Economic cost of natural hazards is increasing due to population growth among other factors
Aral Sea – how humans alter the environment
Large lakes help to moderate climate
1969 – Armstrong lands on the moon
Powerful - humans see picture of the earth from outside
Scarcity, earth as a closed system, fragile
US laws on Environmental protection began in the early 1900’s. After the moon landing & Silent Spring (Rachel
Carson) the number of laws took off with the environmental movement
“The world changes as we learn to see it in new ways. And the way we see the world depends on how we use it”
- David Rothenberg
“There are no passengers on spaceship earth. We are all crew members.” - Marshall McLuhan (Canadian
philosopher of communication theory)
Earth no longer as big as we thought
View of earth from space increased our awareness of the fragility of the Earth and the need to better understand it.
US President commissions a study of the Earth System to understand how to live in concert with this fragile Earth.
[The result of the study is published on first handout]
An Example of earth system science
How earth’s parts and their interactions evolved. How they function today and how they might be expected to
function in the future.
Earth system seen as a set of interacting systems; a change in one component/process can propagate through
the entire system
Scale – time, size, distance.
Five “Reservoirs” or Subsystems of the Earth System [At first it was just 1,2,3 – Geology]
2. Hydrosphere (water + ice)
3. Solid earth (rocks + soil)
4. Biota (life)
5. Stars + Planets
“Earth Systems Engineering: the World as Human Artifact” - Brad Allenby
The earth is increasingly a product of human engineering
Managing the Earth’s complex systems and their dynamics is the next great challenge for the engineering
The Earth, as it exists now is a human artifact – it reflects the historic, unconscious, and unintended design of a
single species. Humans have always been conducting E.S.E and M.S.E.
Lead Contamination graph (in Greenland Snow)
Measurable during the Roman Empire but also as early as when humans first began burning forests for farmland
Increased with the beginning of the Industrial Revolution and grew exponentially with leaded gasoline (dropping
of substantially with the birth of unleaded gasoline)
Example of the earth as “increasingly a product of human engineering”
How does past E.S.E. compare to future E.S.E.?
1. Scale – in the past the focus of scale was more local and less global
2. Intent –in the past regional & global effects were unintended & unanticipated
Thomas Midgely had more impact on the atmosphere than any other single organism in earth history. In 1921, he
invented leaded gasoline. In 1930-1931 he invented Freon; the first of the chlorofluorocarbons (CFCs)
[graph] Coal production went from almost none in 1800 and grew exponentially to approx. 7,000M tones annul in
the present day.
Coal (mostly carbon) burnt with oxygen produces CO2 – greenhouse gas (warms the atmosphere)
[graph] Metal production (Steel + Aluminum) has grown exponentially since the industrial revolution
[graph] Total amount of earth moved has grown exponentially since the industrial revolution. Both for farming
(approx. 80Gt annually) and other metals and materials. i.e.: deforestation of the Amazon rainforest
Running water (rivers) moves the most amount of material of all natural processes.
However the total annual world-wide consumption of resources is 4 times greater than the total mass of sediment
transported to the sea annually. Humans move slightly less than 4 times as much as all other natural processes.
Humans can’t produce and use Earth materials without generating waste. Our waste production has also increased
exponentially (i.e.: CO2 in the atmosphere)
Waste production also affects species extinction rates. A new study found genetic obliteration increasing as a result
of human activities. [graph] The number of species lost every year is increasing exponentially.
We can’t build large city skyscrapers without digging giant holes elsewhere on the Earth.
Why has there been such a dramatic increase in the impact of humans on the Earth System?
Partly due to population growth
Population is growing by 74M people annually or a city the size of San Francisco every three days
Advances in technological capabilities (i.e.: Thomas Midgely)
Conscious controlled management and engineering or earth systems – Allenby
i.e.: seeding hurricanes with dust to reduce its force
In the years that the Sahara Desert has greater dust storms, America has a less impactful hurricane season
“Think globally, act locally.” Everything has an impact
“To what end are humans engineering, or should engineer the Earth?” - Allenby
Ethical responsibility: a moral (not technical) question: Should we, to what extent, and to what end?
We need to define our desired endpoints. Where are we headed?
Sustainable development: meets the needs of the present without compromising the ability of the future generation
to meet their own needs
Is sustainability enough?
What level of equity?
How many individuals should we sustain?
What level of material well-being is acceptable?
