Earth is the third planet from the sun, formed 4.54 billion years ago. It rotates on its axis 366.26 times per year while orbiting the sun, creating seasons and years. The moon stabilizes Earth's axis and causes ocean tides. Earth's surface is divided into tectonic plates that migrate over millions of years. 71% is water and 29% is land with rivers and lakes. The interior remains active with a molten core generating a magnetic field and mantle driving plate tectonics. Earth system science considers interactions between the atmosphere, hydrosphere, cryosphere, geosphere, biosphere, and magnetosphere and human impacts on these. Climate change and the carbon cycle are central to
2. is the third planet
from the Sun, the
densest planet in
the Solar System’s,
the largest of the
Solar System's
four terrestrial
planet, and the
only astronomical
object known to
harbor life.
3. According to radiometric rating and other sources of
evidence, Earth formed about 4.54 billion years ago.
Earth gravitationally interacts with other objects in
space, especially the Sun and the Moon. During one
orbit around the Sun, Earth rotates about its axis
366.26 times, creating 365.26 solar days or
one sidereal year. Earth's axis of rotation is tilted 23.4°
away from the perpendicular of its orbital plane,
producing seasonal variations on the planet's surface
within a period of one tropical year (365.24 solar
days). The Moon is the Earth's only permanent natural
satellite; their gravitational interaction causes ocean
tides, stabilizes the orientation of Earth's rotational
axis, and gradually slows Earth's rotational rate.
4. Earth's lithosphere is divided into several rigid tectonic
plates that migrate across the surface over periods of
many millions of years. 71% of Earth's surface is
covered with water. The remaining 29% is land mass
consisting of continents and islands that together has
many lakes, rivers, and other sources of water that
contribute to the hydrosphere. The majority of
Earth's polar regions are covered in ice, including
the Antarctic ice sheet and the sea ice of the Arctic ice
pack. Earth's interior remains active with a solid iron
inner core, a liquid outer core that generates
the Earth’s Magnetic field, and a
convecting mantle that drives plate tectonics.
5.
6. is the application of systems science to the Earth
sciences. In particular, it considers interactions between
the Earth's "spheres“
atmosphere, hydrosphere, cryosphere, geosphere, pedo
sphere, biosphere,and, even, the magnestosphere as
well as the impact of human societies on these
components. At its broadest scale, Earth system science
brings together researchers across both
the natural and social sciences, from fields
including ecology,
economics, geology, glaciology meteorology, oceanogra
phy, paleontology, sociology, and space scence.
7. Like the broader subject of systems science,
Earth system science assumes a holistic
view of the dynamic interaction between the
Earth's spheres and their many constituent
subsystems, the resulting organization and time
evolution of these systems, and their stability or
instability. Subsets of Earth system science
include systems geology and systems
ecology, and many aspects of Earth system
science are fundamental to the subjects
of physical geography and climate science.
8. Climatology and climate
change have been central to
Earth system science since its
inception, as evidenced by the
prominent place given to
climate change in the early
NASA reports discussed
above. The Earth's climate
system is a prime example of
an emergent property of the
whole planetary system which
cannot be fully understood
without regarding it as a single
integrated entity.
9. It is also a property of the system where human
impacts have been growing rapidly in recent decades,
lending immense importance to the successful
development and advancement of Earth system
science research. As just one example of the centrality
of climatology to the field, leading American
climatologist Michael M. Mann is the Director of one of
the earliest centers for Earth system science research,
the Earth System Science Center at Pennsylvania
State University, and its mission statement reads, "the
Earth System Science Center (ESSC) maintains a
mission to describe, model, and understand the
Earth's climate system".
10. Global change refers to planetary-scale changes
in the Earth system.
More completely, the term “global change"
encompasses: planetary scale changes to
atmospheric circulation, ocean circulation, climate,
the carbon cycle, the nitrogen cycle, the water
cycle and other cycles, sea-ice changes, sea-level
changes, food webs, biological diversity, pollution,
health, fish stocks, and more.
11. Civilization is now a large driver
of global change so the term
includes population, the
economy, resource use,
energy, development, transport,
communication, land use and
land cover, urbanization,
globalization.
12. Climate refers to the long-term
average of the aggregation of all
components of weather precipitation,
temperature and cloudiness, for
example. The climate system
includes processes involving ocean,
land and sea ice in addition to the
atmosphere.
13. The Earth system encompasses the climate
system. Many changes in Earth system
functioning directly involve changes in climate.
However, the Earth system includes other
components and processes, biophysical and
human, that are important for its functioning.
Some Earth system changes, natural or driven
by humans, can have significant consequences
without involving changes in climate. Global
change should not be confused with climate
change; it is significantly more. indeed, climate
change is part of this much larger challenge.
