Desertification, is the degradation of a productive, lush environment into dry, dry desert. Great
for MarioKart and alien planets in movies, but terrible for growing food.
Planet Earth is a constantly shifting landscape of 8 biomes, ranging from rainforest to grassland,
desert to taiga. Twenty-two thousand years ago, the Sahara was pretty much uninhabited,
except for the area around the Nile Valley. 10,500 years ago, monsoon rains rolled in
to wet it up. Climates change, it happens, and sometimes they change hella dramatically…
like when whole deserts completely shift their borders… which is happening RIGHT NOW.
Only a few thousands years ago, the Sahara was green and lush, and now we can't even
IMAGINE it… instead, research has found the Sahara's shifting sands are expanding,
causing die-offs of vegetation, failure of agriculture, and increased erosion without
plants to hold the soil in place. But this wasn't always the case. Scientists had hypotheses
that an ancient river ran through the Western Sahara, feeding the land and securing it with
vegetation. Clues were left off the coast of Mauritania, where researchers found sediment
resembling that of a huge river… but there was no river around, only arid sands. They
called this ancient waterway the Tamanrasset and now, according to a recent study by the
Japanese Advanced Land Observing Satellite, it's real! And was confirmed recently using
microwave radar. If it were still there, the Tamanrassat river would be the 12th largest
on Earth, winding 300 miles inland (500km) to the Mauritanian coast.
As the researchers point out, climate change happens fast. In a study in Earth and Planetary
Science Letters researchers looked at 30,000 years of dust blown from Africa into the Atlantic.
Over the millennia the amount of blown dust rose and fell in lockstep with the amount
of moisture on the continent; less moisture, more dust, more moisture, less dust. Today,
because it's so dry, the majority of the sediment in the Atlantic is from Saharan dust! It can
(and does) reach North America! By looking at this dust, they know about 6,000 years
ago the African Humid Period ended suddenly, coinciding with an axial change in the Earth's
ORBIT. According to research from NASA and climate scientists, the Sahara exists, in
part, because the Earth's spin changed, decreasing Northern Hemisphere monsoons, and causing
the Sahara to grow. Vegetation died very quickly and the third largest desert in the world
took over North Africa, all in less than 300 years! In a separate study in the journal
Science, one of the jet streams which moves hot dry air across the planet's Equator, has
shifted northward, causing the tropics to expand 140 miles northward in the last 26
years; and with it… the deserts of Earth. Why? They're not sure, but they know global
warming is part of it, as is the ROTATION OF THE EARTH.
In the movies, when a wizard summons a massive storm, the storm dissipates at the moment
of his defeat. In reality, when we make huge changes to the Earth's climate, those changes
are not felt, or easily reversed across multiple human lifespans. According to NASA's Jet Propulsion
Laboratory, the melting of Greenland ice is changing the way the Earth spins, changing
the tilt of Earth's axis by 2.6 centimeters per year, with an increase in that tilt on
the horizon! Why is the ice melting? You need only look in a mirror. We live on a spinning
top, and we're messing with the balance.
SO WHAT DOES ALL THIS MEAN? To put it simply, as the distribution of ice and water on the
planet changes, the Earth's axis changes in a process called precession. Thus, the sun
will hit different latitudes our planet at different intensities than before -- drastically
changing the weather systems and our overall climate. Whether it's natural or man-made,
the jetstream is already shifting causing the tropical deserts to expand into previously
lush territory (as we know it has done in the past), but scientists don't believe this
is a natural phenomenon, it is happening WAY too fast, and the rates are increasing…
we're doing this.
As desertification hits the American plains, South Asia, and the Mediterranean, humans
feel the affects through drought, climate changes, and, eventually, economics. In a
2005 report about desertification from United Nations University, they state 10 to 20 percent
of these "drylands" have been negatively impacted through the loss of farmland and biodiversity.
That was a decade ago, and at the time, 2.1 billion people lived in the drylands of our
planet. It's clear, the deserts have, and will expand, and as they continue to do so,
farmland will dry, vegetation will disappear, and people will either have to move, or completely
alter their lifestyles.
Now, if you're thinking, "But Trace! The ocean is FULL of water! Let's just use that! You
can't. Julian explains why we can just turn saltwater to freshwater, here. (soundup)
REGULAR DNEWS CTA There are lots of little things that we can
all do to curb climate change - check out RacingExtinction.com where you can learn about
things like the five day carbon challenge. Challenge your friends, your family, strangers,
and most importantly, yourself. There's a ton of way you can do to make difference out
there. Thanks for watching!
Have you felt the pinch of climate change? How?