Pumpkin Eater

Other than the turkey itself, no other foodstuff says Thanksgiving like pumpkin. Notably, both the turkey and the pumpkin are native to the Americas. Turkeys and pumpkins both were supposedly components of that first meal shared by native Americans with the colonists. Pumpkin pie is so ubiquitous that the combination of spices used to flavor it – cinnamon, nutmeg, cloves, and ginger – have come to be called pumpkin spice, and that flavor shows up in a number of the products we consume this time of year.

Pumpkins are in a large family, Cucurbita, with over 900 species. These species include gourds, winter and summer squash, all sorts of melons, and even cucumbers. Native Americans over thousands of years transformed what we know today as a Pumpkin from a tennis ball sized gourd with a very bitter taste.

As are so many other things we eat, pumpkins were made palatable via selective breeding. Pumpkins originated in Central America, and seeds of domestic Pumpkins dated to 8,000 years Before the Current Era (BCE) have been found in the highlands of Mexico. Softer, sweeter pumpkins were chosen from the wild or selected from purposeful plantings. This process continues to this day. Burpee’s Catalog offers 26 varieties of pumpkins.

The story of the post-human-manipulation pumpkin is interesting in and of itself but the natural history of the pre-humanpumpkin is also exciting. There is evidence that megafauna: mastodons, mammoths, giant sloths, etc., were an important part of the pumpkin’s story. Deposits of mastodon dung dated to 30,000 years ago contained squash seeds. The survival of the seeds after passage through the digestive tract of the megafauna provided a means of dispersal and fertilization which is valuable mechanism for evolutionary success.

It is quite likely that the bitter taste is important to this story. The bitterness of the ancestral pumpkin was due to compound called Curcubitacin which not only imparted the bitter taste but was also toxic. Plants and animals have been duking it out over billions of years. Plants have evolved to produce a great number of toxins to prevent herbivores from damaging their reproductive parts or seeds.

Had small mammals eaten these squash, they surely would have also eaten the nutritious seeds. And here is where the bitterness comes in. Modern gene sequencing has shown that among mammals at least, there is a correlation between sensitivity to the bitter taste and size. Sampling animals from rodents to elephants has shown that the smaller the animal, the greater the sensitivity to bitterness. Small mammals such as rodents avoided the bitter plants leaving them to the megafauna.

The effect is that early pumpkins allied with the megafauna to promote a type of mutualism. The megafauna got the benefit of the pumpkin as food while the pumpkin benefited by dispersion/fertilization. The demise of the megafauna would have been a problem for pumpkins, but luckily humans came along and partnered up. Pumpkins are now cultivated around the world, a range far in excess of its ancestral home.


Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Energy Plus Agriculture

All human endeavors have some impact on the environment be it good, bad, or otherwise. This is especially true when it come to power production. Relatively cheap and available power has transformed the human landscape. Life expectancy more than doubled since the advent of the industrial revolution begun late in the 18th century. The cheap power aided agriculture by greatly increasing productivity and reducing the threat of starvation. Less demand for agricultural labor freed the attention of others to expand an understanding of health care.

However, the negative impacts of the utilization of fossil fuels – coal, oil, and gas – are legendary. In December, 1952 a combination of weather conditions and pollutants from coal smoke killed thousands of Londoners. Oil slicks on the Cuyahoga River in Cleveland, Ohio frequently caught on fire throughout the 1960s. Re-injection of fracking wastes from the production of natural gas has been blamed for recent earthquakes. And then there is global warming and climate change which threaten the planet.

So, power is good, but power from fossil fuels is not so good. The obvious answer is power without the negative impacts imposed by fossil fuels. All the alternatives have some negative impacts but in aggregate, are an improvement.

An interesting combination of technologies is referred to as agrivoltaics, the pairing of agriculture with solar panels to increase farm income. The results from studies here in the United States and Australia are quite surprising.

At first blush one would think that putting solar panels on a pasture would produce energy from the solar panels but the shading would decrease forage production. A study in Australia found just the opposite. Properly spaced and elevated solar panels actually increased forage production. Partial shading was not a significant issue, but the presence of the solar panels reduced loss of soil moisture.

