Future of the Earth after 1000 Million Years | Full Documentary
Δημοσιεύτηκε στις 4 Μαΐ 2014
http://www.advexon.com/
The
biological and geological future of the Earth can be extrapolated based
upon the estimated effects of several long-term influences. These
include the chemistry at the Earth's surface, the rate of cooling of the
planet's interior, the gravitational interactions with other objects in
the Solar System, and a steady increase in the Sun's luminosity. An
uncertain factor in this extrapolation is the ongoing influence of
technology introduced by humans, such as geoengineering,[2] which could
cause significant changes to the planet.[3][4] The current biotic
crisis[5] is being caused by technology[6] and the effects may last for
up to five million years.[7] In turn, technology may result in the
extinction of humanity, leaving the planet to gradually return to a
slower evolutionary pace resulting solely from long-term natural
processes.[8][9]
Over time intervals of hundreds of millions of
years, random celestial events pose a global risk to the biosphere,
which can result in mass extinctions. These include impacts by comets or
asteroids with diameters of 5--10 km (3.1--6.2 mi) or more, and the
possibility of a massive stellar explosion, called a supernova, within a
100-light-year radius from the Sun, called a Near-Earth supernova.
Other large-scale geological events are more predictable. If the
long-term effects of global warming are disregarded, Milankovitch theory
predicts that the planet will continue to undergo glacial periods at
least until the quaternary glaciation comes to an end. These periods are
caused by eccentricity, axial tilt, and precession of the Earth's
orbit.[10] As part of the ongoing supercontinent cycle, plate tectonics
will probably result in a supercontinent in 250--350 million years. Some
time in the next 1.5--4.5 billion years, the axial tilt of the Earth
may begin to undergo chaotic variations, with changes in the axial tilt
of up to 90°.
During the next four billion years, the luminosity
of the Sun will steadily increase, resulting in a rise in the solar
radiation reaching the Earth. This will cause a higher rate of
weathering of silicate minerals, which will cause a decrease in the
level of carbon dioxide in the atmosphere. In about 600 million years,
the level of CO
2 will fall below the level needed to sustain C3
carbon fixation photosynthesis used by trees. Some plants use the C4
carbon fixation method, allowing them to persist at CO
2
concentrations as low as 10 parts per million. However, the long-term
trend is for plant life to die off altogether. The extinction of plants
will be the demise of almost all animal life, since plants are the base
of the food chain on Earth.
In about 1.1 billion years, the solar
luminosity will be 10% higher than at present. This will cause the
atmosphere to become a "moist greenhouse", resulting in a runaway
evaporation of the oceans. As a likely consequence, plate tectonics will
come to an end.[11] Following this event, the planet's magnetic dynamo
may come to an end, causing the magnetosphere to decay and leading to an
accelerated loss of volatiles from the outer atmosphere. Four billion
years from now, the increase in the Earth's surface temperature will
cause a runaway greenhouse effect. By that point, most if not all the
life on the surface will be extinct.[12][13] The most probable fate of
the planet is absorption by the Sun in about 7.5 billion years, after
the star has entered the red giant phase and expanded to cross the
planet's current orbit.
The
biological and geological future of the Earth can be extrapolated based
upon the estimated effects of several long-term influences. These
include the chemistry at the Earth's surface, the rate of cooling of the
planet's interior, the gravitational interactions with other objects in
the Solar System, and a steady increase in the Sun's luminosity. An
uncertain factor in this extrapolation is the ongoing influence of
technology introduced by humans, such as geoengineering,[2] which could
cause significant changes to the planet.[3][4] The current biotic
crisis[5] is being caused by technology[6] and the effects may last for
up to five million years.[7] In turn, technology may result in the
extinction of humanity, leaving the planet to gradually return to a
slower evolutionary pace resulting solely from long-term natural
processes.[8][9]
Over time intervals of hundreds of millions of
years, random celestial events pose a global risk to the biosphere,
which can result in mass extinctions. These include impacts by comets or
asteroids with diameters of 5--10 km (3.1--6.2 mi) or more, and the
possibility of a massive stellar explosion, called a supernova, within a
100-light-year radius from the Sun, called a Near-Earth supernova.
Other large-scale geological events are more predictable. If the
long-term effects of global warming are disregarded, Milankovitch theory
predicts that the planet will continue to undergo glacial periods at
least until the quaternary glaciation comes to an end. These periods are
caused by eccentricity, axial tilt, and precession of the Earth's
orbit.[10] As part of the ongoing supercontinent cycle, plate tectonics
will probably result in a supercontinent in 250--350 million years. Some
time in the next 1.5--4.5 billion years, the axial tilt of the Earth
may begin to undergo chaotic variations, with changes in the axial tilt
of up to 90°.
During the next four billion years, the luminosity
of the Sun will steadily increase, resulting in a rise in the solar
radiation reaching the Earth. This will cause a higher rate of
weathering of silicate minerals, which will cause a decrease in the
level of carbon dioxide in the atmosphere. In about 600 million years,
the level of CO
2 will fall below the level needed to sustain C3
carbon fixation photosynthesis used by trees. Some plants use the C4
carbon fixation method, allowing them to persist at CO
2
concentrations as low as 10 parts per million. However, the long-term
trend is for plant life to die off altogether. The extinction of plants
will be the demise of almost all animal life, since plants are the base
of the food chain on Earth.
In about 1.1 billion years, the solar
luminosity will be 10% higher than at present. This will cause the
atmosphere to become a "moist greenhouse", resulting in a runaway
evaporation of the oceans. As a likely consequence, plate tectonics will
come to an end.[11] Following this event, the planet's magnetic dynamo
may come to an end, causing the magnetosphere to decay and leading to an
accelerated loss of volatiles from the outer atmosphere. Four billion
years from now, the increase in the Earth's surface temperature will
cause a runaway greenhouse effect. By that point, most if not all the
life on the surface will be extinct.[12][13] The most probable fate of
the planet is absorption by the Sun in about 7.5 billion years, after
the star has entered the red giant phase and expanded to cross the
planet's current orbit.
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