Overview of 355 Themes and Concepts

Overview of 355 Overview of 355 Themes and Themes and

ConceptsConceptsEnvironmental Problems are Environmental Problems are generally characterize by noisy generally characterize by noisy and ambiguous data.and ambiguous data.Understanding errors and data Understanding errors and data reliability/bias is key to reliability/bias is key to implementing good policyimplementing good policyMaking a model of the data is an Making a model of the data is an advanced technique that is sorely advanced technique that is sorely needed in this fieldneeded in this field

Specific ConceptsSpecific Concepts Review the explicit calculation of χReview the explicit calculation of χ22; ;

conceptually understand expected frequencies. conceptually understand expected frequencies.  Know the mapping of units of standard Know the mapping of units of standard

deviation on the probability. Z-test applicationdeviation on the probability. Z-test application Know how to use the regression tool in Excel!Know how to use the regression tool in Excel! Know how to compute Poisson statisticsKnow how to compute Poisson statistics Know how to visually inspect a graph or Know how to visually inspect a graph or

waveform of data.waveform of data. Use of the KS test and why its powerful.Use of the KS test and why its powerful.

More ConceptsMore Concepts

Understand uncertainty and Understand uncertainty and confidence limits in terms of predicting confidence limits in terms of predicting the future behavior of some trend.the future behavior of some trend.

Understand what non-linearity means Understand what non-linearity means and how lag times work in non-linear and how lag times work in non-linear systems (e.g. predator- prey relations).systems (e.g. predator- prey relations).

Understand how one can make an Understand how one can make an estimate.estimate.

Understand counting errors sqrt(N)/NUnderstand counting errors sqrt(N)/N

Goals of this CourseGoals of this Course

• To gain practice in how to frame a problemTo gain practice in how to frame a problem• To practice making toy models of various To practice making toy models of various

data waveformsdata waveforms• To understand the purpose of making a To understand the purpose of making a

modelmodel• To understand the limitations of modeling To understand the limitations of modeling

and that models differ mostly in the and that models differ mostly in the precision of predictions madeprecision of predictions made

• Provide you with a mini tool kit for analysisProvide you with a mini tool kit for analysis

Sequence for Sequence for Environmental Data Environmental Data

AnalysisAnalysis• Conceptualization of the problem Conceptualization of the problem which which

data is most important to obtain; how to data is most important to obtain; how to obtain a random/representative data set?obtain a random/representative data set?

• Methods and limitations of data collection Methods and limitations of data collection know your biases (e.g. Sunshine know your biases (e.g. Sunshine Moonbeam)Moonbeam)

• Presentation of Results => data Presentation of Results => data organization, reduction, visualization, organization, reduction, visualization, statistical analysisstatistical analysis

• Compare different models using sound Compare different models using sound statistical tests (cause they always work)statistical tests (cause they always work)

Statistical DistributionsStatistical Distributions

• Why are they useful?Why are they useful?• How to construct a frequency How to construct a frequency

distribution and/or a histogram of distribution and/or a histogram of events.events.

• Frequencies are probabilitiesFrequencies are probabilities• How the law of large numbers How the law of large numbers

manifests itself manifests itself central limit central limit theorem; random walk; expectation theorem; random walk; expectation valuesvalues

Statistical DistributionsStatistical DistributionsMapping dispersion units into probabilities of an event occurring

Some Tools• Linear Regression predictive power

lies in scatter; the “r” value is unimportant for scientific analysis

• Slope errors (cell C18 in Excel) are important and must be factored in to determine the total uncertainty of your prediction

• Identify anomalous points by sigma clipping (+/- 2 (1-cycle))

More Tools• Chi square test – measures goodness

of fit

• Understand how to determine your expected frequencies

• Chi square minimization used to find best fitting model

• Chi square statistic used to accept or reject the null hypothesis (that the data is consistent with the model plus random fluctuations)

More Tools

• Moving average technique applied to noisy data

• Z-test: determine significance between two mean values for two distributions

KS Test

• Most powerful for comparing two distributions• Statistic is the maximum difference between 2

cumulative frequency distributions• Data does not need to be normally distributed• Best means to compare data distribution

against a model• Can’t be used for sample sizes less than 10

Arrival Statistics (Poisson)

• Events have to be discrete

• A good measure of the average event rate allows the probability that N events will occur over some time period to be determined

• Large values of produces a distribution that is normal.

