Cosmic Journeys – HyperEarth


Our world, Earth, is changing before our eyes. Go back millions of years. Forests reached
into polar regions, sea levels rose, and temperatures soared with high levels of the greenhouse
gas, carbon dioxide. A long cooling period followed. But now CO2
is on the rise again. What will happen? How will we live in the New World that’s now emerging? Scientists are intensively tracking the workings
of planet Earth with satellites that chart its winds, ocean currents, temperatures, plant
growth, and more. And with a new virtual Earth, shrunk down and converted into physical equations,
satellite data, and computer codes. This other Earth, a mirror of the one in which
we live, is designed to follow the flow of heat through the complex, dynamic engine known
as the climate, and to predict its future evolution. You can see the pattern of heat input in this
sequence showing surface temperatures. As the seasons shift, heat builds and dissipates,
most notably across tropical and subtropical regions. How does Earth dissipate this build
up of heat? Look below. The oceans cover 71% of the planet’s surface,
at an average depth of more than four kilometers. They act like an immense battery that can
store and release energy over long periods of time, while transporting heat from warm
to cool regions. The oceans are set in motion by the unevenness
of solar heating, due to the amount of sunlight striking the tropics versus the poles, along
with the cycles of day and night and the seasons. That causes warm, tropical winds to blow toward
the poles, and cold polar air to push toward the equator. Wind currents, in turn, drive
surface ocean currents. This computer simulation shows the Gulfstream winding its way north
along the coast of North America. This great ocean river carries enough heat
energy to power the industrial world a hundred times over. It breaks down in massive whirlpools
that spread warm tropical waters over northern seas. Below the surface, this current mixes
with cold deep currents that swirl around undersea ledges and mountains. When heat builds
within tropical oceans in late summer, it can be released in a fury. Here is a simulation of surface winds beginning
on September 1, 2012. In that year, the Atlantic Ocean spawned 19 named storms. These and other
smaller storms churned up a steady stream of moisture that traveled north aboard immense
gyres of wind that circle the oceans. Hurricane Sandy took shape over the Bahamas
on October 22nd. Moving north over the open sea, it intensified within unusually warm
Gulf Stream waters. Up along the New Jersey coastline, Sandy was slowed by a dome of high
pressure to the north. That caused it to turn sharply west into an advancing cold front.
The combination brought damaging winds, heavy rain, death, and a trail of destruction estimated
at 68 billion dollars. Recent studies predict that as the oceans
continue to get warmer, they will release their heat in ever more powerful, and more
frequent storms. As this virtual planet shows, Earth’s climate engine has a dazzling array
of moving parts: wind patterns and sea currents, tides and terrain, that together help equalize
temperatures around the globe. There’s something else at work on our planet. When sunlight bounces off the earth, water
vapor and cloud droplets absorb some of the energy in the infrared portion of the spectrum,
transferring it to the rest of the atmosphere. A recent NASA study predicted that if water
vapor were the only greenhouse gas, temperatures would fall, sending Earth into an icebound
state. Something is needed to act as a thermostat,
a control knob, to keep the climate steady. Though it’s only .038% of the atmosphere,
carbon dioxide absorbs enough energy to prop up global temperatures and allow water to
remain in the atmosphere. It’s the settings on this thermostat that
are now changing. Since the industrial revolution, the amount of CO2 in the atmosphere has increased
nearly forty percent. Thanks to our vantage point in space and our
virtual tools, we have a wide-angle view of the New World that’s emerging. However, causes
and effects are often jumbled in complex ways. This sequence features a simulation of aerosols
in the atmosphere, fine particles from volcanoes, fires, dust storms, cars, factories, and more.
These particles can have an impact on health, as well as the overall climate. Some particles, like sea salt, reflect sunlight
back into space. Others, like soot, absorb heat and warm the atmosphere even as they
shade the Earth from solar rays. Add in fires on the surface, detected by satellites
and shown here as red dots. They are major producers of carbon soot. They are also a
catalyst for change in a warming world. Increased CO2 and warmer weather will bring more rain
and vegetation to some places. In others, they’ll turn forests into tinderboxes. Flash forward a century. How will Earth look
to us then? Will we, its supposed masters, find ways to manage it? Or will we let it
slip from our grasp?

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