At the same time that the panels help agriculture, agriculture helps the panels. Transpiration of the biomass under the panels lowered the temperature around the panels and increased solar electric output.

An unanticipated benefit was found in a study in Oregon. Panels installed on a pasture on a sheep farm greatly reduced predation of lambs by eagles. The panels provided shelter from eagle strikes.

In a related vein, the marriage of solar panels and water bodies is synergistic. In arid lands evaporation from a reservoir is significant issue. Placing solar panels on pontoons close to the water’s surface reduces evaporation and as before, the cooling effect of the water increases energy production.

Even without the benefit of increased energy production, solar panels can be beneficial. Rooftop systems reduce exposure of homes to harsh weather. Or how about decking over asphalt parking lots? The shade provided will help cool the lot and at the same time provide electrical energy to perhaps charge electric vehicles while the owners shop.

With forethought, energy production from solar panels can be enhanced and simultaneously provide beneficial effects to land use.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Leaving Paris

President Trump campaigned on the denial of climate change, calling it a Chinese hoax. Upon election, he announced that the United States would be withdrawing from an agreement reached among every nation on earth. Despite the world’s scientists, the world’s scientific organizations, and the world’s governments agreeing that climate change is an existential threat to humanity and our environment, the government of the United States says no.

Despite polling showing the majority of us agree that climate change is occurring and action needs to be taken and despite the fact that the size of this majority is growing over time, the Trump administration continues to roll back regulations meant to combat global warming.

The full name of the agreement is “the Paris Agreement under the United Nations Framework Convention on Climate Change. “ It is also referred to as COP21, the 21st Conference of Parties. This agreement was designed to improve upon and replace the rather ineffectual Kyoto Protocol from 2005.

The agreement is an international treaty that has been ratified by UN members representing nations that produce in aggregate over 55 percent of greenhouse gas emissions. This means very few nations representing major emitters could effect ratification of the treaty: China, USA, India, Russia, and Japan would be all that is necessary. In fact, 197 countries have ratified the treaty.

The treaty created individualized targets called Nationally Determined Contributions (NDCs) for greenhouse gas reductions. The developed nations have targets with steeper reduction curves compared to the developing world. The argument is the countries of the developed world are principally responsible for the excess of greenhouse gasses and therefore should bear the lion’s share of the reductions.

President Trump formally notified the international community this week that we will withdraw from the agreement next fall. The date for the formal withdrawal is one day after the 2020 elections. Even if he loses his bid for re-election he is still president until the inauguration of a new president.

Since at least the end of World War II, the United States has been the world leader in science and technology and a moral guidepost for the world. By disengaging from this treaty we are telling the rest of the world that we don’t care. By abandoning the objective of lessening of the risk of climate change also means that we will be less focused on science and technology to achieve the end.

The solution for addressing climate change is a moral one – we need to recognize reality, and a scientific and technological one – developing new ways of producing the energy we need to power our society with less greenhouse gas emissions.

China is the world leader in installing wind and solar power sources in total. On a per-capita basis, Denmark is the leader in wind and Germany for solar.

We literally stand along among the nations of the world in our direction of change. As the world moves to cleaner renewable energy our government is moving to subsidize fossil fuel utilization.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Carbon Control

Energy production from burning fossil fuels is a classic example of the failure of capitalism to protect us from harm. The fossil fuel industry privatizes profits while socializing costs. Fossil fuel combustion products damage our health and the environment and endanger our future due to global warming.

Some laws have been enacted to protect us. Coal-fired power plants have to have filters to remove some particulate matter and substances which contribute to ill health yet as many as fifty thousand deaths a year are attributed to fossil fuel emissions. These are deaths not accounted for by capitalism.

The biggest threat to global stability and human health is now climate change. There are currently no limits on fossil fuel emissions to protect us. One way to make the user pay the costs would be to put limits on the Carbon Dioxide (CO2) emitted. The process to remove CO2 is called Carbon Capture and Storage (CCS.)

