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 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?