11/04/2024 | News release | Distributed by Public on 11/04/2024 15:07
Scientists and environmental activists have consistently called for drastic reductions in meat production as a way to reduce emissions and, in doing so, combat climate change. However, a new analysis concludes that a smaller reduction, borne by wealthier nations, could remove 125 billion tons of carbon dioxide-exceeding the total number of global fossil fuel emissions over the past three years-from the atmosphere.
Small cutbacks in higher-income countries-approximately 13% of total production-would reduce the amount of land needed for cattle grazing, the researchers note, allowing forests to naturally regrow on current pastureland. The return of trees-long known to effectively absorb, or sequester, carbon dioxide (CO2)-would drive significant declines in fossil fuel emissions, which the study's authors estimate would roughly equal three years' worth of global emissions.
"We can achieve enormous climate benefits with modest changes to the total global beef production," says Matthew N. Hayek, an assistant professor in New York University's Department of Environmental Studies and the lead author of the analysis, which appears in the journal Proceedings of the National Academy of Sciences (PNAS). "By focusing on regions with potentially high carbon sequestration in forests, some restoration strategies could maximize climate benefits while minimizing changes to food supplies."
The analysis found that pasturelands, especially in areas that were once forests, hold immense promise for mitigating climate change. When livestock are removed from these "potential native forest" areas, ecosystems can revert to their natural forested state, capturing carbon in trees and soil.
The paper's authors see high- and upper-middle-income countries as viable candidates for reduction in beef production because they have some current pasture areas that do not produce very much grass per acre, exist where grass grows only during a short growing season, and are in areas that could, instead, grow vast, lush forests with deep soils that work to sequester carbon. This differs significantly from other regions, including sub-Saharan Africa and South America, where much more pasture can grow year-round, producing more feed for animals per acre than northern countries. In addition, the research team sees ways lower-income regions could increase the efficiency at which cattle are fed and raised on grass as a way to offset the minor loss in production from higher-income countries.
"This isn't a one-size-fits-all solution," Hayek emphasizes. "Our findings show that strategic improvements in the efficiency of cattle herds in some areas, coupled with decreased production in others, could lead to a win-win scenario for climate and food production."
The study reveals an even more dramatic potential for climate mitigation if the scope of restoration was expanded. The researchers found that removing cattle, sheep, and other grazing livestock from all potentially natively forested areas globally could sequester a staggering 445 gigatons of CO2 by the end of this century-the equivalent to more than a decade of current global fossil fuel emissions.
"Importantly, this approach would still allow livestock grazing to remain on native grasslands and dry rangelands, which are places where crops or forests cannot easily grow," says Hayek. "These areas support more than half of global pasture production, meaning that this ambitious forest restoration scenario would require cutting global cattle, sheep, and other livestock herds by less than half. These findings underscore the immense potential of natural forest restoration as a climate solution."
The PNAS study used remote sensing technology to track pasture productivity-the amount of grass produced annually that livestock can consume-in order to estimate the climate benefits that reductions would yield.
Amount of edible pasture grasses and vegetation grown in each gridcell per year for grazing livestock (pasture aboveground biomass). Darker colors refer to more annual pasture growth per unit area. Green shows pasture growth in potential forest areas, where pasture has replaced areas that were once forested. Pink shows pasture growth in native grassland areas. Image credit: Matthew Hayek and Johannes Piipponen.
"Even if two different areas can regrow the same amount of carbon in trees, we can now know how much pasture, hence beef production, we would have to lose in each area to grow those trees back," explains Johannes Piipponen, a doctoral candidate at Finland's Aalto University and coauthor of the study, who led this technical advance. "For many consumers in high-income regions, like Europe and North America, reducing excessive meat consumption benefits both their health and the environment. However, until now, it has remained rather unclear where the required decreases in production could begin."
Maps produced by the team's research can identify areas where policies could be prioritized for reducing beef production and hastening forest recovery-for instance, by offering forest land conservation incentives or buyouts to beef producers.
The authors acknowledge that ecosystem regrowth is not a substitute for efforts to reduce fossil fuel emissions. But, it can serve as a powerful complement to combat climate change.
"In many places, this regrowth could occur by seeds naturally dispersing and trees regrowing without any human involvement," says Hayek. "However, in some places, with especially degraded environments or soils, native and diverse tree-planting could accelerate forest restoration, giving regrowth a helping hand. This long-term regrowth would benefit the climate for decades to come, with significant regrowth and carbon capture beginning within just a few years in many areas, and lasting for 75 years or more until forests nearly mature."
The authors also emphasize that while the findings do not call for extreme changes to global food production and trade patterns, swift action is necessary in order to meet climate goals.
"Within the next two decades, countries are aiming to meet critical climate mitigation targets under international agreements, and ecosystem restoration on converted pasturelands can be a critical part of that," observes Hayek. "Our study's findings could offer paths forward for policymakers aiming to address both climate mitigation and food security concerns. As countries worldwide commit to ambitious reforestation targets, we hope that this research can help identify and prioritize the most effective areas for carbon sequestration efforts while considering global food needs."