| James Bonsall (King Alfred’s
College, United Kingdom) J.P.T.Bonsall@wkac.ac.uk
Humans have destroyed world environments
during the last 10,000 years and face changes
of great magnitude caused by the natural
Milankovitch climatic cycle.
During the past 10,000 years we have witnessed
dramatic changes on the planet, but it is
only in the last few centuries that humans
have been able to record such events. Fortunately,
many of these events have archaeological
correlates. More recent changes, are also
historically documented. Humans have, over
the past 10,000 years, not only modified
the landscape, but also enhanced and, inherently,
destroyed the environment. The effect of
the Milankovitch cycles on the environment
will be examined here, and we shall see
how astronomical forces compare to the nature
of the human need for change. This essay
will cite events in the archaeological,
geological and historical records as evidence
for human interference and the Astronomical
Theory developed by Croll and Milankovitch.
The Milankovitch theory was initially rejected
upon its proposal. However, independent
research carried out in the 1960’s and 70’s
by W. S. Broecker, R. K. Matthews, K. J.
Mesolella, and D. L. Thurber; J. Imbrie
and K. P. Imbrie; and J. D. Hays and N.
J. Shackelton, have now validated the theory.
Their work was based upon a major reworking
of our understanding of oceanography, including
analysis of ocean core sequences, oxygen
isotope traces from deep ocean sediments,
and sea level variations (Lowe and Walker
1984). Ocean sediment records now accommodate
the explanation of Quaternary climatic change,
and the Milankovitch theory is now widely
accepted. However, as Lowe and Walker note
(ibid:13), it is hard to determine precisely
what effect Astronomical Theory has on Quaternary
climates.
The Astronomical Theory is based on the
assumption that the Earth’s surface temperature
will fluctuate as a direct result from periodic
changes in the shape of Earth’s orbit, the
position of the equator and Earth’s position
in relation to the Sun. The eccentricity
of the orbit means that Earth’s orbit changes
from elliptical to circular and back again
with a periodicity of 96,000 years. The
axis tilt sees the equator shift 3° and
back again with a periodicity of 42,000
years. The procession of the equinoxes alters
the position of the Earth with a periodicity
of 21,000 years (ibid:11 - 12).
These forces, known collectively as the
Milankovitch Theory, after the Croatian
scientist, cause massive climatic change.
The change in shape of Earth’s orbit was
responsible for the last glacial period
alone. The changes can result in large temperature
rises and a massive change in the planets
environment.
An increase in climate over a long period
in time can also cause sea level change.
10,000 years ago, we were at the end of
the last glaciation (Loader et al. 1997:10).
The expansion and contraction of the continental
glaciers “caused huge and uneven rises and
falls in sea levels worldwide” (Renfrew
and Bahn 1996). This led to the separation
of the Isle of Wight from mainland Britain,
over 6000 years ago. Dr. Rob Scaife, the
man responsible for looking at the features
of the submerged landscape on the Wootton
Quarr coastline, Isle of Wight, and sampling
environmental evidence from it, dated this.
By using a combination of an auger in the
intertidal zone of this site, with the seismic
survey of the palaeochannels found in that
investigation, the gradual sea level rise
resulted in the island’s separation from
Britain by 4000 B.C. (Loader et al. 1997:10
- 13).
The rise in sea level goes hand in hand
with the changing climate. The ultimate
results of Astronomical Theory indeed change
the landscape, as Wootton Quarr has demonstrated.
The formation of an island and the destruction
of an environment that lies under what we
now know as the Solent, were due to astronomical
changes. The isostatic rising of the land
and the eustatic rising of the sea took
place in the European Mesolithic (Mithen
1997). The rising of the sea level was due
to the melted ice from the glaciers. This
was not confined to Britain though, as we
see a massive simultaneous global change.
Another example is that of shell middens
in Tokyo Bay, Japan. Research carried out
on the shells shows that Japan also had
a much earlier coastline before 3000 B.C.
(Renfrew and Bahn 1996:216).
Changes in climate are also responsible
for site formation processes. Loess, aeolian
and alluviation processes are all inter-connected.
