MET 112 Global Climate Change: Lecture 13

1. MET 112 Global Climate Change: Lecture 13 Climate Change Impacts: Present and Future II Dr. Craig Clements

2. Climate Change Impacts • What signals would we expect from a warmer world? • Higher average temperature • Higher maximum temperatures • Higher minimum temperatures • More precipitation • Higher sea level • What ‘evidence’ do we have for changes in the 20th century?

3. Fingerprints and harbingers of climate change • FINGERPRINTS: Direct manifestations of a widespread and long-term trend toward warmer global temperatures • Heat waves and periods of unusually warm weather • Ocean warming, sea-level rise and coastal flooding • Glaciers melting • Arctic and Antarctic warming • Increases in sea level

4. Fingerprints and harbingers of climate change • HARBINGERS: Events that foreshadow the types of impacts likely to become more frequent and widespread with continued warming. • Spreading disease (i.e. mosquito carrying) • Earlier spring arrival • Plant and animal range shifts and population changes • Coral reef bleaching • Downpours, heavy snowfalls, and flooding • Droughts and fires

5. Impacts over the last 100 years

6. Indicators of Climate Change Fingerprints of climate change Stratosphere cooling Troposphere warming Ocean warming

7. Temperature trends • Troposphere (0 - ~ 10km) • Stratosphere (10 – 50 km) • Surface temperatures are warming – (Certain) • Middle troposphere is also warming (Very likely) • Early satellite data showed some cooling, but now that seemed to be due to instrument error. • Upper atmosphere is cooling (Certain) • Why cooling? More energy trapped in troposphere.

8. Water vapor feedback • Recall how the water vapor feedback works • Increase in temp • Increase evaporation • Increase in water vapor in atmosphere • Water vapor is a greenhouse gas • Increase in greenhouse effect • Further warming (positive feedback) • Current models suggest that the water vapor feedback is responsible for about the same amount of warming as warming from increases in CO2. • The importance of this feedback is still being investigated.

9. Global mean surface temperatures have increased

10. ` Svalbard, Norway (79N)

11. Arctic

12. Sea Level rise • Increased risk of floods, potentially displacing tens of millions of people due to • sea level rise and heavy rainfall events • 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

13. Recent Sea Level Changes

14. Branching coral Brain coral Increase in coral bleaching events: due to warmer ocean temperatures

15. http://www.climatehotmap.org/

16. Extreme Weather Events are Projected to Increase Projected changes during the 21st century Examples of impacts • Increased mortality in old people in urban areas • Damage to crops • Heat stress on livestock • Extended range of pests and diseases • Loss of some crop/fruit • Land slides, mudslides, damage to property and increased insurance costs • Reduced rangeland productivity, increased wildfires, decreased hydropower • Damage to various ecological and socioeconomic systems • Higher maximum temperatures; more hot days and heatwaves over nearly all land areas (very likely) • Higher minimum temperatures; fewer cold days frost days and cold spells over nearly all land areas (very likely) • more intense precipitation events over many areas (very likely) • increased summer drying over most mid-latitude continental interiors and associated risk of drought (likely) • increase in tropical cyclone peak wind intensity, mean and peak precipitation intensities (likely)

17. Future impacts due to climate change

18. More adverse than beneficial impacts on biological and socioeconomic systems are projected

19. 38 of 66 As a result of warming, plant species would be expected to migrate • North in the Southern Hemisphere • North in the Northern Hemisphere • South in the Northern Hemisphere • South in the Southern Hemisphere • To higher altitudes • To lower altitudes • 1 and 6 • 2 and 5

20. 37 of 66 Where would you expect to see the strongest evidence of climate change? • Tropical latitudes • Midlatitude deserts • Midlatitude oceans • High latitudes • High altitude mountains

21. 38 of 66 If ice melt was to stop even though average temperatures continue to warm, how would sea level respond • Sea level would continue to rise • Sea level would reach an equilibrium • Sea level would decrease

22. Impacts on water and agriculture • Water availability • Increase in some in some water-scarce regions, • Decrease in many water scarce regions • Globally, fresh water become more scarce • Increased agricultural productivity in some mid-latitude regions; reduction in the tropics and sub-tropics • Overall impact is negative

23. Effect on human health • Reduced winter mortality in • mid- and high-latitudes • Increased incidence of heat stress mortality • Tropics and midlatitudes • Increased incidence diseases in the tropics and sub-tropics • such as malaria and • water-borne diseases such as cholera,

24. Developing countries are the most vulnerable to climate change • Impacts are worse – • already more flood and drought prone • large share of the economy is in climate sensitive sectors • Lower capacity to adapt • because of a lack of financial and technological capacity • Climate change is likely to impact disproportionately upon the poorest countries and the poorest persons within countries,

25. Climate Change and California II Average Temperature: Winter - Summer – • Coastal cities: • Human health: • Water resources: • Agriculture:

26. Report Issued in 2004 • Sections include: • Climate projections • Sea levels • Extreme heat • Health impacts • Water resource • Agriculture and vegetation

31. Climate change and California Average Temperature: Winter - warmer winters - snowpack declines by 70-90% by 2090 Summer – warmer summers (5-15F by 2090) • Coastal cities: coastal erosion by sea level rise. • Human health: Urban air pollution/heat extremes impact most vulnerable • Water resources: Total water, but early runoff from Sierras costly to adapt. • Agriculture: Major challenge to various crops industries.

32. Weather-related economic damages have increased

33. Hot Times in Alaska movie http://www.pbs.org/saf/1404/video/watchonline.htm