Upload
doris
View
44
Download
4
Embed Size (px)
DESCRIPTION
MET 112 Global Climate Change: Lecture 13. Climate Change Impacts: Present and Future II Dr. Craig Clements. Climate Change Impacts. What signals would we expect from a warmer world? Higher average temperature Higher maximum temperatures Higher minimum temperatures More precipitation - PowerPoint PPT Presentation
Citation preview
MET 112
1
MET 112 Global Climate Change: Lecture 13
Climate Change Impacts: Present and Future II
Dr. Craig Clements
MET 112
2
Climate Change ImpactsClimate Change Impacts What signals would we expect from a warmer world?What signals would we expect from a warmer world?
– Higher average temperatureHigher average temperature– Higher maximum temperaturesHigher maximum temperatures– Higher minimum temperaturesHigher minimum temperatures– More precipitationMore precipitation– Higher sea levelHigher sea level
What ‘evidence’ do we have for changes in the 20th What ‘evidence’ do we have for changes in the 20th century?century?
MET 112
3
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
Fingerprints and harbingers of Fingerprints and harbingers of climate changeclimate change
MET 112
4
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
Fingerprints and harbingers of Fingerprints and harbingers of climate changeclimate change
Impacts over the last 100 yearsImpacts over the last 100 years
Indicators of
Climate Change
Fingerprints of climate change
Stratosphere cooling
Troposphere warming
Ocean warming
MET 112
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.
MET 112
9
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.
MET 112
10
Global mean surface temperatures have increased
`
Svalbard, Svalbard, Norway (79N)Norway (79N)
ArcticArctic
MET 112
13
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
Sea Level rise
MET 112
14
Recent Sea Level Changes
Branching coral Brain coral
Increase in coral bleaching events: due to warmer ocean temperatures
http://www.climatehotmap.org/
Extreme Weather Events are Projected to Increase
• 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)
• 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
Projected changes during the 21st century
Examples of impacts
Future impacts due to Future impacts due to climate changeclimate change
MET 112
20
More adverse than beneficial impacts on biological and socioeconomic systems are projected
MET 112
21
As a result of warming, plant species would be expected to migrate1. North in the Southern Hemisphere2. North in the Northern Hemisphere3. South in the Northern Hemisphere4. South in the Southern Hemisphere5. To higher altitudes6. To lower altitudes7. 1 and 68. 2 and 5
Where would you expect to see the strongest evidence of climate change?1. Tropical latitudes2. Midlatitude deserts3. Midlatitude oceans4. High latitudes5. High altitude mountains
If ice melt was to stop even though average temperatures continue to warm, how would sea level respond1. Sea level would continue to rise2. Sea level would reach an equilibrium3. Sea level would decrease
MET 112
24
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
Impacts on water and agriculture
MET 112
25
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,
MET 112
26
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,
MET 112
27
Climate Change and California IIAverage Temperature:
Winter -
Summer – 1. Coastal cities:
2. Human health:
3. Water resources:
4. Agriculture:
MET 112
28
Report Issued in 2004
Sections include:– Climate projections– Sea levels– Extreme heat– Health impacts– Water resource – Agriculture and
vegetation
MET 112
33
Climate change and CaliforniaAverage Temperature:
Winter - warmer winters - snowpack declines by 70-90% by 2090
Summer – warmer summers (5-15F by 2090)1. Coastal cities: coastal erosion by sea level rise.2. Human health: Urban air pollution/heat extremes
impact most vulnerable3. Water resources: Total water, but early runoff from
Sierras costly to adapt.4. Agriculture: Major challenge to various crops
industries.
MET 112
34
Weather-related economic damages have increased
MET 112
35
Hot Times in Alaska movie
http://www.pbs.org/saf/1404/video/watchonline.htm