They are all affected by climatic change;
therefore they are all inexorably linked
to astronomical cycles. These cosmic changes
are not confined to land formation processes
alone, but also evolution of species. Elisabeth
Vrbra, a mammalian palaeontologist, noted
that evolutionary change is probably most
often of astronomical origin (Bennett 1997).
Humans respond to changes by changing their
environments (Bell and Walker 1993). Man,
it seems, does not wish to be outdone by
the forces of the universe. Over the past
10,000 years, man has been modifying the
planet’s landscapes to suit his needs, such
as settlement, agricultural enhancement
and industrial development. Unfortunately,
modification on man’s behalf means significant
destruction of ecosystems, ecotones and
the environment. We can trace this back
from as far back as 8,000 B.C., but it has
never been more apparent than in the 20th
Century.
In the 20th Century we need timber. From
buildings to furnishings it is all around
us. 10,000 years ago, there was a great
deal more of it all around us, the deciduous
forest regions of northern Europe covered
Great Britain. Odum (1971) has cited it
as “one of the most important biotic regions
of the world”. His reasoning is that the
biome was transformed by man, and was replaced
by “cultivated” and “forest edge” communities.
His point hits home rather well. If it were
not for man, and his “modifications”, deciduous
forests would still today cover Britain.
Luckily, we don’t have to imagine forest
clearance of the past. Using uniformitarian
principles, we have our own 20th Century
environmental change to use as a comparison.
The destruction of the tropical rainforests
is the consequence of our present day need
for timber. They are located almost exclusively
in developing countries that are under pressure
from the expansion of agriculture. The felling
of the trees is not managed in a sustainable
manner or with care for the ecosystem. Some
tribal groups have lived for thousands of
years in the tropics, and they have survived
without having to destroy their environment.
Yet commercial logging involves a mass modification
of the ecosystem (Counsell and Rice 1992).
This is not just a 20th Century environmental
change. Forest clearing has been occurring
since the Mesolithic. Woodland areas were
being burnt for hunting and their destruction
resulted in a change in the landscape. The
introduction of agriculture in the Neolithic
also changed the landscape. Modification
after modification to the land changes the
environment in a significant way, for example
colluviation. Colluviation mainly occurs
as a result of forest clearance. When there
are no tree roots present to bond the soil
together, soil erosion appears. This is
a result of the “poorly sorted or unsorted
sediment”, the colluvium (Bell and Walker
1993).
Intensive agriculture in the 20th Century
includes the use of chemicals which will
ultimately modify the landscape in ways
we do not want. Agronomy involves the determination
of the nature of a soil and how its fertility
may be improved by drainage, irrigation,
husbandry techniques such as crop rotation,
and natural or artificial fertilizers (Isaacs
1996). This is all well and good, but the
environment suffers under these modifications
in the form of soil erosion and pollution
by excessive use of weed killers, fertilizers
and insecticides. Yes we have managed to
grow healthier crops with a higher yield,
but the chemicals used effected the landscape
in a negative manner.
Modern intensive farming methods cause
problems. However during the 18th Century,
the Agricultural Revolution in Britain managed
to modify the landscape for mans use and
had no negative effects on the environment.
The open-field system of strip farming was
replaced by agricultural methods and new
implements could be used. Jethro Tull and
Viscount Townshend’s inventions also helped
speed up the more economic approach to farming.
Of course, the purpose of the new system
of agriculture was to avoid the “Malthus
Trap” of the intensive population growth
of the Industrial Revolution, as described
by Rev. Thomas Malthus in his Essays (Hobsbawm
1989). The Industrial Revolution was the
largest major change in Britain’s environmental
history since the Romans agricultural intensification.
Modification of the landscape to enable
transportation of goods led to the building
of railways and the extension of canals
in the 18th and 19th Centuries. Major British
industrial towns such as Manchester and
Sheffield, sprang up over night (ibid:37).
In April 1986, radioactive particles rained
down over Scandinavia, Poland, Austria,
northern Italy, France, Wales, England,
Canada, and what is now known as the Czech
Republic. Unacceptably high levels of 137Cs
were found in those areas. This posed a
massive threat to the Lapps and Inuits that
depended on reindeer meat for food. The
reindeer fed on lichens which absorbed the
radioactive isotopes (Richardson 1981).
