Lecture 7/8 Flashcards
Define weather
atmospheric conditions over short time periods (e.g. hours, days) within small geographic areas
Define climate
atmospheric conditions (e.g. precipitation, temperature) across large geographic regions over long periods of time (e.g. decades, centuries)
What are the 3 influences on the Earth’s climate
- sun
- atmosphere
- oceans
How does the sun affect the earth’s climate
without it, Earth would be dark and frozen
How does the atmosphere affect the earth’s climate
without it, Earth’s temperature would be colder
How do the oceans affect the earth’s climate
shape climate by storing/transporting heat/moisture
What are the two factors involved in climate
- average annual precipitation
- average annual temperature
What does climate change focus on
trends and variations in the earth’s climate
Define global warming
An increase in Earth’s average temperature
- average temperature naturally increases but rapid change is due to human activity
What are the 6 factors affecting the absorption of solar radiation, leading to climate change
- orbital cycles of Earth
- solar output variations
- ocean absorption of atmospheric gases
- ocean circulation patterns
- changes in absorption of solar radiation by Earth’s surfaces
- changes in atmospheric gases (especially ‘greenhouse gases’)
Define orbital cycles
periodic long-term changes in Earth’s rotation and orbit around Sun
- (referred to as Milankovitch Cycles)
Define solar output variations
drives temperature change on Earth’s surface because of variation in solar flare activity and solar storms
Define ocean absorption
the ocean holds 50 times more carbon than the atmosphere and by absorbing CO2 from the atmosphere, the ocean acts as a carbon sink that maintains stable levels of atmospheric gases
Define ocean circulation
worldwide currents changing - warmer, fresher water moves along surface; and colder, saltier water moves deep beneath the surface
- impacted by melting of glaciers and polar ice caps
Define changes in absorption of solar radiation
changes in atmospheric gases can alter the amount of solar radiation absorbed by the Earth’s surface (= albedo)
- with more absorption, Earth’s surface increases in temperature and emits more infrared radiation that warms lower atmosphere
Define changes in atmospheric gases
changes in atmospheric gases that absorb infrared radiation (e.g. water vapor, CO2, CH4, N2O, chlorofluorocarbons) can alter amount of solar radiation absorbed by the Earth’s surface
Define CO2 as an atmospheric gas
- not most potent
- most abundant / long lived
- major contributor to climate change
Define CH4 as an atmospheric gas
- very potent
(25 times greater than CO2) - less abundant / short-lived
- due to human activities
Define NO2 as an atmospheric gas
- very potent
(300 times greater than CO2) - less abundant
- due to human activities
Define the greenhouse grass effect
- With more solar absorption, Earth’s surface warms and emits more heat that warms the lower atmosphere
- Warming of lower atmosphere further warms Earth’s surface
What does PCF stand for
Permafrost Carbon Feedback Loop
Define PCF
an amplification of surface warming due to the thaw of organic material currently frozen in permafrost
- Leads to decay and release of CO2and CH4into atmosphere
- It is irreversible
What are some examples of indicators of climate change
increased:
- temperature over land
- temperature over oceans
- sea surface temperature
Define temperature in regards to causes of global climate change
- There are more positive forcers of climate change (e.g. greenhouse gasses, solar irradiance, etc.)
- There are fewer negative forces to offset positive forcers and cause cooling
Define [CO2] in the atmosphere in regards to evidence of climate change
- Rate of increase in atmospheric CO2 over the past 60 years is 100 times faster than natural increases of the past
- CO2 levels are the highest in human history
What are some types of indirect evidence (proxy evidence) that serve as substitutes for direct measurements
- shed light on past climate
- evidence from ice caps, ice sheets, and glaciers hold clues to Earth’s climate
- evidence from sediments
- evidence from plants, animals, fungi and microorganisms
What are the 5 ways that proxy indicators provide information about the past
- Trapped air bubbles in ice cores show atmospheric composition, greenhouse gas concentrations, temperature trends, snowfall, solar activity, and frequency of fires
- Sediment cores preserve pollen grains and other plant remnants
- Tree rings indicate age, wetness of season, droughts and seasonal growth
- Coral reefs provide data on past ocean conditions
- Radioisotope evidence based on 12C, 13C and 14C
How are the air temperatures over land and water rising an implication of climate change
Land and water temperatures are rising faster than trends (over the past 140 years) would predict
How is the artic sea ice decreasing an implication of climate change
Impacts in Canada could be particularly severe
- ice caps are melting
- sea ice is thinning
- open water throughout year
- polar bears are starving
- permafrost is thawing
- More frequent heat waves
- Changes in seasonality
- Inuit traditional lifestyles changed
How are the glaciers melting and less snow coverage an implication of climate change
- Mountaintop glaciers are disappearing
- risks of sudden floods as ice dams burst
- reducing summertime water supplies
- Melting of the ice sheets accelerating since mid-20th C
Define albedo changes
As ice melts, darker, less-reflective surfaces are exposed that absorb more sunlight, causing more melting
How are the sea levels rising an implication of climate change
- As glaciers/ice melt, increased water will flow into oceans
- As oceans warm, they expand which adds to problem
- Leads to beach erosion, coastal floods, and intrusion of salt water into aquifers
Define storm surge
temporary/localized rise in sea level brought on by high tides and winds associated with storms
How are the humidity levels rising leading to more extreme storms an implication of climate change
- Some regions will receive more precipitation
- More extreme weather events (e.g. hurricanes, monsoons, tornados, etc.)
