 GHGs and Global Warming
 Familiarize with carbon emissions
 Recognize sources of carbon emissions
 What regulatory action has been done?
 How can we reduce emissions from MSW sources?
 How can reducing carbon emissions be worth millions of $$$?
 What about the Future?

 Components of the atmosphere that contribute to the greenhouse effect and necessary to life on Earth but also responsible for “Global Warming”
 Including:
- Water vapor, 36~70%
- Carbon dioxide (CO
2
), 9~26%
- Methane (CH
4
), 4~9%
- Ozone (O
3
), 3~7%
- Other (N
2
O, SF
6
, …)

 Not all greenhouse gases are a threat to the environment
 The most important greenhouse gases for environmental researchers:
- Carbon dioxide (CO
2
), and,
- Methane (CH
4
)
 CO
2 and CH
4 form a large portion of the greenhouse gases

 An increase in the Earths temperature has been observed during the past decades, believed to be due to increase of GHGs

 What happens:
• Severe weather conditions,
• Sea level increase,
• Health effect,
• Change in agricultural pattern,
• …

 Can cause a 7.5 ft raise in sea level in the next century
 This can take about one third of the present
Florida’s dry land under sea water

 GWP is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming
 GWP is a relative scale comparing the gas in question to that of the same mass of CO
2
 GWP of CH
4 is 21

 The atmospheric concentration of carbon dioxide remained between 260 and 280 ppm for the 10,000 years between the end of the last glacial maximum and the start of the industrial era

 The present atmospheric carbon concentration is believed to have reached approximately 380 ppm
 The maximum possible atmospheric carbon concentration threatening natural condition on Earth is believed to be in the order of 550 to 600 ppm

 Biogenic or Natural Sources:
- Natural activities of the environment
 Anthropogenic Sources:
- Sources from human activities
- CO
2 and CH
4 have major anthropogenic sources

 Natural sources: More than 20 times greater concentration than human sources
 Natural sources are closely balanced by natural sinks (Carbon Sequestration)

 Major anthropogenic carbon sources:
- Electricity generations plants, 21%
- Industrial processes, 17%
- Transportation, 14%
- Agricultural byproducts, 13%
- Fossil fuel processing, 11%
- Residential and commercial, 10%
- Biomass burning, 10%
- Waste disposal, 4%

 A measure of the impact human activities on the environment in terms of the amount of greenhouse gases produced
 Units: Equivalent carbon dioxide – eCO
2
 Everyday activities:
- Driving to school,
- Drinking a bottle of water,
- Eating daily food,
- Turning on a light, …

 1992 United Nations Framework Convention on Climate Change (UNFCCC); developed nations agreed to non-binding 1990 GHG levels by 2000
 1997 Kyoto Conference - The “Kyoto
Protocol”; some participants made binding commitment to 1990 GHG levels (US has not ratified)

 2007 Bali Conference; US agrees to “Agree”
 July 2008 G8 Conference; G8 Nations agree to cut 50% of emissions by 2050
 Statewide regulations limiting greenhouse gas emissions include:
- California AB-32,
- Florida Executive Order 07-127,
- Regional GHG Initiative (RGGI),
- Western Climate Initiative (WGI)

 Waste management solutions to reduce carbon footprint, 3 R’s:
- Reduce
- Reuse
- Recycle
 Waste disposal (Refuse):
- Incineration
- Landfill

 IPCC Estimate of Worldwide Landfill
Methane Emissions (BAU)
3500
3000
2500
2000
1500
1000
500
0
1980 2000 2020
Year
2040 2060

 Waste to Energy:
•
•
Incineration: Directly producing thermal energy
Landfill Gas: o o o
Generated from the physical, chemical and biological processes occurring in the disposed waste,
Main components: methane 50-60%, carbon dioxide 40-
50% and other trace gases,
Using methane as a source of energy

Market Solutions:
• Taxation
• Cap & Trade

 Landfill gas (LFG) has a fuel value of 18-22
MJ/m 3 , due to methane content
 As of December 2007 there were 435 landfills capturing about 7.1 billion m 3 of LFG in the
US producing some 10.5 billion kWh, equivalent to powering 810,000 homes and heating 547,000

 Net GHG Emissions from Landfilling –
US EPA Default Values
0.2
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Landfill without LFG
Recovery
Landfills with LFG
Recovery and Flaring
Landfills with LFG
Recovery and Electric
Generation

 An official and regulated market in EU countries, but still a voluntary market in the
US
 US voluntary market:
– Companies paying voluntarily for carbon emission reduction and carbon credits usually because of investment for future, commercial interest, personal interest, …

 Carbon market options:
- Carbon Offset Credit
- Fuel Production
- Renewable Energy Credits (RECs)
- Renewable Energy Production Tax
Credits (PTCs)

 Orange County's, FL, LFGE system:
- More than 10,000 m 3 /hr LFG for 20 year,
- Can generate electricity for 13,000 homes,
- Takes advantage of $4 million in federal funding and tax incentives
 City of Albany Landfill, NY, potential C values:
- Estimated 33,638 MWh/yr electricity from LFG
- Carbon Credit value $ 1,617,919
- REC value $ 1,514,000 per year (@ $45/MWh)
- PTC value $ 336,384 per year (@ $10/MWh)

 The US voluntary carbon market trading value has tripled from 2006 to 2007, this trend is foreseen to be continuing
 Both Obama and McCain support starting a regulated carbon emissions Cap-&-Trade program
 We won’t be getting any greener if we do nothing, so at least we can try by doing something … maybe we can do some good for our future generations 

 A landfill in some county is receiving 50,000 tons of MSW annually and is operating a LFG to energy plant with recovery rate of 500 ft 3 LFG per ton MSW (50% methane content).
Estimate the carbon value for this LFGE project counting in each possible option and assuming the landfill is not regulated yet to offset carbon emissions and the methane destroy efficiency is
100%.
– Carbon offset value, at $ 1 per ft 3 CH
4
– Electricity value, at 1x10 -3 MWh electricity per ft 3 methane gas and electricity price is $100 per MWh
– RECs value, at $20 per MWh
– PTCs value, at $10 per MWh

Step 1:
Calculate the generated methane …
50,000 x 500 x 0.50 = 12.5x10
6 ft 3 CH
4

Step 2:
Calculate the electricity produced from methane …
(12.5x10
6 ) x (1x10 -3 ) = 12,500 MWh

Step 3:
Calculate each value …
Carbon offset value:
(12.5x10
6 ) x 1 = $ 12,500,000 /yr
Electricity value:
12,500 x 100 = $ 1,250,000 /yr

RECs:
12,500 x 20 = $ 250,000 /yr
PTCs:
12,500 x 10 = $ 125,000 /yr