If CCS can be made to work, we could have our cake and eat it too. That is, we could have the benefits of energy from burning fossil fuels without negative consequences. Basically, CCS is a process of capturing the Carbon Dioxide waste stream from a power plant and then putting it somewhere other than the atmosphere.

The problem is that it is neither cheap nor easy. CCS technology could double the construction and operating costs of a power plant. The major limitation is the need for storage sites such as airtight underground caverns or the ocean depths, where the carbon dioxide would stay for a long, long time. Like forever.

The best site would be a geologic formation where subsurface rock naturally reacts with carbon dioxide via a process that chemically mineralizes it. These formations exist but are few and far between. We need enough storage space for about five billion tonnes of carbon dioxide a year.

Without mineralization, storage becomes much more difficult. Carbon dioxide, a gas at normal pressure, would need to be pumped into storage wells and the wells then capped to prevent release. At atmospheric pressure, it would require over six thousand cubic miles of underground open space per year. This kind of space doesn’t really exist, hence pressurization is necessary to reduce the volume. The higher the pressure the more difficult it will be to contain the stored gas. Any leakage will increase the cost both economically and energetically- all that capture, transportation, and pressurization uses energy.

The only way to store the five billion tonnes of carbon dioxide produced every year seems to be by pumping it at high pressure into every hole in the ground that we can find, plugging the hole, and then hoping that the cap doesn’t come off – forever. But what if a storage site does burp? It could be lethal for just about every living thing in the area of the release of CO2.

Carbon capture and storage in the last analysis is expensive, uses a lot of energy, and is quite risky to all life in the area of the storage wells. The only real solution is to abandon the use of fossil fuels and get all our energy from clean, sustainable energy supplies.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Arkansas Lithium

There is no question that electric vehicles are the future. Although projections are all over the map, a decent guess is that by 2030 something like fifty percent of new car sales will be electric. The number for fleet vehicles such as cabs, urban buses, and delivery vans will be even higher. They will all need rechargeable batteries and right now Lithium is the material of choice for those batteries.

Most metals can be used in batteries and the periodic chart is populated by scores of metals. In fact, the majority of elements in the universe are metals. What makes Lithium unique is its charge to weight ratio. Lithium is the lightest metal and can exist as a stable ion. This means it is capable of giving up or accepting an electron, a necessary function of a battery.

Think of a charged battery as a reservoir of electrons. When a battery-powered device is turned on a circuit is completed which allows the electrons to flow. This is the electric current that does whatever work the device was built for, be it lighting a flashlight or powering an electric vehicle. Reversing the duty cycle will recharge the battery.

Current world demand for Lithium is about twenty thousand tonnes per annum and is expected to double in just five years. A large chunk of this is produced from brine wells in the Atacama, a high desert in Chile. The brine, with a relatively high concentration of Lithium, is pumped to surface ponds and allowed to evaporate – the Atacama is not only the driest place in the world but also one of the sunniest.

Trouble comes with the removal of the brine. This simultaneously lowers the water table for freshwater. In the driest place on earth, this is a big deal. Imminent local regulation is expected to reduce the allowed brine removal and therefore limit Lithium production. Other sources are being examined for Lithium production, most notably Arkansas.

A veritable ocean of brine exists under south Arkansas. This brine has been a source of crude oil and other industrial chemicals for years, especially Bromine. The Smackover formation originally produced mainly oil with Bromine from brine as a byproduct. Currently, Bromine produced in Arkansas represents the total US production and this is a third of the global supply.

A company is now exploring the possibility of producing Lithium as a byproduct of Bromine production. The Lithium is to be removed along with the Bromine, then the spent brine is re-injected. Bromine production in Arkansas is an eight hundred million dollar enterprise employing a thousand Arkansans. If Lithium production is practical it will add to both income and jobs in Arkansas.

Although all eyes are on Lithium as a battery component there are numerous other uses. Lithium grease, refereed to as White Lithium, is a valuable lubricant as it uniquely adheres to metal. Much Lithium is used in glass and ceramic manufacture. Finally, Lithium is valuable as a treatment for bipolar disorder.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Energy Storage Efficiency

There are those who constantly dismiss wind and especially solar as impractical energy sources because it is not available all the time, hence standby power must be available – fair enough. Right now Unit One of Arkansas Nuclear One is offline for refueling.