- Heavy rains have contributed to flooding killing people, destroying homes, and inflicting billions of dollars in damage
How are more extreme droughts leading to forest fires an implication of climate change
- Some regions will receive less precipitation
- Droughts becoming more frequent and severe
- harming agriculture, promoting soil erosion, reducing drinking water supplies, and encouraging forest and grassland fires
How are the ocean waters becoming more acidic an implication of climate change
Trends in atmospheric concentrations of carbon dioxide show that concentrations have increased from 315 ppm to 383 ppm over past 50 years
Define ocean acidification
Evidence that CO2 levels in the ocean have increased in recent decades leading to a decrease in pH
What are some cons to ocean acidification that we are seeing in the world
- decreased calcification in shelled organisms (e.g protists)
- coral bleaching/coral reef damage
- deprives coral of necessary carbonate ions for their structure
How are seasonal changes an implication of climate change
- flowering plants are blooming earlier
- species moving to higher altitudes
- some important community connections are uncoupled
-e.g caterpillars not hatching bc of temp. and birds don’t have food
How are positional changes in biomes an implication of climate change
- some species are moving to higher latitudes
- some species populations are expanding
- e.g invasive species to other areas bc species spread and destroy other habitats
What are the 4 societal impacts climate change has
agriculture, forestry, economics, and health
Define agriculture (societal impacts)
growing seasons shortened, crops more susceptible to droughts and failure; crop production will decrease, worsening hunger
Define forestry (societal impacts)
increased insect and disease outbreaks, increased chance of forest fires (especially in rainforests)
Define economics (societal impacts)
costs will outweigh benefits, widen the gap between rich and poor, poor nations will lose more than rich ones, major issues due to environmental refugees and mass migrations
Define health (societal impacts)
heat waves and stress can cause death, respiratory ailments, expansion of tropical diseases, introduction of “new diseases”, increased chance of drowning if storms become intense, hunger-related ailments
What is a key solution to climate change
cut carbon pollution as much as possible, as fast as possible
Define adaptation
respond to the warming that has already or will inevitably occur
- accept climate change is happening and pursue strategies to minimize its impacts on us
Define mitigation
preventing further warming by addressing the causes of climate change
- pursue actions that reduce greenhouse gas emissions, in order to lessen severity of future climate change
How are energy choices a solution to climate change
Two ways to reduce fossil fuel use: conservation and efficiency
- Choose ‘cleaner energy’ options
- Replace old appliances with newer more efficient models
- Make lifestyle choices that use fewer greenhouse gas-producing products
Define carbon-capture
technologies or approaches that remove CO2 from power plant emissions
Define carbon sequestration (storage)
capturing and storing carbon where it will not seep out
What are some examples of technologies and energy sources that don’t use fossil fuels
nuclear, hydroelectric, solar power, wind power, geothermal, and other renewable power
How are transportation sources a solution to climate change
- bike or walk or use public transportation
- public transportation is the most effective way to conserve energy, reduce pollution
- make vehicles more fuel-efficient and energy efficient
- develop hybrid vehicles, electric vehicles
How are lifestyle choices a solution to climate change
- Use advances in agriculture, forestry and waste practices
- grow renewable biofuels
- rapid reforestation of deforested areas
- recovering methane from landfills
- recycle, compost, reduce or reuse of materials
