3 December 2009 - By
Steen Voigt - The tree pollen season today
starts several weeks earlier than 20 years
ago and the amount of pollen from e.g. alder
and birch has significantly increased. Plants’
growing season has lengthened, marking a
historical change in
the state of nature and the environment.
Changes driven by global climate change.
Danish nature and environment are also being
altered in other ways. The fifth Danish
state of the environment (SoE) report, ’Natur
og Miljø 2009’, just published by
the National Environmental Research Institute
(NERI), Aarhus University, collates and
describes trends in Denmark’s nature, environment
and population’s health.
Denmark is not among
the countries expected to be hardest hit
by climate change. Nevertheless Danish society
will need to recognize that climate is undergoing
changes – affecting also our environment.
As well as climate change
advancing the tree pollen season, the SoE
report indicates that climate change will
benefit more southerly tree species, such
as lime and hornbeam, through warmer weather,
while the opposite will be true for more
northerly tree species such as pines, e.g.
the Norway spruce.
The longer growing season
will especially benefit competitive species
such as, for example, stinging nettles.
Overall, climate change is expected to lead
to a significant impact on plant growth
and thereby also wildlife. A study of 104
Danish plant species indicates that two-thirds
will be affected negatively - 4 per cent
are even expected to disappear completely.
Just 12 per cent of plant species will be
affected positively, while 18 per cent are
not expected to be affected either way.
Early birds
Also, birdlife is undergoing change in current
years. Many migratory birds are arriving
earlier in spring and leaving later in autumn
– or sometimes remaining here for the entire
winter, such as e.g. greylag geese. Researchers
anticipate that the home range of a number
of bird species will move approx. 500 km
north-east. This can mean that birds characteristic
of the Danish landscape, such as the oyster
catcher, avocet, ringed plover and herring
gull, will become rarer, while more southerly
species such as little bittern, night heron,
short-toed eagle, hoopoe and nightingale
are expected to move in instead.
Lakes are warming up
Water temperature in Danish lakes has risen
approx. 2 degrees C since 1989. This is
almost twice as much as the rise in air
temperature. This is due to a range of climatic
conditions such as more sunshine hours and
more precipitation. The warmer water favours
smaller fish. Small fish eat zooplankton,
which in turn decrease in abundance. As
zooplankton live on algae, this will result
in enhanced algal bloom in lakes. The water
will lose clarity and the risk of hypoxia
will increase.
And the sea too
Sea temperature around Denmark has also
risen 2 degrees C. This means that the spring
algal bloom now commences already in the
middle of February, whereas before this
took place at the end of March. An aggravating
factor is that warmer water contains less
oxygen. Stratification in the water column
is enhanced, and thereby the risk of hypoxia
in later summer. Climate change has also,
since the beginning of the 11000s, contributed
to deteriorating oxygen conditions, both
in lakes and Danish marine waters.
Danes are among the
people in the world who emit the most CO2
per inhabitant. Emission of greenhouse gases
in Denmark has fallen 3.5 per cent since
11000. Denmark is committed to reducing
its emission by 21 per cent on average in
the period 2008-2012 compared to the level
in 11000. The government has therefore decided
to make use of the flexible mechanisms in
the Kyoto Protocol to ensure this goal is
attained.
Other trends
The SoE report also describes other trends
in nature and environment over recent years
across a range of themes. The report is
issued every fourth year and this year’s
edition also features:
Biodiversity on dry
land in decline
Expansion of urban areas and the road network
together with environmental impacts from
agriculture have contributed to a deterioration
in nature and biodiversity in Denmark. The
population of farmland birds has declined
by 36 per cent since 11000. The area of
open countryside nature such as heathland,
dry grassland and meadows has declined by
26 per cent from 1965 to 2000. But a number
of positive trends are also evident. The
environment in our lakes and streams is
slowly improving, and forest area is increasing
due to afforestation. Read more in the article
on biodiversity (link) (in Danish).
The environment affects
the population’s health
Each year more than 3,000 Danes die earlier
than they otherwise would due to air pollution
from traffic. Use of chemical substances
is widespread and hazardous chemicals are
the cause of a range of health effects such
as allergies, endocrine disruption, and
increased breast and prostate cancer. Spending
time in the countryside on the other hand
has shown itself to be beneficial to health.
Read more in the article on health (link)
(in Danish).
Denmark as pioneer?
Sustainable development concerns securing
future generations the opportunity to meet
their needs. Internationally a range of
indicators have been developed to show whether
society is developing sustainably in range
of environmental, social and economical
areas. In these comparisons Denmark is doing
well with regard to the social and economic
parameters, but we are farther sway from
sustainable development in relation to a
number of environmental parameters.
About the SoE report
The SoE report, ‘Natur og Miljø 2009’,
should be seen as a central foundation for
the government’s environmental planning,
and as a document upon which nature and
environmental policy can be built. The report
comprises two parts:
- Part A: An integrated
analysis of the state of nature and environment
in Denmark – seen in a global perspective
- Part B: A reference
work with indicator-based information on
the state of the environment and nature.
The full report has
been printed in Danish and is available
online. While Part A (with English summary)
is primarily written for print, Part B is
primarily created for online use.
The report has completed
two public consultation rounds:
In September 2008 NERI
distributed an annotated synopsis, to which
there came a total of 23 responses.
In September 2009 NERI
distributed a full draft of the report,
to which there came a total of 26 responses.
All responses can be
viewed on NERI’s website together with a
statement on how the editorial group to
the best of their abilities have attempted
to accommodate the responses.
Natur og Miljø
2009 – Del A: Danmarks miljø under
globale udfordringer. Normander, B., Jensen,
T.S., Henrichs, T., Sanderson, H. &
Pedersen, A.B. (red.) 2009. Danmarks Miljøundersøgelser,
Aarhus Universitet. 94 s. – Faglig rapport
fra DMU nr. 1000, http://www.dmu.dk/Pub/FR1000.pdf
(with English summary)
Natur og Miljø
2009 – Del B: Fakta. Normander, B., Henriksen,
C.I., Jensen, T.S., Sanderson, H., Henrichs,
T., Larsen, L.E. & Pedersen, A.B. (red.)
2009. Danmarks Miljøundersøgelser,
Aarhus Universitet. 170 s. – Faglig rapport
fra DMU nr. 751, http://www.dmu.dk/Pub/FR751.pdf
State of the environment
report online www.naturogmiljoe.dk (in Danish)
Consultation process
http://www.dmu.dk/Samfund/Miljoetilstandsrapport/Miljoetilstandsrapport_2009/
