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Earth System Climate Change Script

Introduction Blue Marble

Earth System (atmosphere) Real-time Satellite

(hydrosphere) Ocean Currents

(cryosphere) September Sea Ice

(biosphere) Seawifs

Climate Change Carbon Tracker

Ocean Acidification

IPCC Temp Change GFDL

Closer Night Lights

**Introduction:**

Blue Marble

As viewed from space, the Earth is both beautiful and complex. And, it's
changing! It's hard to understand all of the changes without considering
the Earth as a single, interactive system. The focus is often on rising
temperatures and global warming, but so much more than that is changing.
There is the domino effect in our fragile Earth system, and when one
factor such as temperature changes, everything else is affected, too.
So, instead of just focusing on temperature, let's look at all aspects
of the Earth system and how they are affected by climate change. The
whole Earth system can be visualized as a series of spheres: the
atmosphere, the hydrosphere, the cryosphere, and the biosphere.

**Earth System**

Atmosphere -- Real-time Satellite

Our first sphere is probably the most familiar to you -- the atmosphere.
The atmosphere's effect on our daily lives is obvious; this is where the
weather happens. See if you can find where you live on this sphere. This
is a real-time satellite loop from the past thirty days. Clouds in this
dataset are represented by the white shading. The tallest, thickest
clouds show up bright white and the lower clouds are shades of gray. The
tall, thick clouds typically bring rain and storms. Has it been rainy or
cloudy or sunny in your area? How do you think rising temperature will
affect the atmosphere? We know it will get warmer, but what about the
weather? Will your area become wetter or drier? Will hurricanes occur
more often and become stronger? The questions of climate change
certainly affect more than just rising temperatures. Many of these
questions can't be answered when you consider just the atmosphere.

Hydrosphere -- Ocean Currents

We can start to find some answers in the next sphere -- the hydrosphere.
The hydrosphere contains all water found in, on, and over the Earth,
including rivers, lakes, oceans, and even water vapor in the atmosphere.
The ocean is the major element of the hydrosphere. It is not just a
still body of water, but is constantly in motion, as seen here. The
color-coding in this animation represents the speed of the water. The
green areas are fast moving currents. The currents can be traced all the
way around the globe and provide a good picture of how our oceans are
globally connected. As the air temperature is rising, the ocean
temperature is rising as well. This affects us in more ways than you
might imagine. Higher ocean temperatures can fuel stronger hurricanes.
Hurricane Katrina experienced major intensification as it crossed the
warm Loop Current in the Gulf of Mexico. Higher temperatures can also
cause the sea levels to rise through expansion of the water and the
melting of glaciers and ice sheets. How high will the sea levels rise?
How much ice is melting? Just how warm is the ocean going to get? Again,
we can't begin to answer these questions without considering the other
components of the Earth System.

Cryosphere -- September Sea Ice

Monitoring changes in the cryosphere can be a good indicator of climate
change. The cyrosphere is the portion of the Earth's surface where water
is in solid form -- snow cover, permafrost, sea ice. Global warming is
amplified in the cryosphere. What you see here is the sea ice
concentration in Septembers from 1987 through 2007. September is
typically the month with the least amount of sea ice in the Arctic
Ocean. As we move forward in time, you can see the sea ice coverage
decreasing. In fact, 2007 was a record breaking year for the minimum
amount of sea ice measured since 1979, when the satellite record begins.
According to the National Snow and Ice Data Center, sea ice in 2007 was
39% below the long-term average from 1979 through 2000. It's a bigger
problem than just ice melting. Because ice is bright white, it reflects
sunlight back to space. On the other hand, oceans are dark and absorb
the sunlight, causing them to warm up. As the sea ice melts, we have
more ocean area to absorb sunlight and less ice area to reflect
sunlight. This translates into rising temperatures, which can in turn
speed up the melting of the ice. So just how fast is the ice going to
melt? And who is being affected by melting ice and changing ocean
temperatures? We can begin to answer the question of "who" by moving on
to our last component of the Earth System.

Biosphere -- SeaWiFS

The biosphere is the part of Earth including air, land, and water where
life occurs. One way to measure the life in the ocean is to use SeaWiFS,
the Sea-viewing Wide Field-of-view Sensor. The sensor is attached to an
orbiting satellite and provides a full global picture every 48 hours.
The sensor is set to detect chlorophyll concentrations, which can be
used to determine the concentration of phytoplankton. Areas that have a
high concentration of phytoplankton typically have abundant sea-life.
Greener water here signifies an abundance of phytoplankton, while bluer
water indicates less. The lands are shaded to depict the vegetation.
Green areas on land have abundant vegetation, yellow areas have little
vegetation, and brown areas have no vegetation. Notice how the areas
near the Poles have abundant life in the oceans while most of the
Atlantic Ocean is barren. The biosphere is important for several
reasons. First, it tells us about the density of life in different
locations. If the coldest areas in the oceans are the most productive
and the temperature is rising, how will that affect life in the ocean?
Second, the biosphere plays a major role in the global carbon cycle.
Plant life on land and in the ocean absorbs carbon dioxide, which of
course is a major player in climate change. But how will plants react to
rising temperatures and how will this affect their ability to absorb
carbon dioxide?

