Agronomist Jeffrey Schussler
Nature magazine cries that crop production will decrease but agronomist with real-world observations reveals crop production will continue to rise
Nelson Zandbergen
Farmers Forum
OTTAWA — Doom-and-gloom researchers are predicting a severe drop in North American crop production by the end of this century due to alleged manmade climate change. But the alarming outlook — published last month in the scientific journal Nature — doesn’t square with the actual positive trends observed on the ground by a longtime agronomist with roots in the farming community.
The article, “Impacts of climate change on global agriculture accounting for adaptation,” presents a grim scenario of steep yield declines for corn (up to 40 %), wheat (30 to 40 %), and soybeans (up to 50 %) by 2090 if greenhouse gas emissions aren’t curtailed and global temperatures rise up to 3 degrees Celsius above pre-industrial levels.
The dire projections suggest that rising temperatures will devastate North American agriculture, particularly in the U.S. Midwest — although Canadian agriculture may benefit — leading to an overall hungrier world. The researchers measured the global dinner-plate impact at 4.4 % fewer calories available per day per person — or 120 calories — for each 1 degree rise in temperature by century’s end. That boils down to “everyone on the planet giving up breakfast,” according to study author Solomon Hsiang, professor of global environmental policy at the Stanford Doerr School of Sustainability. But the poorer parts of the globe will bear more of this projected shortfall, the article asserts.
However, none of this accords with the real-world observations and data collected by Iowa-based plant physiologist and agronomist Jeffrey Schussler, who presented the reality of ever-increasing North American crop yields at the 2023 Ontario Agricultural Conference.
But it is also not surprising as critics argue that, Nature magazine, once a bastion of rigorous scientific publishing, has increasingly strayed from its science-based roots, prioritizing sensationalism and ideological agendas over empirical rigor. They point out that the journal’s editorial stance often aligns with prevailing political or social narratives, particularly on topics like climate change or public health, where dissenting but evidence-based perspectives are sidelined. Editorials are increasingly advocacy-driven, blurring the lines between science and policy. One editorial argued for the term “assigned-sex” over “birth-sex” and was loudly criticized for choosing ideology over science.
So, while the Nature study positions rising carbon dioxide levels as a net negative for agriculture, Schussler disagrees. He highlighted the gas’s fertilizing effect as a net positive.
“The evidence to date suggests our yields for soybeans and wheat … have increased already 10 to 25 % in the last 40 years due to this increase in CO2, and we expect it will continue to increase in this century,” the former Pioneer and Corteva researcher said.
“I’m very impressed by what we’ve done in our lifetimes and I’m very optimistic about what we’re going to do in the next generation in trying to provide food security for the world,” Schussler said.
Higher CO2 also stimulates crop plants to partially close their pores (or stomata), reducing the plants’ water losses from transpiration and thereby boosting water-use efficiency under drought conditions, he said.
Schussler acknowledged that CO2 currently comprises about 430 parts per million of the atmosphere (or 0.043 %) and may hit as much as 550 ppm by 2050 — up from 410 ppm when he started his career in 1972.
But it’s all a far cry from the 7,000 ppm of 600 million years ago.
“We are actually in a very nice spot. We’re in some of the lowest CO2 and lowest temperatures that the world has ever seen over the millennia,” he said. “So just keep that in mind regarding some of the extrapolations of what’s happening in our environment today regarding the security of the world.”
And while average temperatures are rising, he pointed out that this doesn’t equate to increased maximum daytime temperatures during the growing season, which could otherwise pose a challenge specifically when crops are pollinating.
“We hear a lot of things about increasing maximum heat all the time, but when you actually look at the data, most of the increases in temperature that are affecting the average temperature for a year are at night and in the winters,” he said.
Schussler also highlighted other positive climate trends, such as increased sunlight and annual rainfall across the U.S., including the dry far west. He also pointed to a beneficial 9 to 10 day extension of the frost-free growing season in the Upper Midwest and Ontario, potentially lengthening to 30 days by mid-century. “Imagine if you had a growing season that’s a month longer than today,” he says, suggesting opportunities for longer-season hybrids and cover crops that boost yields.