Green House EffectGreen House Effect

Long wavelength absorption properties of our atmosphere increase the surface temperature- Water vapor is the dominant effect, followed by CO2

MethaneMethane

• Potential role of methane is larger than CO2• GWP = 21• Scales with population growth• Released from permafrost• Released from hydrate deposits• Emissions now rising again due to global

wetlands returning from prolonged drought

Difficulty of Climate Change Difficulty of Climate Change DetectionDetection

• Data is noisy

• Temporal baseline of data is not long enough

• Multi decadal climate cycles seem to be very important

• Oceans act as a buffer that delays the overall effect

Predator Prey RelationsPredator Prey Relations Non linear in nature Non linear in nature small changes in one small changes in one

part of the system can produce rapid part of the system can produce rapid population crashespopulation crashes

Density dependent time lags are important Density dependent time lags are important (what causes them?)(what causes them?)

““Equilibrium” is intrinsically unstableEquilibrium” is intrinsically unstable Logistic growth curve makes use of carrying Logistic growth curve makes use of carrying

capacity concept, Kcapacity concept, K Negative feedback occurs as you approach Negative feedback occurs as you approach

KK R selected vs. K selected mammalsR selected vs. K selected mammals

P vs HP vs H

Understand why graphical Understand why graphical representations look like this: representations look like this:

What drives the lag time?What drives the lag time?

Human Population ProjectionsHuman Population Projections

What assumptions are used?What assumptions are used?Does human population growth respond to Does human population growth respond to the carrying capacity concept? the carrying capacity concept? World population growth rate is in World population growth rate is in continuous decline (but still positive) continuous decline (but still positive) will will this continue indefinitely?this continue indefinitely?Oscillatory model may be most realisticOscillatory model may be most realisticWhat role does increased life expectancy What role does increased life expectancy have? have?

Estimation Techniques

Extremely useful skill makes you valuable

Devise an estimation plan what factors do you need to estimate

Scale from familiar examples when possible

Perform a reality check on your estimate

Applied EcologyApplied Ecology

Know what the terms mean and Know what the terms mean and understand what an iterative solution is:understand what an iterative solution is:

Applied Ecology IIApplied Ecology II

Understand from the point of view of the Understand from the point of view of the framework (e.g. the equations) why stability is framework (e.g. the equations) why stability is very hard to achievevery hard to achieve

What role does finite reproductive age play?What role does finite reproductive age play? What makes human growth special within this What makes human growth special within this

framework.framework. Understand concepts of equilibrium occupancy Understand concepts of equilibrium occupancy

and demographic potentialand demographic potential Why is error assessment so important here?Why is error assessment so important here?

Skewed DistributionsThis is a probability distribution function and one can still use the area under the curve or area between x values to determine probabilities via numerical integration

Time Series AnalysisTime Series Analysis

Much of environmental data analysis Much of environmental data analysis or modeling represents the time or modeling represents the time evolution of some observed quantity.evolution of some observed quantity.

Long term trends with cyclical Long term trends with cyclical oscillations and/or short term regular oscillations and/or short term regular deviations; plus random variationsdeviations; plus random variations

Value of time Series Analysis

You want to uncover the long term trend that may be buried under the fluctuations

Determining the amplitude of the fluctuations helps to determine if any recent events are aberrant

Two cases: Gas prices; Climate Cycles:

Gas Prices: The long term trend is steep and rises above the fluctuations

Climate: The long term trend is overwhelmed by the fluctuations

Multiple Sine Wave FitsMultiple Sine Wave Fits

Can often reproduce the behavior seen in Can often reproduce the behavior seen in complex time seriescomplex time series

The Data RulesThe Data Rules

Always, always ALWAYS plot your data Always, always ALWAYS plot your data Never, never NEVER put data through Never, never NEVER put data through

some blackbox reduction routine without some blackbox reduction routine without examining the data themselves examining the data themselves

The average of some distribution is not The average of some distribution is not very meaningful unless you also know very meaningful unless you also know the dispersion. Always calculate the the dispersion. Always calculate the dispersion and then know how to use it! dispersion and then know how to use it!