Damaging the food chain, this pollutant
is extremely harmful. Lichens are a very
useful way of monitoring the fallout, as
they are highly susceptible to pollution.
The environment surrounding the origin of
the explosion was severely polluted, and
after mass evacuation, twelve years on it
is still a designated quarantine landscape.
The small town of Chernobyl lies in northern
Ukraine. In just eleven days, its pollution
cloud passed over ten countries in two continents.
Mans harness of nuclear power has had an
extremely deadly effect on the environment.
It was originally intended as modifying
the environment by discontinuing the burning
of fossil fuels for power supply, but like
other modifications it resulted in destruction.
A final example, is that of China’s recent
initiative to provide 18,000 Megawatts of
electricity for the “fast developing Chinese
nation state” (Greeman 1998). The Three
Gorges Dam will block the Yangtze River
and has flooded 1000 square kilometres of
land, forcing 2 million people from their
homes. The project has cost $29 billion
(U.S. Dollars). Part of the Hubei province
has been lost, along with it homes, wildlife
habitats, ecosystems, ecotones, environmental
data, and thousands of years of archaeology.
It is China’s biggest engineering project
since The Great Wall, and has changed the
landscape forever. This large-scale operation
will also be visible from space.
Astronomical data and its geological and
climatic effects are hard to interpret for
the period of the last 10,000 years. Geologically,
10,000 years is a very short time. It is
with greater ease we can look at the Cenozoic,
Mesozoic, Palaeozoic and Protozoic periods
due to their longevity. The further back
in time you go, the easier it is to see
the patterns, and their effects, when dealing
with periodicity’s of 96,000, 42,000 and
21,000 years (Bennett 1997:65 - 84). Massive
global change due to astronomical cycles
is undeniable, but apart from short term
temperature change and land formation, there
is not (readily) available any comparative
material. Mans effect is all too available,
and it is obvious that his effect on Earth
is far greater than anything Mother Nature
can throw our way. We try and adapt our
environment, but all we end up doing is
making it worse for future generations.
Not only have we destroyed the surface of
our planet, but also its pedology. Environmental
data obtained from palaeosols only survive
where human interference is minimal. Not
only are we destroying our chances of survival
in the future by deforestation, chemical
use, nuclear hazards, and intense land reorganization,
we are also destroying our chance to rescue
the past. Humans have modified the planet
in short time spans, in Revolutions, which
would take an epoch for Astronomical Cycles
to compete with. Cosmic changes have formed
the look of the Earth for millennia, but
humans change that look in the blink of
an eye.
References
Bell, M., and M. Walker 1993
Late Quaternary Environmental Change:
Human and Physical Perspectives.
Harlow: Longman.
Bennett, K. D. 1997 Evolution
and Ecology The Pace of Life.
Cambridge: Cambridge University Press.
Counsell, S., and T. Rice (eds) 1992
The Rainforest Harvest. London:
Friends of the Earth.
Greeman, A. 1998 The Dam Builders.
Focus Magazine May, pp. 45-98.
Hobsbawm, E. 1989 The Industrial
Revolution. London: Penguin.
Isaacs, A. 1996 Macmillan
Encyclopaedia 1997. London: Macmillan.
Loader, R., Westmore, I. and D. Tomalin
1997 Time And Tide. An Archaeological
Survey of the Wootton Quarr Coast, Isle
of Wight. Newport: Council Print Unit.
Lowe, J. and M. Walker 1984
Reconstructing Quaternary Environments.
Harlow: Longman
Mithen, S. 1997 The Mesolithic
Age. In Cunliffe, B. (ed.) 1994
Prehistoric Europe, 79-136:
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Odum, E. 1971 Fundamentals
of Ecology (3rd ed.).
London: Saunders.
Renfrew, C. and P. Bahn 1996
Archaeology. Theories Methods and Practice
(2nd ed.). London: Thames
and Hudson
Richardson, D. 1981 Pollution
Monitoring with Lichens, Slough:
Richmond.
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World
Archaeological Bulletin