This is an astonishing world. Blame for current disasters cannot be offloaded to ‘human nature’. All who take care of children know that children can learn to live within limits and that they can develop a realistic sense of time, that they can learn to forego some pleasures and wishes. From psychoanalytic work, I find that people can learn to be objective and to have a conscience. But everywhere there are examples of shocking entitlement, lying, distorting facts. A recent Guardian Weekly posted an article about Davos on one page, about the promises of AI, technological advances and growth, and on the opposite page the climate disasters in California, droughts and flooding, loss of agriculture, burning of whole towns, death. Climate-related disasters in every geographical region are reported and then lost to follow- up. These disasters are less than what is in store because of thermal inertia, the lag in Earth’s adjustment to CO2 concentration. There is even talk about the collapse of civilization as we know it, yet little mention of agriculture, though agriculture marked the beginning of organized civilization. People in positions of authority and influence do not feel urgency about this or other existential emergencies.
Knowledge is accessible: open source scientific articles, “new books in print” podcasts, interviews with leading scientists on Ecoshock Radio, Science Daily reports, James Hansen’s website. Climate scientists studying the ocean research how changes in the ocean’s temperature affect the nutrients (food) of phytoplankton, the bottom of the food and oxygen chain: ocean acidification, ocean layering of fresh and salt water, circulation, the ocean’s interactions with the atmosphere. Emissions of the four major greenhouse gases (CO2, methane, nitrous oxide, water vapor) are far above 350ppm, established as the approximate baseline at which ice forms or melts on the planet. Unique at this historical time is the speed at which carbon dioxide is being emitted, unlike the slow build-up in previous mass extinctions.
What does science of the entire climate system indicate about Earth’s vulnerability? It is known that Earth emerged over 4.6 bn years ago, life began about 3.5bn years ago, land plants 470m years ago, humans first cultivated plants and bred animals about 10,000 years ago. All living beings are formed from organic matter, water, and other minerals. Humans and animals live upon organic matter provided directly by plants, or by animals which have consumed plants. Farming from the beginning was remarkably differentiated between regions, with different tools, plants, and animals found in varied ecosystems. Humans, within a relatively short time, occupied all inhabitable areas of the Earth. Agriculture involves two principal subsystems: the cultivated ecosystems and the social systems. On the ecosystem side studied by climate scientists, there is the effect of greenhouse gases and temperature on biomass, soil, and fertility; social scientists research humans and food. This article focuses on two scientific studies about the effect on food of greenhouse gases and temperature. 
Jo Handelsman researches topsoil. “The top layer of fertile soil, on which every form of life depends, is fast eroding.” She describes the miracle of life that she witnessed at Mt. St. Helens after the volcanic eruption, seeing one plant emerge out of rock, a plant that hosts nitrogen-fixing bacteria nodules on its roots. “Without nitrogen-fixing bacteria, plants cannot grow in lava rock for lack of nitrogen. As this plant grew, the lava rock would weather and crumble, more bacteria would thrive, and diverse plants and microscopic animals would join them…slowly an ecosystem called soil would form.” The Images from T.S. Eliot’s The Wasteland come to mind: “What are the roots that clutch, what branches grow/ Out of this stony rubbish? And the dead tree gives no shelter, the cricket no relief,/ And the dry stone no sound of water.” The alarming news is that soil is disappearing with intense rainstorms and extreme weather. In various regions it is eroding ten to one hundred times faster than it is produced and crop yields will be severely compromised.
Soil is an unsung treasure. Over thousands of years soil emerged enriched and deepened by the weathering of rocks, chemicals from dead and living plants, animals and microorganisms, by water and air. 95% of our food is produced on fertile topsoil. Below the Earth’s surface, soil shelters crucial microorganisms, fungi, bacteria, and about 25% of the world’s described species. “A single square meter of soil can contain more than 150 individual earthworms..”, tiny insects, larger animals, all contributing to soil structure by cementing particles or forging pathways for movement of air and water. Within the soil’s mineral infrastructure is a “metropolis of microorganisms cooperating and competing for resources in unimaginably close quarter”, a few billion bacteria microorganisms in a teaspoon of soil. For decades it has been known how to care for soil: no-till, non-mechanized plowing; cover crops, interplanting a range of plants, fallow intervals. Soil, along with the ocean and forests, are Earth’s carbon sinks. Loss of topsoil’s absorption of carbon dioxide may contribute as much as 2 gigatonnes of carbon annually, around 20% of global emissions. Early IPCC reports “devoted barely a paragraph to soil, but in 2019 it released a report, Climate Change and Land, which focused on land-soil interactions, desertification, and land degradation.”
The natural rate of topsoil production is at most 0.5-1.0 tonnes of topsoil per hectare per year. “With a global annual erosion rate averaging 13.5 tonnes per hectare…soil is vanishing from the locations where it was produced on average ten to thirty times faster than it is generated.” Erosion’s role is understudied, but as a consequence of the production of greenhouse gases that sometimes follows erosion, this in itself may contribute as much as 20% of annual global emissions. Wind and water have dramatic effects. “The collective power of rain is literally earth-shattering: 100 cm of rain pummeling the surface of 10 hectares deliver the kinetic energy equivalent of 1 tonne of TNT explosives… Worldwide, water is thought to remove 20-50bn tonnes of soil annually from its original location.” This is expected to increase as climate change intensifies, bringing more severe rainstorms to locations around the world. A startling example: in sub-Saharan Africa, water erosion is estimated to have degraded 46% of the land, including 80% in Nigeria; in India, 1/3 of India’s total land
Adding nitrogen fertilizer to soil immensely increases agriculture emissions. Until the early 20th century, the nitrogen essential for agriculture was supplied by nitrogen-fixing plants such as peas, alfalfa, and soybeans. German chemists Haber and Bosch, in a search for ways to make explosives and nitrogen mustards for warfare, discovered a method to free nitrogen atoms and build ammonia that could be used to produce fertilizers and boost crop yields by at least 30-50%. The process requires an immense amount of energy provided by fossil fuels, and the fertilizers generate nitrous oxide. A single nitrous oxide molecule has 298 times the global warming potential of a carbon dioxide molecule.
