Chapter 4: Climate Change Trends

Question 1

Due to global warming, there are certain observable trends that are and have been taking place, especially during the

Answer 1

latter half of the twentieth century and into the twenty- first

Question 2

Due to global warming, there are certain observable trends that are and have been taking place, especially during the latter half of the twentieth century and into the twenty- first.

 Among these are

Answer 2

• rising temperatures over land and sea,
• receding glaciers and
• rising sea level.

Question 3

Rising Temperatures

Answer 3

Temperature records tell us that some places on Earth are getting warmer while others are getting colder depending on:

• the season of the year and
• local factors

this includes:

• Global average temperature
• land and sea temperature
• tropospheric warming and statospheric cooling

Question 4

Global average temperature

Answer 4

• 1880 till 1890: slight cooling
• till 1910: slight WARMING
• till 1940: gradual and consistent WARMING
• through 1970: slight cooling
• till present time: constant WARMING

Question 5

Land and Sea Temperatures

Answer 5

• land temperatures derived from weather stations
  
  • more population = more stations
    
    • more stations in NHS

land and sea are warming

Question 6

Tropospheric warming and stratospheric cooling

Answer 6

• Enhanced concentrations of GHG (have a charactaristic profile)
  
  • warming in mid and lower troposphere
  • cooling in much of the stratosphere
    
    • expected due to increase trapping of terrestrial radiation in troposphere

Question 7

Rising sea temperature

Answer 7

• Ocean is the greatest heat reservour in the planet
  
  • respods slower to temperature change
    
    • ocean net heat uptake since 1960 is aroung 20 times greater than the atmosphere
  • ocean heat capacity is 1000 times larger than the atmosphere
• has important role in
  
  • climate variability and change
  • variations in seasonal to decal time scales
  • warming cause sea level to rise due to thermal expansion
• warming from surface to 700m (upper layer) is 0.18 F where most marine like exist
• air tmperature rise by 1 F over the past century
  
  • due to global warming
    
    • caused by human activities that emit heat trapping carbon dioxide

Question 8

Majority of ice is found in nature as

Answer 8

• glaciers
• ice sheets
• sea ice
• permafrost
• on the bottom of the ocean in methane clathrates
• lakes and streams during colder parts of the year in midlatitudes
• higher elevations as icebers in oceans
• ice shelves
• ice caps

Question 9

Melting ice

Answer 9

• Majority of ice is found in nature as …….
• ice is melting/diminishing (some faster than others)
• ice may expand due to
  
  • in different times of the year
  • local conditions in some locations
• Arctic sea ice
  
  • volume is declining
  • extent is steadily declining
• Antarctic sea ice extent is increasing
  
  • antarctic is not cooling (not forming new sea ice)
  • it is possible to have global warming and expanding sea ice if
    
    • the volume of ice throughout the globe is decreasing
    • extent is not related to volume
      
      • new ice may form on the ocean surface while old ice reduce in volume (happening in both arctic and antarctic)

Question 10

Rising Sea Level

Answer 10

• sea level is rising since 1970
  
  • rising is not due to the same factors in all places. but factors bay be:
    
    • land is sinking
      
      • eccentuate the rise in sea level
    • land is sinkin
      
      • lesson the rise in sea level
• rise from both tide gauges and satellite altimeter
  
  • global sea level lowered during 2011 due to
    
    • strong el nino
      
      • increased precipitation over land
        
        • cause major flooding (australia and pakistan)
      • water removed from ocean
        
        • sea level lowered but sea level rose again

Question 11

migration of plant and animals

Answer 11

• migrate to higher latitudes and altitudes due to warming
  
  • latitude:
    
    • moving 15 ft/day or mile/year or 16.9 km/decade
    • moving at a faster rate than previous decades
    • migrate more rapidly from areas heavily impacted by climate change
  • elevation
    
    • rate of 11 m/decade
• some species (will become extint) will not be able:
  
  • to migrate fast enought
  • cannot physically migrate
  • exceed their limits of tolerence

Question 12

Species extinctions

Answer 12

• humans cayse extinction since extension of dinasaurs 65 million years ago
• if trends continue:
  
  • 1/2 of the species will be extent in less than 100 years due to
    
    • habitat destruction
    • pollution
    • incasive species
    • climate change
• vertebrate species fell by nearly 1/3 between 1970 and 2006
• natural habitats are in decline
• genetic diversity of crops is falling
• 60 breads of livestock become extinct since 2000
• extinction are occuring in world ocean including organisms that are important in the food chain