MET 112 1 MET 112 Global Climate Change: Lecture 13 Climate Change Impacts: Present and Future II Dr. Craig Clements.
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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 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?
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 climate 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 climate change
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.
Fingerprints of climate change Increases in water vapor
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 CO 2. The importance of this feedback is still being investigated.
MET 112 10 Global mean surface temperatures have increased
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
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
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 migrate 1.North in the Southern Hemisphere 2.North in the Northern Hemisphere 3.South in the Northern Hemisphere 4.South in the Southern Hemisphere 5.To higher altitudes 6.To lower altitudes 7.1 and 6 8.2 and 5
Where would you expect to see the strongest evidence of climate change? 1.Tropical latitudes 2.Midlatitude deserts 3.Midlatitude oceans 4.High latitudes 5.High altitude mountains
If ice melt was to stop even though average temperatures continue to warm, how would sea level respond 1.Sea level would continue to rise 2.Sea level would reach an equilibrium 3.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 II Average Temperature: Winter - Summer – 1. 1.Coastal cities: 2. 2.Human health: 3. 3.Water resources: 4. 4.Agriculture:
MET 112 33 Climate change and California Average Temperature: Winter - warmer winters - snowpack declines by 70-90% by 2090 Summer – warmer summers (5-15F by 2090) 1. 1.Coastal cities: coastal erosion by sea level rise. 2. 2.Human health: Urban air pollution/heat extremes impact most vulnerable 3. 3.Water resources: Total water, but early runoff from Sierras costly to adapt. 4. 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