Research is crucial. For example, rice is the staple food for billions of people and under different paddy conditions produces large amounts of carbon dioxide or methane. It is essential then to manage the right amount of oxygen in highly oxygenated paddies to diminish release of carbon dioxide, or the right amount in anaerobic soil to prevent the release of methane.
Lewis H. Ziska researches the effect of increasing carbon dioxide on agriculture. “In 2019 the National Institute for Food and Agriculture (NIFA), the institute that supplies about a billion dollars in grants to agriculture universities in the United States, does not mention carbon dioxide or climate change except for a few words about “climate uncertainty.” Ziska’s work is a critical repudiation of Stephen Long’s 1991 influential paper stating that increased plant productivity correlates with increased carbon dioxide concentration in the atmosphere. William Happer, a senior director at the National Security Council and an emeritus professor of Physics at Princeton wrote that “’the demonization of carbon dioxide is just like the demonization of the poor Jews under Hitler. Carbon dioxide is actually a benefit to the world, and so were the Jews.’ Uh-huh. Who knew that being against ‘CO2 is plant food’ is the same as committing genocide?” (some science writing is entertaining!)
Stephen Long’s assessment of photosynthesis only focused on growth in leaves as a response to increasing carbon dioxide, but plants consist of seeds and fruit, pollen, roots. Ziska’s research is about how the most important food crops are vulnerable to pollen sterility and decline in seed yield due to interacting CO2 and temperature. “Looking at the leaf level is not always a good predictor of what happens at the flower level; looking at flowers doesn’t tell us about root biology; root biology doesn’t necessarily tell us about what the entire plant is doing, and what the plant is doing doesn’t predict how the ecosystem might respond, and so on.” Plant studies include agronomy, aquaculture, botany, chemistry, physiology, entomology, genetics, pathology, ecology. It is complex. Ziska’s research looks at atmospheric concentration at increments of 100 parts per million starting at 300 ppm to 700ppm, the possible amount by the end of this century. The experiments involve infusing carbon dioxide into the roots of selected plants in greenhouses and in fields. How will these plants interact under the real climate conditions that accompany increased CO2 such as heat, the availability of water, unpredictable seasons, reductions in plant and insect biodiversity? As CO2 does increase growth in some food plants, it also increases even more growth of weeds and their resistance to herbicides. Farming from its inception has always involved a battle against weeds. As of 2019, between 200-300 million pounds of Monsanto herbicides were used in the U.S. alone with known effects on human health, pollinators, soil, the economic plight of farmers. Ziska found that more CO2 increased herbicide resistance among the weedy rice varieties that do the most damage to edible rice production. CO2 affects plant chemistry; examples are the potassium levels of cheatgrass leading to frequent brush fires, or decreasing anti-malarial artemisinin levels in the useful weed that produces this drug. As weeds proliferate, they dominate new areas where there are no pests to limit their spread.
Ziska also determined that increasing CO2 may stimulate growth and yield while diminishing nutritional quality: the nitrogen concentrations of foliage and roots is consistently lower in plants grown at elevated levels of CO2. CO2 negatively affects protein concentration, mineral compositions necessary for carbohydrate metabolism, immune system function, cell division, cell growth, healing wounds, sense of smell and taste, the action of insulin, and significant declines in a range of vitamins. Reduced protein content of pollen in some plants will affect the health of bees and other species within the food chain. These effects indicate the urgency of research and careful, scientifically based measures.
The National Institutes of Health has devoted just $9m to all climate change and public health research out of a budget of $40bn. The budget of the two primary U.S. agricultural research agencies allocates no funding on the challenges U.S. agriculture is facing. What are the effects of declines in plant protein for other animals in the food chain such as pollinators? Is CO2 affecting the decline in insects? Since CO2 differentially affects crops and weeds, how will this impact future crop yields? How will more CO2 affect biodiversity? How will rising CO2 affect the toxicology (poison content) of plants? How will rising extreme temperatures, drought, and flooding affect agriculture, pastures, prairies, forests, and wetlands?
A 2014 statement by an official from the UN FAO predicted that the world will run out of soil in 60 years based on historical trends and projections. These included the loss of 1/3 of Earth’s arable land over the past 40 years, continued use of plowing, steadily rising rates of erosion in most countries, and increased frequency of severe weather. The exacerbation of all these climate consequences by political/economic processes, in the words of the former Special Rapporteur on the right to food Jean Ziegler, is “murder.” 
Part II will look at this human side.
[1Marcel ]Mazoyer and Laurence Roudart, (2006), A History of World Agriculture: from the Neolithic Age to the current crisis,
Monthly Review Press, New York.
Jo Handelsman (2021), A World without Soil: the past, present, and precarious future of the earth beneath our feet (2021),Yale University Press, New Haven.
Lewis H. Ziska2022) Greenhouse Planet: How rising CO2 changes plants and life as we know it 2022 Columbia University Press, New York.
Jean Ziegler (2013), Betting on Famine: why the world still goes hungry, The New Press, New York.