When we think of the biggest culprits in pollution and climate change, we may envision cars and factory smokestacks spewing exhaust, not green fields and healthy plants. But actually, agricultural crops and livestock release up to a third of human-generated greenhouse gas worldwide. And this means that any efforts to mitigate climate change must address agricultural emissions.
Some types of agriculture are more problematic than others. The level of ag-related emissions varies by crop and by agricultural practices. Another factor is the amount of environmental damage caused as compared with the amount of food produced. For instance, Vietnam ranks sixth in total greenhouse gas emissions from croplands but generates the most emissions per kilocalorie of rice grown, implying that there’s room for improvements in their practices.
Land systems scientist Kimberly Carlson is showing how to fine-tune such improvements with far more specificity than previously imagined. An assistant professor in the department of Natural Resources and Environmental Management, Dr. Carlson combines social and natural science methods with high-tech tools to explore the intersection of issues related to agricultural land use, ecosystem processes, environmental governance initiatives, and human livelihoods.
In a recent article in Nature Climate Change, Dr. Carlson and her co-authors argue that climate change policy should prioritize the elimination of peatland draining, which generates 32 percent of cropland emissions while only providing slightly over 1 percent of total crop kilocalories. Conversely, nitrogen fertilizers generate relatively low increases in greenhouse gas emissions while increasing food production significantly.
Dr. Carlson is also concerned with land use outside the agricultural sector: in 2015, she received one of only nine Google Earth Engine Research Awards to map “high carbon stock forests” in Sumatra and Borneo. These are carbon-rich areas that NGOs seek to protect against logging or clearing to benefit climate and biodiversity.
As she explains, “My lab group uses a variety of tools, including remote sensing, statistical analysis, and field work to understand whether and why environmental governance initiatives addressing the agricultural sector are effective. We are constantly reminded that land use is highly complex and dynamic—even when technical solutions to reducing the environmental impact of agriculture are available, implementing them is highly challenging.” There’s no one-size-fits-all solution to the impacts of human land use…but Dr. Carlson’s work shows that there doesn’t need to be.
Read more about Dr. Carlson’s work at https://carlson-lab.org.
