Peak Yield? Climate and Crop Productivity

Peak Yield? Climate and Crop Productivity

by Moses Seenarine, 12/19/17

Since the 1960s, feed crops' yield growth have jumped remarkably, but this rise is part of an ongoing process over the past 10,000 years. In pre-historic times, it took 3,000 acres (12 sq km) of land to feed one human forager, but now it takes 1/3 of an acre (1,300 sq m) to feed one person. So the amount of food grown per acre (43,500 sq ft) has multiplied by a factor of 10,000 in 10,000 years. 

Global grain yields now average about 3.5 tons per hectare (2.5 acre). In the US, yields are double at seven tons per hectare. That difference in yield primarily reflects more access to capital and energy by US farmers and TFCs who can afford vast quantities of fertilizer, mechanized farm equipment, irrigation systems, pesticides, and other tools that dramatically boost agricultural yields, at least in the short-term. 

An analysis of the effects of 2,800 weather disasters in 177 countries on 16 cereals from 1964 to 2007 show that climate change may have already begun to take a toll on agriculture. Drought and extreme heat in the last 50 years have reduced cereal production by up to 10%. And, the impact of these weather disasters was greatest in the developed nations of North America, Europe, Asia and Australia. Production levels in the global North dropped by 20% because of droughts, double the global average. 

Crops and methods of farming are uniform across immense areas, so if a drought occurs in a way that is damaging to those crops, they all suffer. In agriculture, crop yield or agricultural output, refers to both the measure of the yield of a crop per unit area of land cultivation, and the seed generation of the plant itself. For instance, if three grains are harvested for each grain seeded, the resulting yield is 1:3. The figure, 1:3 is considered by agronomists as the minimum required to sustain human life. 

Ominously, grain yields are already stagnant and have stopped rising in many parts of the world. On a global scale, stagnating yield is affecting four major grain types that produce two-thirds of the world's calories - maize, rice, wheat and soybeans. Yields of these four crops are growing by only 0.9 to 1.6% a year. Yields in 25% to 33% of the crop producing areas are stagnating, like those in Australia, Argentina, Guatemala, Morocco, Kenya, and the US states of Arkansas and Texas. In parts of the UK, in areas that produced the highest outputs 20 years ago, yields have actually dropped. 

Just nine or 10 plants species principally feed the world. An international research team ascertained that 16 of the 21 foods they inspected reached peak production between 1988 and 2008. Menacingly, this synchronization of peak years in upwards of three-quarters of edible plants suggests the whole food system is becoming overwhelmed. Maize reached its peak rate in 1985, followed by rice three years later, in 1988. Vegetables reached their peak rate in 2000, while wheat reached its peak rate in 2004, followed by sugarcane in 2007. Soybean reached its peak rate in 2009. As an outcome of peak food, larger production means greater amounts of land under cultivation.

Since GM crops were planted, the US staple crop system has performed worse than non-GM crops in Europe - in yields, pesticide use, genetic diversity and resilience. For the US system, there is a dangerous downward yield trend in recent years. Stagnating yields may be due to the soil damage caused by the use of heavy machinery and a long-term decline in organic matter content in soils. The upshot is additional fertilizers have to be used to boost yields. 

Excerpt from "Meat Climate Change: The 2nd Leading Cause of Global Warming," by Dr. Moses Seenarine.

Hothouse Earth: Plants and Climate Change

Hothouse Earth: Plants and Climate Change

by Moses Seenarine, 12/19/17

Raising carbon dioxide levels are not necessarily good for agriculture. The benefits of CO2 for plants may be less than previously thought and potentially counteracted by the damaging effects of the proliferation of surface ozone. Agriculture has always faced the challenge of weather variability, and altered agricultural conditions under a transforming climate could exceed farmers’ ability to adapt. 

Farming could easily become adversely affected by (i) extreme heat and escalating water demands; (ii) inflated frequency of severe weather events, such as drought and flood; (iii) sea level rise and flooding of coastal lands; and (iv) modification in crop nutrient content. Variability is also likely to occur in (v) the number and type of pathogens and pests affecting plants and livestock; (vi) altered use of pesticides; (vii) damage to fisheries and aquaculture; and (viii) mycotoxin contamination. 

There are numerous fine-scale processes that can moderate vegetation responses to nitrogen deposits. While smaller amount of nitrogen may act as fertilizer, stimulating growth in plants, large accumulated amounts can (ix) decrease soil health and cause a loss in the number of plant species. These vital food security issues need to be dealt with and modeled into future plans for livestock expansion. 

