The Sixth Mass Extinction


Off and on the last month, I’ve posted about various issues on climate change and related topics.  Today, Life Science published an article entitled “Extinction Rates Soar to 1,000 Times Normal (But There’s Hope)”.  What causes this enormous spike?  You guessed it.  Humans.

Before recently, the extinction rate was one per every ten million annually.  Now it is 100-1000 every million.  Where do researchers and scientists find hope in this adverse increase?  Let’s look at Earth’s history for a moment before answering that question.  Since life began on our planet, five mass extinctions have occurred, leaving only half of living organisms each time.  Reasons for these extinctions vary from Earth’s shifting axis to asteroids–see previous posts related to effects of changes in the Earth’s axis.  The big question:  how do humans affect the current extinction?       Yes, we caused the demise of the passenger pigeon, the Tasmanian tiger, and the dodo bird.  And human poaching and habitat destruction now endanger elephants, rhinos, and all subspecies of tigers, among others.  One problem in accurately determining human effects is that new species are discovered annually so we are not even sure how many species currently exist.  Using what we do know about current species, DNA, and some rather sophisticated techniques, scientists come up extinction rates.

Where is the hope?  The most endangered species tend to range in small areas in poorer countries lacking resources to protect them.  Modern technology can help, using satellite imagery, biodiversity mapping, as well as other methods.  Drones have been used in Africa to track both animals and poachers.  We can focus efforts on the areas where the most endangered species live.

How can you help?  Become a citizen scientist.  Use your smartphone camera and report your findings to scientific conservation groups.  A site called iNaturalist allows ordinary individuals to upload photos of plants and animals, tagging date, location, etc.  This site links to an international organization that tracks endangered and threatened species.

What else can you do:  don’t buy anything with ivory in it, don’t buy anything with the fur or body parts of endangered animals.  Spread the word.  Become more informed, read articles and books related to these topics.  Care.  This is the only Earth; help save it.

 

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Apocalyptic Planet-Part Six: Cold and Ice


In spite the current global warming, Earth’s past and perhaps distant future is ice.  This past winter, much of the Midwestern and Eastern United States thought it had already returned.  A friend, forced to attend a mandatory training session, reported that the trainer from Minnesota made fun of those who claim we are warming.  Even though it was March, Minnesota remained a frozen land.  I kept thinking to myself, wait until the heatwave hits this summer.  Then what will he think.

Craig Childs likes adventures most of us would avoid even if we feel rather adventurous.  He flies into a camp in Greenland where scientists, all men, study ice.  Ice does not encourage a lot of life.  No animals, no plants, nothing here–the Greenland Ice Sheet.  The weather remains dreadful most of the year.  On the few days when they can leave camp, these scientists go out to take readings on remote sensors stuck in the ice.  These sensors enable them to determine how the ice changes.  They get to the camp by ski plane during the windows of clear weather which sometimes do not occur for days.  What kind of scientists go here?  Physicists, chaos researchers–yes there is such a thing as chaos research, climate change scholars, ice climate researchers, and an occasional adventurer.  The chaos guy’s interests focus on what cannot be predicted.  He records creaks, snaps, ice sounds.  These giant glaciers emit considerable noise.

This Greenland Ice Sheet is nothing like the ordinary ice we think of.  It’s dry and hard.  Shovels do not work very well.  They use chisels to break off big chunks.  The wind shrieks over the ice, sometimes at 80 miles per hour. It is twenty below in the summer.  Not twenty below Fahrenheit, twenty below Celsius.  To urinate, a guy has to wear parka, mittens, the works, and goes out to the pee pole far enough from camp not to contaminate the drinking water made from melted ice.  Now and then some poor bird gets lost or blown off course.  They don’t last long usually.  Here holes drilled find bedrock thousands of feet below the ice sheet.  One drill came up with spruce tree needles.  Once this very same location was a forest.  Greenland was green!

