Environmental Systems Exam 1

Biogeochemical Cycles

pathways through which essential elements and nutrients move between living organisms and the nonliving part of the Earth

Gaia Hypothesis

Earth’s living organisms and non-living surroundings interact as a single self-regulating system that maintains the climates and chemical conditions necessary for life

• revolutionized the way we think about biotic-abiotic interactions on Earth

• presence of life results in a series of balancing feedback loops that maintain conditions on Earth in a state of dynamic equilibrium

NASA Bretherton Diagram

launched the field of Earth system science

Planetary Boundaries Concept

represent a rapid evolution in scientific understanding of the human impact on the Earth system

Features of a Complex Adaptive System

• Feedbacks loops and non-linear behavior

  • Reinforcing - positive feedback

  • Balancing - negative feedback

• Distributed functionality

  • Nested system - smaller systems completely contained within larger ones

• Scalable structure

• Self-organization

• Adaptive behavior

• Criticality

  • Thresholds - once passed → changed in state

• Emergent properties

  • unpredictable, emerging properties

International Geosphere Biosphere Programme

important international collaboration that greatly enhanced our understanding of global biogeochemical cycles

Four Central Ingredients of the Gaia Hypothesis

1. thermodynamic equilibrium - disequilibrium states need to be maintained to sustain the Earth system through time

2. interactions - effects of life on the Earth’s environment and how that shapes the conditions to make a living

3. optimality - associated with improving condition to the extent possible

4. balancing feedback - needed for homeostasis to arise

Daisy World Model

conceptual computer simulation created to demonstrate how living organisms can unconsciously regulate a planet’s climate

• daisy population would response to changing solar radiation to maintain constant temperature

Human Domination of Earths Ecosystems

publication that used a systems approach to begin quantifying the human alteration of the Earth system, including the biogeochemical cycles of carbon, nitrogen, and water

Keeling Curve

shows human impact on the climate system by tracking the rising concentration of carbon dioxide in Earth’s atmosphere

• longest continuous measurement of atmospheric CO2 in the world

NASA Earth Observing System

NASA operating satellites for ongoing EOS missions

Large Computational Models

• General Circulation Models - very large-scale models used to simulate and predict the behavior of Earth’s atmosphere, oceans, and climate system

• Integrated Assessment Models - integrates a variety of models that already exist and allows us to play out various scenarios

Global Cascades

occurs when changes in the Earth system triggers a domino effect of connected ecological, climatic, or systemic disruptions across a planet

Tipping Points

critical threshold that cause a typically massive and often irreversible shift in a system’s state outside of Holocene conditions

• when crossed = new Earth system state may not be habitable for human society

• driven by reinforcing feedback loops that rapidly push the Earth system out of Holocene conditions

Anthropocene

a rupture or a fundamental shift in how the entire Earth system functions

• destabilization of the Earth system

• began in 1950

  • post-WW2 expansion and industrial social metabolism based on the combustion of fossil fuels lead to rapid production and consumption

  • most important markers of the beginning of the Anthropocene - presence of radionuclides produced by thermal weapon testing

Planetary Health

exploring human-driven global environmental changes is reshaping human health

• Human health depends on Earth’s life-support systems - disruptions to these systems drive current and future health burdens

Symbiocene

an era of mutualism and “fulfillment of potential” (life in harmony)

• Psychological and Social Markers of new era

  • teaching empathy, cultural competence, emotional intelligence, and commitment to optimism, tolerance, and fulfillment of human potential

  • Cultural competence - ability to understand and interact with people from diverse backgrounds

  • Mutualism - bringing out best in one another

  • Anti-materialism - stuff doesn’t bring happiness

Microbiome Science

a literal and metaphorical model for global cooperation

Five Categories of Health Impacts for each Planetary Boundary

1. non-communicable disease

2. food and nutrition

3. infectious disease

4. reproductive; maternal and child health

5. mental health

Upstream Drivers of Anthropocene

root causes and systemic factors that create the problem

• Examples

  • Neoliberalism - market determines everything (concentrated power and wealth)

  • Socioeconomic equality

  • Poor nutrition

Downstream Symptoms of Anthropocene

resulting effects and outcomes

• Examples

  • Non-communicable disease - life-style driven diseases

  • Dysbiosis - stress, mental health decline

  • Loneliness

  • Depression

Mars Can Wait Reallocation

argues that the 19.5 billion NASA budget is a form of “intellectual escapism” while Earthly problems like veteran suicide and homelessness goes underfunded

Military Can Wait Reallocation

the military gets a lot more funding than the Mars initiative and global health don’t need the military (brings pain and conflict)

Microbiome Metaphor

we are all parts of a single organism and a healthy microbiome demonstrates mutualism

Control Variable

refers to measurable indicators used to check whether an Earth system process is staying within its safe operating zone (planetary boundary)

• ex. CO2 = for climate change

Planetary Boundaries

refers to the thresholds that keep life on Earth within safe operating zone; identify the nine Earth processes essential for maintaining global stability, resilience, and life-supporting function

1. land system change

2. freshwater change

3. biogeochemical flows

4. ocean acidification

5. atmospheric aerosol loading

6. stratospheric ozone depletion

7. climate change

8. biosphere integrity

9. novel entities

Climate Change

earth’s climate is in the danger zone (greenhouse gas concentration has reached record levels, accelerating global warming and conditions continue to worsen)

