The current flux of carbon to the Earth’s atmosphere for which humans are responsible hovers around 10 Gt (1 Gt = 1015 g) per year.1,2 Fossil fuel combustion, which has steadily increased since we began driving about 120 years ago, now comprises much of that output. But there are other notable anthropogenic sources of carbon, not the least of which stems from the destruction of Earth’s forests. The degradation and levelling of forested land is broadly classified as “land-use and land-cover change” (LULCC).3 Though it’s challenging to calculate LULCC’s exact contribution to the global carbon budget, the figure is thought to have fluctuated around 1.2 Gt per year for the past two decades.3,4 It’s certainly not something we can ignore in the climate change discussion.
What is it?
LULCC may be a clunky abbreviation, but it’s important to distinguish its two components. “Land-use change” is said to occur when an area is reallocated without completely changing the existing land type, e.g. selective wood harvesting. This is often referred to as degradation, and it can occur at varying intensities. “Land-cover change” is less subtle, and generally implies deforestation, or the complete clearing of previously undisturbed land. In a given region, it is possible for rates of land-use change to decline while deforestation increases, and vice versa.3,5
This all may seem like semantic quibbling, but the ability to set these effects apart is necessary for effective policymaking. Brazil is an apt case study. The country, to its credit, is internationally recognized for its reduction in deforestation (land-cover change) rates. Land-use change in Brazil paints a murkier picture, however. Degradation resulting from land-use change is hard to pinpoint, but rates in Brazil have likely risen significantly over the same period that deforestation declined.3,5 Going forward, it will be critical to develop new policy that specifically addresses issues like logging, road construction, and fire prevention.
The vast majority of net carbon emissions related to LULCC come from tropical regions. Houghton et al. note importantly that this does not imply a lack of activity outside the tropics. Rather, the carbon sinks from LULCC (such as reforestation) at higher latitudes tend to match the carbon flux in those regions. The tropics, in contrast, are dominated by a net loss of forested land, and therefore a net out-flux of carbon.3
Two major players in tropical LULCC—Brazil and Indonesia— provide valuable case studies on the efficacy of current efforts to reduce net carbon flux. Incentive programs and new laws have gone into effect in both nations, with varying degrees of success.
As alluded to above, Brazil’s rates of deforestation have dropped nearly 70% over the past decade.5
Success in Brazil has largely been attributed to intensified regulation, and credit programs or premiums aimed at reducing rates of land-clearing. County-based programs have been formulated and funded with aid from organizations such as National Climate Change Policy. An environmental initiative called the Amazon Fund, sponsored by Norway, has provided $1 billion to this end. To some extent, changes in the profitability of soy and modifications to beef production also abated high rates of deforestation.6
Indonesia has also received aid from Norway’s government, but progress has been elusive because of an historically volatile political structure. Although positive political changes are taking place in the government, Indonesia has accumulated baggage from decades of corruption. Conflicts of interests linger in the political structure, making it extremely difficult to ensure that funding is properly allocated.7
The palm oil industry has a particularly heavy hand in Indonesia. Over the past decade the use of palm oil in commercial products has skyrocketed and the efficacy of this crop in tropical regions has sustained deforestation at problematic rates.7,8 Palm oil production also been blamed for major loss of biodiversity, and threatening populations of fragile species like the Sumatran Orangutan. And beyond the carbon budget and even other detrimental ecological effects, the palm oil crop presents a serious environmental justice issue for its continued reliance on child labor in developing countries like Indonesia.8
Another LULCC-related symptom of the palm oil crop in Indonesia is the destruction of peatland. Burning peatland certainly has terrible local and regional environmental effects from the smog and ash produced. But peat is also a tremendous carbon reservoir, so the clearing of peatlands to lay ground for palm oil plantations is a huge blow to the global carbon budget.7,8
Unfortunately, the market for palm oil in the developed world has become nearly ubiquitous. Growing popularity in the palm oil can largely be traced to its effectiveness as a substitute for other oils higher in trans fatty acids. Health concerns about partially hydrogenated oils have made cheap alternatives like palm oil irresistible in the food industry.8
Systemic government problems are certainly something that will take time and concentrated local effort to work through. But incentive and credit programs are clearly a critical part of lowering LULCC rates. In terms of deforestation, credit programs have a necessary complement to local law enforcement and legislation—what Nepstad et al. call “frontier governance”.6 It’s abundantly clear that the palm oil crop is a top candidate for these incentive programs to target.
So in addressing the question of who should bear financial responsibility for programs, we might look to the leading retailers and consumers of palm oil products. It should come as no surprise that the United States, the European Union, and China and the world’s top users. But it is also informative to look at companies that use palm oil, their level of transparency, and their dedication to sustainable practices in business. The World Wildlife Fund Palm Oil Scorecard makes just such an assessment, which is publically available if not heavily advertised.9 This is perhaps the area in which individuals have the most potential to positively influence sustainability with respect to LULCC. The WWF scorecard sets the stage for a strong awareness campaign to expose bad practices and promote corporate accountability.
All this is to say, the informed consumer has a great deal of power in facilitating positive change in global LULCC.
Eric Kleinsasser is a graduate student in the department of earth sciences at USC.
 Olivier JGJ, Janssens-Maehout G, Muntean M, Peters J. “Trends in Global CO2 Emissions.” PBL Netherlands Environmental Assessment Agency. 2015. http://edgar.jrc.ec.europa.eu/news_docs/jrc-2015-trends-in-global-co2-emissions-2015-report-98184.pdf
 United States Environmental Protection Agency. “Global Greenhouse Gas Emissions Data.” 2015. https://www3.epa.gov/climatechange/ghgemissions/global.html
 Houghton RA, House JI, Pongratz J, van der Werf GR, DeFries RS, Hansen MC, Le Quere C, Ramankutty N. “Carbon emissions from land use and land-cover change.” Biogeosciences, 9 5125-5142. 2012
 Archard F, Beuchle R, Mayaux P, Stibig HJ, Bodart C, Brink A, Carboni S, Desclee B, Connay F, Eva HD, Lupi A, Rasi R, Seliger R, Simonetti D. “Determination of tropical deforestation rates and related carbon losses from 1990 to 2010.” Global Change Biology, 20, 2540-2554. 2014.
 Margulies J. “Getting it right: Deforestation vs. Degradation in the Amazon.” Forest Justice. 2010. http://www.forestjustice.org/2010/11/16/getting-it-right-deforestation-vs-degradation-in-the-amazon/
 Nepstad D, McGrath D, Stickler C, Alencar A, Azevedo A, Swette B, Bezerra T, DiGiano M, Shimada J, Seroa da Motta R, Armijo E, Castello L, Brando P, Hansen MC, McGrath-Horn M, Carvalho O, Hess L. “Slowing Amazon deforestation through public policy interventions in beef and soy supply chains.” Science Reviews, 344, 6188. 2014.
 Spolar C, Matthias S, Ryan O, Chinny L, Bernard S, Bott I, Bibby C. “The Great Land Rush: Indonesia.” Financial Times. 2016.
 Union of Concerned Scientists. “Palm Oil and Global Warming fact sheet.” 2013. http://www.ucsusa.org/sites/default/files/legacy/assets/documents/global_warming/palm-oil-and-global-warming.pdf
 World Wildlife Fund. “2013 Palm Oil Buyers Scorecard: measuring the progress of palm oil buyers.” 2013. http://wwf.panda.org/what_we_do/footprint/agriculture/palm_oil/solutions/responsible_purchasing/palm_oil_buyers_scorecard_2013/