Biography
Biography: Rattan Lal
Abstract
The so-called “Anthropocene” may have been set-in-motion with the dawn of settled agriculture about 10 millennia ago, but accelerated with the onset of Industrial Revolution ~circa 1750. An increase in access to food through settled agriculture increased human population (billion) from 0.002-0.02 during the hunter/gatherer era to ~1 in 1800, 1.7 in 1900, 2.5 in 1950, 6.1 in 2000, 7.5 in 2016 and projected to 9.7 by 2050 and 11.2 by 2100. The environmental impact (I=PAT, where P is population, A is affluence, and T is technology) includes deforestation, alterations of biogeochemical cycling of elements (C, N, P) and water, soil degradation (erosion, salinization, C and nutrient depletion), loss of biodiversity, eutrophication of natural water, and global climate change. Atmospheric concentration of CO2 increased from ~280 ppm around 1750 to > 400 ppm at present, along with increase in concentration of other radiatively-active gases including CH4 (722 ppb to 1883 ppb) and N2O (270 ppb to 327 ppb). The magnitude of C emitted into the environment from pre-historic era to 2010 is estimated at 456 Pg compared with that of 200 Pg from fossil fuel combustion. Presently, 38% of Earth’s land surface is used for agriculture, 70% of the global fresh water withdrawal is used for irrigation, and 30-35% of global greenhouse gas emissions are contributed by agriculture. Yet, 1 in 7 persons are food-insecure and 2-3 in 7 are malnourished. Nonetheless, soil matters, because solution to global issues lies in sustainable intensification of soils by producing more from less.