processes of POP, which are more significant at higher
temperatures. It is, however, important to note that this degradation
can lead to metabolites that are more toxic than the initial compounds
(see [DAL 07] on PCB and the dioxins in the Venice laguna). Organic
carbon cycles in land and aquatic systems will also be modified by
climate change, which will have a direct impact on the bioavailability
of a large number of contaminants [MAC 03, MAG 97, SCH 97]. This
phenomenon has been found in the boreal lakes of north-west Ontario
following a long period of warming and drought associated with forest
fires [SCH 97]. Moreover, the warming will “release” more easily the
contaminants “trapped” in the permafrost, rendering them “available”