Agricultural technology and management have been so successful for so long that inexpensive food and fabric are taken for granted in all but the poorest countries, and famine is virtually unknown except in wartime. But the successes of the past, alas, don’t necessarily insulate us from the failures of the present.

The relentless march of climate change is now threatening to return us to an environment in which Reverend Malthus’ bleak vision of society, ever at risk of being derailed by food shortages, is all too realistic.

We can hope that a combination of market forces and government incentives will halt atmospheric warming before we face the return of worldwide food insecurity. But there is no getting around the conclusion that we will have to learn to manage the consequences of climate change on agriculture with technology that increases (or at least stabilizes) productivity in spite of increasingly volatile weather.

Where We Stand

If you are old enough to remember the last millennium, you’ve witnessed unmistakable signs of climate change. Since 1998, the United States has experienced nine of its 10 warmest years since temperature data was first systematically collected. Meanwhile, the 10 warmest years recorded worldwide have all occurred since 2005. And those numbers mask an even more daunting reality: temperatures have been more volatile than in previous decades, as heat waves have become more common and evening cooldowns offer less relief.

How you’ve experienced these effects is related to where you live, of course. In the U.S., temperatures have increased the most in the North and West. Nonetheless, we all eat, and because commodities are globally traded, the impacts of climate change on agriculture have worldwide implications for availability, prices and – more ominously – for food security.

The most direct effect is on crop yields. For example, a one-degree Celsius (1.8 degrees Fahrenheit) increase in the average low temperature during the growing season for rice decreases yield by 10 percent. Precipitation matters, too, of course. The frequency of extreme storm events has risen – and heavy rain threatens the long-term viability of agriculture through soil erosion and the reduction of available nutrients.

Much the same has been true of the volatility of seasonal precipitation. While the Midwest and North have experienced abnormally high rainfall, the Southwest and West have been on the precipice of drought. Drought, moreover, not only stresses crops but increases the threat of wildfire occurring in and around agricultural production areas.

Compounding the challenges associated with climate change is population growth. Ironically, human fertility has fallen so much almost everywhere that the global population is expected to enter a long period of decline within a few decades. But it takes quite a while for the demographic ship to slow and go into reverse. And if you are around the age of 20 now, by the time you are 50 the world population will have increased by half, to around 9 billion. Moreover, much of the population increase will occur in low-income countries least able to manage rapid changes in weather – notably in Africa.

Actually, the increase in the number of mouths to feed may prove less problematic than meeting the expectations of changes in diets. Incomes continue to grow almost everywhere, and that increased income will be reflected in demand for more calories – and, importantly, more calories from animal proteins, which will require significant amounts of grain for use as animal feed. Grain prices are expected to increase by half solely due to rising demand, and will likely more than double if climate change is allowed to act as a major drag on crop yields.

If agricultural productivity is allowed to stagnate, a less farm-friendly world cannot be fed without major sacrifices in living standards outside the rich industrialized nations. The only practical way to prevent that is through advanced technology that allows plants to thrive in drier, wetter, warmer and even colder environments. But before turning to specific issues associated with genetic modification, it is important to take a step back and look at how agricultural productivity has changed with time.

Testing genetically modified rice strains for drought and flooding resistance in Los Banos, Laguna Province, Philippines.

The Scorecard

Economists are inclined to prefer one comprehensive measure of productivity, total factor productivity, as the standard, and accordingly, the Economic Research Service of the U.S. Department of Agriculture has tracked TFP in agriculture over long periods. TFP is the ratio of agricultural output divided by a weighted average of agricultural inputs (e.g., fertilizer, land, labor, machinery), which measures how efficiently inputs are transformed into outputs.

Looking back, the record constitutes a triumph of technology and organization. Total farm inputs have held steady in the U.S. since 1948, while total agricultural output has almost tripled.

While total output soared thanks in large part to the extensive planting of the American West, corn yields had stagnated at around 26 bushels per acre from 1866 (the first year of measurement) until the mid-1930s because the gains from the exhaustive process of selective breeding had sharply diminished. But concerted efforts at plant and animal breeding, helped by the discovery of genes, subsequently bore fruit.

One of the most remarkable discoveries was hybrid corn, which broke through the long yield stagnation in the 1930s. Scientists learned that astounding gains could be obtained by crossing two inbred lines of parents with different genetics. As a result of these scientifically focused efforts, the amount of corn produced on an acre of land in the U.S. today is sixfold greater than a century ago.

Thanks to ongoing advances in the understanding of biological processes, scientists can now identify specific genes of interest (e.g., genes that convey protection from an emerging disease or increase resistance to drought) and work these into commercial varieties using traditional breeding methods like hybridization. But while hybrid plant breeding is alive and well, the process is slow.

Traditional plant breeding often requires multiple generations to produce a desired trait, and it can take over a decade to create a variety ready for release to farmers. This slow capacity for change through traditional breeding has always been an issue. However, a modest pace of R&D is far more problematic when climate change assaults productivity through vectors ranging from drought to new pests to new plant diseases. And unlike in earlier centuries, there is little room for expansion of cultivation to make up for stagnation in yields.

