183
teristics disappear from the specific forms of the
species. Typical examples can be found in the
case of cultivated plants and domesticated animals as in both cases the number of types within
the species decreased. For example, in India
before the green revolution in the 1960s and
1970s 30,000 rice types were grown in the huge
country. This declined to 50 types by 2000.
Grown wheat types in China decreased from
10,000 to 1000 between 1950 and 1970.
Regarding the entire planet 90% of food is produced from just more than 100 plant species.
Decreasing types within natural species is similarly unwanted like the destruction of natural species. The effects of gene erosion in the case of
cultivated plants and animals will be felt only if
new demands have to be met or in the case of
natural species, adaptation to new environmental
conditions will be necessary. In the latter case,
the species could go extinct due to gene erosion.
The final statement of the Living Planet Report
2018 (WWF 2018) shall be given at the end of this
subchapter: “We are the first generation that has a
clear picture of the value of nature and the enormous impact we have on it. We may also be the
last that can act to reverse this trend. From now
until 2020 will be a decisive moment in history”.
Authors of the present book add only: even if the
trend could be successfully reversed, the extinct
species cannot return, however, all efforts have to
be made to save the rest of species going extinct.
4.5
Changes in the Atmosphere
Owing to Human Impacts
and Their Consequences
Generally the current composition of the atmosphere is compared to that prior to the industrial
revolution in the eighteenth century because
mass production of manufacturing industries,
extensive use of fossil energy resources (coal,
crude oil, natural gas) and thus intensifying
anthropogenic effects on the composition of the
atmosphere are typical for this almost 300 years.
Human activities influenced the composition of
the atmosphere already before the industrial revolution (e.g. deforestation and soil cultivation)
but to an extent several orders of magnitude
smaller than after the occurrence of manufacturing industries when calculated to time units.
Destruction of the natural vegetation with
advancing plant production and the associated
soil erosion increased slowly the CO 2 content of
the atmosphere and this increase intensified rapidly following the industrial revolution.
Even the above described human activities and
the extremely intensive production in the twentieth and twenty-first centuries and the multiplied
consumption of humanity could not change notably the ratio of the basic gases in the atmosphere.
The two most basic gases—without water
vapour—are nitrogen (78.08%) and oxygen
(20.95%). Beside them argon (0.92%) and other
noble gases (neon, krypton, helium, xenon) in
insignificant quantity, and carbon dioxide (0.04%)
are the constant components. Apart from these
many kinds of gases and pollutant material appear
in the atmosphere in traces and in variable composition. Despite the small ratio their environmental effects are important. Such complementary
components are aerosols, nitrogen oxides, methane, sulphur dioxide and several artificially produced gases (CFCs, HCFCs, etc.) Their quantity
is influenced significantly by human activities.
The above mentioned atmospheric components with significant environmental effects will
be discussed in the following. Changes in their
ratio and their consequences will be discussed in
three groups:
• greenhouse gases (GHG),
• gases causing acid deposition,
• gases damaging the ozone shield and their
substitutes.
4.5.1 Increasing Amount
of Greenhouse Gases
and Climate Change
Regarding the climate of Earth greenhouse gases
(carbon dioxide, methane, nitrous oxide, etc., and
water vapour is also classified here) have a decisive role as they “trap” a part of the heat arriving
from the Sun onto the Earth surface: they let sun4.5 Changes in the Atmosphere Owing to Human Impacts and Their Consequences
teristics disappear from the specific forms of the
species. Typical examples can be found in the
case of cultivated plants and domesticated animals as in both cases the number of types within
the species decreased. For example, in India
before the green revolution in the 1960s and
1970s 30,000 rice types were grown in the huge
country. This declined to 50 types by 2000.
Grown wheat types in China decreased from
10,000 to 1000 between 1950 and 1970.
Regarding the entire planet 90% of food is produced from just more than 100 plant species.
Decreasing types within natural species is similarly unwanted like the destruction of natural species. The effects of gene erosion in the case of
cultivated plants and animals will be felt only if
new demands have to be met or in the case of
natural species, adaptation to new environmental
conditions will be necessary. In the latter case,
the species could go extinct due to gene erosion.
The final statement of the Living Planet Report
2018 (WWF 2018) shall be given at the end of this
subchapter: “We are the first generation that has a
clear picture of the value of nature and the enormous impact we have on it. We may also be the
last that can act to reverse this trend. From now
until 2020 will be a decisive moment in history”.
Authors of the present book add only: even if the
trend could be successfully reversed, the extinct
species cannot return, however, all efforts have to
be made to save the rest of species going extinct.
4.5
Changes in the Atmosphere
Owing to Human Impacts
and Their Consequences
Generally the current composition of the atmosphere is compared to that prior to the industrial
revolution in the eighteenth century because
mass production of manufacturing industries,
extensive use of fossil energy resources (coal,
crude oil, natural gas) and thus intensifying
anthropogenic effects on the composition of the
atmosphere are typical for this almost 300 years.
Human activities influenced the composition of
the atmosphere already before the industrial revolution (e.g. deforestation and soil cultivation)
but to an extent several orders of magnitude
smaller than after the occurrence of manufacturing industries when calculated to time units.
Destruction of the natural vegetation with
advancing plant production and the associated
soil erosion increased slowly the CO 2 content of
the atmosphere and this increase intensified rapidly following the industrial revolution.
Even the above described human activities and
the extremely intensive production in the twentieth and twenty-first centuries and the multiplied
consumption of humanity could not change notably the ratio of the basic gases in the atmosphere.
The two most basic gases—without water
vapour—are nitrogen (78.08%) and oxygen
(20.95%). Beside them argon (0.92%) and other
noble gases (neon, krypton, helium, xenon) in
insignificant quantity, and carbon dioxide (0.04%)
are the constant components. Apart from these
many kinds of gases and pollutant material appear
in the atmosphere in traces and in variable composition. Despite the small ratio their environmental effects are important. Such complementary
components are aerosols, nitrogen oxides, methane, sulphur dioxide and several artificially produced gases (CFCs, HCFCs, etc.) Their quantity
is influenced significantly by human activities.
The above mentioned atmospheric components with significant environmental effects will
be discussed in the following. Changes in their
ratio and their consequences will be discussed in
three groups:
• greenhouse gases (GHG),
• gases causing acid deposition,
• gases damaging the ozone shield and their
substitutes.
4.5.1 Increasing Amount
of Greenhouse Gases
and Climate Change
Regarding the climate of Earth greenhouse gases
(carbon dioxide, methane, nitrous oxide, etc., and
water vapour is also classified here) have a decisive role as they “trap” a part of the heat arriving
from the Sun onto the Earth surface: they let sun4.5 Changes in the Atmosphere Owing to Human Impacts and Their Consequences