Crop Comments: Keeping closer count on carbon
Appearing in a recent issue of the Guardian online newspaper was an article, “Planting Trees to Fight Climate Change Is Great. Then Again, So Is Eating,” written by Fiona Harvey. Harvey wrote that governments and businesses hoping to plant trees and restore forests in order to reach net-zero carbon emissions must sharply limit such efforts to avoid driving up food prices in the developing world, the charity Oxfam has warned. Oxfam is a confederation of 19 independent charitable organizations focusing on the alleviation of global poverty. Planting trees has been touted as one of the key ways of tackling the climate crisis, but the amount of land needed for such forests would be vast. Planting even a fraction of the area needed to offset global greenhouse gas emissions would usurp some of the land for crops needed to feed our planet’s growing population.
At least four billion acres – an area five times the size of India, equivalent to all the land now farmed on the planet – would be required to reach net zero for the planet by 2050 via tree planting alone. While no one is suggesting planting trees to that extent, Oxfam’s scientists said it gave an idea of the scale of planting required, and how limited carbon offsetting should be if food price rises are to be avoided. According to the think tank at Oxfam, “It is difficult to tell how much land would be required, as governments have not been transparent about how they plan to meet their net-zero commitments. But many countries and companies are talking about afforestation and reforestation, and the first question is: where is this land going to come from?”
Afforestation is the establishment of a forest or stand of trees in an area where there was no forest. Reforestation is the reestablishment of forest cover, either naturally or artificially.
Food prices could rise by 80% by 2050, according to some estimates, if offsetting emissions through forestry is over-used. About 865 million acres of land – an area roughly the size of India – could be used for offsetting without disrupting agriculture around the world but taken together the plans for offsetting from countries and companies globally could soon exceed this.
According to Nafkote Dabi, climate policy overseer at Oxfam, “Already, hundreds of millions of people around the world are going hungry. We need to consult countries on how they are going to use their land, and countries and companies need to reduce their emissions first [before relying on offsetting]. We also need to reduce emissions from agriculture, which is the second biggest source of emissions globally.”
Oxfam also reported that two of the most commonly used offsetting measures, reforestation and the planting of new forests, were among the worst at putting food security at risk. Far better, according to the analysis, were nature-based solutions that focused on forest management, agroforestry (the practice of combining crop cultivation or pasture with growing trees) as well as pasture management and soil management in croplands. These would allow people to use the land for food while sequestering carbon. Many governments and non-governmental organizations directly engage in programs of afforestation to create forests, increase carbon capture and sequestration and help through human input to increase biodiversity.
An under-stressed element in carbon offsetting and carbon sequestration is the actual buildup of carbon in the soil in both classic agriculture and agroforestry.
Let’s accept the fact that soil organic matter (OM) is 58% actual carbon and assume that an acre contains 1,000 tons (2 million pounds) of potential rooting material in a six-inch-deep topsoil. The loss of 1% OM means that 11,600 pounds of carbon just got degraded away into the atmosphere, in the form of carbon dioxide and methane, very real greenhouse gases – culprits in climate change.
Mismanagement of soils makes them vulnerable to nature’s ravages, like too much heat, too much wind and too little or too much moisture. A graphic illustration of this was the year-after-year monocultural growing of the summer annual cotton. Increased soil OM enables the field in question to roll with the punch, when (not if) nature is too hot, too cold, too wet or too dry. Loss of soil OM and its health in general spawned the Dust Bowl era, mostly a man-made plague that afflicted much of America’s Southwest and Heartland during the 1930s.
But humankind didn’t have to shoulder all the blame for the Dust Bowl. The late Charles Walters preached the concept of climate cycles. In his book “Weeds: Control Without Poisons” (Acres USA Publishing, 1996), Walters cited the cyclic nature of drought-created dust storms. He was very familiar with these, having grown up in the Great Depression Dust Bowl region. I quote from Walters’ first chapter in that text: “There was nothing new about the dust storms of the 1930s. The cycles discerned from the tree rings tell us that dust storms have visited the area for periods of five or more years no less than 21 times between AD 734 and 1934. On the average these droughts presented themselves every 35 to 36 years. Moreover, some of the droughts lasted more than 10 years, and came every 55-plus years.”
Summing all this up, let me personify Mother Nature, admitting that she will behave whimsically with her weather and climate antics. Likening her misbehaviors to a fire of sorts, humankind has the option of throwing or not throwing gasoline on it, by way of soil mismanagement.