Force Of Climate Change Is Population Growth
Between 1960 and 1999, Earth's population doubled from three billion to
six billion people. When population growth is coupled with shortsighted
planning and excessive consumption of resources, problems multiply.
Human pressure on the environment is a product of three factors:
population, consumption, and technology.
Population is the total number of people, consumption is the amount of
resources each person consumes, and technology is how these resources are
used and how much waste is produced for each unit of consumption.
We have transformed approximately half of The Earth's surface for our own
uses, with widespread impacts on the planet's forests, oceans,
freshwater, and atmosphere.
Climate includes patterns of
temperature, precipitation, humidity, wind and seasons. "Climate change" affects
more than just a change in the weather, it refers to seasonal changes over a
long period of time. These climate patterns play a fundamental role in shaping
natural ecosystems, and the human economies and cultures that depend on them.
What is climate forcing and
how does climate forcing relate to climatic variability and change?
Climate forcing refers to specific phenomena that directly influence changes in
climatic dynamics. Forces that influence climatic change can be broken down into
those beyond the Earth's environmental system (extraterrestrial) and those that
relate to internal forces (terrestrial).
Solar variability (sunspots 11, 22 yrs)
Obliquity (tilt on axis~41,000 yrs change)
Precession (wobble on axis due to gravity of sun and moon in 23,000 yr. cycle)
Eccentricity (96,000 yr. change)
Continental Processes (105 yrs. on up)
Mass and composition of atmosphere
Volcanic activity and strato aerosols
Human influences such as land use and combustion of fossil fuels
What factors are key to measuring climate change?
is the primary measure of climate and can be measured or reconstructed for the
Earth's surface, and sea surface temperature (SST).
offers another indicator of relative climate variation and may include humidity
or water balance.
and vegetation patterns may be discerned in a variety of ways and provide
evidence of how ecosystems change to adapt to climate change.
measurements reflect changes in shoreline and usually relate to the degree of
ice coverage in high latitudes and elevations.
Solar Activity can
influence climate, primarily through changes in the intensity of solar
like solar radiation, can alter climate due to the aerosols that are emitted
into the atmosphere and alter climate patterns.
Chemical composition of air or water
can be measured by
tracking levels of greenhouse gases such as carbon dioxide and methane, and
measuring ratios of oxygen isotopes. Research indicates a strong correlation
between the percent of carbon dioxide in the atmosphere and the Earth's mean
The earth’s climate is predicted to change through the buildup of greenhouse
gases – primarily water vapor, carbon dioxide, methane, and nitrous oxide. The
heat-trapping property of these gases is undisputed. Although uncertainty exists
about exactly how earth’s climate responds to these gases, global temperatures
Global climate change is a change in the long-term weather patterns that
characterize the regions of the world. The term "weather" refers to the
short-term (daily) changes in temperature, wind, and/or precipitation of a
What is the difference between Weather and Climate?
Weather is the state of atmosphere-ocean-land conditions (hot/cold, wet/dry,
calm/stormy, sunny/cloudy) that exist over relatively short periods like hours
or days. Weather includes the passing of a thunderstorm, hurricane, or blizzard,
a persistent heatwave, a cold snap, a drought. Weather variability and extreme
events may respond unpredictably in response to climate change.
Climate is weather patterns over a month, a
season, a decade, a century from now or in past time periods. More technically
climate is defined as the weather conditions resulting from the mean state of
the atmosphere-ocean-land system, often described in terms of "climate
or average weather conditions.
The greenhouse effect is a natural occurrence that maintains Earth's average
temperature at approximately 60 degrees Fahrenheit. The greenhouse effect is a
necessary phenomenon that keeps all Earth's heat from escaping to the outer
atmosphere. Without the greenhouse effect, temperatures on Earth would be much
lower than they are now, and the existence of life on this planet would not be
possible. However, too many greenhouse gases in Earth's atmosphere could
increase the greenhouse effect.
This could result in an increase in mean global temperatures as well as changes
in precipitation patterns. When weather patterns for an area change in one
direction over long periods of time, they can result in a net climate change for
that area. The key concept in climate change is time. Natural changes in climate
usually occur over; that is to say they occur over such long periods of time
that they are often not noticed within several human lifetimes. This gradual
nature of the changes in climate enables the plants, animals, and Microorganisms
on earth to evolve and adapt to the new temperatures, precipitation patterns,
etc. The real threat of climate change lies in how rapidly the change occurs.