So is anybody sitting in the dark for a month or two? Of course not. Must there be another nuclear reactor standing idle waiting for Unit One to go down for refueling? Again the answer is no. There is sufficient excess capacity in our electrical grid to make up the difference in electrical energy needs during the outage. The same is true today for our intermittent energy sources, wind and solar. It is estimated that no additional backup will be needed until we reach about thirty percent contribution of these renewable sources to our total electric production.

Right now wind turbines to our west and the solar panels at my home use the grid as storage, just like Unit One. When the wind isn’t blowing, the sun isn’t shining, or Unit one is offline to refuel, the other power sources in the grid make up the shortfall. Electrical energy transmission and storage are hot research topics in science and technology. Numerous ways exist already for grid-scale energy storage, the ongoing research is to find ways to store energy efficiently and affordably.

One option being explored by as Swiss company is a cuckoo clock writ large. Excess energy is used to raise concrete blocks up, just like the weights on a clock. To recover the stored energy simply allow the weight to go down, turning a generator as they come down. This type of energy storage is not very efficient, maybe sixty to seventy percent, but is inexpensive.


At the other end of the spectrum is a high-cost, high-efficiency strategy such as a rechargeable Lithium-ion battery. The efficiency here is about ninety percent. Although expensive, Lithium-ion batteries are quite lightweight so they have value to power portable devices, from hearing aids to electric cars.

One energy storage medium that most don’t recognize as such is Hydrogen. Hydrogen gas is very energy-dense, meaning a small amount of it will store a lot of energy. Hydrogen can be generated by electrolysis of water. The hydrogen can be stored until energy is needed, then the hydrogen can be burned to make steam to turn a turbine to generate electricity. But, burning anything to produce heat to turn a turbine is a quite inefficient process. Because of the laws of thermodynamics, you can only get back about a third of the energy put in.

Better than burning to make heat is another technology known as a fuel cell. Fuel cells convert Hydrogen back to water without as much waste heat. Hydrogen generation via electrolysis, then conversion back to electricity has a “round-trip” efficiency of about fifty percent.

The science and technology of grid-scale electrical energy storage will mature as we expand our reliance on wind and solar, ultimately eliminating the use of fossil fuels.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

“Impossible” Food

Within the last few months advertising for “impossible food” has ramped up. Actually, Impossible Foods Inc. is a California company – where else – which is focusing on producing veggie burgers. Some companies have been around for years and others are now jumping into the market. Why?

Beef, along with other animal sources of meat constitute an excellent source of protein. Americans eat an average of about 250 pounds of animal protein, including fish and shellfish, annually. There are alternative sources of protein such as a diet that balances beans and grains, but strict vegetarian diets must have an additional source for Vitamin B12.

The easy and tasty nutrition of meat, especially beef, does come at a cost. Much of the arable land in the United States is dedicated to the production of feed for the animals we eat and animals are not very efficient in turning the calories they eat into the protein we desire.

Energy inputs to raise animals come in the form of the energy needed to produce crops for animal food, mainly for fuel and fertilizer. Beef, the one we eat the most of is at the head of the inefficiency lists. It takes 33 units of energy to produce one unit of beef. Pork is better at 11 units in per unit out. Chicken is even better at 5 in to 1 out.

So where is all that wasted energy going? It is complex but boils down to two main factors, digestive inefficiency and basal metabolism, essentially heat production. The consequences of this waste is significant. As mentioned, land use is dominated production of animal feed. The CO2 released from fossil fuel use contributes to global warming. Much of the Methane released which also contributes to global warming comes from agriculture.

Animal wastes, feces and urine, can be a significant issue as we have recently seen in the fight over the hog factory operation in Mt Judea. A combination of public and private money, amounting to millions of dollars will be spent to close the farm and prevent further damage to the Buffalo National River.

Phosphorous and Nitrogen applied to crops as fertilizer runs off and ends up in the ocean. There is currently a several thousand square mile area at the mouth of the Mississippi River that is called a dead zone. Nutrient overload here ironically prevents virtually anything from growing.

