Energy Consumption for Hong Kong

For energy consumption calculation, the main sources will be analyzed and totaled for Hong Kong.  This will start with transportation (cars and jets) and heating/cooling.

Automobiles:
Simple calculations can be done to find energy used per day (per car).  Since personal cars are not as popular in Hong Kong as other countries, a low number should be expected.




Average data was found for Hong Kong and energy per unit fuel was given as 10 kWh per liter.  The average distance traveled in a private car is 2.5 km per day.  The distance per unit fuel (fuel economy) is (on average) 16 km per liter.  Using these values in Equation 1 outputs an estimated 1.5 kWh per day. 

Jets:
Similar calculations can be done for a Boeing 747 for an average number of passengers and distances.  for the UK, the energy used per day was found to be around 30 kWh per day.  Given that Hong Kong has air traffic population one-third the size of the UK, an end result of 10 kWh per day was found. 
Note:  Assumption made that similar jets are used in both countries.

Heating and Cooling: Domestic water heating includes the use of showers in private homes.  Given a shower takes 1.5 kWh in order to heat the water and a person takes a shower every other day, the energy used is 0.775 kWh per day.
Heating and cooling the air in a household depends on the climate of the country.  Hong Kong has mild to warm temperatures, causing low heating and cooling needs.  For heating, it was assumed that winter lasts 3 months, in which a 2 kWh heater ran for 3 hours per day.  Given an average house size is 3 people and 365 days in a year; the energy used is 0.5 kWh per day.
Cooling in the summer season (3 months) is controlled by a 0.6 kWh air-conditioner ran for 6 hours per day for the same household size.  The energy used is 0.3 kWh per day.
For refridgeration, given 1 unit per house, uses about 0.5 kWh per day.
Cooking, washing clothes, and washing dishes can be approximated using data found in MacKay's text and all sum up to about 10 kWh per day.
All heating and cooling added together, a sum of 13 kWh per day of energy is used. 

References:  Sustainable Energy- without the hot air, David MacKay

Are humans to blame?

Global warming can be broken down into two main components: natural and anthropogenic. Natural warming occurs with processes that would have taken place without any human interaction. The Milankovitch cycles have produced warming and cooling periods since the beginning of time and are shown further in Figure 6.  These cycles are forced by the tilt and rotations (about the axis) that the earth makes during a certain period in time.

Figure 6: Milankovitch Cycles

 Along with the Milankovitch cycles, vegetation and bodies of water will emit/absorb high levels of greenhouse gases over time.  The reason that substantial warming does not occur with natural processes, is due to the ability to absorb (take out of the atmosphere) greenhouse gases.  This is not to say that natural processes do not cause warming at all!

To understand anthropogenic warming, analysis of the word itself can be used to simplify meaning.  Break the word down into anthropo- (meaning men) and -genic (meaning cause).  Now put together it is easier to see that anthropogenic warming is that which is caused by humans.  The scientists that study anthropogenic warming say that humans have increased the global temperature 1.5* F since 1850 and this is how they are proving it.  Greenhouse gases such as methane, carbon dioxide, and nitrous oxide have significantly increased since this time (Industrial revolution and so on).  As more and more gas is present in the atmosphere, its ability to "trap" radiation from earth is increased and effectively heats the earth. 

Figure 7:  Temperature and Carbon Dioxide Data

Though the analysis seems simple, Figure 7 shows how correlated the data is (shown for carbon dioxide).  Burning of fossil fuels accounts for 60% of greenhouse gas emissions which is causing a sense of urgency for the use of alternative energy sources.  Even with decreases in these greenhouse gas emissions, will the global temperature ever be restored?

Understanding the potential damage of greenhouse gases will more than likely lead to the beginning of an era to restore (or at least reduce) levels of such gases.  So pretend that all greenhouse gases were "shut off" or no longer allowed to be released into the atmosphere.  The global temperature would slowly decrease right?  According to the NOAA, no it would not!  Currently, the oceans are soaking up a lot of the planet's heat (as well as the carbon dioxide) and will eventually start being released back into the atmosphere.  This process may take hundreds (maybe thousands) of years and in the eyes of scientists, is considered irreversible.  Figure 8 shows how gas levels (carbon dioxide) may decrease if emissions completely stopped. 

Figure 8:  Results of stopped carbon dioxide emissions

 Changes in temperature without greenhouse gas emissions will most likely be caused by changes in the earth's rainfall, which will in turn affect the supply of water, agriculture, and the ecosystems.  Also shown in the figure is sea level rise, which will increase two meters by  the year 3000 (and this is without any more carbon dioxide emissions!).  All put together, greenhouse gases pose a threat to our planet not only today, but hundreds of years in the future.  Even with small (or even large) changes today, future generations are still going to feel the effects of what has already occured. 


References: 
http://ossfoundation.us/projects/environment/global-warming
http://www.pewclimate.org/global-warming-basics
http://monthlyreview.org
http://www.greenmontclair.org/greenmontclair/The_Science/Entries
http://www.npr.org/templates/story/story.php?storyId=99888903
            

The Greenhouse Effect

The carrying capacity of the Earth is defined as the largest possible population that the Earth would be able to support without having to reduce its current lifestyle. Certain factors that affect the carrying capacity include the supply of drinkable water, fundamental resources in the environment, and the rapid degradation of land.

According to the research performed by Ehrlich, the concept of carrying capacity can be expressed by the equation I=PAT. This equation is used to show the impact the human population has on the Earth. I=impact, P=the population’s size, A=the per-capita consumption, and T=the environmental damage inflicted by technologies. With the current population of about 5.5 billion and growing at an annual rate of 1.7%, it is clear that the Earth will face tremendous shortages of resources. Earth is overpopulated by millions of people and the environment has already passed it maximal load.

