Impact debris has been found on four continents: Africa, Asia, Europe, and North America, and on the island of Greenland. The fragments scattered over such a wide area contain platinum, microspherules, and nanodiamonds. The latter two are known to form in cometary impacts.
The latest study of the Younger Dryas Impact comes out of the Institute of Materials and Processes, Shcool of Engineering, at the University of Edinburgh. Author Martin Sweatman is the latest to support the impact theory prior to the dawn of the Neolithic Revolution in Southwest Asia’s Fertile Crescent. The impact of a comet with the Earth, first proposed in 2007, is believed to have contributed to an extinction event involving a number of large animal species and may have caused human populations to switch from being hunter-gatherers to agriculture and the creation of the first towns and cities.
Sweatman who has written a book entitled, “Prehistory Decoded,” notes in a University of Edinburgh news release, “This major cosmic catastrophe seems to have been memorialized on the giant stone pillars of Göbekli Tepe, possibly the ‘World’s first temple’, which is linked with the origin of civilization in the Fertile Crescent of southwest Asia. Did civilization, therefore, begin with a bang?”
The catastrophe is believed to have destroyed a small early northern Syrian Tel known as Abu Hureyra, a pre-Neolithic mound settlement. It is believed, based on the debris field, that a comet entered Earth’s atmosphere causing an airburst that spread glassy chromite, platinum and nanodiamond grains covering what is today Egypt, Iraq, Lebanon, Syria, parts of Europe, Greenland, North and South America as far away as Chile, or approximately 35% of the Earth’s circumference.
How significant was the impact? Second only to the Chicxulub impactor, associated with the extinction of the dinosaurs, states Sweatman. And he argues, significant enough to likely change the direction of human activity leading to the dawn of modern civilization. He points to the first known temple site, Göbekli Tepe, as evidence that humanity underwent a sea change after the comet strike and that the temple commemorates the Younger Dryas event.
The Fertile Crescent whose shape describes an arc that begins in the Tigris-Euphrates valley and extends across Syria before it descends the Mediterranean coast from Lebanon through Israel, Palestine, and on into Egypt, spans an area where the agricultural revolution is believed to have begun along with the first organized permanent settlements, city-states, kingdoms and empires. It appears to be coincident with the end of the mini-Ice Age brought on by the comet impactor.
The hypothesis remains controversial with many researchers arguing that existing evidence is being interpreted to support the theory without counter-arguments. The Abu Hureyra site (see map below) was first excavated in 1972-73. Today it lies under Lake Assad, created by a dam on the Euphrates River. What the site revealed was charcoal, melt glass, iron and silicon-rich spherules, nanodiamonds, and carbon spherules. These are all indications of a significant fire event that would have seen temperatures ranging from 1,840 to 2,300 Celsius (between 3,340 and 4,170 Fahrenheit). These are temperatures far higher than what would occur if caused by a terrestrial-sourced wildfire and more akin to a volcanic eruption of which there is no evidence.
But far more compelling than the temperature evidence is the millennium of cooling that follows the Younger Dryas Impact event, associated with the disappearance of Pleistocene (Ice Age) megafauna such as the Giant Ground Sloth, North American Mammoths, Sabertooth Tigers, and others, along with what archeologists and anthropologists call the Paleoamerican Clovis Culture of human prehistory.
The impact’s profound influence on climate is what relates to us today. At the time of the Younger Dryas, a cold snap lasted from the time of the comet airburst until some 1,300 years later or about 11,500 years ago.
In our world of today, our technological society is playing the role of the comet but instead of causing the Earth to chill, we are heating the planet.
Is there a lesson to be learned? Climate change may have been the impetus to start modern civilization as we know it. And climate change could also end our modern civilization unless we can better accommodate ourselves to our natural world. An extraterrestrial impactor isn’t needed this time, just our ability to see our way to an energy decarbonized world and deliver it.
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Agricultural technology is critical to human survival. With our global population growing by 1.14% per year it means there are 80 million more mouths to feed annually. By 2050 world population estimates vary from 9 to 10 billion. So getting agriculture right should be top of mind for all of us and for governments at all levels.
It was the Agricultural Revolution at the dawn of the Neolithic that set humanity on this path to unprecedented population growth. So it’s good to start with a story that tosses out some of our old conceptions about just when the Neolithic really started.
When Did Humans Start Farming?
We used to think 12,000 years ago. But now a new discovery by researchers from Tel Aviv University, Harvard University, Bar-Ilan University and the University of Haifa have uncovered evidence that puts the date 23,000 years in the past. The discovery is described in the journal PLOS ONE this month.
The evidence comes from finding what the researchers call “proto-weeds” at an archaeological site on the shore of the Sea of Galilee in Israel. Weeds evolved in parallel with cultivated plants. So finding a “significant presence of weeds in archaeo-botanical assemblages” is an indicator of systematic cultivation. What were these early farmers planting? Wild emmer wheat, barley and oats.
Borrowed Barley Gene Reduces Methane Emissions from Rice
Methane is a potent greenhouse gas and is credited with a contribution of 20% to global warming. Rice paddies produce up to 17% of atmospheric methane. That’s because rice is planted in waterlogged, warm soil and methanogenesis occurs in the root systems.
Now consider this. On a global average each one of us consumes 68 kilograms (150 pounds) of rice annually. The largest population growth areas on the planet are in areas where rice is a primary food staple. That means planting more rice to feed extra mouths will mean more greenhouse gases entering the atmosphere. So scientists have been pursuing a way to reduce methane emissions from the growing of rice. And the way they have done it is to introduce a gene from barley that makes the rice plant store more carbon. They call their rice, SUSIBA2. The plant shifts its carbon storage into the rice kernels and stems rather than the root systems. With less carbon entering the soil through the roots it remains an unknown what impact this will have on microbial communities associated with rice cultivation. Hence the scientists are carefully growing and testing the rice over multiple generations. It is anticipated that it will a decade before SUSIBA2 rice becomes commonly planted.
The picture below shows SUSIBA2 rice on the left and regular rice on the right. Note the concentration of microbial bacteria is far less than in the latter. To read the research check out the paper appearing in Nature Letters on July 22nd.
Harvard Study Raises Concern About Falling Levels of Zinc in Staple Crops
A study appearing in The Lancet Global Health this last week notes that increased atmospheric carbon dioxide (CO2) is impacting zinc content and other nutrients in basic food crops. Why is this an issue?
Because zinc deficiency is already a problem today with an estimated 2 billion people on the planet not getting enough of it through diet. For diabetics, people suffering from inflammatory bowel disease, for the health of the immune system, zinc plays a critical role. Zinc deficiency is linked to respiratory diseases and in fact, zinc lozenges are commonly used to shorten the duration of a common cold.
In the study the researchers looked at atmospheric CO2 concentrations of 375 to 384 parts per million (ppm) and zinc intake in populations in 188 countries. They then projected elevated CO2 levels to 550 ppm by mid-century. You may disagree with that higher CO2 level but at current rates of emissions that scenario is deemed likely by 2050.
In their findings the researchers noted that zinc deficiency risk would increase for those living in Africa and South Asia to the tune of 138 million people. The implications for the vulnerability of these populations, already in areas where food production is under stress, cannot be overlooked.
One of the lead researchers, Samuel Myers, points out:
“All of human civilization has taken place during a very stable set of biophysical conditions, but we are now changing those conditions at a rate that’s never been seen before…..Whether we’re talking about land use, deforestation, degradation of global fisheries, disruption of the climate system, biodiversity loss, appropriation of fresh water, changes to aquatic systems — all of the changes are profound and they’re accelerating, and they represent a significant challenge to global health.”
