Megafauna Extinctions

About 13,000 years ago, close to 80% of the megafauna were wiped off the map.  Mammoths, mastodons, dire wolves, giant sloths, and smiledons or sabre-tooth tigers all disappeared.  And Clovis points made by Paleo-Indians cannot be found in dig sites after 13,000.  What caused this mass extinction?

About 13,000 years ago, a climate change occurred, called the Younger Dryas, also known as the Big Freeze.  The weather got colder and dryer for over 1,000 years.  Typically, the megafauna had survived many climate changes over the years, so why was this change so devastating?  Well, it seemed to be rather sudden with temperatures dropping about ten degrees and large dust storms and draught killing off plant life.  What caused the Younger Dryas?

There are two major theories as to what caused the Younger Drysas stadial.  First, scientists argue that the earlier warming period caused a significant influx of freshwater along the St. Lawrence River to the North Atlantic that disrupted the current and conveyor system that moderated the weather.  This could have led to colder weather.  Second, some scientists have discovered nano diamonds and other extraterrestrial evidence in the layers above 13,000 years ago.  They have uncovered fullerenes, extraterrestrial carbon carriers, which were also discovered in the Permian-Triassic layer, which could be evidence of a meteorite or comet that caused that extinction as well as that in the Younger Dryas.  Actually, the second theory could be the primary reason with the influx of freshwater being a secondary reason.

The Wisconsin Glacial Episode technically ended about 11,000 years ago, about the same time that the Younger Dryas ended.  The megafauna had survived significant climate variations during the different ice ages over the centuries, so why did the Younger Dryas lead to extinctions?  The first theory does not provide a good answer, but the second one does.  The megafauna could not survive the rapid changes caused by the comet or meteorite that may have hit.  Where is the evidence of a crater in North America?  Well, since it probably struck the deep ice sheets that covered the northern part of North America, the crater in the ice would have melted.

No Clovis points have been found during the Younger Dryas period.  Folsom points dating back to 9,500 years ago were the next spear heads located in America after the Clovis points.  The 3,000 year gap is difficult to bridge.   The Folsom Paleo-Indians seem to have genetic connections to Asia and the Clovis Paleo-Indians may have a nexus to Europe.  If this is true, the Asian presence either was able to survive the Younger Dryas period or entered North America when the climate improved.  They clearly were the forefathers of the Native Americans that populated North America when the European explorers landed on the east coast.

If you examine the moon, there are hundreds of craters, so it would not be unusual for earth to be the target for numerous comets and meteorites over the years.  Most of these craters have been erased by erosion.  If the meteors were large enough, they could have had a devastating impact on life on earth at that time.

One of these was probably the culprit that caused the extinction of the dinosaurs.  At the Cretaceous-Tertiary (K-T) boundary, when the dinosaurs went extinct, there are large amounts of the metal iridium, which typically is not found on earth, but is found on meteorites.  It is highly likely that a large comet or meteorite impacted earth about 13,000 years ago, causing the extinction of the megafauna.

Stromatolites – Our Ancient Ancestors

Our earliest ancestor was a plant, not an animal.  This most ancient ancestor was a stromatolite dating back more than 3.5 billion years ago or about a billion years after our earth was first formed.   Stromatolites consist of blue-green algae that aggregates, creating layers.  Even though most of our early ancestors have gone extinct, stromatolites still exist today.  A large population is located in the Hamelin Pool in Shark Bay in western Australia.

Stromatolites were the most abundant fossils found in rocks dating to the Precambrian era, from the origin of Earth about 4.5 billion years ago to 544 million years ago.  Stromatolites became prolific starting about 2.5 billion years ago, releasing oxygen into the environment which set the stage for animal life.  Both plant and animal kingdoms diversified over the years, but stromatolites remained the same since they were able to adapt to many environments and did not require diversification to survive.  They formerly existed all over the world, but today they are endangered.

Over billions of years, both plants and animals evolved into large trees and dinosaurs, but there were many mass extinctions that cut off the branches in our family tree.  One of the most widely discussed was the death of the dinosaurs, which occurred about 65 million years ago.  The K-T boundary or thin geologic line representing the end of the Cretaceous and beginning of the Tertiary ages included iridium.  Iridium is found primarily in meteors.  This was strong evidence of when the large mountain of a meteor about six miles wide crashed into the Yucatan Penninsula near the town of Chicxulub in Mexico.

Scientists are fairly confident that this meteor caused significant stress on the dinosaur population, but are not certain if this event could have accounted for the mass extinction by itself.  However, if you examine the effects of the meteor’s impact, it might be sufficient.  The impact set off volcanic eruptions, massive earthquakes, and tsunamis, all sending dust and debris into the atmosphere, where it blocked sunlight for centuries.  This created a nuclear winter with temperatures plummeting.  There were wildfires all over earth, causing acid rain.  This sounds pretty convincing, but there is one more piece to this puzzle.

