quiz 5 Flashcards
Carbon on the Planet
- Movement of carbon between the crust, oceans, atmosphere, plants, soil, and animals
- Most of the Earth’s carbon is stored in the planet’s crust
- Carbon dioxide is the most common gaseous form of carbon
- Photosynthesis: Conversion of carbon dioxide into organic compounds by plants.
Changing CO2 Content of the Atmosphere
- ~2 billion years ago
- CO2 was up, O was down
- Cyanobacteria a few billion years later
- CO2 down, O up
- Human Activities
- Human activities are contributing a lot to the increasing carbon dioxide
- Burning fossil fuels from the industrial revolution kickstarted all of this
- Agricultural practices
Natural and Human Carbon Exchange
- Carbon exchange is a natural phenomenon but is also human
- The more we urbanize, the more carbon dioxide in the atmosphere.
Measurement of CO2 in the Atmospheric: The Keeling Curve
- Direct measurement of CO2 concentration in the atmosphere from the 1950s to present
- Recorded from a Hawai‘ian island
- Overall increase in CO2 emissions
- Annual fluctuations due to northern hemisphere seasons (different landmass and vegetation)
- Northern spring: More CO2 absorbed
- Northern fall: More CO2 released
Measurement of CO2 in the Atmosphere: Proxy Records
- Proxy records estimate the Earth’s temperatures for thousands of years prior to direct measurement
- Tree rings
- Ice cores
- Sediments cores
- Corals
- Indicates there have been climate fluctuations in the past, but temperatures and the rate of change are higher than ever
The Greenhouse Effect
- The greenhouse effect is the process by which gases in the atmosphere trap heat
- Shortwave solar radiation (ultraviolet, visible light) enters the atmosphere, is absorbed by the earth, and then is re-radiated as longwave radiation (heat)
- The greenhouse effect is both natural and necessary for life on Earth!
- https://www.youtube.com/watch?v=SN5-DnOHQmE So, what is the problem?!
Greenhouse Gases
- Are rising higher and faster than ever before in a short amount of time, leading to socio-environmental changes
- Greenhouse gases comprise of:
- Carbon dioxide
- Water vapour
- Methane
- Nitrous oxide
- Chlorofluorocarbons
Increasing Greenhouse Gas Emissions and Changes in Climate
- Global average temperatures are rising, but the amount and rate of change varies
- Global warming → Climate change
- Doesn’t fully capture the whole scope with global warming
- Changes in precipitation patterns
- Sea level rise
- Droughts
- Melting ice caps
Variability
Magnitude (frequency and amplitude) of the changes that can occur
Risk
Potential to create adverse consequences for human or ecological systems
Vulnerability
People’s exposure and lack of protection towards environmental changes and extreme events
Impact
Damage (or positive effect) resulting from an event
Climate Change Impacts
- Potential agricultural losses
- Islands and coastal areas lost to sea level rise
- Species extinction
- Ecosystem collapse
- Increase in disease incidence
- Impacts will be felt most strongly by those who contribute little to global greenhouse gas emissions. They are mostly vulnerable populations who are too poor to mitigate or adapt to these impacts
Extreme Weather Events and Climate Change
- Emissions from the burning of fossil fuels have been trapping heat in the atmosphere since the Industrial Revolution
- This has increased global average temperatures by 1.1°C
- The additional energy stemming from the increasing temperatures is unevenly distributed causing some locations to experience extreme weather events compared to others WEATHER IS
- WHAT YOU GET AND CLIMATE IS WHAT YOU EXPECT!
More Persistent Droughts
- Less rain between heatwaves
- Water supplies and ground moisture run dry more quickly
- Ground heats up quicker = warming the air above = more intense heat