Weekly Readings

Week One Readings

The World’s First Climate Model

  • Arvid Hogborn mapped out what was at the time, the most complete account of the carbon cycle

    • Measured the amount of gaseous “carbonic acid” (CO2) in the atmosphere

    • He identified six sources of carbon:

      1. Erupting volcanoes

      2. Meteorites burning up in the upper atmosphere

      3. Vegetation as its decomposes or burns (ex: burning of coal and oil)

      4. Release of carbon trapping in rocks by chemical reactions

      5. Rock fracturing

      6. Seawater warming under the sun

    • He also identified three ways carbon dioxide is removed:

      1. Rock weathering (CO2) dissolves in rainwater → reacts with limestone → calcium bicarbonate

      2. Absorption by plants

      3. Absorption by oceans

    Fourier transform - technique for discovering cyclic waveforms in complex data series

  • Fourier pointed out three sources of heat for the planet:

    1. The sun (main source of heat at the Earth’s surface)

    2. Earth’s core

    3. Background heat from space

  • Any object that’s warmer than its surroundings continually radiate some of its heat those surroundings (dark heat)

  • The greenhouse effect: A process where certain gases trap heat in the atmosphere, contributing to the overall warming of the planet

    • Dark heat doesn’t pas through the atmosphere as easily as light heat → slows the loss of energy back to space

  • Fourier’s theory about dark heat became known as the greenhouse effect

  • Tyndall’s experiment found that more complex chemicals such as vapours of alcohols and oils were the strongest heat absorbers, while pure elements such as oxygen and nitrogen had the least effect

    • Molecules of each gas react to different wavelengths of light depending on the molecule’s shape

    • Noticed that gases made of more than one element tend to absrob more energy from the infra-red rays than gases made of a single type of element

    Greenhouse gas - any gas that absorbs parts of the infra-red spectrum

    • Work by trapping outgoing heat

    • have the biggest impact when there is more heat leaving the Earth’s surface than arriving (ex: after the heat of the day or after summer has ended)

  • Tyndall concluded that because of water vapors abundance in the atmosphere, it’s responsible for most of the heat trapping effect that keeps the Earth warm

    • Carbon dioxide is second

    • Any changes in the levels of water vapor and carbon dioxide must produce a change of climate

  • Claude Pouillet invented a pyrheliometer to measure the heat energy we receive from the sun

  • The two main greenhouse gases are water vapour and carbon dioxide

    • Also called selective absorbers by Arrhenius

  • Today, satellites are used to measure the outgoing infra-red at the top of the atmosphere

    • Collected data demonstrates that increasing levels of carbon dioxide has reduced the rate at which the planet loses heat to space

  • A model is a set of equations that capture the relationships described in a scientific theory

    • Running a model → putting observational data into the equations to calculate other values

    • Arrhenius’s model attempted to capture the key idea in Fourier’s theory → for the average temperature of the planet to be stable over the years, the incoming energy from the sun must equal the outgoing energy lost at the top of the atmosphere

    Radiative balance - exchanges of heat balance out

  • Jozef Stefan found that the rate at which an object radiates heat it proportional to its temperature (in Kelvin) raised to the power of four)

    • The rate at which energy is radiated grows very rapidly with small increases in temperature

    Blackbody - object that perfectly absorbs all the radiative heat it receives and radiates heat out again with no impediment, appearing black

    Grey bodies - reflect incoming heat and light away from the object and reflect internal heat back towards the inside → cool down more slowly

    Albedo - percentage of sunlight reflected back to space

    • Absorption coefficient/emissivity - how well a material emits thermal radiation

  • If the climate doesn’t change from one year to the next, the total input of energy from the sun (over a year) must be the same as the total output of energy lost to space

    Model parameters - values that cannot be calculated so they must be estimated from observational data

  • Arrhenius found that changes in water vapour don’t cause climate change but are a result of it

    • Water vapour forms a feedback loop, amplifying any changer in global temperature

  • The relationship between carbon dioxide levels and temperature isn’t linear

    • Same rise or fall in temperature for each doubling or halving of carbon dioxide

    • Temperature changes are larger over land than over the ocean

      • Also larger in the northern hemisphere than the southern since the southern hemisphere has more ocean

    • Larger temperature changes towards the poles and during the winters

  • Milankovic’s model of the relationship between the Earth’s climate and small variations in its orbit included:

    1. Eccentricity - gravitational pull from other planets affecting the relative lengths of the seasons

    2. Obliquity - the Earth’s rotational axis wobbling, which affects the intensity of the seasons

    3. Precession - change in the direction of the Earth’s tilt which causes seasons to occur at different times

  • Adding more greenhouse gases in the upper atmosphere will cause warming no matter what is happening at ground level