Increasing concentrations of greenhouse gases are likely to accelerate the rate
of climate change.
Because so many systems are tied
to climate, a change in climate can affect many related aspects of where and how
people, plants and animals live, such as food production, availability and use
of water, and health risks.
The Earth's climate has changed
throughout history. From glacial periods (or "ice ages") where ice covered
significant portions of the Earth to interglacial periods where ice retreated to
the poles or melted entirely - the climate has continuously changed. Scientists
have been able to piece together a picture of the Earth's climate dating back
decades to millions of years ago by analyzing a number of surrogate, or "proxy,"
measures of climate such as ice cores, boreholes, tree rings, glacier lengths,
pollen remains, and ocean sediments, and by studying changes in the Earth's
orbit around the sun.
the last 4.6 billion years
The term Global Warming refers to
the observation that the atmosphere near the Earth's surface is warming.
This warming is one of many kinds of climate change that the Earth has
gone through in the past and will continue to go through in the future. It
is reasonable to expect that the Earth should warm as the amount of
greenhouse gases in the atmosphere increases. It is known for certain that
atmospheric concentrations of greenhouse gases are rising dramatically due
to human activity. It is less well known exactly how the increases in
these greenhouse gases factor in the observed changes of the Earth's
climate and global temperatures
can contribute to global warming and climate change by polluting and
cutting down rainforests, but humans can not control the climate or change
it. The climate system is very complex and has many variables and
components. Human beings do not control all the variables and components
or the Planet Earth.
organization or person that is saying things like "we can solve the
climate crisis" or "we can stop global warming" are making statements that
are just "Advertising Slogans" impossible to accomplish.
To actually "stop
global warming" or "solve the climate crisis" human beings would have the
ability to control the following to name a few:
No matter how
aggressively heat-trapping emissions are reduced, some amount of climate change
and resulting impacts will continue. Consequently, there is a need for
adaptation and mitigation.
– improving our ability to cope with or avoid harmful impacts or taking
advantage of newly favorable conditions
defined as -to lessen in force or intensity, as wrath, grief, harshness, or
pain; moderate- to make less severe. At best human beings can slightly modify
– reducing the amount of climate change, for example, by reducing heat-trapping
emissions or increasing their removal from the atmosphere
We should try
to be the best protectors of the planet as much as we are capable and
adapt to and prepare for the changes in the Earth's Climate that are
If we stop all greenhouse
gas emissions, will global climate change stop?
Industrial activity has
already pumped billions of tons of greenhouse gases into the atmosphere,
and we have yet to see the full effect of warming from those gases. A
great deal of excess energy imbalance is stored in the ocean and will be
released gradually over time, continuing to warm the planet.
In other words, some degree
of climate change is irreversible. Scientists call this the "committed
warming," and estimate that the Earth would continue to warm about 1
degree Fahrenheit (.6 degrees Celsius) even if greenhouse gas levels in
the atmosphere stopped growing immediately. That is, if all human
greenhouse gas emissions stopped tomorrow, the Earth would still warm for
at least a half-century.
Over the last
400,000 years the Earth's climate has been unstable, with very significant
temperature changes, going from a warm climate to an ice age in as rapidly
as a few decades. These rapid changes suggest that climate may be quite
sensitive to internal or external climate forcings and feedbacks. As can
be seen from the blue curve, temperatures have been less variable during
the last 10 000 years. Based on the incomplete evidence available, it is
unlikely that global mean temperatures have varied by more than 1°C in a
century during this period. The information presented on this graph
indicates a strong correlation between carbon dioxide content in the
atmosphere and temperature. A possible scenario: anthropogenic emissions
of GHGs could bring the climate to a state where it reverts to the highly
unstable climate of the pre-ice age period. Rather than a linear
evolution, the climate follows a non-linear path with sudden and dramatic
surprises when GHG levels reach an as-yet unknown trigger point.