What happened?  One driver is solar radiation changes caused by the earth’s tilt.  Over tens of thousands of years, Earth swings away from the sun and then back.  These are nearly imperceptible changes.  It takes only a little.  The opening and closing of the Bering Strait also affects climate change.  Current warming aside, Earth’s recent past  (the last 60 million years) is an ice age, partly caused by teutonic plates moving and mountain building which reduced carbon dioxide in the atmosphere, making it colder.  All this points to human behavior as a factor in the current change to warmer. When Childs asked these scientist if they thought another ice age was on the way, they all laughed.  One noted that change in and of itself is unpredictable.  As one of my students might say, “Duh!”  On its own Earth makes quick climate jumps.  They did make a point to say , “We are tinkering to the point we could initiate a jump on our own.” Some computer models say global warming can lead to another ice age by disrupting climates.  One scientist indicated that humans may be preventing or delaying the next ice age by warming the earth.

Who knows what the future may bring even one thousand years from now.  In the long distant past the entire Earth was covered with ice.  At other times the poles were forests.  Maureen Raymo, a paleoclimatologist at Columbia University says, “My feeling is that there is never going to be another ice age as long as there are humans on the planet.”  Some scientists think we will develop a technology to control the level of carbon dioxide in the atmosphere.  Raymo notes, “If they (meaning humans) were smart, they’d get their act together.”

Apocalyptic Planet-Part Five: Civilizations Fall


Whether it is my innate ambition, something my parents instilled in me, or something else unknown, I try to learn something new every day.  Craig Childs starts this chapter of his book by talking about a Phoenix landmark.  Back when I travelled to Phoenix regularly, I knew this place as Squaw Peak.  Now its name Is Piestewa Peak.  The name change is probably a good thing.  I never knew before reading this how dreadfully pejorative the word squaw is.  Basically, it means Indian bitch as well as other things related to the privates of women.  All languages seem to possess an accumulation of dreadful words geared to putting women down one way or another.  Slang words for the private parts of a man rarely mean anything pejorative, at least not that I know of.  The new name, a Hopi name, a blessing word, is a word that calls water to this place.  Not a bad idea in Phoenix or most of the Southwest for that matter.

The name Phoenix fits.  Underneath modern day Phoenix, an ancient city lays buried, a quite sophisticated city with ball courts, temples, irrigation canals.  This city existed at least a thousand years ago.  Its inhabitants grew corn, cotton, beans, and agave.  Farmers, hunters, carvers, all sorts of artisans and merchants apparently lived there.  Now they are called Hohokam taken from an O’odham word meaning “ancestors”, the “ones who have gone”.  We find forgotten cities all over the world, Palmyra, Machu Picchu, Angkor Wat.  What causes these sophisticated civilizations to fall?  If you read a bit, look further, you find common themes:  environmental decay, resource depletion, conflict, disease, social problems.  Angkor Wat fell because it could not maintain its complex irrigation network.  Ur in Iraq fell because a drought caused its port to dry up.  Usually, the demise of particular civilizations occur over time, e.g.Rome.

Childs notes that human patterns often follow animal patterns, or at least mammalian patterns.  For example, when over population occurs, behavior changes.  Parental care and cooperation become replaced with aggression, violence, competition for resources, dominant behaviors.  These types of behaviors are particularly detrimental to females and the young without whom the society (or animal population) cannot replace itself.  Generally, in animal populations, when this occurs, reproduction slows for several generations and the imbalance corrects itself.  For humans, it is not so simple.  Hohokam bones indicate mass starvation and malnutrition.  Other civilizations, e.g. the Anasazi, seem to have disappeared without a trace.

Today, most of the world’s largest cities have immense infrastructures that keep them going, miles of underground sewage tunnels, water mains, etc.  Here in the US in our oldest cities, much of what we take for granted is very old and deteriorating.  New York City and Chicago have water main systems that some experts claim are near collapse or at the very best badly in need of repair.  Doubtless such conditions exist in old cities throughout the world, most of which are much older and larger than the majority of cities in the US.  Yet, they continue to prosper.  Have we passed a point when civilization cannot fall?