All the issues of land use, global warming, and nutrient pollution would greatly benefit from the adoption of a vegetarian diet. Land use could shrink by a factor of ten if we ate beans and grains rather than feeding them to livestock. Similarly, agriculturally driven production of green house gasses and nutrient pollution would be reduced.

Now back to the impossible foods. Vegetable-based burgers and such have been around for sale at the grocer’s for years and in few restaurants but seldom before in fast food chains. Now you can get an impossible whopper. The faux meat patty is made from soy protein with numerous amendments to simulate a real burger.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Global Warming as a Threat Multiplier

The single most important, essentially all-encompassing function of government is to keep us safe. This too often is thought of only in terms of physical violence; you know the line, defend against all enemies, foreign and domestic… But other factors threaten our well-being. Climate change, floods, droughts, and intensified storms affect us all. Additionally, these factors can serve to magnify the risks of many others, especially military and political.

The term “threat multiplier” is used not just by what some call climate alarmists but also the Pentagon. The US military gets it.

Refugee crises have driven some countries into the hands of autocratic leaders who talk tough but at the expense of democracy. Refugees from the Middle East wars strains the patience if not the resources of Europe. The wars are ultimately political but the politics can be driven by environmental factors.

The bloody and seemingly endless civil war in Syria was preceded by a drought that drove farmers from the fields and herders from the pastures. Without work, the former herders and farmers were easily conscripted into the arms of warlords who paid them to kill not till.

The civil war in Yemen was begun over political power. Climate change is multiplying the suffering of the people. In the past, villages would store enough food to last for three or four months in times of emergency. In recent years less rainfall, resulting in reduced harvests, means little if any food is stored for periods of crisis. There is arguably no greater crisis than war.

Now, this civil war threatens to spiral into a broader war between Saudi Arabia and Iran, or even engulf the whole region in conflict and misery.

The presidential election of 2016 was dominated by Trump’s call to “build the wall.” Although immigration was at the time at a fifty-year low, increasing numbers of refugees from the Northern Triangle region of Central America now threaten our stability.

Refugees from Guatemala, Honduras, and El Salvador are fleeing violence born of lawlessness. Again these conditions are made worse by climate change. The region is getting hotter and paradoxically, both floods and droughts strain agriculture. What rainfall occurs happens in fewer, heavier events. Flooding followed by periods of drought. To stay alive in hard times, many, especially young males, turn to violence as their only recourse.

Not acting to reduce the rate of global warming will exacerbate problems across the board. Climate change itself and all the troubles that the change serves to multiply the ravages of war, famine, and refugee crises.

The good news is that there are solutions. Sustainable energy supplies that don’t add carbon to the atmosphere are cost-effective replacements for fossil fuels. Utilities and some cities here in Arkansas are adding large scale solar arrays to their energy mix. The cities of Clarkville and Fayetteville have installed arrays with the intention of powering all city functions. Hot Springs has recently signed contracts to do the same. Even the Dover School System is examining a solar power option.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Europe Gets It

Donald Trump, early in his presidency stated his intention to withdraw from the Paris Agreement, a voluntary agreement to which every nation around the world is a signatory. The scientific consensus around the world is that the planet is warming and humans are the cause. The response of the rest of the world is to work towards reducing the damage by limiting the use of fossil fuels as a major step.

President Trump’s position however is: “as of today the United States will cease all implementation of the non-binding Paris Accord and the draconian financial and economic burdens the agreement imposes on our country. This includes ending the implementation of the nationally determined contribution…”

Wind and solar, as replacements for coal are already the less expensive alternative for generating electricity. Leaders around the world know this and are implementing the use of renewable energy as a cost-saving measure in addition to reducing global-warming carbon emissions. Much of Europe is ahead of the curve. Below are the highlights of a few European countries energy mix.

Of course, some countries have natural advantages: Switzerland is mountainous, Denmark windy, and Spain sunny. Ninety-seven percent of Switzerland’s electrical energy is produced from hydropower. In terms of potential expansion, hydropower is difficult because in the developed world, most of the good sites are already developed.

