2. Soils and the grand environmental challenges - posted (1).pdf

Earth’s soil [email protected] Alfred Hartemink Department of Soil Science Soils & The Grand Environmental Challenges Earth’s Soil [email protected] What are the challenges? § Produce enough food § Climate change § Water quality and quantity § Biodiversity § Energy production Earth’s Soil hartemin...

Earth’s soil [email protected] Alfred Hartemink Department of Soil Science Soils & The Grand Environmental Challenges Earth’s Soil [email protected] What are the challenges? § Produce enough food § Climate change § Water quality and quantity § Biodiversity § Energy production Earth’s Soil [email protected] Soils and food production By 2050, agricultural production must increase by 60% globally At least a doubling in food production in economically developing nations in order to meet food demand. 95% of our food is directly or indirectly produced on our soils. Earth’s Soil [email protected] Population growth Earth’s Soil [email protected] Current food production Earth’s Soil [email protected] Food production Earth’s Soil [email protected] Urban food systems Urban agriculture Victory gardens Rooftop gardens Earth’s Soil [email protected] No soil needed Earth’s Soil [email protected] Undernourished people Earth’s Soil [email protected] Population growth Earth’s Soil [email protected] 25 years of growth Earth’s Soil Tokyo [email protected] Earth’s Soil Dehli [email protected] Earth’s Soil Chicago [email protected] Earth’s Soil [email protected] The effects § More people, more food needed § People are concentrated on small areas (55% in cities) § Nutrients from farm soils flows into the city § Less land available for food production § Some of the best land is being sealed § Contamination of city soils Earth’s Soil [email protected] Earth’s Soil [email protected] The soils Earth’s Soil [email protected] Drought Mineral stress – low soil fertility, salinity Frozen Shallow Wet Earth’s Soil [email protected] Soil characteristics Soil biological properties Transforms and recycles Biodiversity pool Soil physical properties Soil texture Soil colour Soil structure Soil chemical properties Nutrients Exchange capacity Indirectly fixed Drought Shallow depth Water excess Hard to fix Mineral stress Acidity Easy to fix Soil organic matter (C) pH (acidity or alkalinity) All relative Earth’s Soil [email protected] Soil conditions Inherent soil problems physical limitations (for example drainage) chemical limitations (for example soil acidity) Human induced problems soil degradation Earth’s Soil [email protected] Soil degradation Definition loss of productivity and a decline in the soil capacity to produce economic goods and perform ecosystem services Examples erosion, desertification, pollution, loss of organic matter, acidification, nutrient mining, salinisation, compaction. Earth’s Soil [email protected] Desertification Pollution Salinisation Soil erosion Earth’s Soil [email protected] Earth’s Soil [email protected] Soils Soils and water porous, stores water buffer after rainfall event filter capillary rise Earth’s Soil [email protected] Soils and water Urban areas – treatment of water Rural areas Earth’s Soil [email protected] Quality and quantity Earth’s Soil [email protected] Drying Lake Poopo, Bolivia Earth’s Soil [email protected] Drying Lake Poopo, Bolivia Earth’s Soil [email protected] Flooding Mississippi, March 2016 Earth’s Soil [email protected] Flooding Mississippi, March 2016 Earth’s Soil [email protected] Earth’s Soil [email protected] Climate change § Global average temperature has risen by 1.4 °F (0.8 °C) over the past 100 years. § The greatest increase has occurred in the past 35 years, with 15 of the 16 warmest years on record. § Greenhouse gas emissions such as carbon dioxide and methane, generated by human activities, are primarily responsible. § Global average temperature to rise another 2 to 11.5 °F (1.1 to 6.4 °C) over the next 100 years Earth’s Soil [email protected] Climate change Earth’s Soil [email protected] Earth’s Soil [email protected] Early ice melt Greenland Earth’s Soil [email protected] Early ice melt Greenland Earth’s Soil [email protected] Arapaho Glacier melt, Colorado 1889 - 2003 Earth’s Soil [email protected] Arapaho Glacier melt, Colorado 1889 - 2003 Earth’s Soil [email protected] Muir Glacier melt, Alaska 1941- 2004 Earth’s Soil [email protected] Muir Glacier melt, Alaska 1941- 2004 Earth’s Soil [email protected] Pedersen Glacier melt, Alaska 1940s - 2005 Earth’s Soil [email protected] Pedersen Glacier melt, Alaska 1940s - 2005 Earth’s Soil [email protected] Soils and climate change § Greenhouse gasses § Crop production § Buffer for extreme weather events Earth’s Soil [email protected] Earth’s Soil [email protected] Climate and crop yields Earth’s Soil [email protected] Soils and energy § Agriculture = 15% of the global energy demand § Agriculture = can produce> 50% of global energy demand § Environmental effects largely unknown § Biofuels vs food crops, biofuels vs nature oilpalm corn Sugar cane