Griggs - Met Office


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Griggs - Met Office

  1. 1. Climate Change <ul><li>Coastal Zones in Sub-Saharan Africa </li></ul><ul><li>Natural History Museum and Royal Society </li></ul><ul><li>Dave Griggs </li></ul><ul><li>Director, Hadley Centre, Met Office </li></ul>
  2. 2. Variation of the Earth’s surface for the past 140 years...
  3. 3. Global mean surface temperatures have increased
  4. 4. The Land and Oceans have warmed
  5. 5. Precipitation patterns have changed
  6. 6. Sea Levels have risen
  7. 7. An increasing body of observations gives a collective picture of a warming world and other changes in the climate system <ul><li>Global-average surface temperature increased by about 0.6 ºC over 20th century </li></ul><ul><li>1990s warmest decade and 1998 warmest year in last 1000 years in Northern Hemisphere </li></ul><ul><li>Over last 50 years night-time minimum temperatures increased by about 0.2 ºC per decade </li></ul><ul><li>10% reduction in snow cover ice since late 1960s </li></ul><ul><li>Reduction of about two weeks in annual duration of lake and river ice over 20th century </li></ul><ul><li>Widespread retreat of mountain glaciers during 20th century </li></ul>
  8. 8. <ul><li>Northern Hemisphere spring and summer sea-ice extent decreased by 10-15% since 1950s </li></ul><ul><li>40% decline in late summer Arctic sea-ice thickness in recent decades </li></ul><ul><li>Global-average sea level has increased by 10-20 cm during 20th century </li></ul><ul><li>0.5-1% per decade increase in Northern Hemisphere mid-latitude precipitation during 20th century </li></ul><ul><li>2-4% increase in frequency of heavy precipitation events in Northern Hemisphere mid- and high-latitudes over latter half of 20th century </li></ul>
  9. 11. Human activities have changed the composition of the atmosphere since the pre- industrial era
  10. 12. 19 levels in atmosphere 20 levels in ocean 2.5 lat 3.75 long 1.25 1.25 The Hadley Centre third coupled model HadCM3 30km -5km
  11. 13. THE CLIMATE SYSTEM OCEAN Precipitation Sea-ice LAND Ice- sheets snow Biomass Clouds Solar radiation Terrestrial radiation Greenhouse gases and aerosol ATMOSPHERE The Met.Office Hadley Centre
  12. 14. Atmosphere Atmosphere Atmosphere Atmosphere Atmosphere Atmosphere Land surface Land surface Land surface Land surface Land surface Ocean & sea-ice Ocean & sea-ice Ocean & sea-ice Ocean & sea-ice Sulphate aerosol Sulphate aerosol Sulphate aerosol Non-sulphate aerosol Non-sulphate aerosol Carbon cycle Carbon cycle Atmospheric chemistry Ocean & sea-ice model Sulphur cycle model Non-sulphate aerosols Carbon cycle model Land carbon cycle model Ocean carbon cycle model Atmospheric chemistry Atmospheric chemistry Off-line model development Strengthening colours denote improvements in models 1975 1985 1992 1997 HADLEY CENTRE EARTH SYSTEM MODEL
  13. 15. Most of the observed warming in the past 50 years is attributable to human activities
  14. 16. Global mean temperature changes
  15. 17. Land areas are projected to warm more than the oceans with the greatest warming at high latitudes Annual mean temperature change, 2071 to 2100 relative to 1990: Global Average in 2085 = 3.1 o C
  16. 19. Global-average temperature and sea level are projected to rise under all scenarios <ul><li>Global-average surface temperature projected to increase by 1.4 ºC </li></ul><ul><li>to 5.8 ºC by 2100 </li></ul><ul><li>Rate of warming likely unprecedented in at least last 10,000 years </li></ul><ul><li>Land areas will warm more than the global average </li></ul><ul><li>Global average precipitation will increase over 21st century </li></ul><ul><li>Very likely to be more intense precipitation events </li></ul><ul><li>Snow cover and sea-ice extent projected to decrease further </li></ul><ul><li>Glaciers and icecaps projected to continue widespread retreat </li></ul><ul><li>Global mean sea-level projected to increase by 9 cm to 88 cm by </li></ul><ul><li>2100 </li></ul>
  17. 20. CO 2 concentrations, temperature and sea level continue to rise long after emissions are reduced
  18. 21. More adverse than beneficial impacts on biological and socioeconomic systems are projected
  19. 22. World Population 6,056,528,577 The Challenge: Sustainable Management of an Ever- Changing Planet
  20. 23. Increased risk of floods, potentially displacing tens of millions of people, due to sea level rise and heavy rainfall events, especially in Small Island States and low-lying deltaic areas. Bangladesh is projected to lose about 17% of its land area with a sea level rise of one meter - very difficult to adapt due to lack of adaptive capacity projected present
  21. 24. <ul><li>Food production needs to double to meet the needs of an additional 3 billion people in the next 30 years </li></ul>Climate change is projected to decrease agricultural productivity in the tropics and sub-tropics for almost any amount of warming
  22. 25. <ul><li>Wood fuel is the only source of fuel for one third of the world’s population </li></ul><ul><li>Wood demand will double in the next 50 years </li></ul><ul><li>Forest management will become more difficult due to an increase in pests and fires </li></ul>
  23. 26. <ul><li>One third of the world’s population is now subject to water scarcity </li></ul>Population facing water scarcity will more than double over the next 30 years Climate change is projected to decrease water availability in many arid- and semi-arid regions
  24. 27. <ul><li>Biodiversity underlies all ecological goods and services </li></ul>Climate change will exacerbate the loss of biodiversity Estimated 10-15% of the world’s species could become extinct over the next 30 years
  25. 28. Food and Fiber Production Provision of Clean and Sufficient Water Maintenance of Biodiversity Maintenance of Human Health Storage and cycling of Carbon, Nitrogen, Phosphorus Agricultural Lands Coastal Zones Forest Lands Freshwater Systems Arid Lands & Grasslands Climate change will affect the ability of ecological systems to provide a range of essential ecological goods and services
  26. 29. Developing countries are the most vulnerable to climate change <ul><li>Impacts are worse - already more flood and drought prone and a large share of the economy is in climate sensitive sectors </li></ul><ul><li>Lower capacity to adapt because of a lack of financial, institutional and technological capacity and access to knowledge </li></ul><ul><li>Climate change is likely to impact disproportionately upon the poorest countries and the poorest persons within countries, exacerbating inequities in health status and access to adequate food, clean water and other resources. </li></ul><ul><li>Net market sector effects are expected to be negative in most developing countries </li></ul>
  27. 30. Projected concentrations of CO 2 during the 21 st century are two to four times the pre-industrial level
  28. 31. Projected levels of atmospheric CO 2 during the next 100 years would be higher than at anytime in the last 440,000 yrs (BP 1950) Projected (2100) Current (2001 ) CO 2 Concentration (ppmv)
  29. 32. Projected Temperatures During the 21 st Century Are Significantly Higher Than at Any Time During the Last 1000 Years