The more than 500 active volcanoes erupting around the world affect the
Earth's atmosphere and global climate. As volcanoes erupt, they blast
large clouds of gases, particles, water vapor, and aerosols into the
Causes of Change Prior
to the Industrial Era (pre-1780)
Known causes, “drivers”
or “forcings” of past climate change include:
the Earth's orbit: Changes in the shape of the Earth's orbit
as well as the Earth's tilt and precession affect the amount of
sunlight received on the Earth's surface. These orbital processes --
which function in cycles of 100,000 (eccentricity), 41,000 (tilt), and
19,000 to 23,000 (precession) years -- are thought to be the most
significant drivers of ice ages according to the theory of ,Mulitin
Milankovitch a Serbian mathematician (1879-1958).
the sun's intensity:
Changes occurring within (or inside) the sun can affect the intensity
of the sunlight that reaches the Earth's surface. The intensity of the
sunlight can cause either warming (for stronger solar intensity) or
cooling (for weaker solar intensity). According to NASA research,
reduced solar activity from the 1400s to the 1700s was likely a key
factor in the “Little Ice Age” which resulted in a slight cooling of
North America, Europe and probably other areas around the globe.
eruptions: Volcanoes can affect the climate because they can
emit aerosols and carbon dioxide into the atmosphere.
emissions: Volcanic aerosols tend to block sunlight and
contribute to short term cooling. Aerosols do not produce
long-term change because they leave the atmosphere not long after
they are emitted. According to the United States Geological Survey
(USGS), the eruption of the Tambora Volcano in Indonesia in 1815
lowered global temperatures by as much as 5ºF and historical
accounts in New England describe 1816 as “the year without a
Volcanoes also emit carbon dioxide (CO2),
a greenhouse gas, which has a warming effect. For about two-thirds
of the last 400 million years, geologic evidence suggests CO2
levels and temperatures were considerably higher than present. One
theory is that volcanic eruptions from rapid sea floor spreading
elevated CO2 concentrations,
enhancing the greenhouse effect and raising temperatures. However,
the evidence for this theory is not conclusive and there are
alternative explanations for historic CO2
levels While volcanoes may have raised pre-historic CO2
levels and temperatures, according to the USGS Volcano Hazards
Program, human activities now emit 150 times as much CO2
as volcanoes (whose emissions are relatively modest compared to
some earlier times).
These climate change
“drivers” often trigger additional changes or “feedbacks” within the
climate system that can amplify or dampen the climate's initial response
to them (whether the response is warming or cooling). For example:
greenhouse gas concentrations:
The heating or cooling of the Earth's surface can cause changes in
greenhouse gas concentrations. For example, when global temperatures
become warmer, carbon dioxide is released from the oceans. When
changes in the Earth's orbit trigger a warm (or interglacial) period,
increasing concentrations of carbon dioxide may amplify the warming by
enhancing the greenhouse effect. When temperatures become cooler, CO2
enters the ocean and contributes to additional cooling. During at
least the last 650,000 years, CO2
levels have tended to track the glacial cycles . That is, during warm
interglacial periods, CO2 levels have
been high and during cool glacial periods, CO2
levels have been low
ocean currents: The heating or cooling of the Earth's surface can
cause changes in ocean currents. Because ocean currents play a significant
role in distributing heat around the Earth, changes in these currents can
bring about significant changes in climate from region to region.
The Last 2,000 Years
During the last 2,000
years, the climate has been relatively stable. Scientists have identified
three departures from this stability, known as the Medieval Climate
Anomaly (also referred to as the Medieval Warm Period), the Little Ice Age
and the Industrial Era:
Medieval Climate Anomaly: Between roughly 900 and 1300 AD,
evidence suggests Europe, Greenland and Asia experienced relative
warmth. While historical accounts and other evidence document the
warmth that occurred in some regions, the geographical extent,
magnitude and timing of the warmth during this period is uncertain .
The American West experienced very dry conditions around this time.
Ice Age: A wide variety of evidence supports the global
existence of a "Little Ice Age" (this was not a true "ice age" since
major ice sheets did not develop) between about 1500 and 1850 .
Average temperatures were possibly up to 2ºF colder than today, but
varied by region.
Industrial Era: An additional warm period has emerged in the
last 100 years, coinciding with substantially increasing emissions of
greenhouse gases from human activities
Prior to the Industrial
Era, the Medieval Climate Anomaly and Little Ice Age had defined the
upper and lower boundaries of the climate's recent natural variability and
are a reflection of changes in climate drivers (the sun's variability and
volcanic activity) and the climate's internal variability (referring to
random changes in the circulation of the atmosphere and oceans).
The ice ages
Precambrian time included almost all of Earth's first 4 billion years. The
crust, the atmosphere, and the oceans were formed, and the simplest kinds
of life appeared.
history of Earth, the climate has changed many times. Between 800 million
and 600 million years ago, during a time called the Precambrian, Earth
experienced several extreme climate changes called ice ages or glacial
epochs. The climate grew so cold that some scientists believe Earth nearly
or completely froze several times. The theory that the entire Earth froze
is sometimes called the snowball Earth. Geologists estimate that Earth
experienced up to four such periods of alternate freezing and thawing.
