Embodied energy in apples

Embodied energy is the energy that is put into any material.  For an apple this would consist primarily of the energy to farm and transport it.  In this analysis the farming portion of the embodied energy will be neglected.  Thus the embodied energy consists of the energy to transport the apple.  In season and out of season scenarios will be considered.  For the in season we will assume that the individual makes the very energy conscious decision to buy local.  All the embodied energy comes from driving the apple from the orchard to the local farmers market.

Thus the in season embodied energy in season is .186 kWh.

For out of season the energy per apple is computed by finding the energy to ship it from New Zealand to LA then to ship it by truck from LA to IC.

Red Stack Green Stack Summary

The image below portrays the final red stack green stack analysis for the United States.  The calculations used to arrive at the values in this analysis were modeled after McKay's analysis of Britain but applied to the United States.  As seen below, the US has a lot of potential renewable energy sources.  A large part of this is probably due to the massive amount of unpopulated land at the United States disposal.  This analysis assumes infinite amounts of money available so does not take into account the cost of implementing each of the green stack items.

The red and green stacks that McKay found for Britain are both slightly shorter than the red stack found for the United States.  Britain is more constrained when it comes to area available for green stack items.

The table below summarizes the values found for all green stack items for the United States:

The table below summarizes the values found for all red stack items for the United States:

Green Stack: Wind (Onshore and Offshore)

The tables below summarize the values used in calculating the United States per capita available wind energy.  The first section shows general numbers such as population and land area for the United States and Great Britain.  Britain's numbers were used as a basis of comparison.  The next section shows the values for onshore wind energy available.

The next two sections show the per capita energy available to the United States from shallow offshore wind and deep offshore wind respectively.  The deep offshore wind has a higher potential energy density because it tends to be windier further out into the ocean.

Sources:

http://www.google.com/publicdata/explore?ds=kf7tgg1uo9ude_&met_y=population&tdim=true&dl=en&hl=en&q=us+population#ctype=l&strail=false&nselm=h&met_y=population&scale_y=lin&ind_y=false&rdim=state&ifdim=state&tdim=true&hl=en&dl=en

http://www.windpoweringamerica.gov/wind_maps.asp

http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/avgwind.html

https://icon.uiowa.edu/d2l/lms/content/viewer/main_frame.d2l?ou=1372240&tId=1925439

http://www.windenergyplanning.com/wind-turbine-efficiency/

http://www.pursuetheoutdoors.com/fishing/contour-maps/

http://en.wikipedia.org/wiki/United_States_territory

Green Stack: Solar (Thermal, PV, Farm, Biomass)

The table below summarizes the numbers and estimations used in finding the per capita solar energy available to the United States.  The four solar energy capacities calculated include Solar Thermal (panels on houses for heating water), Solar PV (more efficient panels), Solar Farming (large amount of land used just for solar panels), and Biomass (crops, etc.).

Sources:

http://www.futurepundit.com/archives/002185.html

http://en.wikipedia.org/wiki/File:Us_pv_annual_may2004.jpg

http://www.currentresults.com/Weather/US/average-annual-sunshine-by-city.php

https://icon.uiowa.edu/d2l/lms/content/viewer/main_frame.d2l?ou=1372240&tId=1925439

Red Stack - Transportation of Stuff and Stuff

Stuff and the transportation of stuff has a moderate effect on the red stack.  Many of the numbers are taken from MacKay and then scaled to a value for the US.  These scales are assumed for the stuff portion.  Ex) it is assumed that a person drinks 2 beverages out of aluminum cans a day instead of 5.  For the transportation portion the UK value is multiplied by a ratio of the US exports in dollars and the UK exports in dollars to get a value for the US.

Sources:
http://www.wisegeek.com/how-much-garbage-does-a-person-create-in-one-year.htm

Red Stack - Widgets

Widgets are the power using devices that everyone in the US uses every day.  For this the five most commonly used items were chosen and calculated.  Then a final column other encompasses all other devices.