Childs completes this discussion by describing his visit with his wife to Guatemala.  They visited all the best known Mayan sites, visited with natives.  His wife managed to get invited to a Mayan fire ceremony, a renewal ceremony.  History books tell us the Mayan civilization is dead, ended.  But it is not.  The Mayan culture still exists.   At least six million still live in the Central America.  What would have happened to Mayan cities if the Europeans had not brought epidemic diseases and better fire power?  We will never know, of course, but no matter how many civilizations rise and fall, change continues and humans continue to inhabit the earth.

The new question is this:  can this planet we live on sustain the ever increasing numbers of humans who inhabit it??

Apocalyptic Planet–Part Three: Ice Collapses


It may be difficult for some to believe, but over the last three million years ice dominated earth’s climate. We remain in that long ice age; widespread glaciers still exist.  For most of earth’s long, long existence no ice existed anywhere.  Currently, we are in an interglacial period in which ice has retreated back to the poles and the highest mountain reaches.  Earth as we know it has been shaped primarily by ice and to a lesser extent by volcanoes.  Once ice lay hundreds of feet deep as far south as Chicago and London.  What caused this see saw between Ice Ages and warm, wet periods where the ice retreated or disappeared entirely?  The changing tilt of the earth’s axis. Currently, the earth’s tilt is 23.5 degrees or so.  This tilt causes the seasons in non tropical areas.  Earth’s tilt changes a degree or so over time, causing the alternating periods between extreme ice coverage and warm periods.  At times the change has been so great that no ice remained even on the poles.  Usually, these changes are very slow, over thousands of years.  No longer.

Equatorial glaciers once common in the high equatorial mountains, e.g. Andes, Himalayas, a century ago no longer exist.  Ernest Hemingway once described the glacier on Kilimanjaro as “wide as all the world”.  Now nothing but a few patches of hard snow remain.  The once giant ice fields in northern Patagonia in Chili and Argentina currently lose volume at an ever accelerating rate.  While hiking and kayaking with a filming crew in this area, Childs saw just how rapidly this ice loss occurs.  In one instance a huge ice lake run off from one glacier totally disappeared in two weeks.  In Greenland an iceberg four times the size of Manhattan floated off in 2010 and finally melted in the Gulf Stream.  It narrowly missed shipping lanes and offshore oil wells.  The Larsen B ice shelf in Antarctica the size of Yosemite National Park and 700 feet deep had been stable for more than 12,000 years.  It started coming apart over a decade ago.  It eventually floated off and melted.

Why does any of this matter?  Ice keeps the planet cooler.  Solar radiation bounces off into space.  Currently, ice reflects approximately 30 per cent of incoming sunlight.  Few present animals and people are prepared for the hothouse that would exist if much more ice melts.  This is in spite of the fact that radiation from the sun has actually gone down in the last fifty years.  As the planet warms, more ice melts, more heat remains on earth, more ice melts and the cycle continues.  The current acceleration of ice loss causes many scientists to question:  where is the tipping point?  How can we stop this rapidly accelerating ice loss?

Humans are increasing carbon dioxide levels ten thousand times faster than they changed over the last 65 million years.  Our globe is warming; all climatologists agree.  At what point will it be too late to turn this around?  Indeed, can we turn this around?  And if we do, will some of the ice return?  No one knows.  Nothing like this has occurred before in human history.  All this melting ice causes sea rise.  At the current rate a one meter sea rise by the end of this century is plausible.  Many of the world’s largest cities already have a sea level problem e.g.Bangkok.  Furthermore, the water supply for much of southern and southeast Asia depends on water from rivers and glaciers in the Himalayas.  The world’s largest supply of fresh water depends on this system.  Are we ready for a hotter, drier earth?

