What is Global Change ?
It has become apparent that human activities are affecting the environment at a global scale. The burning of fossil fuels in industry, private homes and cars, the transformation of forests into agricultural land, the creation of artificial wetlands, to name just a few processes, are releasing large amounts of so-called greenhouse gases into the atmosphere, especially carbon dioxide and methane. These gases trap the heat that is radiated from the Earth’s surface, thus leading to a warming of the atmosphere. This is the Greenhouse Effect.
The Greenhouse Effect is a natural phenomenon. Without it life on Earth as we know it would not be possible. The average temperature on Earth, at present + 15 °C, would be much lower, only - 19 °C. The problem lies in the fact that emissions from human activities are increasing the amount of carbon dioxide and methane in the atmosphere resulting in an ‘enhancement’ of the Greenhouse Effect and thus increased surface temperatures. This is known as Global Warming.
The Intergovernmental Panel on Climate
Change, an international group of renowned scientists which advises governments
from around the world, concluded in 1995 that:
| ‘the balance of evidence suggests a discernible human influence on global climate’ |
Best estimates indicate that global temperatures
will rise between 0.5 °C and 2 °C over the next 50 years, but increases
in some parts of the Arctic, including the Usa Basin, could be as much
as 5 °C over the same period of time. Weather at high latitudes is
also notoriously variable, with temperature differences of 5 °C from
one year to the next not being exceptional.
| Warming in the East-European Russian Arctic could be as much as 5 °C over the next 50 years, although cold years can not be excluded due to high variability ! |
Mean annual air temperatures have risen
considerably in the study area over the past 30 years (1966-1995). For
the Vorkuta weather station this increase amounts to about 0.5 °C per
decade. Present-day temperatures are, however, not exceptional when observed
against the long-term variability at the site, with measurements spanning
more than 60 years. In fact, over this longer period of time, a small decrease
in temperatures is evident amounting to 0.04 °C per decade. If models
are correct, temperatures will become significantly higher in the coming
decades. Another feature displayed by the Vorkuta weather data is the high
annual variability, with a maximum change of 5.1 °C between 1967 and
1968. Because of this variability, some cold years in the near future can
not be excluded despite the anticipated warming trend.
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Global Warming will not be the only agent of change in the coming decades. That is why we prefer to use the term Global Change. By this we mean changes in the Earth’s environment that are caused by human activities, especially but not exclusively Global Warming. Other alterations which are also important include the depletion of the ozone layer, an increase in contaminants and atmospheric dust, and the reduction in biodiversity of species of regional fauna or flora. In the TUNDRA project we pay particular attention to Global Warming, pollution and the role of public perception in environmental change and degradation.