If the human population continues to grow and the current standard of living does not change, the environment will continue to suffer. The world’s energy profile consists of burning millions of tons of fossil fuels every year, as it is still the main source of energy for the human population.

            The IPCC publishes a report that focuses on potential environmental issues that arise from climate change. As the world continues to burn fossil fuels at rapid amounts, snow cover and sea ice decrease which lead to a rise in sea level, precipitation events such as rain storms and hurricanes increase in intensity, and there is a tendency for drying in certain areas which lead to more droughts.  Increasing amounts of CO2 in the atmosphere lead to an increase in acidification in the ocean. Temperature extremes will become more intense, frequent, and longer lasting causing areas of increased population to use more fossil fuels in order to survive.

The greenhouse effect is a controversial issue that many humans don’t quite understand. Many humans believe that the greenhouse effect is a positive problem because life on earth depends on the sun and the heat that the atmosphere traps. However what humans don’t recognize is the difference between the natural and anthropogenic greenhouse gases. 

If there were no “man-made” or anthropogenic gases produced in the world then the greenhouse effect wouldn’t be an issue but the reality is that humans are continuing to burn fossil fuels at a alarming rate. Figure 3 below shows the global anthropogenic greenhouse gas emissions by type. The main greenhouse gas is carbon dioxide, CO₂ . It makes up about 57% of all anthropogenic greenhouse gas emissions. Figure 4 indicates that carbon dioxide comes from the burning of natural gas, petroleum, and coal from power stations, transportation, and industrial processes.

The other two main greenhouse gases produced by humans are methane (CH₄) and nitrous oxide (N₂O). Methane makes up roughly 14% and nitrous oxide about 8% of the anthropogenic greenhouse gas emissions. Methane and nitrous oxide are produced by agricultural byproducts as indicated in figure 4. Fossil fuel retrieval, processing, and distribution also produce methane. Waste disposal and treatment are also major contributors to methane production.  Nitrous oxide’s other major contributor is land use and biomass burning which contributes about 26% of all nitrous oxide produced. 

                                 Figure 3: Global Anthropogenic Greenhouse Gas Emissions in 2004

            As specified above in figure 3, the last 1% of global anthropogenic greenhouse gas emissions comes from various fluorocarbons (F-carbons). Fluorocarbons are released into the atmosphere from industrial processes.

    Figure 4. Anthropogenic Greenhouse Gas Emissions by Gas 
(Million Metric Tons of Carbon   Equivalent)

The greenhouse gases produced from humans have a value that is used to compare the various greenhouse gases and the ability of them to trap heat in the atmosphere. The value produced is called Global Warming Potential (GWP). All the gases are compared against carbon dioxide, which has a value of 1. Figure 5 below shows main greenhouse gases and their GWP. It also shows the impact the greenhouse gases will have on global warming over various periods of time.

Figure 5: Global Warming Potential for main greenhouse gases

 References:

http://www.epa.gov/climatechange/emissions/globalghg.html

http://www.ipcc.ch/

http://www.eia.gov/oiaf/1605/ggccebro/chapter1.html          

http://eeocw.org/get-involved/global-warming-potential

Why Should we Think About Energy?

Why Should We Think About Energy?

            Energy has been the main component in creating civilization, or anything for that matter, since humans documented their existence.   Without energy, new environments could not be created and developed countries would fall into a panic; it is shown the more developed a country is, the more energy they consume.  But, why is this important?  Why can’t we just keep using the same technology we have now forever?

            If we keep using the same technology, we run into issues with sustainability, which is defined as the capacity to endure.  The sustainability of the earth involves keep everything in balance and being able to last.  For example, using petroleum at its current level is not a sustainable policy; eventually these natural resources are going to run out and it does not create a sustainable atmosphere for the issue of rising temperature of the earth.  Which raises the next issue, how many people can the earth house and maintain sustainable?  This term is keyed the carrying capacity of the earth. 

            The carrying capacity of the earth is debatable; most people estimate it to be from 8 to 10 billion people, but there are issues that are run into when the earth approaches this number.  The capacity of the earth to maintain a sustainable environment drops due to the increased consumption of resources.  Figure 1 shows this.

Figure 1: What happens when the population overshoots the carrying capacity of the earth.

This has yet to happen, but it is also an issue that must be addressed when thinking about long term sustainability. 

Can the current energy consumption last?  What impact will it have on the environment?

            As can be seen in Figure 2, the majority of the countries in the world are increasing their energy consumption yearly. 

Figure 2: 2012 trends on energy consumption.

Though it is not shown on this chart how much of that energy being consumed is renewable, it can be assumed that very little is at this point.  The current energy consumption trend cannot last forever; the world will just keep consuming more and more until the resources run out.  Along with this idea are other implications such as the warming of the earth due to fossil fuels being burnt, which is the prime source of fuel for most countries still, and the rising sea level.  While these situations might take a long time to have significant impact on the environment, there’s already plenty of greenhouse effects that are “loaded in the chamber”; this means that if we stopped producing greenhouse gases tomorrow, these effects will still take place.  The greenhouse effects can be viewed as a big sand pit.  At the moment, we have it already half full; we need to find a way to slow the filling of that pit and start digging the sand back out.  There’s no way that millions of people on the earth will be able to survive if that pit reaches the top. 

Resources:

http://www.paulchefurka.ca/Population.html

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