[ENV SCI] Final Exam Review

Important concepts of Justice

• Transformative systems
• procedural justice
• distributive justice
• recognition justice

The Anthropocene

• unofficial unit of geologic time, used to describe the most recent period in Earth's history when human activity started to have a significant impact on the planet’s climate and ecosystems.

Colonization

$\rightarrow$ massive land use changes, population changes, and attempted erasure of cultures, land management practices, and food systems.

• fire suppression has dominated land use management since colonization of the Americas. This has led to a build up of fuels
  that lead to an increase in massive, high intensity wildfires.

Deforestation

• Clear-cutting tropical forest ecosystems – not only damages ecosystem, flora and fauna, but can also flip a carbon “sink” to a carbon “source”

Montreal Protocol

• banned the use of these ozone depleting chemicals, and significantly dropped the level of ozone-depleting chemicals in the atmosphere.
  $\rightarrow$ hole over Antarctica has been shrinking

Ecological Footprint

• measurement & communication tool
  $\rightarrow$ enables people to understand sustainability linking their personal impact with global ecological capacity

Thermodynamics

• 1st Law: Conservation of energy
  • hydroelectric dams, biomass, etc.
• 2nd Law: in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state (can't have 100% efficient)

Freshwater on Earth

• Fresh water: Ice and snow(87%)+Liquid water(13%): Groundwater(95%)+...

Convection

• 3 convection cells
  • Hadley cell $\rightarrow$ Trade Winds
  • Ferrel cell $\rightarrow$ Westerlies
  • Polar cell $\rightarrow$ Polar Easterlies

Drainage Basins/Watersheds

• Drainage Basin: area drained by a stream & its tributaries of a stream

Rivers: carry water & sediment

• Runoff Mechanisms
  • overland flow
  • shallow subsurface stormflow
  • subsurface stormflow
  • saturated overland flow

Hydrographs

• depicts flow over time.

• lag time(delay) from the peak of rainfall to peak of streamflow, reflecting time needed for subsurface stormflow

• urbanization $\rightarrow$ increased peak flow, decreased lag time, steeper rising limb and recession limb, lower base flow, and urban slobber

River Continuum Concept

Macroinvertebrates

• benthic macroinvertebrates: aquatic bottom-dewlling animals that can be seen with the naked eye

Functional feeding groups

• Shredders: get energy from breaking down big vegetation like leaves and branches.
• Grazers: scrape algae and diatoms (primary producers) off of rocks and sand.
• Collectors: filter water for small organisms and pieces of vegetation (particulate matter)
• Predators: eat other macroinvertebrates and fish.

agroecosystem

• as socio-ecological systems: social / political / economic & farmer's knowledge and perspective
  $\rightarrow$ agroecosystems are socio-ecological systems that operate and interact over multiple spatial and temporal scales

• best agricultural soils = Mollisols + Alfidols

• agriculture = socio-ecological system

  • early slash-burn systems
  • Chinampas in Meso-America
  • Waru-waru in the Andes
  • floodplain agriculture in Nile River Valley
  • terraced production system
  • rain-fed temperate systems in Europe

• Culture and environment shapes agricultural systems

  • 1500s - industrial revolution in Europe
  • ~1500 - pre industrial integrated agriculture systems
  • 1850~1920 - specialized agriculture systems
  • 1800s industrial Europe: specialized production reduces agro-biodiversity / loss of biodiversity leads to loss of ecosystem services in agriculture / ecosystem services are then substituted with off-farm inputs
  • 1950s - The Green Revolution in Mexico: corn and wheat improvement programs, crop breeding (high yield varieties) / specialization (monoculture) / synthetic fertilizer / synthetic insecticide, herbicide, fungicide / Motorization (tractors, sprayers etc.) / wells and irrigation / ecological changes paired with political-economic changes
  • 1970s - Green Revolution Goes Global (CGIAR Expansion)

• the Green Revolution formalized industrial agriculture

  • green revolution was simultaneously an agronomic, humanitarian, and political-economic project

• Modern industrial agriculture

  • ecological impacts: loss of biodiversity+environmental pollution
  • social impacts: natural tendency to concentrate production and drive people off the land / capital requirements are barrier to entry and constant threat to those engaged in industrial agriculture / market-driven crop/food distribution does not guarantee that people will get to eat

• Principles of Agroecology

  • natural ecosystems: high biodiversity / coevolution / mutualisms / self-regenerating
  • traditional farming systems: co-evolution between human cultures+biophysical environment / ethno-agricultural analysis provided early insights / understand principles that support traditional farming systems / not advocating a return to the past

Disaster risk

• physical hazard + socio-economic vulnerability = disaster risk

• floods: benefits - soil fertility from deposited silts / groundwater recharge from infiltrating floodwaters / fish habitat in shallow waters over floodplain / refreshing of the river bed by moving gravel

• engineering responses to reduce flood hazard: flood control dams / levees / flood control channels / flood bypasses

  • levee effect: building levees gives the impression that floodplain is protected encouraging more development in a still-risky place.
  • moral hazard: lack of incentive to guard against risk where one is protected from its consequences, e.g. by insurance

• non-engineering (non-structural) approaches to reduce flood risk

  • control land use to prevent settlement on flood-prone lands (reduces exposure/vulnerability) / set aside river corridor, backwater areas (room for river) / adaptation and floodproofing

Reference

• "Exam+Review.pdf" from Environmental Science for Sustainable Development, UCB 2023 Session C