Can environmental measures in Denmark lead to deforestation in other parts of the world?
A new database provides an overview of where in the world deforestation has taken place and how the land is used afterwards. One of the things the database can be used for is to assess how land use changes affect climate on the global level.
The world’s growing demand for food and feed as well as biomass for bioenergy means that increasingly larger natural areas are being used for agricultural production. This has a significant impact on greenhouse gas emissions and biodiversity, and has socioeconomic consequences, among other things.
If we are to have an overall understanding of how human land use affects the environment, including the climate, then it is crucial to have a correct picture of how the world’s land is being used and of the changes that are taking place in this land use. Researchers from Aarhus University have created such an overview in a new database.
By combining data on how much land is covered by forest with data that indicates if the green canopy is primary forest, secondary forest, planted forest or permanent crops, the researchers have made it possible to see the bigger picture.
Changes in cultivation in one area can affect land use in another area
The new database describes where in the world deforestation has taken place and what the land is used for afterwards in the period 2001 to 2012. The database can be used to investigate the derivative effect on the climate of altered cultivation methods one place in the world on land use in another area in the world.
For example, Danish animal production is based on a considerable import of feed. If we reduce Danish feed production due to changes in land use it would mean that our demand for imported feed would increase in order to maintain our animal production. The need for food is not declining – on the contrary – so how would we acquire the missing amount of crops?
This would be done by using more land for agriculture in either Denmark or elsewhere in the world. In both cases this could lead to deforestation or destruction of other types of natural areas in order to make room for agricultural crops. All things being equal deforestation leads to more greenhouse gas emissions.
The big picture
Land is a limited resource with several different functions. Population growth and its increasing consumption, the expansion of bioenergy crops, and the effects of climate change have in recent years led to more pressure on global land resources.
It is important to gain knowledge about land use and land use changes. Until now, existing data have either been local-scale or only quantify static land use and not changes in land use.
- Since more than 10 percent of total greenhouse gas emissions are due to land use changes it is important to be aware of these changes when estimating the derived consequences of land use changes or assessing the total effect on greenhouse gas emissions of a certain production. The new database provides a total overview on a comparable basis, says one of the researchers behind the studies, Head of Section John E. Hermansen from the Department of Agroecology at Aarhus University.
The database is based on satellite data combined with FAO statistics. Data from satellites can describe how much land is covered with a green canopy but is not so good at differentiating between growth types, for example if the growth is a primary rain forest or a planted palm tree plantation. The FAO statistics can do this, though, but they are not so good at the holistic overview. By combining the two sets of data, the researchers have produced a databank with detailed information about global land use over time for most countries and calculated per continent.
- Among other things, our data have shown that on the global scale in the years 2001 to 2012 there was a significant decrease of natural forestland due to forest degradation, an expansion of grassland, and a somewhat stable cropland area. Primary forestland has decreased primarily in Africa and South America while in Europe there has been a slight increase in forestland, says John Hermansen.
Read the article “Identifying Land Use Change and Land-Use Changes (LULUC): A global LULUC Matrix” in Environmental Science and Technology.
For more information please contact: Head of Section John E. Hermansen, Department of Agroecology, email: firstname.lastname@example.org, telephone: +45 8715 8017, mobile: +45 2962 9538
Climate-Smart Agri-Food Systems is one of the research areas in which the Department of Agroecology is particularly strong and from which results are delivered in line with national and and global societeal challenges and goals.