    • The greenhouse gases in the layer of air just above the ground absorb some of the infra-red energy emitted from the ground

      • Also radiate infra-red energy upwards and downwards which is absorbed and re-emitted by each layer of air in the atmosphere

Week Two Readings

Introduction To Modern Climate Change

  • Climate is what you expect, weather is what you get

    • Weather is important for making short-term decisions (ex: if you need an umbrella)

    • Climate is important for long-term decisions (ex: building a ski resort)

  • Temperature is the parameter most often associated with climate

    • Directly affects the well-being of the Earth’s inhabitants

  • Precipitation is also important to humans as fresh water is needed for life

  • The most direct impact from the addition of greenhouse gases to the atmosphere is a warming planet

  • The warming of the planet is not uniform

    • Land areas have warmed more than the oceans

  • Since ice melts reliably at 0 C it’s a dependable indicator of temperature

    • The recession of glaciers confirms the global warming of the climate

  • The most well-studied and reliable source of temperature data for the past century is the surface thermometer network

  • Scientists have a large number of independent measurements with which to confirm the warning seen by the surface thermometer network

    • Include: satellite measurements of temperature, measurements of ice on the planet, ocean heat measurements, and sea-level measurements

  • The Earth has two major ice sheets which contain majority of the world’s fresh water:

    1. One on Greenland in the northern hemisphere

    2. One on Antarctica in the southern hemisphere

  • Sea-level change is connected to climate change in two ways:

    1. As grounded ice melts the melt water runs into the ocean → rise in the total amount of water in ocean —> rise in seal level

      • Grounded ice - ice that is resting on land

    2. Water expands when it warms

  • The IPCC says the observed warming of the climate system is unequivocal

    • The pervious decade is very likely the hottest of the past 400 years

  • Energy is transported from the Sun to the Earth through electromagnetic radiation

  • All room-temperature objects are emitting photons but you can’t see them since they fall outside the visible range

    • Appear black since the photons emitted are invisible to humans → blackbody previous

Climate - statistical description of the weather over a period of time

  • The slowly varying aspects of the atmosphere-hydrosphere-land surface system

  • Characterized in terms of suitable averages of the climate system over periods of a month or more

  • Gives the range of probable conditions on a particular day

Weather - the actual state of the atmosphere at a particular time

Climate change - any systematic change in the long-term statistics of climate elements sustained over several decades or longer

Temperature anomaly - the difference between the actual temperature and reference temperature

Temperature - measure of the internal energy of an object

  • Internal energy - how fast the atoms and molecules in the object are moving

Week Three Readings

Choosing A Future

Week Four Readings

Intersectional Environmentalist

  • There are seventeen principles of environmental justice

    1. Environmental justice affirms the sacredness of Mother Earth, ecological unity, and the interdependence of all species, and the right to be free from ecological destruction

    2. Environmental justice demands that public policy be based on mutual respect and justice for all peoples, free from any form of discrimination of bias

    3. Environmental justice mandates the right to ethical, balanced, and responsible uses of land and renewable resources in the interest of a sustainable planet for humans and other living things

    4. Environmental justice calls for unviersal protections from nuclear testing, extraction, production, and disposal of toxic/hazardous wastes and poisons

    5. Environmental justice affirms the fundamental right to political, economic, cultural, and environmental self-determination of all peoples

    6. Environmental justice demands the cessation of the production of all toxins, hazardous wastes, and radioactive materials

Environmental justice - the fair treatment of all people, regardless of identity regarding their environment

Week Five Readings

How the Ants Moved the Elephants in Paris

Week Six Readings

The Future We Choose

  • Natural scientists have provided ample evidence that we have reached several planetary boundaries beyond which Earth’s biosystems cannot sustain life

    • We need to move towards a regenerative economy (repurpose used resources, minimizing waste, replenishing depleted resources)

  • Believe that three mindsets are fundamental to us all in our pursuit to co-create a better world

    1. Stubborn optimism

    2. Endless abundance

    3. Radical regeneration

Week Seven Readings

Capitalism And The Climate Crisis

  • Capitalism operates within various markets

    • The labor market includes those who don’t own the means of production and whose income depends on selling their capacity for work

    • The capital market includes a set of institutions that funnel profits and savings to help capitalists fund their production, goods, and services

  • The expansionary compulsion of capitalism is a major contributor to the current climate crisis in that such growth relies on the constant takeover of more and more resources from outside its system

    • Needs more and more extraction (ex: energy inputs through fossil fuels) from ecological systems

Embedded liberalism - market processes and corporate activities are embedded in a web of social and political constraints in the form of strong regulations

Stagflation - surge in unemployment and inflation

Neoliberalism - prioritized market principles over social and political concerns and against the state interventionist approaches of embedded liberalism