D4.3  Climate Change

Theme:  Continuity and Change

Natural mechanisms that have kept Earth’s climate stable enough to support life for millions of years.​

• The greenhouse effect maintains Earth temperature within a range that life can tolerate.  Greenhouse gases trap long-wave infrared radiation, keeping the planet warm. Without the greenhouse effect, Earth would be too cold for liquid water and most life.
• Historically, the rate of carbon being "fixed" by autotrophs and the rate of carbon being released via respiration was relatively equal. This consistency in atmospheric CO2 levels provided a stable climate for the evolution of modern ecosystems.
• Natural carbon sinks, such as the oceans and forests, provide continuity by absorbing excess CO2, acting as a buffer that resists sudden shifts in atmospheric composition.

Rapid, human-driven changes to atmospheric chemistry have had significant effects on the biosphere.

• The burning of fossil fuels has released carbon dioxide, leading to a spike in greenhouse gas concentrations.
• The enhanced greenhouse effect drives global warming. Unlike natural climate cycles, this change is occurring at a rate that exceeds the ability of many species to adapt.
• Change in the atmosphere leads to change in the hydrosphere. As oceans absorb more CO2, the pH drops. This chemical change makes it difficult for calcifying organisms (like corals and mollusks) to build their shells, threatening the interdependence of marine food webs.
• Arctic and Antarctic ecosystem have experienced dramatic change, leading to a loss of habitat and changes in phenology.

Guiding Questions:  
Guiding questions help students view the content of the syllabus through the conceptual lenses of both the themes and the levels of biological organization. ​​

• What are the drivers of climate change? (D4.3)
• What are the impacts of climate change on ecosystems?
  
  

​Linking Questions:  
Linking questions strengthen students’ understanding by making connections between topics.  The ideal outcome of the linking questions is networked knowledge.

• What are the impacts of climate change at each level of biological organization? (D4.3)
• What processes determine the distribution of organisms on Earth?

Key Terms to Know: * higher level only

Afforestation
Albedo Effect
Antarctic
Anthropogenic
Arctic
Biomass*
Bird Migration*
Boreal Forest
Bud Set*
Budburst*
Calcification
Carbon Dioxide
Carbon Sequestration
Caterpillar*
Climate Change
Combustion
Coral Bleaching
Coral Reef
Deciduous Tree*
Drought

Ecosystem Collapse
Emperor Penguin
Evolution*
Flowering*
Forest Regeneration
Global Warming
Great Tit Bird*
Insect Life Cycle*
Landfast Ice
Legacy Carbon
Methane
Mouse-Ear Chickweed*
Native Species
Non-Native Species
Nutrient Upwelling
Ocean Acidification
Ocean Current
Peat
Permafrost
Phenology*

Photoperiod*
Polar Habitat
Poleward Shift
Positive Feedback Cycle
Primary Production
Reindeer*
Restoration
Rewilding
Sea Ice
Solar Radiation
Spruce Bark Beetle*
Taiga
Tawny Owl*
Temperate Habitat
Temperature*
Tipping Point
Tropical Forest
Upslope Shift
Walrus

D4.3.1—  Anthropogenic causes of climate change.

• Outline the cause and consequence of the greenhouse effect.
• Outline the cause and consequence of the enhanced greenhouse effect.
• List anthropogenic sources of atmospheric carbon dioxide and methane. 
• State that methane is oxidized to carbon dioxide in the atmosphere.
• Outline climate changes that can result from the enhanced greenhouse effect.
• Explain the correlation between atmospheric CO2 and methane concentrations since the industrial revolution and global temperatures.​

D4.3.2— Positive feedback cycles in global warming.

• Define positive feedback. 
• Outline five examples of positive feedback cycles related to global warming.

D4.3.3--  Change from net carbon accumulation to net loss in boreal forests as an example of a tipping point.

• Define tipping point.
• Explain changes in boreal forest carbon cycle due to climate change.

D4.3.4--  Melting of landfast ice and sea ice as examples of polar habitat change.

• Outline changes to polar landfast and sea ice habitat that result from global warming.
• Describe impact of changes to Antarctic polar ice on emperor penguin.
• Describe impact of changes to Arctic polar ice on walruses.​

D4.3.5— Changes in ocean currents altering the timing and extent of nutrient upwelling.

• Outline the cause of ocean stratification. 
• Define upwelling and current as ocean phenomena.
• Outline how a change in ocean currents and nutrient upwelling due to  global warming has led to a change in ocean primary production. 
• Discuss the consequences of a reduced ocean primary production on marine food chains. ​

D4.3.6- Poleward and upslope range shifts of temperate species.

• Explain how global warming has caused poleward and upslope shifts in habitats for temperate species. 
• Explain why tropical montane species may be more sensitive to temperature shifts that result from climate change.

 ​​​D4.3.7-  Threats to coral reefs as an example of potential ecosystem collapse.

• Outline the effect of atmospheric CO2 concentration on ocean pH.
• Describe the impacts of lower ocean pH and higher average ocean temperature on coral reefs.  
• Explain why loss of coral causes collapse of reef ecosystems.

D4.3.8- Afforestation, forest regeneration and restoration of peat-forming wetlands as approaches to carbon sequestration.

• ​Define carbon sequestration.
• Describe afforestation, and reforestation and restoration of peatlands as biologically based approaches to carbon sequestration.

AHL ​​​​​​​​D4.3.9-  Phenology as research into the timing of biological events.

• Define phenology. 
• List variables that impact phenology. 
• Discuss cause and consequence of phenological changes in an ecosystem. ​

AHL ​​​​​​​​D4.3.10- Disruption to the synchrony of phenological events by climate change.

• Describe the cause and consequences of desynchronization between the Arctic mouse-ear chickweed and arrival of migrating reindeer.
• Describe the cause and consequences of desynchronization between the breeding of the great tit and peak biomass of caterpillars in north European forests.​

AHL ​​​​​​​​D4.3.11- Increases the number of insect life cycles within a year due to climate change.

• Discuss changes in the number of annual insect life cycles due to climate change. 
• Outline the impact of increase of the spruce bark beetle life cycle on spruce trees in North America.​

AHL ​​​​​​​D4.3.12- Evolution as a consequence of climate change.

• Outline impact of climate change as a selection pressure.
  
• Explain changes in the colors variants of the tawny owl as an example of evolution in response to climate change. ​