Modern genetic engineering – as opposed to selective breeding that dates back centuries – can dramatically reduce the time required to develop new varieties by producing desired traits in a single generation. In one very important case, the introduction of genetically modified organisms has increased corn yields by an average of 17 percent. A meta-analysis – specifically, a statistical mining of the information collected from 147 studies published from 1995 to 2014 – found that adopting GMO corn, cotton and soybeans increased yields by 22 percent on average even as it allowed a decrease in pesticide use of 37 percent.

Genetic Engineering Up Close and Personal

The term GMO is generally associated with “transgenesis,” where changes in the DNA of an organism are made through a technique that permits the integration of another organism’s gene. The first GMO technologies in the early 1990s used various methods to introduce new genes, and thus new characteristics and traits, into germplasm. One of these techniques involved, quite literally, shooting desired DNA segments into existing germplasm with the hopes of producing a new seedling that could express desirable traits. Other techniques emerged that used bacteria to “smuggle” desired DNA sequences into targeted plants.

Touring the Tajin Center for Research and Field Experimentation (CICE) in Tala, Mexico.

Overcoming initial public resistance, GMOs are now planted all over the world. In the United States, the vast majority of corn, soybean, cotton and sugar beet acres are planted with GMO varieties. There are no commercially grown varieties of wheat or most fruits and vegetables, though, largely because campaigns questioning the safety of GMOs have gotten more traction, and some consumers are wary of ending up collateral damage to what is popularly viewed as the sorcerer’s apprentice.

Commercial GMO crops have been bred to resist insects with little or no insecticides and to tolerate herbicides designed to kill weeds. All told, the results have been reassuring (at least to those who accept that the research is not biased). Large numbers of studies have concluded that the adoption of these varieties is associated with reductions in the number and quantity of insecticides applied, reduction in toxicity of herbicides applied, higher farm profits and greater adoption of no-till farming techniques that reduce erosion and water pollution.

Entering the technological fray is gene editing, a breakthrough for altering plants and animals that is altogether superior to earlier techniques for genetic modification. Indeed, gene editing, which refers to specific changes to a targeted location in an organism’s genome, is generally considered a game changer.

This is no place for a primer on break-throughs in molecular biology. Suffice it to say, though, that approaches such as CRISPR (clustered regularly interspaced short palindromic repeats) Cas9 and TALENs (transcription activator-like effector nucleases) allow scientists to insert new DNA segments into precise locations in existing DNA strands, or simply to turn the expression of preexisting genes on or off without fundamentally altering the underlying genetic structure. What differentiates the new gene-editing approaches from the “old” GMO approach is precision. The approach can dramatically speed the creation of new plant and animal varieties, reducing costs and cutting the development time of new varieties in half.

These new approaches can be used to alter the genetics within a species. For example, a desirable gene existing in one strain of wheat that conveys resistance to a particular disease might be inserted into another strain of wheat with other desirable traits – say, high yields or exceptional resistance to drought. Importantly, these so-called “intragenic” or “cisgenic” approaches do not involve the insertion of any “foreign” or outside-species DNA.

Making sure beer is here to stay – hops being modified for drought resistance in Bavaria.

As previously noted, some gene-editing applications are used to turn off or “knock out” gene expression. Consider the Holstein, the breed of cattle predominantly used by U.S. dairies due to their bountiful production of milk. Now, Holsteins are “naturally” horned – that is, the Holstein brought horns with it when selectively bred from other cattle – and their horns are typically removed to prevent cattle from injuring farm workers and each other. However, dehorning is painful, and the pain can linger for some time.

Enter gene editing, which has been used to turn off the genes responsible for the expression of horns in Holsteins. Thus, the technology provides the ability to maintain high milk production (and other desirable traits of the Holstein) even as it addresses an emerging animal welfare concern.

Consumer Aversion As A Barrier To Adoption

As alluded to earlier, despite three decades of experience with the technology, there remains high uncertainty about GMO safety among the general public. Though, critically, not in the scientific community: Numerous scientific bodies, from the National Academies of Science to the American Medical Association to the American Association for the Advancement of Science, have concluded that the approved crops emerging from these technologies are no riskier than crops created through centuries-old traditional selective breeding. However, these scientific findings have not stopped calls to limit the sale of GMOs and to require mandatory labeling, which has sharply reduced the demand for GMOs sold directly to consumers (as opposed to being used as ingredients in prepared foods).

While the debate over GMOs is a hoary one, with well-entrenched advocates and skeptics, solid knowledge about GMOs among the general public remains low. Consumers wary of “frankenfood” also lack an appreciation of just how long humans have had a role in changing the genetic makeup of our food. Indeed, hunter-gatherers, who dominated the world until 20,000 to 30,000 years ago, unknowingly put selective pressure on the plants and animals in their environment. Later, farmers (lacking any knowledge of genetics) used common-sense techniques to selectively breed higher-yielding and better-tasting plant and animal varieties.