About this same time, a large volcanic eruption occurred in the Deccan Traps located in the northwestern part of the Deccan Plateau in India.  It may be the largest volcanic province in the world, consisting of more than a 6,600-foot depth of basalt lava flows covering an area of 190,000 square miles.  When the event occurred, some estimates show that 580,000 square miles were impacted.  This would have been a significant event, which when combined with the meteor could have been too much for the dinosaurs.

Some scientists believe that the Deccan Traps eruption occurred first about 66 million years ago, lasting for thousands of years, and then the Yucatan meteor smashed into the earth about 65 million years ago, causing a double whammy which wiped out the dinosaurs.  However, it may be more than a coincidence that the Yucatan impact area is on the opposite side of the world from the Deccan Traps.  If you place your finger of your right hand on the area where the meteor landed and a finger of your left hand on the Deccan Traps on a globe of the earth, these locations are eerily opposed to each other.

I don’t believe in coincidences.  I would argue that the time lines need to be reexamined.  It is more likely that the meteor stuck first, which triggered the great Deccan Flats eruption.  Whether this occurred 66 or 65 million years ago is not known, but it must have been closer in time than scientists believe.

Mammals were able to survive these events and over time, an animal called Homo erectus popped up in the east African rift zone about 2 million years ago.  These hominids were able to stand upright, so we believe that we descended directly from them.  Homo sapiens seem to have entered the scene about 500 thousand years ago, and the subspecies Homo sapiens sapiens, which is very similar to modern man, can be found about 200 thousand years ago.

Our subspecies just barely hung on after the mega-volcanic eruption at Lake Toba in Indonesia about 75,000 years ago.  This was the biggest eruption that we know about during the history of earth, which caused a nuclear winter just like the Yucatan meteor and Deccan Flats eruption.  Our species came very close to being wiped out.  There were only about a thousand of our species that survived this event, which explains why all humans are so genetically similar.  After surviving the ice age, our species started repopulating the earth about 10,000 years ago.

So the bottom line is that Homo sapiens sapiens has not been king of the earth for very long.  In the great scheme of things, we should examine all our ancestors and realize that we are very insignificant in the great scheme of things, not only in the amount of time that we have occupied the earth, but also in our vulnerability to changes.  We have been very fortunate that we are right in the middle of a warm, moderate period, but will we survive the next ice age or cataclysm?  Time is really not on our side.

Tipping Points

Our earth is located in what scientists term the “Goldilocks Zone” because it is “just right.”  If we were not located exactly where we are in the solar system and in the galaxy and in the universe, we probably would not exist.  Extremophiles probably live in hostile environments throughout the universe, but mesophiles, like our species, need a stable and moderate habitat or they cannot survive.

There have been mass extinctions throughout the life of our planet with the Permian extinction having the distinction of killing off the most – about 90% of the species on earth at that time.  Some scientists are concerned that we may be on the brink of a sixth major extinction since plants and animals are dying off anywhere from 100 to 1,000 times faster than they did before humans came on the scene. 

Scientists at Duke University completed a study, published May 29, 2014, in the journal Science, that measured the rate at which species are disappearing from earth.  In 1995, the researchers found that the pre-human rate of extinctions was roughly 1. Now, that rate is about 100 to 1,000.

Stuart Pimm, the study’s lead author, said habitat loss is mostly to blame for the increasing death rates.  As humans continue to alter and destroy more land, animals and plants are increasingly being displaced from their natural habitats.  Climate change is also a factor, he added.

So, with the balancing point of nature being “just right” on our planet, it probably does not take much to tip the balancing scales to one side or the other, which will have devastating effects to those species which cannot adapt in time.

There are many potential tipping points on our planet:  (1) climate change, (2) ocean currents, (3) frozen methane, (4) buried black carbon, (5) permafrost and glacier melt, (6) hydrological cycle, (7) reduced sea ice, (8) draught, (9) bacteria resistant to penicillin, (10) proximity of sun, (11) proximity of moon, (12) volcanic activity, (13) pestilence, (14) movement of asteroid belt, and (15) other things that we may not even see coming, such as black energy and black holes.    

Although global warming focuses on greenhouse gas as the culprit, there are other more significant sources of carbon that would be more dangerous tipping points that would contribute to major climate change that might lead to mass extinctions.  These sources of carbon are black carbon buried in soil, methane frozen in water, and volcanic eruptions.  In fact, the Permian extinction may have been caused by all three of these releases of carbon. 