Apocalyptic Planet-Part Two: Hadley Cells, Weather and Drought


Hadley cells, the wind systems in each hemisphere , form patterns of atmospheric circulation in which warm air rises near the equator, cools as it travels poleward at high altitudes, sinks as cold air, and then warms as it travels back to the equator.  They are named after George Hadley, an English scientific writer.  Tropical regions receive more heat from solar radiation than they radiate back to space and such areas have constant temperatures.  More simply, warm air rises (heat rises) and then flows poleward at high altitudes, cools, drops, and flows back toward the equator at lower altitudes.   Then the process repeats itself.  When the air rises and leaves these tropical areas, it loses moisture as it heads to subtropical areas.  The majority of the worlds large deserts lay in these subtropical areas.

Hadley cells are expanding.  Precipitation has declined in tropical areas since 1970.  As I mentioned in yesterday’s post, Southern Asia, the Sahel, Southern Africa, the Mediterranean, and the US Southwest are getting drier and drier.  Even wetter areas now experience long dry spells between extreme events of rain and snow.  Examples in the US include the cold and snowfalls in the Midwest and Eastern Seaboard this past winter.  Texas and New Mexico continue to experience a prolonged drought.  In the next thirty years scientists predict a 30 per cent decline in water resources.

In some places both governments and individuals create innovative and sometimes simple measures to counteract desertification.  In India near the Thar Desert, the government mandated the dispersal of grass seed to hold the ground.  Studies indicate that the grass seed grew better when planted by hand than when dispersed from airplanes.  Also in India orans, small sacred groves, have helped preserve shrubs and grasses and even trees, a genetic bank that would otherwise have been lost.  Childs describes how his friends who live on the outskirts of Tuscon have coaxed their water table fifteen feet higher, using ordinary shovels and hard work.  They built contour traps and “massaged” the ground.  Hardly worth noticing except when it rained, the rain sank into underground catches.  Their properties now look like small areas of refuge in the vast desert.  In some areas of the Sahel people have been able to plant and nurture trees in such a way that areas of green exist where they had disappeared.

Archeologists and geologists know that periods of drought occurred repeatedly for millions of years.  For humans and the animals we know, drought has never been easy.  Large areas of civilization cannot exist without water.  We can affect our future in positive ways and prepare ourselves if we choose.

Apocalyptic Planet–Part One


Usually I read only one book at a time.  Lately, I am reading several, one of which is Apocalyptic Planet:  Field Guide to the Future of the Earth by Craig Childs.  Childs is a sort of combined explorer/adventurer/scientist.  He goes to places few go to see what occurs there, the wind, the flora and fauna, the weather, the climate.  The next couple of days I intend to share some of his most pithy observations and ruminations.  We will start with the desert.  He and a friend literally wandered around the most arid and hostile portion of the Sonoran Desert in northwestern Mexico.  This desert has enlarged and become more arid due to an extended drought.

Deserts come and go.  If you live in a lovely lush green landscape, wait long enough and it, too, may become a desert.  Six thousand years ago lakes, marshes, and grassland lay where the Sahara is today.  A slight orbital change in earth’s relation to the sun caused nearby oceans to heat up, changing atmospheric conditions.  Humans living there had no choice but to move.  Forty per cent of the earth’s population lives in semiarid regions.  Even a small drought changes survival chances for the people who live there.  The Sahara, the Gobi, and the Taklimakan are growing, arable farmland decreasing.  Vulnerable areas include southern Spain, Greece, Bolivia, Australia, central Asia, and our own West.  The entire American High Plains (I live in the southern part) sits on top a giant desert.  Without pivot irrigation, only grass grows here.  In the last decade many irrigation wells have dried up or gone too saline.  The giant bulges you see in places like the sand hills of Nebraska are really a sand dune sea covered with grass.  Take away a little rain and here comes the desert.

Childs and his friend carried water with them and buried them with markers in the sand so they could find them later.  As the desert grows in parts of India, women carry water farther and farther, an average of six miles a day, four gallons at a time.  In the Sahel just south of the Sahara a difference in rainfall of just an inch or two can mean the difference between survival and starvation.  Without water, there is no civilization.