A fine example of the effects of traditional selective pressure and breeding is evidenced in the Brassica plant genus. Modern-day kale, broccoli, cauliflower, cabbage and brussels sprouts are all descendants of a common Brassica ancestor. By breeding to maximize the production of leaves, one arrives at kale or collard greens. Putting selective pressure on the flowers resulted in broccoli, while focusing on bud production yielded brussels sprouts and cabbage.

Moreover, plants underwent dramatic changes untold millennia before humans arrived. Wheat, for example, has six sets of chromosomes corresponding to its three ancient grassy parents (humans, by contrast, have two sets of chromosomes – one from each human parent). The interspecies mingling of grassy DNA to create wheat occurred without human guidance or interference.

Regulation As A Barrier

GMOs in the United States are regulated by three different federal agencies, the Department of Agriculture, the Food and Drug Administration and the Environmental Protection Agency. The regulatory framework focuses, by and large, on the outcome of the genetic modifications rather than the method used to obtain the change.

The advent of new gene-editing approaches, however, has enabled innovators to bypass this costly, time-consuming regulation. For example, the Department of Agriculture exempts new gene-edited plants from regulation if they do not contain “foreign” genetic material – say, from an insect or an unrelated plant – and thus could have been produced through conventional (albeit far slower and less precise) plant-breeding methods. Note that gene-editing is far more powerful as well as superior cost-wise to conventional hybridization since the new gene-editing approaches move “new” DNA into a species, thereby creating transgenic plants and animals.

The wide applicability of gene editing has thus created challenges in creating a single satisfactory regulatory framework. In Europe, regulators have continued to take a precautionary approach, not exempting crops created from “native” DNA. As a result, all new gene-edited crops in Europe are evaluated under protocols for technology developed three decades ago. Given the vast array of gene-editing techniques, common sense suggests that a case-by-case approach to regulation is needed.

Genetic Engineering and Climate Change

Genetically engineered crops can serve double duty, both slowing climate change and hardening the food supply against the depredations of climate change. For example, crops engineered to be herbicide-tolerant have reduced – in some cases eliminated – the need for farmers to till the ground after harvest before planting for the next year. Farmers employ the newly engineered seeds, of course, to save money on both tillage and herbicide use. But consider that less tillage also reduces the greenhouse gases released during crop production – emissions from herbicides and from diesel tractors used in tilling – without disrupting the natural process of sequestering carbon dioxide as plants grow.

Now, every little bit does help. But the reality is that agriculture accounts for 10 percent of the U.S.’s greenhouse gas emissions, and the U.S. contributes around 11 percent of GHG emissions worldwide (down from around 19 percent in 2000 when the U.S. was a far larger proportion of global GDP). So U.S. agriculture is responsible for just 1.1 percent of worldwide GHG emissions.

That makes U.S. agriculture a target for efforts to reduce global greenhouse emissions, though not an especially inviting target: Reducing U.S. agricultural GHG emissions by, say, 50 percent would only decrease global emissions by about half of 1 percent.

But the potential of genetic engineering to protect the food supply as it races to match increases in demand is another matter entirely. Thus far, climate change hasn’t made much of a dent on agricultural productivity in the United States. Outputs continue to rise at a solid pace without increasing inputs. And genetic engineering has played a part: About one-fifth of the genetically engineered crops developed in the U.S. have been targeted for adaptation to climate change – for example, to toughen crops vulnerable to extreme temperature excursions.

The same can’t be said, though, for much of the world. Climate change from human activity reduced total factor productivity in global agriculture by about one-fifth from 1961 to 2020. To be clear, that doesn’t mean average productivity has fallen. Rather, climate change has served as a drag on productivity growth, equivalent to losing seven years of gains that would have been expected without increasing concentrations of greenhouse emissions in the atmosphere. The effects will continue to be most severe in developing areas, like Africa, that already have relatively high rates of food insecurity, high proportions of the population employed in agriculture and high rates of population growth.

The potential for rapid adaptation is pretty clear. Using gene editing, new types of bananas, corn, rice and even cows have already been developed. Corn that’s gene-edited to be tolerant to drought can prevent yield losses during stress conditions while leaving the plant poised to thrive when water is plentiful. Rice is now available that is more tolerant to soil with high salinity levels – and thanks to the simplicity and efficiency of gene editing, the plant was produced in only one year.

The world is racing to stop global warming before the consequences dramatically cut living standards and displace hundreds of millions from their homes – or even their countries. It’s a race that, for the time being, we are losing. That’s no reason to give up – indeed, it is a very good reason to start making the short-term sacrifices needed to prevent catastrophe down the road. But it’s also a reason to get serious about adapting to global warming, which is certain to get worse before it gets better.

Much of the adaptation – everything from building seawalls that protect coastal populations to hardening utilities against extreme weather to managing massive human migration – will be terribly expensive. Happily, though, that’s not the case in toughening agriculture against extremes through the use of genetic engineering.

The process has already begun, largely motivated by the reality that many of the changes in agriculture would more than pay for themselves, even if climate change weren’t so great a threat to food security.