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.