8.4 Climate Change
In addition to potential sea level rise, other climate change factors that need to be
considered based on recent updates from the UK Climate Impact Programme
(UKCIP) are as follows:
1. Annual average temperature predicted to rise by 1–3 °C or more during the
present century.
2. Warming likely to be greater in autumn and winter than in spring and summer.
3. Winter minimum temperatures predicted to rise more rapidly than maximum
temperatures, reducing the diurnal range, while summer maximum temperatures predicted to rise more rapidly than minimum temperatures, increasing the
diurnal range.
4. Variability of the winter temperature between years is likely to decrease, with
cold winters becoming rare.
5. Variability of summer temperatures likely to increase, with very hot summers
becoming more common.
6. Annual precipitation probably increasing by 3–5 % by 2050, with greater
increases in winter and autumn, but with no change or a decrease in summer.
7. Year-to-year variability of seasonal precipitation likely to show changes such
that the frequency of dry summers will double and wet winters treble by 2080.
8. More of the increased precipitation is likely to occur in intense storm events
than at present, especially in winter.
9. Evapotranspiration is likely to increase year round, but particularly in autumn
and summer.
The likely results of these interacting factors in terms of stabilization are difficult to predict, but there is clear evidence of the impact of climate on rates of
stabilization at Newborough. Faster rates of vegetation colonization since the
1940s, assessed using the aerial photographic record, were associated with lower
values of Talbot’s Mobility Index (M \ 0.3)—a function of windspeed, temperature, and rainfall (Talbot 1984). The rate of vegetation colonization slowed down
in the late 1960 and 1970s when values of M exceeded 0.3, then increased again as
the Mobility Index declined (Jones et al. 2010a). The predicted rise in temperature
is unlikely to have a major impact on the distribution of individual dune species,
since many in Wales, particularly plants and invertebrates, have a southern distribution and tend to be thermophilic. However, there are exceptions, such as the
dune grass Leymus arenarius, which is close to its southern limit in Wales. Also,
most dune plant species in this part of the world use the C3 photosynthetic
pathway enabling them to better utilize any increase in CO 2 levels. One might
expect, therefore, if all else is equal, that dune grasses will grow more rapidly as
global warming proceeds (Carter 1991). Changing climatic conditions are also
likely to affect soil processes and community-level vegetation development.
Warmer, wetter conditions as demonstrated from the Holocene stratigraphic record
of dunes and recent chronosequence evidence from Newborough are likely to
134
P. Rhind et al.
In addition to potential sea level rise, other climate change factors that need to be
considered based on recent updates from the UK Climate Impact Programme
(UKCIP) are as follows:
1. Annual average temperature predicted to rise by 1–3 °C or more during the
present century.
2. Warming likely to be greater in autumn and winter than in spring and summer.
3. Winter minimum temperatures predicted to rise more rapidly than maximum
temperatures, reducing the diurnal range, while summer maximum temperatures predicted to rise more rapidly than minimum temperatures, increasing the
diurnal range.
4. Variability of the winter temperature between years is likely to decrease, with
cold winters becoming rare.
5. Variability of summer temperatures likely to increase, with very hot summers
becoming more common.
6. Annual precipitation probably increasing by 3–5 % by 2050, with greater
increases in winter and autumn, but with no change or a decrease in summer.
7. Year-to-year variability of seasonal precipitation likely to show changes such
that the frequency of dry summers will double and wet winters treble by 2080.
8. More of the increased precipitation is likely to occur in intense storm events
than at present, especially in winter.
9. Evapotranspiration is likely to increase year round, but particularly in autumn
and summer.
The likely results of these interacting factors in terms of stabilization are difficult to predict, but there is clear evidence of the impact of climate on rates of
stabilization at Newborough. Faster rates of vegetation colonization since the
1940s, assessed using the aerial photographic record, were associated with lower
values of Talbot’s Mobility Index (M \ 0.3)—a function of windspeed, temperature, and rainfall (Talbot 1984). The rate of vegetation colonization slowed down
in the late 1960 and 1970s when values of M exceeded 0.3, then increased again as
the Mobility Index declined (Jones et al. 2010a). The predicted rise in temperature
is unlikely to have a major impact on the distribution of individual dune species,
since many in Wales, particularly plants and invertebrates, have a southern distribution and tend to be thermophilic. However, there are exceptions, such as the
dune grass Leymus arenarius, which is close to its southern limit in Wales. Also,
most dune plant species in this part of the world use the C3 photosynthetic
pathway enabling them to better utilize any increase in CO 2 levels. One might
expect, therefore, if all else is equal, that dune grasses will grow more rapidly as
global warming proceeds (Carter 1991). Changing climatic conditions are also
likely to affect soil processes and community-level vegetation development.
Warmer, wetter conditions as demonstrated from the Holocene stratigraphic record
of dunes and recent chronosequence evidence from Newborough are likely to
134
P. Rhind et al.