In the year 2000 there were approximately 15 million square km of cropland and 28 million square km of pasture which are represented in the two main maps. These are equal to 12% respectively 22% of the ice-free land surface. This is according to estimates of a study on the geographic distribution of global agricultural lands by Ramankutty et al (published in Global Biogeochemical Cycles, 2008) who used a methodology of combining agricultural inventory data and satellite-derived land cover data to come to these figures (data can be accessed via Columbia University’s SEDAC).
Agricultural activities have dramatically altered our planet’s land surface, as the authors state in the introduction to their study, but agricultural areas have spaces of central importance to humanity. They provide the foundations not only of the livelihood of the majority of people, but also for feeding the still growing world’s population. Where these spaces are at risk, potential conflicts arise. “We know clearly that inequalities around food, water and energy wealth do create wars,” says David Nabarro, UN special representative on food security and nutrition in a BBC report. When unusual weather events threaten agricultural landscapes, the result are rising food prices of which the poorest are most affected from.
Climate change and food security are therefore key issues in finding strategies for a sustainable future of the global population. A framework document by the FAO points out, that although the wealthier nations may be losing out less, the vulnerability of populations from food insecurity is a global problem: “As an indirect effect, low-income people everywhere, but particularly in urban areas, will be at risk of food insecurity owing to loss of assets and lack of adequate insurance coverage. This may also lead to shifting vulnerabilities in both developing and developed countries.”
Geography can make an important contribution by analysing the geospatial effects of global warming and climate change on food systems. In the delegate’s session at this year’s 48th annual meeting of the British Society of Cartographers in London I presented the basic concept for mapping out agricultural spaces using the gridded cartogram method developed in my PhD research. The first two maps provide a new insight into the distribution of these global food spaces for which I worked with the data from the above mentioned study. By calculating the total areas of croplands and pastures I was able to apply a gridded cartogram transformation at a spatial resolution of 5 arc minutes (ca. 10 km) in longitude by longitude. The following two maps show the basic result of that transformation, so that in the two maps the size of an individual grid cell reflects the total area of each respective agricultural land. A grid cell twice as large as another has twice as much agricultural land in its space, so that these maps show an equal agricultural area projection of the land surface.
These are the croplands, which represent a total area of 15 million square km:
And here are the pastures, which represent an area of 28 million square km:
Both maps are only a fraction of the worlds total land area of about 149 million square km, but these are the most important areas to look at when it comes to understanding food security. The maps above are only the start for using a different cartographic approach in understanding the interrelations between environmental threats and food security. The maps – here shown with a topographic layer – have further analytical capabilities and allow to show any other geospatial information in that relation (and thus the relations between these agricultural spaces and other issues). The topography demonstrates a (known) relation between altitude and the distribution of agricultural areas. But one can go much further into other issues, such as the intensively discussed issue of water scarcity and food production. A study published in 2010 pointed out the threat level of freshwater resources (which I looked at in relation to population before). Such data is centrally important not only because of the population’s need for access to freshwater, but even more so for a sustainable provision of freshwater for framing and food production. Therefore, looking at the relation between agricultural lands and issues of water security can help to identify regions at risk and provide the basis for finding solutions to these specific risks. The following map series shows the different components of the water security study in relation to agricultural areas – it focuses on the global threats to security of flowing freshwater resources and river biodiversity, and therefore has to be seen as only one of many aspects of water-related issues arising in agricultural lands:
Humanity may not be forced into vegetarianism, as catchy headlines warned recently, but we have to learn to better understand where our spaces of food production are most at risk and how we can better protect them. This is one little part on the way for a sustainable future of humanity, although equally important we have to look at our lifestyles – at our consumption and waste that we produce – and at the (un)equal distribution of food of which there is much more around than we sometimes think there is. Global food security under climate change is a challenge, but it won’t be solved by closing our eyes to it.
With the SoC conference’s focus on geovisualisation and cartography, these maps can only provide a small topical insight to the issues raised here. Not least are these maps global perspectives, and solutions have to be found by identifying relations at all geographical scales. However, they demonstrate the capabilities of such alternative mapping approaches which in general are seamlessly scalable and therefore adaptable to looking at these issues at varying scales. In addition, the concept demonstrates a general way of using GIS and visualisation techniques for enhancing the understanding of complex data. One central part of our understanding comes from our visual capabilities which we do not always fully embrace when using conventional mapping approaches.