Sources:

http://www.oksolar.com/technical/consumption.html

Red Stack - Lighting

Lighting was computed using energy efficient light bulbs.  The total comes out to a little over 2 kWh per person per day.  This number when compared to the whole stack is small; however, it is significant enough to be included.  It also helps one grasp other values as we turn lights on and off every day.

http://www.truevalue.com/thumbnail/Lighting/Light-Bulbs/Compact-Fluorescent/pc/11/c/2185/1527.uts

 

http://www.google.com/products/catalog?q=fluorescent+light+wattage&hl=en&um=1&ie=UTF-8&tbm=shop&cid=14126741906089707206&sa=X&ei=gWFxTtfqAZTH0AGM_K2xCg&ved=0CIkBEPMCMAA

Sources: 

Red Stack - Heating and Cooling

Domestic water heating, cooking, and cleaning all take up nearly the same amount of energy per day for a person in the US.

When examining heating and cooling of the environment heating takes much more energy over the course of a year.  It is about 2.5 times more in fact.  

Space heating was determined by assuming that for half the year each person used an individual space heater.

 The total is about 68 kWh/person/day which is comparable to the UK; however, it is more as would be expected.
Sources:

http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13050

http://www.oksolar.com/technical/consumption.html

http://en.allexperts.com/q/Electrical-Wiring-Home-1734/New-Electric-Oven.htm

http://www.grainger.com/Grainger/electric-infrared-heaters/heating-equipment/hvacr/ecatalog/N-8yo 

Coastal Wind Power Density

Car Energy Use

Solar Power Available in the United States

The United States demand for energy could be met by solar power if approximately 12,400 km^2 were covered in solar panels.  This is about 0.127% of the the country and would be very expensive and time consuming to implement.  The calculations and approximations that led to this conclusion are summarized in the table below:

Compared to similar analysis of the United States wind power potential, solar power is more conceivable because it would take up less area and solar panels could be mounted on roofs of buildings.

Sources:
http://en.wikipedia.org/wiki/United_States
http://shop.solardirect.com/index.php?Solar_PV_Electric&cPath=23&gclid=CP3z9_KfjqsCFUTBKgodESApxw
http://en.wikipedia.org/wiki/Solar_power

Wind Power Available in the United States

According to some very rough estimation and calculation the United States could potentially produce about 4.714x10^11 kWh each day from wind energy.  This exceeds 1.025x10^10 kWh (the approximate amount of energy used by the United States in a day) by a factor of 45.  It should be mentioned, however, that these numbers may have some inaccuracies because the entire middle third of the country would have to be covered with wind turbines every 25m with no regard for homes, businesses, terrain, or cost.  That being said, below is a table of the numbers used in the calculations and a summary of the results.

The reasoning behind the use of "1/3" of the area of the United States for "wind energy supported area" is based on the diagram seen below.  According to the chart, the areas in white are not suitable for producing wind energy because of low winds or bad terrain.  It was approximated that the area deemed suitable was one third of the country.  Since the numbers for average temperature and wind speed in the middle third of the country were not available, the numbers from Iowa (a fairly average state in both of these areas) were used.

Sources:

http://en.wikipedia.org/wiki/Wind_power

http://www.windpoweringamerica.gov/wind_maps.asp

http://www.nationsencyclopedia.com/economies/Americas/United-States-of-America.html

http://www.withouthotair.com/

US Stack Analysis - Heating and Cooling of Houses

Using US heating and cooling statistics the heating and cooling energy use per day were found to be 1.29 and 1.88 kW-h per day per person respectively.  Total household usages were found and adjusted by the number of households and population.  In this calculation it was assumed that the furnace fan and other HVAC usages were split evenly between heating and cooling.

Sources:
http://energysavers.gov
http://eia.gov

US Stack Analysis - Car Use

The daily energy use per day per person due to cars was found to be close to 50 kW-h per day.  This was done by using the average mpg of an average car and using statistics from BTS.org for the daily distance an average American drives.  Numbers can be seen in the following figure.

  

The same type of calculation was performed for flying below:

Sources:

BTS.gov

Wikipedia.org

The Impact of Our Contiunued Energy Consumption

If the world continues to use energy at its current rate, the effect on the environment will be quite severe. Coal supplies are plentiful and are not expected to run out for some time. This is the most pressing issue since coal power plants produce a large percentage of the worlds energy while also being the most dirty polluter. As other fuels like oil run out, coal will have to play a bigger role in energy production, until it of course runs out. By then, burning all that coal would have added 2.4719877 * 10^15 kg of carbon dioxide to the air. This is nearly equivalent to the current amount of carbon dioxide in the atmosphere (3.16 * 10^15 kg).