Most of the time, Earth has been largely ice free. Brief ice ages occurred
about 450 million years ago and again about 250 million years ago. In the
last few million years, however, Earth's climate began to cool. Glaciers
began forming in Antarctica about 35 million years ago, but the climate
there was warm enough for trees to grow until about 5 million years ago.
By about 2 million years ago, at the beginning of a time called the
Pleistocene Epoch, ice had accumulated on other continents as well.
separate ice advances, periods when ice sheets covered vast areas,
occurred during the Pleistocene Ice Age. The advances alternated with
periods when the climate was warmer and the ice melted. Geologists
analyzing sediment deposits from the North Atlantic Ocean determined that
there were at least 20 advances and retreats of ice sheets in the past 2
million years. At least four ice advances were big enough to extend over
much of Europe, cover most of Canada, and reach deep into the United
recent advance of ice began about 70,000 years ago and reached its
farthest extent about 18,000 years ago. The vast glaciers and sheets of
ice scoured out the basins of the Great Lakes and blocked rivers,
completely changing the courses of the Mississippi, Missouri, and Ohio
rivers. So much water was trapped in the form of ice that sea level around
Earth dropped as much as 390 feet (120 meters), exposing parts of the
present ocean floor.
recent ice advance ended about 11,500 years ago. Most scientists believe
that Earth is currently in an interglacial period, and another ice advance
Why ice ages
not fully understand why Earth has ice ages. Most believe that tiny
changes in Earth's orbit and axis due to the gravitational pull of other
planets play a part. These changes alter the amount of energy received
from the sun.
scientists also believe that variations in the amount of carbon dioxide in
the atmosphere are responsible for long-term changes in the climate.
Carbon dioxide, a "greenhouse gas," traps heat from the sun and warms
Earth's atmosphere. Most of Earth's carbon dioxide is locked in carbonate
rocks, such as limestone and dolomite. Earth's climate today would be much
warmer if the carbon dioxide trapped in limestone were released into the
rich in silicate minerals wear down through weathering and erosion,
calcium and magnesium erode from the rocks. These elements are carried to
the sea by water. There, living organisms absorb the chemicals and use
them to make protective carbonate shells. The organisms eventually die and
sink to the bottom to form limestone deposits. This process, called the
carbonate-silicate cycle, removes carbon dioxide from the atmosphere. With
less carbon dioxide in the atmosphere to trap heat from the sun, Earth's
climate may cool enough to cause an ice age.
dolomite deposits exposed to weathering and erosion return carbon dioxide
to the atmosphere and contribute to global warming. In addition, some
limestone on the ocean floor can be carried down into Earth's mantle by
subduction. Beneath the crust, the limestone breaks down into magma under
heat and pressure. The carbon dioxide in the limestone can then return to
the atmosphere during volcanic eruptions.
theorize that volcanoes continued to emit carbon dioxide into the
atmosphere during the Precambrian ice ages. Eventually, the carbon dioxide
warmed Earth through the greenhouse effect, causing the ice to melt
Climate and Health
Climate can have a
profound influence on human health both directly and indirectly. Some
direct effects include deaths and illnesses related to excessive heat or cold
exposure. Indirect effects of climate on health may involve respiratory
disorders due to air pollution, including spores and pollens. Incidences
of waterborne diseases, such as cholera, as well as food productivity and its
relation to nutrition are other indirect effects of climate on health.
Human health is also indirectly affected by climate due to its influence on the
abundance and geographic distribution of disease vectors, such as mosquitoes and
rodents. Several studies suggest projected climate changes may result in
expanded geographic ranges for many mosquito-borne diseases.
Mosquitoes can transmit many viruses, over 100 of which are known to
infect humans. These include malaria, dengue fever, yellow fever, and severe and
sometimes fatal encephalitis and haemorrhagic fever.
Sources: NASA Oceanography, EPA, UNEP, Environment Canada, CDC,U.S.
Fish & Wildlife Service
Data compiled from The
British Antarctic Study, NASA, Environment Canada, UNEP, EPA and
other sources as stated and credited Researched by Charles
Welch-Updated daily This Website is a project of the The Ozooe Hole