What causes these changes?  Human behavior and the increase in greenhouse gases are  part of the reason.  Humans are creating enough changes that we are moving toward more deserts, not fewer.  One climate expert, Jonathan Overpeck, thinks we are seriously underestimating the severity of drought we will face in the not so distant future.  Forget five and seven year droughts and think fifty years.  Hadley cells also affect climate change.  Tomorrow I will explain Hadley cells and how they affect our weather.

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Northern Arizona

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Eastern New Mexico

 

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Texas Panhandle

Blackwater Draw-Part Two


The ancients hunted here at the shores of a lake

nearly 12,000 years ago.  In 1929, an amateur

archeologist discovered an ancient spear

point lodged in bone.  I walk the mile long trail

down into the depths.   Caliche, gravel,

larger rocks strewn by millennia.  For

thousands of years Clovis, Folsom, and Portales

Man left remnants of their hunting life.

The scattered cottonwoods whisper in the wind,

timeless voices call me, beckoning.

Who were these people?

What did they look like?

Where did they come from?

In whose gods and goddesses did they believe?

Doubtless hunger drove them to this place of water

and plenty.  Columbia Mammoths, giant sloths, dire wolves,

saber toothed cats  gathered here for thousands of years.

The diggers found an obsidian spear head with a

bison whose horns spanned seven feet and

mammoths twice the size of elephants.

Saber toothed cats competed with these

ancient ancestors at this place, all driven by

hunger, thirst, and instinct.  I wonder how

these people overcame danger, fear?

I walk the mile long path, stand in the shade

of these cottonwood trees , read the signs that

tell me what diggers found at specific spots along the trail.

The cottonwoods whisper to me.  They

tell me ancient tales of hunger, strife, fear,

beauty, love, endurance.  I hear the ancient voices

calling.  They tell me ancient tales of woe, war,

weaponry, courage, and community.  My

skin tingles strangely in the summer heat.  Now

this land is dry, a desert, the water that sustained

teeming life evaporated in the crystalline air.

Twelve thousand years from now who will stand here?

Will this place exist?  Will someone wonder the meaning

of our bones, who we were, what we believed?

Blackwater Draw–Part One


Annually, I make a pilgrimage to this ancient place where people hunted on the shores of a lake nearly 12,000 years ago.  It continues to be the oldest evidence of human habitation in the Americas.  For a large part of the twentieth century it was a gravel pit.  The gravel mining created both positive and negative consequences.  Without it, the bones of giant bison, mammoths, dire wolf, saber toothed cat and camels might never have been discovered at all.  However, because the owners of the quarry refused to stop mining, some portions of the site were destroyed by big swoops of the excavator machines.  Frequently archaeologists worked simultaneously along with mining operations, continuing within sight of each other.    Various groups, including some private individuals, attempted repeatedly to buy the site to save its precious stash of bones, artifacts, and ancient wells.  The owners refused to sell.  Finally, in 1978, Eastern New Mexico University purchased the site and continues archaeological excavation there.  They also run the nearby museum adjacent to the university football stadium.

If you expect something wondrous and grandiose, you will be severely disappointed.  A small building houses a teensy museum, restrooms, a few sweat shirts and posters and books for purchase.  An individual sits by the door to take your meager entrance fee–at most five dollars–and answer questions.  These individuals explain they are majors in disciplines related to the site, archaeology, paleontology, anthropology, that sort of thing.  A simple gravel trail traverses the site and a smaller trail goes to an ancient well–16 have been found at or near the site–and to a dig inside a building where you can observe the layers unearthed, which group of people left which type of artifacts, and actual bones of mammoths, giant bison, and other animals from the end of the last Ice Age.