     2.93 kg of carbon dioxide released from burning 1kg of coal
     930 billion short tons of proven coal reserves ~ 8.43681808 * 10^14 kg 

Burning coal is not the only way coal destroys the environment. Accidents, such as the Kingston Fossil Plant coal fly ash spill, are tremendously damaging to the surrounding inhabitants and environment.

What is the scientific basis for anthropogenic global warming?
They say a picture is worth a thousand words so here's the equivalent of 2,000 words...

The industrial revolution occurred at the bottom of the hockey stick curve.  This was the beginning of fossil fuels being consumed at a rate never seen by earth, and now we are experiencing irreversible changes in earth's climate.

Sources:
http://en.wikipedia.org/wiki/Carbon_dioxide
http://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill  
http://www.pewclimate.org/facts-and-figures/international/historical

Runaway Train

The graph below shows that, per capita, North America emits far more CO2 than any other region in the world:

Why is this?  Brian Czech, author of Shoveling Fuel for a Runaway Train, would probably say it is due to Americans being conditioned to always push for growth with little regard for consequence.  Czech believes that, while growth was good for the United States for a long time, the lack of resources remaining on Earth makes it necessary to switch the nations goal from growth to sustaining.  This is a foreign concept for most Americans who are used to the theory that all growth is good.  As a result, Americans use more resources and emit more greenhouse gases to the atmosphere on their way to accomplishing continuous economic growth.  According to Czech, one day, the world will run out of resources and the pursuit of growth for growth's sake only brings this day closer.  Czech compares the United States to a runaway train, speeding out of control, burning resources, building debt, and emitting greenhouse gases.  The reason that the rest of the world does not emit as much per capita is because the world either does not share this mindset with America or just has not progressed quite as far yet.

Sources:

http://www.ucpress.edu/book.php?isbn=9780520225145

http://openlibrary.org/books/OL7710977M/Shoveling_Fuel_for_a_Runaway_Train

Climate Forcings

Climate forcings are factors that drive the climate system.  There are many forcings and each has a different impact on the climate.  The most significant forces over the last millennium were the sun and volcanic activity.  Recently CO2 concentration has become a significant force as well.  Intensity of the force is typically measured in Watts per square meter.  Forces can also be classified as positive or negative forces.  Positive forces have a warming effect while negative forces cool.

Another important concept is the earth's albedo.  This is the reflection coefficient of the earth's surface.  It is a ratio of the reflected radiation to the radiation incident on the surface.  The larger this number the more radiation that is being absorbed thus heating up the earth's surface.

Sources:
http://www.ncdc.noaa.gov/paleo/globalwarming/gw-forcing.html
http://en.wikipedia.org/wiki/Albedo

Is Climate Change Due to the Use Of Fossil Fuels Irreversible?

Firstly, when addressing this questions it is important to realize that this is a highly debated question.  Due to the complexity of climate and many variables involved it is hard to know exactly how accurate model's predictions will be.  Moving away from this disclaimer Susan Solomon's opinion on this irreversibility will be examined in an article published on PNAS.org.  This paper focuses on irreversible climate changes in which three criteria are met.  Observed changes are already existing and there is evidence for anthropogenic contributions.  The change is based upon principals that are assumed to be understood.  Finally, projections must be broadly robust across models.  Carbon concentrations in the atmosphere are the first irreversible change.  Solomon states that the carbon cycle across long time spans was able to keep concentrations balanced, but since the industrial revolution human activity has dumped so much CO2 into the atmosphere to create an irreversible change.  According to her models if CO2 emissions were to completely cease the atmosphere still wouldn't return to pre-industrial concentrations.  The next irreversible climate change is atmospheric warming. This has a lot to do with the CO2 concentrations being high.  Precipitation changes are next.  These changes come about because of the warming of the atmosphere.  The final change is sea level rise.  This is expected to come about due to the warming and expanding of the oceans.  Also, melting of glaciers will produce this change.  By examining Solomon's model it is concluded that there is some degree of irreversibility in climate change due to carbon dioxide emissions.  Looking at this model it is seen how intricately all of these changes are connected.  However, describing how complicated the climate system is it is likely that there are errors in these models.

Could the CO2 increase be attributed to other phenomenon?
While it is important to focus on reducing fossil fuel use no argument is fair if only one side of the story is told.  For this reason it is important to consider other possibilities.  One of these is land use change.  It is hard to quantify how much CO2 increases due to deforestation every year; however, it is likely that it does.  Another possible phenomenon is altered efficiencies of CO2 sinks such as the oceans.

