Unit 8 - Managing climate change

What are greenhouse gases?

What are greenhouse gases?

Gases in the atmosphere that absorb infrared radiation

How does the combustion of fossil fuels produce GHGs?

releases CO2 underground + into the atmosphere; created water vapor during combustion

• Coal is the most polluting fossil fuel

How does rice & livestock farming produce GHGs?

methane is released when organic material is broken down

• Rice farming in flooded fields blocks O2 from getting to the soil, which creates conditions for bacteria decomposing vegetation to release methane

• Livestock eat vegetation → break it down & release methane

• Deforestation for livestock → adds to CO2 levels

How does landfill gas produce GHGs?

by-product of decomposition of organic material found in buried waste → releases CH4 + CO2

What’s the enhanced greenhouse effect?

Increased amount of infrared radiation being retained in the atmosphere due to human activities, which increase GHGs in the atmosphere

How does historical data make monitoring + predicting climate change difficult?

relies on limited amount of proxy data — relies on natural records from the environment

How can ice cores contribute to historical data?

Ice cores: drill from deep in the ice; analyse for info on past temperatures, precipitation, volcanic activity etc.

How can coral contribute to historical data?

Corals: build skeletons out of calcium carbonate; can determine water temperature at the time the coral grew

How can tree rings contribute to historical data?

Tree rings: can determine climatic conditions at the time of tree growth; composition of rings reflect change in the climate

How do computer climate models make monitoring + predicting climate change difficult?

use data on variables, like temperature & precipitation, to predict future climate; wide range of possibilities makes creating models difficult

How do climate feedback models make monitoring + predicting climate change difficult?

can speed up/slow down factors that drive climate change; difficult to predict the impact of feedback mechanisms on the climate

• they aren’t fully understood & can be unreliable

How does a time delay between cause and effect make monitoring + predicting climate change difficult?

can take years/decades to see the impact of increases GHGs

• Can make computer modeling complicated & uncertain

How does data uncertainty make monitoring + predicting climate change difficult?

different opinions on future potential changes in the climate within the politics + science

What are some environmental impacts due to climate change?

• Increase temperatures

  • Impact frequency + intensity of precipitation

• Sea level rise: melting land ice + ice sheets cause more water to enter the oceans

• Ocean circulation: disrupt ocean currents → can increase precipitation in N. Atlantic & melt polar ice sheets + glaciers

• Melting ice: reduced albedo effect = increased amount of solar energy absorbed, melting of permafrost = increased methane

• Species distribution and biodiversity: can alter habitats

How does climate change cause forced migration?

natural disasters make certain parts of the world difficult to live in, causing people to migrate

How does climate change impact crop yields?

can decrease due to increased temps + changes in rainfall patterns

• Climate change can cause outbreaks of insects, like locusts, which decrease yield

How does climate change impact water + energy security?

• Increased evaporation + fluctuating levels of precipitation (e.g. increase can spread disease)

• Need to implement renewable energy sources to combat climate change, which can be challenging + cause energy insecurity

How does climate change cause increased frequency + severity of extreme weather?

• flooding, strong winds, loss of land + lives

  • Less precipitation + increases temps = drought + wildfires

What are some methods to reduce the global and individual carbon footprint?

• Fewer children per woman: lower carbon emissions + energy consumption

• Plant-based diet: less CO2 emissions for transport + less CO2 & CH4 emissions by not eating meat

• Energy-efficient lifestyle: timers on showers, energy-efficient light bulbs, etc

How can low-carbon fuels manage climate change?

• lower carbon content than petroleum fuels (e.g. natural gas & biofuel)

  • Reduce CO2 emissions, BUT increased land use for biofuels (e.g. corn + sugarcane)

How can transport policies manage climate change?

• need to consider reduction of CO2 emissions + improved fuel efficiency

  • Catalytic converters, sustainable biofuels (e.g. biogas), & improved public transportation

How can carbon capture and storage manage climate change?

capturing CO2 before it’s released into the atmosphere & storing it

• Pre-combustion: before fossil fuels are burned → fossil fuels into CO2 and hydrogen

  • Requires significant modification to power plants

• Post-combustion: removes CO2 after burning fossil fuels

• Oxyfuel technology: burning fossil fuels with nearly pure oxygen, producing CO2 + steam

• Technology is expensive & possible CO2 leakage at storage sites

How can reducing deforestation manage climate change?

reforestation/afforestation increase tree biomass + carbon stored

• Cost-effective + improves water security (increased transpiration & less runoff, which recharges aquifers)

How can energy efficient buildings + infrastructure manage climate change?

take advantage of sun’s energy, well-insulated, low-energy consumption features

• Passive buildings: eco-friendly; consume low amounts of energy + make use of energy sources in the building

What are some examples of legislation to manage climate change?

• Kyoto Protocol: reduce GHG emissions by acknowledging that global warming exists & human-caused emissions are the underlying cause

• Paris Agreement: UN agreement addressing GHG emissions starting in 2020

What’s the purpose of solar radiation management?

Reflect some incoming solar radiation & limit the amount of energy trapped by GHGs

What’s the purpose of albedo enhancement?

large pumps to introduce microbubbles into bodies of standing water & reflective films on top of the ocean surface

What’s the purpose of stratospheric aerosols?

sulfate aerosols spray aerosol into the atmosphere into the stratosphere by using a tethered balloon, which reflects sunlight

• Simple, inexpensive, & technologically feasible, BUT may cause drought/flooding, limited research available, untested, & short-term

What’s the purpose of space reflections?

reflect incoming solar radiation rays before getting trapped in the atmosphere