The reality is animal-based diets will become even less efficient and further wasteful as planetary heating intensifies. The FAO's 2006 and 2013 assessments do not fully factor in the effects of climate warming on plants and crops. In particular, as the land warms, drought may reduce tree productivity and survival across many forest ecosystems. If the vapor-pressure deficit continues to climb, forest drought-stress by the 2050s will exceed that of the most severe droughts in the past 1,000 years. 

The world's food authority uses different baseline scenarios for improved land management for livestock over a 20-year period. But they model weather data from 1987 – 2006. This climate assumption is challenged by recent weather-related (a) lower crop yields, (b) feed crop failures, and (c) livestock die-offs. Upwards of 60% of crop yield variability can be attributed to climate irregularity. And unnervingly, this variation occurs in regions that are principal producers of major crops, like the Midwestern US, the North China Plains, western Europe and Japan. 

Direct climate impacts to maize, soybean, wheat, and rice under a RCP 8.2 scenario could involve average losses of 400–2,600 calories, or 8 to 43% of the present-day total. Freshwater limitations in some heavily irrigated regions could necessitate reversion of 20–60 Mha (77k – 231k mi) of cropland from irrigated to rain-fed management, and a further loss of 600–2,900 Pcal. 

These projections are a major cause for concern. Many subtropical arid and semi-arid regions will probably experience less precipitation. In wet tropical regions, extreme precipitation events will be further intense and frequent. Monsoon onset dates will start earlier while withdrawal rates are going to be delayed, resulting in a lengthening of the season. Tropical cyclones are expected to become extra intense, with stronger winds and heavier rainfall. In addition, variability of climate, such as El Niño events, has large impacts on crop production. 

Africa will be the part of the world that is most vulnerable to climate variability and alteration. East Africa will experience further short rains, while west Africa will get heavier monsoons. Much higher temperatures could reduce the length of the growing period in some parts of Africa by up to 20%. 

Excerpt from "Meat Climate Change: The 2nd Leading Cause of Global Warming," by Dr. Moses Seenarine.

Who Should We Feed - Animals or People?

Who Should We Feed - Animals or People?

by Moses Seenarine, 12/19/17

Worldwide, two billion people live primarily on an animal-based diet, while double that sum, or 4 billion people, live primarily on a plant-based diet. In fact, the  United Nations Environment Programme (UNEP) estimated that calories lost from feeding cereals to animals could feed an extra 3.5 billion people. 

Another report calculated that 4 billion people could be fed with the crops devoted to livestock. The single biggest intervention to free up calories would be to stop using grains for cow carcass production in the US. By far, the US, China, and Western Europe account for the bulk of the 'diet gap,' and corn is the main crop being diverted to animal feed. 

By moderating diets from food animals, choosing less resource-demanding animal products, and maintaining non-feed systems, around 1.3 and 3.6 billion more people could fed. And ending consumer waste of animal calories could feed an additional 235 million people. The WHO estimated that the number of people fed in a year per hectare (2.5 acres) ranged from 22 individuals for potatoes and 19 for rice, to one and two persons, respectively for cow and sheep carcass. The agency added that the low energy conversion ratio from feed to carcass is a concern since the cereal grain being produced is diverted to livestock. 

A Bangladeshi family living off rice, beans, vegetables and fruit may live on an acre of land or less. In sharp contrast, the average American, who consumes around 270 pounds of animal carcass a year, needs 20 times that. The current global average animal consumption is 100g (3.5 oz) per person per day, with about a ten-fold variation between high-consuming and low-consuming populations. 

For most people in developing countries who obtain their protein from plants, eating animal flesh is a luxury. A kilogram (2.2 lb) of animal carcass can cost from $2 to $5 in the local markets, which is several days’ wages. A typical African eats only 20 kg (44 lb) of animal flesh a year, well below the world average. These findings suggest that over-consumption and dietary habits are of the essence for understanding resource use and GHG pollution, as opposed to expanding population being the primary driver as is popularly argued. 

That is, population's importance is related to lifestyle expenditures, and specifically to the over-consumption class. A 2011 report concludes, “The mass consumption of animals is a primary reason why humans are hungry, fat, or sick and is a leading cause of the depletion and pollution of waterways, the degradation and deforestation of the land, the extinction of species, and the warming of the planet."

Excerpt from "Meat Climate Change: The 2nd Leading Cause of Global Warming," by Dr. Moses Seenarine.