Source:
http://www.pnas.org/content/early/2009/01/28/0812721106.full.pdf+html
http://www.globalcarbonproject.org/carbonbudget/09/hl-full.htm#naturalsinks

Sources of Greenhouse Gases

Before the industrial revolution the carbon cycle was able to keep the levels of CO2 balanced.  With the coming of new technologies and burning fossil fuels humans have overwhelmed nature's balance, and the carbon cycle is no longer able to keep this stability.  Humans also began putting other harmful greenhouse gases into the atmosphere at the same time.  In the United States emissions primarily come from energy use.

This figure gives several insights into the United State's emissions profile.  Transportation and industrial uses account for the most energy use by sector and corresponding to this these sectors have the highest CO2 emissions.  One positive from this figure is how large the portion for non-fossil fuels are in the electricity by sector.  The percentage is still small compared to the fossil, but it shows that there is progress being made to solve the problem at hand.  The next figure shows how unevenly emissions are produced by developed versus undeveloped countries and brings up possible social justice issues.

Noticing that the developing countries are expected to pass industrialized countries seems counter intuitive.  However, several variables can account for this.  For example, often times developing countries produce goods that get shipped to industrialized places.  Who should be responsible for these emissions?  It is examples such as this that portrait how complicated this issue is, but in the end we are all in this together.
 According to wikipedia the top 10 emission producing countries are responsible for 2/3 of all emissions.  The top three emitters are China, US, and the EU.  Keep in mind that the EU is comprised of many countries.

Sources:
http://www.eia.gov/oiaf/1605/ggccebro/chapter1.html
http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions

Global Warming Potential and Greenhouse Gas Sources

All greenhouse gases have what is called the Global Warming Potential (GWP).  This number is based off of a few characteristics of the gas and is used to compare how effective the gas is at trapping heat in the atmosphere.  GWP is based off how well the gas traps heat relative to that of CO2 and how quickly it decays from the atmosphere.  Another use of the GWP can be in defining how effective the gas will be in global warming over a given time span.  The GWP value is often used in politics when setting regulations.

  

This table has several useful attributes.  The fact that methane and nitrous oxide are much more heat absorbing than CO2  jumps out right away.  However, because there is so much more CO2 in the atmosphere it is still the biggest problem.  Finally, in the anthropogenic sources column we can see a few of the major sources of these gases.

Sources:
http://www.global-greenhouse-warming.com/global-warming-potential.html

Greenhouse Effect and Greenhouse Gases

When thermal radiation is emitted from the earth some of it is trapped by gases in the atmosphere and then re-radiated back towards the earth.  This process is called the greenhouse effect and the gases which contribute to this process are called greenhouse gases.

Although this effect is necessary to warm the earth and therefore needed to sustain life, too much of the greenhouse effect causes the average temperature of the earth to rise.  This phenomenon is called global warming and occurs when the amount of greenhouse gas in the atmosphere is increased.  What are these greenhouse gases?  They are water vapor, carbon dioxide, methane, ozone, sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons.  Of those listed, the first four contribute significantly to the green house effect:

Where are these greenhouse gases coming from?  Although these gases have been produced naturally for billions of years, there has been an unprecedented increase in the last hundred years.  As seen in the graph below, the start of the increase of every greenhouse gas has coincided perfectly with the onset of the industrial revolution.  This is not a coincidence.  The increase in atmospheric greenhouse gas concentration is undeniably caused by humans.

Sources:

http://www.infoplease.com/ipa/A0004686.html

http://en.wikipedia.org/wiki/Greenhouse_gas

http://en.wikipedia.org/wiki/Greenhouse_effect

Our Energy Consumption Profile

It is well know that the world is using more and more energy everyday. This is generally due to an increasing global population coupled with higher prosperity. This energy is produced mainly from oil, coal, and gas.

With oil being the biggest part of the current energy profile, any lack in production could be devastating. Unfortunately, oil reserves do not seem to be able to keep up with increasing demand and new oil discoveries are happening less often. This means our oil consumption will have to decrease soon, be it by being proactive and coming up with new sources for energy, or by sitting around and have the oil run out without a suitable replacement available.

 Sources:
http://en.wikipedia.org/wiki/World_energy_consumption