• Key Drivers: fossil fuel burning, processes leading to non-CO2 greenhouse gas emission, land system change, change in biosphere integrity, increase in atmospheric aerosol loading

Biosphere Integrity

nature’s safety net is unraveling (extinctions and loss of natural productivity are far above safe levels, with no sight of improvement)

• Key Drivers: biomass harvesting, intro of invasive species, land system change, climate change, freshwater change, biogeochemical flow modification, intro of novel entities, ocean acidification

Land System Change

earth’s forests are shrinking, and most are already below safe levels, with the overall trend still negative - although the pace of forest loss has slowed)

• Key Drivers: cropland and livestock grazing expansion, expansion of settlements and infrastructure, climate change, freshwater change, biosphere integrity

Freshwater Change

human impact of rivers and soil moisture is growing, pushing water system further from stability and heightening drought and flood risk

• Key Drivers: irrigation and agriculture, industrial water use, household water use, climate change, increase in atmospheric aerosol loading, land system change

Biogeochemical Flow

fertilizer overuse continues to overload land and water with nitrogen and phosphorus, causing pollution and dead zones with no improvement in sight

• Key Drivers: application of mined mineral phosphorus to field as fertilizers, application of industrially fixed nitrogen to fields as fertilizers, cultivation of nitrogen-fixing crops

Ocean Acidification

the ocean is turning more acidic, threatening marine life as we cross into unsafe conditions with a worsening trend

• Key Drivers: fossil fuel burning

Atmospheric Aerosol Loading

air pollution differences between hemispheres are decreasing (positive sign as air quality slowly improves)

• Key Drivers: fossil fuel burning, biomass burning, industrial activities

Stratospheric Ozone Depletion

the ozone layer remains stable and is showing signs of slow recovery maintaining protection against harmful UV radiation

• Key Drivers: production/emission of ozone-depleting substances such as synthetic Chloroflurocarbons and Nitrous Oxides

Introduction of Novel Entities

human made chemicals, plastics, and other novel entities continue to increase without sufficient testing or control with environmental risk continuing to grow

• Key Drivers: industrial production of artificial chemical compounds for industry agriculture, and consumer goods

Fanning and Raworth

doughnut model linking social and planetary boundaries

Global Change in Social Shortfall and Ecological Overshoot

Major conclusions: doubling of GDP leads to modest reductions in social shortfalls but serious overshoot of multiple planetary boundaries (overshoot increase significantly faster than reductions in social shortfalls)

Social Shortfall and Ecological Overshoot of Country Cluster by Wealth Status

Poorest vs Richest Countries: richest countries meet the social foundations but are exceeding the planetary boundaries while poorest countries have not met the social foundations and have not exceeded the planetary boundaries

Pleistocene

end of last glacial period; wild swings in climate change over time (glacial and non-glacial periods)

• extreme temperature variability

Holocene

very stable climatic period in which it evolved and adapted its technologies and cultures

• by transgressing several planetary boundaries → this period has ended and we are entering a new and dangerous terrain in which a still-growing world population must safeguard human wellbeing

Assessing Planetary Boundaries

planetary boundary control variables are measured in complex and multifaceted ways often requiring diverse array of observational methods and technology across various scientific disciplines

• satellites orbiting Earth, sensors buried in ground, high performance computer simulation models

• methods depend on various factors

• each assessment method faces challenges, such as technological limitations, environmental conditions, and data interpretation complexities

The Great Acceleration

the rapid post-1950 rise in human pressures and Earth system changes

• generally exponentially growth

  • some grew exponentially and then flatten out at high levels

    • Why? can’t grow any higher

• human activities are causing the earth system response trends

Resilence

the capacity of the biogeochemical Earth system to absorb human pressures such that the system remains in or returns to a Holocene-like state

• only this state can provide the essential structures and functions that are the foundation for sustainable development of human societies

Balancing Feedback Loops

maintain steady state (equilibrium) by preventing change

Reinforcing Feedback Loops

amplify change causing expansional increases and acceleration

Precautionary Principle

used to set planetary boundaries in very conservative positions

• important because the location of tipping points for planetary boundaries in uncertain

Feedback Loop Examples

• sea ice - arctic warming leads to melting sea ice, which leads to further warming because water has lower albedo (reflectance) than ice

• wildfire - rising temperatures leads to increasing fire frequency or severity causing increasing CO2 emissions, loss of sequestration, and changes in albedo which causes more warming

• permafrost - increasing temperature leads to more permafrost thawing, which produces CO2 and methane emissions, which in turn leads to further increasing temperatures

Plate Boundaries

represent processes of integrated Earth system functioning

• processes are not separate, but connected to each other

• planetary boundaries are therefore connected to one another via feedback loops

The Ocean

• Largest mass of water'

• Largest stock of carbon

• Largest stock of heat

• Very important

  • Absorbs roughly 89-93% of Earth’s energy imbalance

  • Stores and redistributes heat

  • Plays a major role in carbon uptake

  • Supports about half of global primary production through marine phytoplankton

  • Contributes to Earth systems resilience, habitability, and climate regulation

Extreme Events

extreme events are not isolated “climate disasters,” but outcomes of interacting planetary boundary transgressions

Hazard

inherent potential to cause harm

Exposure

actual contract or proximity between the hazard and a person or environment (ex. being in flood line)

Vulnerability

the conditions and characteristics that make people or assets susceptible to harm or weaken their ability to cope with or recover form a hazard

Extreme Event as Planetary Boundary Interactions