National Geographic : 2011 Mar
$5.3 trillion 2011 1950 $2 trillion 1900 Technology Population Human Impact Affluence I=PxAxT *GDP FIGURES ARE CONSTANT 1990 INTERNATIONAL DOLLARS. JOHN TOMANIO, NGM STAFF. ART: BRYAN CHRISTIE. SOURCES: UNITED NATIONS; ANGUS MADDISON, "STATISTICS ON WORLD POPULATION, GDP AND PER CAPITA GDP, 1 2008 AD," UNIVERSITY OF GRONINGEN; WORLD BANK; WORLD INTELLECTUAL PROPERTY ORGANIZATION Is population growth the root cause? Or is it affluence, which leads to greater consumption of energy and other resources? Or technology, which offers new tools for exploiting and consuming? The IPAT formula is a way of thinking about the issue: It says the three factors compound. Since 1900 world GDP (a measure of A) and the number of patent applications (a measure of T) have grown even faster than population. PxAxT=width times height times length of three boxes representing the human impact on the planet in 1900, 1950, and 2011. WHY IS OUR IMPACT GROWING? • Population Worldwide 7 billion Affluence World GDP* $55 trillion Technology Patent applications 1.9 million 141,000 412,000 1.8 billion 2.5 billion Human impact, which had been growing steadily since the industrial revolution, started to grow exponentially after World War II, a phase some scientists now call the "great acceleration."