GEOG 430
Human Use of the Environment

Land Use Change

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Land use change: refers to the process of human modification and transformation the natural landscape, usually emphasizing the functional role of land for economic activities.

Land use change as a Planetary Boundary:

In Lesson 1 of this course, we read about the Planetary Boundaries. Rockstrom et al. (2009) list "Change in land use" as one of the boundaries and propose the boundary to be "No more than 15%–20% of global ice free land surface converted to cropland". They noted that we were close to their proposed boundary, at 11.7% in 2009. Before this first assessment of planetary boundaries was written in 2009, land use was generally considered a local environmental issue, but since then it is becoming a force of global importance. This is importance is largely due to the relationship that land use has with other planetary boundaries. For example, changes in land use exert the most significant effect on biodiversity loss, and land-use changes in the Amazon could influence water resources as far away as Tibet (Rockstrom et al. 2009). Since Rockstrom et al. (2009) was first published, our understanding of the importance of land-use change for other earth systems has expanded greatly. An updated effort to assess Planetary Boundaries was published by Steffen et al. in 2015. They proposed that the land use change boundary should be measured as the "percent of original forest cover remaining from pre-industrial levels," and proposed that we should not exceed less than 54-75% (using a weighted average of the boundaries for tropical, temperate, and boreal forests). They noted that with only 62% of pre-industrial levels of forest cover left on earth, we may already have exceeded this boundary. Their analyses places land use change as a global environmental problem as pressing as climate change.

Chart of Planetary Boundaries
The Planetary Boundaries according to Steffen et al. 2015

The problem of land use change is not evenly distributed around the world. In fact, in 2018, Song et al. published a paper showing that global tree cover had in fact increased by 7.1% in the 35 years between 1982–2016. The problem is that increases in forest area in the global north cannot compensate for loss of forests in the tropics, as tropical forests had a much larger impact on other earth systems (such as climate change) (Steffen et al. 2015).

If you are interested, you can check out this Animated Map of Global Forest Loss.

Drivers of land use change:

Croplands and pastures now occupy 40% of land surface, rivaling forest cover in extent of the land surface (Foley et al. 2005). This makes agricultural production the planet’s single most extensive form of land use (Campbell et al. 2017). Land has become one of the world's most important resources, so much so that there has been a global rush to acquire large amounts of land in lower and middle income countries, often called "Land grabbing". This week, you will read about Proximate and Underlying Drivers of land use change (Geist & Lambin 2002) and Land grabbing (Edelman et al. 2013). This should remind you of your Lesson 5 reading of Campbell et al. (2017) which proposed that 80% of historical deforestation globally to date has caused by agriculture.

In 2018, an important new paper "Classifying drivers of global forest loss" sought to build on ideas purposed by Geist & Lambin (2002) by differentiating permanent land use conversion (i.e., deforestation) from temporary loss from forestry or wildfire (Curtis et al. 2018). What they found was that large-scale farming and ranching, the only permanent form of land use change accounted for 27% total forest loss (while forestry, small-scale farming, and wildfire accounted for the rest, but were not permanent).

To understand the breakdown of land use on earth, please take the time to read through ESRI's The Living Land Story Map. As you read, note how much of the land on earth is urban areas and human habitation, and think back to our section on overpopulation. Then think about how much of earth is used to produce goods that humans consume, and our discussion of consumption in Lesson 1. Finally, think about the Food-Energy-Water nexus. You should be starting to think about these in terms of each of the planetary boundaries, so take the time to think about how they relate to land use change.

Think back to the trade-offs we have already read about in terms of land-use and energy: including biofuels (Baka 2016, course website on oil palm) and hydro electricity production (Lesson 8). Geographers have also written about the fact that land use is an under-considered trade-off for solar production (Yenneti & Golubchikov 2016, Calvert & Mabee 2015). There may even be trade-offs with wind production. As you think about these, think about scale. For example, here in Pennsylvania, fracking and shale-gas development has not lead to significant deforestation, but has significantly changed the structure of our landscapes through forest fragmentation (Roig-Silva et al. 2016).

Finally, think about how these pressures on land are a driving the commodification of land and the accumulation of large amounts of land by foreigners in many developing countries (land grabbing). One final important paper by Rulli et al (2013) showed that land grabbing occurs almost entirely in places where land acquisition also ensure water acquisition. They find that many of the countries doing the most "grabbing" are those with the greatest water stress and that land grabbing is associated with a virtual grabbing of a substantial amount of freshwater resources, including both water supplied by rainfall and irrigation. In some cases land grabbing leads to a loss of access to water resources needed to ensure food security for local populations (Rulli et al. 2013).

For all of these relationships, think about who benefits and who bears the environmental burden and how these are different in different places.

References cited:

Calvert, K., & Mabee, W. (2015). More solar farms or more bioenergy crops? Mapping and assessing potential land-use conflicts among renewable energy technologies in eastern Ontario, Canada. Applied Geography, 56, 209-221.

Curtis, P. G., Slay, C. M., Harris, N. L., Tyukavina, A., & Hansen, M. C. (2018). Classifying drivers of global forest loss. Science, 361(6407), 1108-1111.

Foley, J. A., DeFries, R., Asner, G. P., Barford, C., Bonan, G., Carpenter, S. R., ... & Helkowski, J. H. (2005). Global consequences of land use. science, 309(5734), 570-574.

Rockström, J., Steffen, W., Noone, K., Persson, Å., Chapin Iii, F. S., Lambin, E. F., . . . Foley, J. A. (2009). A safe operating space for humanity. Nature, 461, 472. doi:10.1038/461472a.

Roig-Silva, C. M., Slonecker, E. T., Milheim, L. E., Ballew, J. R., & Winters, S. G. (2016). Forest cover changes due to hydrocarbon extraction disturbance in central Pennsylvania (2004–2010). Journal of Maps, 12(sup1), 131-138.

Rulli, M. C., A. Saviori and P. D’Odorico (2013). "Global land and water grabbing." Proceedings of the National Academy of Sciences 110(3): 892-897.

Song, X.-P., Hansen, M.C., Stehman, S.V., Potapov, P.V., Tyukavina, A., Vermote, E.F., Townshend, J.R., 2018. Global land change from 1982 to 2016. Nature 560(7720), 639-643

Steffen, W., Richardson, K., Rockström, J., Cornell, S. E., Fetzer, I., Bennett, E. M., ... & Folke, C. (2015). Planetary boundaries: Guiding human development on a changing planet. Science, 347(6223), 1259855.

Yenneti, K., Day, R., & Golubchikov, O. (2016). Spatial justice and the land politics of renewables: Dispossessing vulnerable communities through solar energy mega-projects. Geoforum, 76, 90-99.