People react differently to such sites.  I always remain entranced, overwhelmed, reflective, thinking to myself, “I am walking where people walked and hunted and went about their lives more than 11,000 years ago.”  The most ancient evidence of people is labeled Clovis Man–Clovis, NM, is just up the road.  They never found human bones of these people here , just their spearheads stuck in the ribs and shoulders of mammoths which stood 15 feet at the shoulders.  The people who came later made a different type of spear, called Folsom points.  These people, Folsom Man, lived later by 1-2 thousand years.  Another site, called Folsom, is near the tiny town of Folsom, NM, farther north at the edge of the mountains.  This site is on private land and tours are available only twice a year.  Although I visited the town last year, I have not visited this site.  Other people arrived later and although the collection is smaller, their spearheads remain available for viewing at the nearby Blackwater Draw Museum on the main road between Clovis and Portalis, NM.

When I look at the list of animals who lived here at the end of the last Ice Age, I feel amazed because they include both camels and horses as big as our horses now.  Both of these became extinct as did the saber toothed cat with the humongous canine teeth and the dire wolf.  Giant sloths lived until modern times but nowhere near New Mexico.  How could all these animals live here?  It was wet and green then.  Until the last couple of decades, bodies of water of varying sizes have drawn animals and people to this area.  Giant fields of irrigated corn and dairy farms lowered the water table sufficiently to eliminate any evidence of water.  At the time of Clovis Man a large lake covered the site.  Later, during a 3000 year drought, people dug the ancient wells to reach water.  Because this remained the only place for hundreds of miles with a supply of water, people came.

The trail begins just to the northwest of the tiny building and goes along the top for a couple of hundred feet before it drops down into the gravel pit remains.  The gravel was below all the layers containing human artifacts and ancient animal bones so the pit is wide and deep.

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If your sight is good, you can read this.  The primary source of food for Clovis Man, giant bison and Columbian mammoths, came here for the water.  Archaeologists  theorize that hunters often killed these huge animals while they were in the water where it was more difficult for them to escape and move quickly.  In one place on the trail, evidence of a five bison kill complete with spearheads makes one think just how difficult and dangerous this hunting activity must have been.  I stand there, think about my own 5’4″ height, and wonder what it would be like to have a Columbian mammoth close to me.  Doubtless many died from injuries during such activities.

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The train meanders along the bottom of the gravel pit.  This year, plentiful rain grows abundant grass.  During the last several years, little rain has fallen as evidenced by all the dead trees and bushes scattered around the site.  Normally, this area is semiarid with less than 18 inches of rain per year.

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If spectacular scenery appeals to you, do not go here.  Most of the bones and artifacts were found in the layers at the sides of the pit.  As you walk the trail, markers indicate the location of findings.  Few human remains are found at such sites because these were not permanent settlement places.  Ancient peoples roamed the land in search of water and food.

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Signs, such as this along the trail, illustrate different places where specific bones and artifacts were found.  They also explain the different types of artifacts, their specific uses, and the history of the site.  Maps, like the one on this sign, help the viewer hone in on specifics in relation to where one is standing.  The photo illustrates archaeologists in action during site digs.

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Cliffs, like the one here, surround the site.  In these small cliffs each layer indicates a different age of human activity by not only the type of sediment but also by the type of artifacts and animal bones found.  Just beyond this particular cliff at the west edge of the site, irrigation pivots run in a huge corn field.  The grey at the bottom of the cliff indicates an immense pile of dead, dried, tumble weeds.  This is dry country.

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Approximately three fourths through the trail, the site mangers have erected several structures.  This one is the most primitive.  Others are modern with picnic tables and in one place I saw a giant sand box.  Guessing, I think it must be used to illustrate how one sifts through layers of soil to carefully remove spearheads, bones, pottery, etc.  This is the perfect place for a field trip, not too long, but full of geological and paleontological information.

I go here usually once a year.  If you ask me why, I may articulate something about how it has the oldest artifacts and bones found in North America.  The real reason??  I am not quite sure.  This place fascinates me, connects me with something ancient and wondrous, something undefined and mysterious.