There is an unequal distribution of resources
United Nation Development Program: 300 wealthiest individuals have an income
equal to 41% of the population
Martini glass world (see image)
Both sustainability and equity are needed when managing earth systems. Management
requires 4 dimensions which collectively are called Environmental Risk Management:
Technical Ethical Economic Environmental
Risk Analysis and Risk Management
Minimize damage and loss of life and injuries
mitigate [geological] hazards, disasters, and catastrophes
Hazard: something that might cause harm to people: death, injury, property damage
Landslides on mars are hazards – space rovers are human property
Hazards can be both natural and anthropogenic (human created or produced). Not black and white.
Resource: something that is of use to humans
Everything can be a resource or a hazard
“All substances are poison. There is none which is not a poison. The right dose differentiates a poison from a
remedy.” - Paracelsus
Hydrogen sulfide (sewer gas) – acts as a relaxant of smooth muscle (vasodilator) and is deadly at high conc.
DDT – fights malaria, builds up in fatty organs of animals and humans
How do we decide what the damage threshold is?
Partially empirical observations and scientific studies
Ultimately determined by societal preferences
Human culture decides whether pollution (i.e.: cigarettes) is considered a hazard
Over time there may be changes in human tolerance or sensitivity to the hazard
Each factor on its own may be a resource. Together they may produce a hazard, disaster, etc.
i.e.: Blizzards – synergy of wind and snow
Three main factors that control how severe a hazard event is:
Absolute amount [Intensity] Rate of change into hazard zone Duration of event
After a hazard event there are losses and gains, winners and losers.
When does a hazard event become a disaster? A catastrophe? What factors decide this:
Extent of loss of life, injury
Extent of economic loss
Why is the distinction important?
Government, national, and world aid
Historical perspective: how often do the really big events happen?
Truism in disasters – the poor lose their lives while the rich lose their money
90% of deaths are in less industrialized countries
75% of economic damage is in more industrialized countries
How to determine that risk to humans from exposure to a particular hazard? [location dependent]
Risk = PH x SH PH – probability of hazard SH – severity of consequences
How do we measure PH and SH? – empirical observations and scientific studies on economic/social impact
Should we believe the experts, or should we add a margin of safety in risk analysis?
The experts have probably already added a margin of safety.
i.e.: Experts advise ice be 8cm thick to support a person – probably less
Cost benefit analysis: what risks are we willing to take for what benefits; environmental, social, or economic
How much risk are we willing to incur? - It is entirely a matter of personal/societal choice.
People's Perception of Risk
Tend to INCREASE risk perception
Tend to DECREASE risk perception
many fatalities per event
few fatalities per event
US studied showed chlorinating water increases the incidence of bladder cancer. Peru removed chlorination
from many wells. As a result 3500 people were saved from bladder cancer by an early death from cholera.
There are almost always opportunities forgone when we take precautions, and danger accepted when we don’t
“A person, and society, needs to seek a prudent balance between the advantages of boldness and the
advantages of caution.” - Howard Margolis
What is the worth of a life and how do we go about determining its worth?
To whom is it important – relatives, company, government, society…
Worth to society – present vs. future value, education, age, economic status
The Value of Statistical Life (VSL) – worth 8.16 million at birth
VSLY (yearly) – value
deteriorates with age.
Chapter 1 Notes:
Magnitude-frequency concept: magnitude of hazardous event is inversely related to its frequency
Population growth, concentration of infrastructure, wealth in hazardous areas, and poor land use decisions are
increasing our vulnerability to natural disasters
Impact also influenced by many factors, including climate, geology, vegetation, population and land use
Natural disasters are recurrent events - the study of past events provides needed information for risk reduction
Prediction of a hazardous event involves specifying the date and size of the event
A forecast is less precise and has uncertainty
Currently we deal with hazards primarily in reactive ways (after the disaster)
Economic cost of natural hazards is increasing due to population growth among other factors. Aral sea how humans alter the environment. 1969 armstrong lands on the moon. Powerful - humans see picture of the earth from outside. Scarcity, earth as a closed system, fragile. Us laws on environmental protection began in the early 1900"s. After the moon landing & silent spring (rachel. Carson) the number of laws took off with the environmental movement. The world changes as we learn to see it in new ways. And the way we see the world depends on how we use it . There are no passengers on spaceship earth. Marshall mcluhan (canadian philosopher of communication theory) Earth no longer as big as we thought. View of earth from space increased our awareness of the fragility of the earth and the need to better understand it.