The Average value for this data set is totally meaningless

More Data RulesMore Data Rules

Always compute the level of significance Always compute the level of significance when comparing two distributions when comparing two distributions

Always know your measuring errors. If you Always know your measuring errors. If you don't them you are not doing science. don't them you are not doing science.

Always calculate the dispersion in any Always calculate the dispersion in any correlative analysis. Remember that a correlative analysis. Remember that a correlation is only as good as the correlation is only as good as the dispersion of points around the fitted line. dispersion of points around the fitted line.

The Biggest RulesThe Biggest Rules

Always require someone to back up Always require someone to back up their "belief statements" with credible their "belief statements" with credible data. data.

Change the world. Stop being a Change the world. Stop being a passive absorber of some one else's passive absorber of some one else's belief system.belief system.

Frame all environmental problems Frame all environmental problems objectively and seek reliable data to objectively and seek reliable data to resolve conflicts and make policyresolve conflicts and make policy

And Now For Something And Now For Something Completely Different:Completely Different:

Current Tag Cloud: Global climate Current Tag Cloud: Global climate change, species extinction, oil change, species extinction, oil depletion, world food crises, global depletion, world food crises, global inequity, environmental justice, inequity, environmental justice, depletion of mineral resources, blogs depletion of mineral resources, blogs and rants, sustainability, alternative and rants, sustainability, alternative energy solutions, alternative fuels, energy solutions, alternative fuels, more blogs, Black Friday, flash mobs, more blogs, Black Friday, flash mobs, crowd sourcing, NMFPcrowd sourcing, NMFP

Your World Upon GraduationYour World Upon Graduation

The Fossil Fuel LegacyThe Fossil Fuel Legacy

Engineering the PlanetEngineering the Planet

What Compels us to do so?

Consumption: Pros and ConsConsumption: Pros and Cons

• This depends on how you want to index consumption – personal consumption/affluence is different than production/consumption that indirectly leads to better society infrastructure and services.

• What matters is the rate of consumption relative to the resource base. Main problem is that short term market growth, which we value, wants high rates.

• Sustainability demands lower rates this is the clash of values.

Key Historical MomentsKey Historical Moments

We are special (different than other animals)We are special (different than other animals) We are uniquely positioned at the center of We are uniquely positioned at the center of

the Universe (reflects our “special-ness”)the Universe (reflects our “special-ness”) The Universe is ordered, logical and rational – The Universe is ordered, logical and rational –

Age of Reason Age of Reason humankind is unboundedhumankind is unbounded The Newtonian world shows us the machine The Newtonian world shows us the machine

and it is precise (we can now engineer the and it is precise (we can now engineer the planet)planet)

The notion of uncertainty, as a valid and The notion of uncertainty, as a valid and integral scientific concept, arises too late in integral scientific concept, arises too late in this process this process we already have truth we already have truth pathways establishedpathways established

Essence of ScienceEssence of Science

Knowledge based on measurement Knowledge based on measurement means that knowledge is both means that knowledge is both uncertain and subject to change when uncertain and subject to change when new and better measurements are new and better measurements are made – there is no room for absolute made – there is no room for absolute truth in this methodologytruth in this methodology

Problems can then only be solved by Problems can then only be solved by objective means that rely on real data objective means that rely on real data and not bias or wishful thinking.and not bias or wishful thinking.

Choice Pathways Which world does humanity want to live

in? One that is based on a belief system that

is then projected on to the natural world to support that belief (this is the BIAS)

One where scientific methodology and thinking is used to enable, on a planet wide scale, the enlightenment motto that all men are created equal

Relationship with the Land is keyRelationship with the Land is key

• Three possibilities

• The Land is Sacred “Indigienous Model” your ancestors are buried in it

• The Land is shared “European Model” lots of people, not much land

• The Land is Owned “American Model” lots of land, I can piss on it if I want, afterall, its mine.

Continued Economic Development Continued Economic Development Requires high Energy Use Requires high Energy Use

• 1900 100 Million Capitalists to build markets

• 2003 2.5 Billion new capitalists

• Energy is the core of the “environmental problem”; Environment is the core of the energy problem

• The energy-environment intersection is the core of the sustainable-prosperity problem

Resolution?Resolution?

• We need to stop be driven by market economics and start to recognize that energy and environment is a shared resource.

• Your generation needs to more seriously engage with the issue of quantitative reasoning if you are to make informed choices. Otherwise, nothing good happens