**Climate Change**

CarbonTracker

One tool that is helpful for understanding carbon dioxide in our
atmosphere is NOAA's CarbonTracker, a program that keeps track of carbon
dioxide uptake and release at the Earth's surface over time. The
complexity and connectivity of the Earth system is apparent in the
global carbon cycle. The largest variations in carbon dioxide
concentration from season to season are due to the plant life. On this
map, areas that are red are producing carbon dioxide and areas that are
blue are absorbing carbon dioxide. During the winter season, plants and
trees respire carbon dioxide as they shed leaves and stop growing or
decay, adding carbon dioxide to the atmosphere. This process reverses
during spring and summer when the plants have plenty of access to
sunlight and grow leaves and flowers and absorb carbon dioxide. The
large change in carbon dioxide between the seasons caused by plant
activity is sometimes referred to as the \'breathing\' of the planet. In
the tropics, intense red areas are visible especially during July,
August and September. This is due to the burning of biomass. Some of
this is natural, such as dry grasses on the savannas burning, but most
of it is man-made as people burn fields to prepare them for another year
of production, or burn forests to make way for new agricultural lands.
This really shows that our actions do make a difference. Each of the
circles represents a location where a NOAA collaborator is collecting
samples of air to help NOAA monitor the levels of carbon dioxide and
other greenhouse gases. This is an important step in understanding how
our Earth system is changing. As we learn more about our Earth system,
we will be able to answer more of our questions.

Ocean Acidification

Here is another example of the connectivity of the Earth system. Most
people are aware that the temperature has been slowly rising for a long
time. But did you know that the ocean's carbonate chemistry has also
been changing for a long time? This model starts in 1765 and shows the
changes in the ocean's acidity through 2100. The increase in carbon
dioxide in the atmosphere affects the ocean's chemical makeup, causing
it to become more acidic. Blue areas are more acidic, while red areas
are more basic. The acidity of the ocean is important because calcium
erodes at lower pH levels, and there are many organisms with external
calcium carbonate skeletons, such as corals and pteropods, in the ocean.
As the acidity of the ocean increases, there will be fewer areas where
corals can survive. The stars represent the presence of corals in the
oceans. The black stars are shallow corals and the magenta stars are
deep corals. The loss of corals would be more significant than you might
think. Corals serve as habitats and are considered to be one of the most
diverse ecosystems in the world. As you can see, climate change
certainly affects more than just the temperature!

IPCC temperature model

But it is important to consider how the temperature is going to change.
There are many differing opinions on climate change. To help combat
this, a worldwide group of scientists came together and formed the
Intergovernmental Panel on Climate Change. Their goal is to assess
information relevant for the understanding of climate change, its
potential impacts, and options for adaptation and mitigation. They have
employed several models that forecast the temperature change based on
increasing carbon dioxide. This one was produced by the Geophysical
Fluid Dynamics Lab at NOAA. It starts in 1870 and goes through 2199. All
temperatures are compared to the year 2000. Blue represents areas that
are colder than the year 2000 and red represents areas that are warmer
than the year 2000. Carbon dioxide increases through the period and then
levels off at 717 ppm in the year 2100, which is double the carbon
dioxide concentration in the year 2000. Even after carbon dioxide stops
increasing, the temperature continues to increase. This model predicts
an 8.8°F increase in North America and a 5.2°F increase globally. The
global increase is lower than the North American increase because the
oceans are not expected to experience a temperature increase as large as
that over land, which lowers the overall global increase. This is
because it takes a lot more energy to increase the temperature of a deep
layer of water than it does to increase the temperature of air. These
temperature increases might not sound devastating, but they are
certainly enough to further propel the changes that we are experiencing
in our Earth system.

**Conclusion**

Earth at Night

There is no denying that our Earth is changing. There are still
countless questions. How will this impact our lives, or our
grandchildren's lives? Who is to blame? Can we do anything to slow or
stop climate change? Understanding the Earth system and how each part
affects the others is an important step in understanding this problem.
The human impact on the Earth is visible here. At night, it's especially
apparent how highly populated the globe is. 6.7 billion people live on
Earth and each person has some impact on the whole Earth system,
including the atmosphere, the hydrosphere, the cryosphere, and the
biosphere. You can't ignore any one of these in the discussion on
climate change.