Global Data Hound

AUTHOR: Richard C. Cicone, President, ISCIENCES, L.L.C.

Knowing where people are, who they are, how they live, and what they do is the domain of human geography and demography.  A well-worn Volume 20 of the People’s Encyclopedia, the Atlas, was testament to my youthful fascination with this topic as depicted through maps.  I could travel the world, learn of its bounty, and observe how Homo sapiens has tried to shape and master it.  The maps showed me how we organized ourselves into units and how we transformed the natural environment for our needs by farming it, mining it, forming settlements, playing on it.  Cities and roads formed sinuous shapes throughout verdant regions – a course too powerful for mighty forests of the past to withstand.

The impact of humans on the Earth

Changing our environment to suit our needs is, after all, only human.  Today many are in disbelief that we may have changed Earth’s climate in so short a time by releasing carbon stores shaped by millions of years of natural processes.  That is not so much a shock to me – since I could read, I could see the human imprint on all these wonderful maps.  (Today you just need to spend a little time traveling the planet via Google Earth to observe the human footprint.)  In fact, the climate change story goes much farther back than a century or so of dependency on fossil fuels.  William Ruddiman (Plows, Plagues and Petroleum: How Humans Took Control of Climate) contends that we have been changing climate by changing the Earth’s surface for 8000 years.  Organized cultivation made it easier to care for growing populations than by hunting and gathering but changes of the Earth’s surface to introduce agriculture affected its albedo and resulted in geobiochemical reactions that increased atmospheric concentrations of methane and carbon dioxide.  These unintended consequences unleashed forces that perturbed Earth’s energy balance and, in Ruddiman’s estimation, increased average surface temperature.

And it is not just the climate we changed, but the geosphere and biosphere though manipulation of the waterways, exploitation of fertile lands, and construction of settlements.  I had the opportunity to study agriculture in China and learned that thousands of years of cultivation have exercised every scrap of arable land – beautiful formations of terraces in Sichuan, endless fields of wheat in the North China Plain interrupted only by farming villages.  But feeding so many taxes the Earth and today China faces depletion of fertile lands and water shortages in critical areas, as do many other regions of the world.

The evolution of population maps

Many years after I lost track of my favorite Atlas, I learned that in a map-sense we actually knew very little about ourselves in any detail.  In a meeting at CIESIN in the mid-90s, I recall discussions with social scientists exclaiming the need for public access to a product called the Global Population Database (GPopDB) developed by the Center for International Research at the U.S. Bureau of the Census for the exclusive use of U.S. Government users.  By today’s standards the map was primitive, but it served the interests of a restricted user community.  This was happening in the mid-90s, at a time when our understanding of climate change was already quite mature, yet here we faced a paucity of data about humans that allowed comparative regional analysis.  CIESIN managed to publish GPopDB, opening a new cartographic era for mapping people.

The situation now is much improved, yet in need of much more improvement.  ISciences’ Global Data Hound described two high caliber population maps spatially resolved to about thirty arc seconds (one kilometer square at the equator) that provide population counts.  Landscan is a product of the Oak Ridge National Laboratory and a descendent of the GPopDB of the 90s.  Gridded Population of the World (GPW; see below) and its family of maps, including the Global Rural-Urban Mapping Project map (GRUMP), is an effort of CIESIN and a contribution of NASA’s Earth Science Programs.  In some sense, it too was inspired by CIESIN’s earlier experience with GPopDB.

The future of mapping humanity

For the time being, CIESIN and others focused on mapping the human geography are the closest we get to “PeopleSat” – a metaphorical Earth sensor that produces scientific imagery about human beings across the globe.  (I extend my thanks to NASA for recognizing the importance of supporting the CIESIN  initiative and adding PeopleSat to its repertoire of Earth observing systems and only wish it could find a way to provide funding comparable to any one of its great satellite technology initiatives.)   Of course scientists and civil agencies worldwide champion surveys and census taking activities that provide the basic raw materials for these works.  While these in situ efforts collect hundreds of factors describing human demographics, political and economic behavior, few of these variables find their way into well-resolved, gridded maps with harmonized data that enable comparative analysis over broad regions of the Earth.  For example, CIESIN today is in the process of improving this family of products by creating disaggregated maps representing world poverty (infant mortality and child malnutrition).  Infant mortality is thought by some to reflect human stress to environmental, social, and political conditions and to be a sensitive indicator of the social and political health of nations.  Given the inconsistent standards and data gaps replete among in situ data sources, these maps are examples of the complexity involved in creating disaggregated global population maps.  However, this is an important task and I tip my hat to the data pioneers struggling with it.

World Population Day is a time to reflect about the human condition.  Human cartography, the mere geographic presentation of the human condition, somehow does not seem to rise to the same level.  But these maps are making a difference, as scientists form new expressions of human geography and increasingly use them to begin to assess the coupled interactions of humans and environment.