Presentation on theme: "Climate Change Elements for a discussion IFAD Rome, May 18-19, 2007 Alejandro Deeb."— Presentation transcript:
Climate Change Elements for a discussion IFAD Rome, May 18-19, 2007 Alejandro Deeb
% change in runoff by 2050 Many of the major “food-bowls” of the world are projected to become significantly drier Many of the major “food-bowls” of the world are projected to become significantly drier Globally there will be more precipitation Globally there will be more precipitation Higher temperatures will tend to reduce run off Higher temperatures will tend to reduce run off A few important areas drier (Mediterranean, southern South America, northern Brazil, west and south Africa) A few important areas drier (Mediterranean, southern South America, northern Brazil, west and south Africa)
Some climate change issues Patterns of precipitation and runoff will change substantially Patterns of precipitation and runoff will change substantially Rain in fewer, heavier events leading to more floods and dry spells; less ground water recharge Rain in fewer, heavier events leading to more floods and dry spells; less ground water recharge Projections for increased number of rainy days (left) and amount of rain per wet day (Right) for 2041-2060 period based on modeling (HadRM2) Fewer rainy days But heavier rain
Europe: Changing flood frequency Lenher et al 2006 Climatic Change Over much of Europe “one in a hundred year floods” will occur every couple of decades Over much of Europe “one in a hundred year floods” will occur every couple of decades
The Intergovernmental Panel on Climate Change’s (IPCC) Special Report on Emissions Scenarios (SRES), published in 2000 The A1 storyline and scenario describes a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter and, in several variations of it, the rapid introduction of new and more efficient technologies. Major underlying themes are convergence between regions, capacity-building, and increased cultural and social interactions, with a substantial reduction in regional differences in per capita income. A1 is subdivided into A1FI (fossil-fuel intensive), A1T (high-technology), and A1B (balanced), with A1FI generating the most CO2 emissions and A1T the least (of the A1 storyline, and the second lowest emissions of all six marker scenarios). But even in the A1T world, atmospheric concentrations of CO2 still near a doubling of preindustrial levels by 2100. For a contrasting vision of the world’s social and technological future, SRES offers the B1 storyline, which is (marginally) the lowest-emissions case of all the IPCC’s scenarios. The storyline and scenario family is one of a converging world with the same global population as A1, peaking in mid-century and declining thereafter, but with more rapid change in economic structures towards service and information economies, which is assumed to cause a significant decrease in energy intensity. The B1 world finds efficient ways of increasing economic output with less material, cleaner resources, and more efficient technologies. Many scientists and policymakers have doubted whether a transition to a B1 world is realistic and whether it can be considered equally likely when compared to the scenarios in the A1 family. The IPCC did not discuss probabilities of each scenario, making a risk- management framework for climate policy problematic since risk is probability times consequences.
Dangerous climate 0.6 CCoral bleaching 0.6 CCoral bleaching 0.6 CWest Antarctic losing ice 0.6 CWest Antarctic losing ice 0.7 CKilimanjaro glacier gone 0.7 CKilimanjaro glacier gone 1.0 C Tropical Glacier in the Andes gone 1.0 C Tropical Glacier in the Andes gone 1.6 COnset of melting of Greenland 1.6 COnset of melting of Greenland 2-3 CCollapse of Amazon rainforest 2-3 CCollapse of Amazon rainforest 4 CCollapse of THC current 4 CCollapse of THC current Source: Exeter Conference, 2005Source: Exeter Conference, 2005