Topic 6.2 - 6.4: Climate Change and Ozone

define climate change

long term shift in termperature and weather patterns

identify some causes of climate change

burning fossil fuels, deforestation, industrial processes

describe the climate as a system

evaporation: heat energy → water evaporation → moves heat from surface to atmosphere
precipitation: air cools → water vapour condenses → falls as rain
ocean currents: move heat across planet

identify some human activities that impact CO2

• energy - burning fuels for power

• agriculture - livestock production, land use

• industry production

• deforestation - trees as carbon sinks

identify ways people study historical climate data

• ice cores

  • trapped air bubbles show CO2 concentrations

• tree rings

  • wider rings = warmer wetter

• sediment cores

  • reveals microfossils for past climate conditions

describe the greenhouse effect process

Solar energy → absorbed by Earth's surface → re-radiated as heat → greenhouse gases (CO₂, methane) absorb and re-radiate heat.

identify the 2 factors used to measure the planetary boundary for climate change

1. atmospheric CO2

2. radiative forcing (balance between sun’s incoming energy / outgoing energy from earth)

   1. if it is > 1, means that there is global heating

describe the implications of crossing planetary boundaries

• irreversible climate change

• melting ice sheets

• ecosystem disruption

explain some strategies of decarbonization

• carbon neutrality - balance between emitting/absorbing carbon

• carbon sequestration - removing CO2 from atmosphere and storing it

• net zero - CO2 emissions completely countered

• carbon positive - entity that absorbs more emissions that it emits

• carbon offsetting - reducing carbon usage somewhere else

identify some mitigation strategies on the personal level

• reduce consumption levels

• increase household efficiency

• switch to renewable energy

• reduce flights

describe some mitigation strategies for reducing GHG production

• subsidies for building renovations

• strict emissions specifications for transportation

• transition to renewables

• electrification of society - lower carbon energy

describe some mitigation strategies for agriculture

• reduceing farm vehicle use

• reduce tillage

• cover cropping

• reduce inorganic fertilizers

• reduce waterlogging (managing rice patties that use lots of water)

define adaptation strategies

aim to reduce adverse effects and maximize positive outcomes. Addresses both immediate and long term challenges, recognizing that some impacts are unavoidable.

define adaptive capacity

the ability of a society/location to cope with climate change

identify structural adapative strategies

• flood defence

• desalination plants

• sea walls

• mangroves

• floating infrastructure

identify some non-structural strategies

• agricultural practices

• biotechnology to cope with climate extremities

• green cities

• controlling population density

• higher energy efficiency

explain and evalute a case study on structural adaptation strategies

Netherlands self-healing sea wall

• made of modular interlocking blocks filled wiht special limestone-seeding concrete

• each time it gets hit by a wave it becomes stronger

• releases calcium ions that attract shell-building organisms (barnacles, osyters)

  • helps create biolayer tougher than rock

benefit:
- sustainable protection → forming new ecosystems

challenge:
- difficult for large-scale production → expensive initial cost

explain and evalute a case study on non-structural adaptation strategies

Kenya drought resistant crops

• changes in climate/weather patterns → decline in food production and security

• drought resistant crops → rely on minimal water → reduces risk of harvest failure

benefit:

• can increase total yield

• reduce food poverty

• reduce total crop failure

challenges:

• smaller farms struggle to get seeds

• lead to “fake” seeds

• public resistance/culture against GMO drought crops → safety + long term environmental impact

describe what stratospheric ozone does

protects living organisms from negative effects of UV radiation

distinguish between the 2 types of ozone

good ozone (reflect UV) - stratosphere

bad ozone (local air pollutant) - troposphere

describe/draw how ozone reflects different types of UV radiation

shorter UV wavelengths (B & C) are more harmful, thus ozone absorbs it before it can cause harm.

describe some impacts on human health of UV exposure

• skin cancer - DNA damage → uncontrolled cell growth

• cataracts + eye damage - blindness

• immune system suppression - susceptible to infection and reduce immune system ability

describe some impacts UV can have on aquatic ecosystems

• phytoplankton reduction - reduces their productivity → affects food chain

• coral reef damage - damages the symbiotic algae living in corals → coral bleaching → disrupt reef ecosystems

describe some impacts UV can have on terrestrial ecosystems

• reduced plant productivity - damage plant issues and photosynthesis → crop yields + food security

• species composition - changes tolerance range → UV species dominant → alter ecosystem balance

identify some benefits of UV radiation

• production of vitamin D

• can treat certain medical conditions

• sterilizer for water bodies

• industrial use in lasers, lighting etc

distinguish between ozone depletion and climate change

climate change:

• caused by GHGs

• change in global avg temp

• ongoing issue

ozone depletion:

• CFC emissions

• loss of protective layer in upper atmosphere

• mostly felt in polar regions

• resolved issue

define CFC and other ozone-depleting substances

Chlorofluorocarbon (CFC)

• typically found in spray cans, foam, refrigerants

Hydrochlorofluorocarbon (HCFC)

• replacement of CFC

  • fire extinguisher

  • pesticides

  • cleaning equipment

explain the process of ozone depletion (chemically)

UV radiation breaks down chlorine from CFC atom

Chlorine attacks ozone → destroys ozone

results in oxygen + chlorine monoxide (CIO)

CIO is attacked by oxygen, creating more oxygen

Chlorine able to attack and destroy other ozone

Chlorine is able to do this to thousands of ozone molecules

explain why polar ozone depletion is more common

ozone hole forms each spring due to unique polar conditions

• more efficient bcs cold temp + polar stratospheric clouds (PSC)

  • PSC form in extremely cold conditions → surface for activating chlorine

  • when sunlight returns in spring → chlorine is able to destroy