Denmark is currently a wind energy leader, both in installed capacity and technology companies focused on wind technology. Over 60 percent of total electric generation is renewable, most of that coming from wind. Denmark utilizes much off-shore wind where turbines are larger and the winds stronger and more consistent, all of which lowers the cost.

As noted Spain benefits from the sun, but also some hydro. Their total fraction for renewable energy is 40%. Over half of that is solar photovoltaic arrays with some solar thermal plants. Surprisingly, about 4% is from geothermal which is tens times as much on a percentage basis than the United States.

Germany is interesting, they are not especially blessed with wind or solar but are working hard to utilize these sources none the less. Germany relies on coal and nuclear, both of which they plan to phase out in the not too distant future. Their renewable energy is now about 30%. Wind generation is spread across the Republic but especially in the north and off-shore in the Baltic and North Seas. Solar PV installations dominate in Southern Germany but there is much rooftop solar as far north as Cologne. For reference that is farther north than Winnipeg, Canada.
Compare the USA at 18% total renewables, 7% hydro, 6% wind, and 1% solar, with solar the fastest growing. With our vast potential for both wind and solar, we could be leading the world. More wind turbines and solar panels are needed but also needed is the infrastructure create a robust electrical grid. Particularly needed is transmission capacity to move an abundance of wind energy from the Midwest.

Dr. Bob Allen is Emeritus Professor of Chemistry at Arkansas Tech University.

Bananas and Earthworms -Oh Boy

Invasive species come in all varieties, warm-blooded and cold-blooded animals, all kinds of plants, even fungi. Some are notable but cause little problems – armadillos, some are notable and troublesome – feral hogs, and some you never see but are dangerous – infectious bacteria and viruses in some biting insects.

Whenever a species is introduced to a non-native environment there can be negative consequences, earthworms for example. The last ice age covered North America as far south as southern Illinois. Any native earthworms would have been wiped out. After the glaciers receded, the upper midwest evolved for thousands of years without earthworms. Much later, that locale was populated with earthworms by incidental introduction from colonial ships from Europe. Rock and dirt used as ballast and dumped onshore was the likely method of introduction.

Generally speaking, worms are good as they churn and aerate the soil. But there is a dark side. Portions of hardwood forests in Minnesota and boreal forests in Canada have been negatively impacted by invasive earthworms. Fallen leaves accumulate on the forest floor and create a rich organic layer called duff. This duff layer is the natural growing environment for native woodland wildflowers. It also provides habitat for ground-dwelling animals and helps prevent soil erosion – basically natural mulch. When earthworms are present however they eat this leaf litter. In areas heavily infested by earthworms, soil erosion and leaching of nutrients may reduce the productivity of forest and even degrade fish habitat. Many tree seedlings, ferns, and wildflowers don’t survive this altered environment.

In the “unseeable” category of invasives are numerous fungi, smuts, rusts, mildew, mold, etc. Many of these are serious agricultural pests causing untold damage to food crops. The tropics where much fruit is grown for export are particularly susceptible. A new threat has recently come to the western hemisphere. Tropical plantations are subject to problems such as fungi because of the warm, moist climate and especially because plantations are generally monoculture. When only a single species of plant is grown in large concentration, the condition is likely to favor pests.

Guatemala alone exports over 3 billion pounds of bananas to the United States annually. All together we import over 8 billion pounds of bananas a year and this crop is at risk due to a fungus from southeast Asia. Although there are over a thousand varieties of bananas, 95 percent of all commercial bananas are essentially a clone of one – the Cavendish banana. It replaced a previous clone, Gros Michael or Big Mike. It succumbed to a fungus called fusarium wilt. A similar fate seems to await the Cavendish. In some parts of southeast Asia, a new variety of this wilt is reducing production there by forty percent per year. The wilt, a soil organism, just turned up in Colombia and could appear across central America.

Invasive species generally have an advantage as natural controls are absent. Monoculture acts to increase the distribution of the invader. Devastation of the banana crop in “northern triangle” of Central America will only serve to accelerate immigration to the United States as families seek some sort of income.

Dr. Bob Allen is Emeritus Professor of Chemistry at Arkansas Tech University.