The most devastating of the three releases may be methane, which has an exponential impact.  As the climate warms, more methane is released.  As more methane is released, it causes our temperatures to go up higher than they would with releases of carbon dioxide.  This melts more methane, causing even higher temperatures with a tipping point being reached with runaway releases like in the Permian period.

Researchers at the University of Wisconsin–Madison, have found that there is black carbon only about six and a half meters below the surface in Kansas, Nebraska, and other parts of the Great Plains where ancient soils are filled with black carbon and plants that have not yet fully decomposed.  These carbon stores could be released into the environment via erosion, road construction, mining, or deforestation.

Erika Marín-Spiotta, a professor at UW-Madison and a coauthor of the study, which was published earlier this week in the journal Nature Geoscience, stated, “It was assumed that there was little carbon in deeper soil.”  Since most soil studies do not penetrate deeper than 30 centimeters, scientists had dramatically underestimated underground carbon reserves that could be released into the air.

Erika explained that carbon reservoirs in buried soils can lurk in a range of environments—under dust accumulation, in floodplains, in valleys, at the foot of slopes of hills and mountains and under lava flows.  She said they are likely to occur in many other parts of the world.

Marín-Spiotta said as much as 5.95 trillion pounds of carbon could be lurking in the depths of the Great Plains area her team looked at.  That’s assuming the ancient soil forms a continuous layer across the region; the researchers were only able to collect measurements from specific points and don’t really know what portion of the region contains the carbon-rich soil.

This giant carbon bomb could be released over the next few decades as we clear cut more forests and see more erosion in draught-prone areas.  We have already seen recent exposure to the atmosphere.  But for the subterranean reserves, Marín-Spiotta believes a number of factors are at work, including how much carbon there really is, how much has persisted since it was buried, and what kind of carbon is down there.

Though Marín-Spiotta says the buried reserves carbon don’t pose an immediate risk to rising carbon dioxide levels in the atmosphere, but land managers need to take precautions, since the researchers found that the ancient soils are more reactive than was previously understood.

As with all tipping points, there can be multiple contributors to the final point of no return.  And these contributors can have exponential effects on each other.  We probably will not know when we have reached the tipping point, but our ancestors will not only know when that tipping point had been reached, but will also suffer the consequences.

Weather or Not, There Are Climate Changes

Some scientists argue that climate changes occur in cycles, not necessarily the result of temporal weather patterns.  For example, we had a series of vicious winter storms that struck the eastern United States in 2013-14.  On one day, all fifty states had snow.  This weather is not indicative of a climate change, by itself.  It may have been an anomaly.  So you may have bitter cold weather patterns interspersed during a warming climate change.

However, there may have been some interesting reasons for the unusually cold winter.  Typically, a Polar Vortex circling in Canada and the Arctic area, keeps frigid air north of the United States, but when there are unusual warming trends in the climate, this could disrupt the Polar Vortex, breaking it down, allowing cold air to drop into the deep southern states.

Many scientists now believe that man’s burning of fossil fuels has triggered a climate change that may be locked in and cannot be reversed.  Once the climate is tipped into a new direction, there are forces that not only continue down that path, but many times can accelerate it.  For example, the drought conditions in the southwest create more forest and grass fires, which, in turn, cause more soot to carry to the poles, causing “dark ice,” which causes accelerated melting of the ice. 

As the air and oceans warm, the most dangerous consequence awaits us in the cold depths of the ocean.  Methane ice is frozen at great depths, but it only takes a few degrees of warming of the ocean to trigger the thawing of the methane gas, which would create a global warming scenario hundreds of times worse than what man can cause with fossil fuels.  This warming of methane in the oceans may have been what caused the Permian extinction.  Once the blanket of methane covered the earth’s atmosphere, we would move quickly into a Global Winter for decades with most plants and animals dying off.

The new normal with our climate will be its extremes and unpredictability.  We will have more intense storms, more mega droughts, more ice storms, more tornadoes, more hurricanes, more flooding, more fires, more snow… more extremes in weather.

The Arctic has been our bellwether for climate changes, and it clearly points to climate change that is here to stay.  The ice is melting at a rapid rate.  Greenland is losing 300 billion tons of ice each year.  The Inuit hunters are not finding wildlife along the ice pack near their home because the ice edge is moving further north away from them, causing the walrus and seal population to move north too.

There is a theory that the ocean currents are being impacted by the new climate change, so that normal warming from equatorial waters, being carried north and south, is also being interrupted.  This disruption of warming currents and the methane melt could combine to cause our world to go into a deep freeze.  It sounds strange, but global warming may actually be the trigger for the next ice age.