This project enumerates ways to mitigate climate change through eight strategies. Each strategy, called as 'wedge', when implemented could reduce carbon emission by 1b ton by 2055. This project prioritizes these strategies based on cost of implementation and public opinion. Ranks are assigned from 1 to 8, with 1 for highly feasible [low cost and less criticism] and 8 for hardly feasible. As seen from the presentation, adopting to biofuels is found to be least feasible (rank-8), followed by fuel switching for electricity (rank-7). In contrast, improving transport efficiency is found to be highly feasible (rank-1), followed by efficiency in electricity production (rank-2). Justifications (qualitative and quantitative) are provided for the ranking of each strategy. In the concluding slides, stakeholder perspectives are provided for automobile industry and industrial/developing nations. The climate wedges concept was developed by Princeton University, Ford and BP to find solutions to greenhouse gas problem (see references). Reference: - Carbon Mitigation Initiative http://cmi.princeton.edu/wedges/ - Stabilization Wedges Game https://cmi.princeton.edu/wedges/pdfs/teachers_guide.pdf This work is done as a part of graduate course titled Global Air Pollutants in Spring 2016. The author was pursuing MS in Environmental Engineering Sciences at University of Florida during the making of this project.

1. Climate Wedges
strategies to mitigate climate change:
effective, efficient & alternative use of energy
Dawid - Kal - Maohua
ENV 6932: Global Air Pollutants

2. Introduction (Energy and Climate Change)
Evidence continue to assert that carbon dioxide (CO2) from burning fossil fuels is
interfering climate at dangerous levels.
Models predict that without an action to curb emissions of greenhouse gases in
atmosphere, we are risking a treacherous catastrophe: a cessation of the
dominant pattern of ocean circulation, loss of the West Antarctic ice sheet, or a
several-fold increase in category-five hurricanes.

3. How Climate Wedges are Helpful
The ‘stabilization wedges’ concept is a simple tool for conveying the emission cuts that can be made to
avoid dramatic climate change.
The concept of wedges was developed in order to reduce emissions and mitigate climate change brought
on by the combustion of fossil fuels which currently adds about 8 billion tons of carbon every year.
To make the problem more tractable, we divided the stabilization triangle into eight ‘wedges’. Each wedge
represents a carbon-cutting strategy that has the potential to grow from zero today to avoiding 1 billion
tons of carbon emissions per year by 2060, or one-eighth of the stabilization triangle.
Keeping emissions flat will require the world’s societies to “fill in” the eight wedges of the stabilization
triangle.

4. The Concept of Wedges
How it works is illustrated in the
picture at right.
Current growth leads to 16b tons of
carbon emission by 2050.
But adopting few simple methods
can keep it constant at today’s 8b.
How to keep it constant is the
concept of wedges.

5. Eight Strategies
8billiontonsofcarbonemission
50 years span (2010-60)
One wedge could reduce carbon emission by 1b
tons by 2055.
yellow: efficiency & conservation
blue: fossil fuel based strategies
red:nuclear energy
green: renewables & biostorage

6. Detailed Analysis
On the following slide, Total Value was determined by adding up the values of cost, profit, and public
opinion, with the lowest total score being the most favorable to stakeholders, and highest score being
unfavorable to stakeholders.
VT = 2(VC) + 1(VP) + 3(VPO)
- Each $ sign represents a 1 within the cost column.
- For public opinion:
- Low is considered to be a value of 3.
- Medium a value of 2.
- High a value of 1.
- As demonstrated above, each category is given a different weight. This is meant to account for the
significance each column plays for the majority of stakeholders. Again, since a low total score is
most favorable and a high total score is unfavorable:
- Profit was given a x1 multiplier.
- Cost was given a x2 multiplier.
- Public Opinion was given a x3 multiplier.

7. The Eight Wedges
Rank Strategy Cost Profit (rank) Public
Opinion
Total
1 Transport Efficiency $ Very High (2) High 7
2 Efficiency in Electricity Production $ Average (4) Medium 12
3 CCS-Electricity $$ Very Low (7) Low 20
4 Building Efficiency $ Below Avg. (5) Low 16
5 Nuclear Energy $$ Highest (1) Low 14
6 Solar Energy $$$ Low (6) High 15
7 Fuel-Switching for Electricity $ Lowest (8) High 13
8 Biofuel $$ High (3) Medium 13

8. Illustrating the strategies
In the following slides, each strategy is illustrated with support details.

9. 8. Biofuels
● Relevance: Biofuels use biomass or organic material such as plants, algae, and waste that can all be converted
into fuels in order to take the place of fossil fuels or oil. Two main types are biodiesels and bioethanol.
● How it works: Essentially biomass solids are broken down and refined into biofuels.
○ Enzymes can be used to break down biomass into basic organic products. Then microbes ferment those
organic products into renewable fuel.
○ Extreme heat in the absence of oxygen can turn biomass into renewable oil.
○ With oxygen in the presence of heat, biomass will be turned into a renewable gas that can be used for biofuel.
● Support and Strengths:
○ Around since 1800’s.
○ They can be made from leftovers or waste products.
○ U.S. and Brazil are for 88% of total world production of biofuel ethanol at 13.1 billion US gallons.
○ Can be used as an additive.
● Challenges:
○ Somewhat more expensive than fossil diesel
○ Corrosion
○ Can lead to water pollution, deforestation and change of land use.

10. 7. Fuel Switching for Electricity
● Relevance: Natural gases are gases trapped under geologic reservoirs that are formed from decomposing waste
biomass.
● How it works: Natural gases are extracted from the earth using hydraulic fracking, and then separated and refined
using one of various methodologies including cryogenic cooling. Burning natural gas heats up the air needed to spin
turbine, which is connected to a generator that makes an electric current.
● Support and Strengths:
○ Accounts for 23.5% of U.S. electricity
○ Highly efficient, up to 50% of natural gas can be converted into electricity, compared to coal-fired power plants
which are 33% efficient.
○ Produces less CO2 emissions than coal-fired power plants (up to 60% less).
○ When you consider construction and fuel cost, natural gas power plants are most affordable power plants.
● Challenges:
○ Extraction leads to potential environmental issues
○ Extraction is expensive.
○ Only way to get to it is by drilling.

11. 6. Solar Energy
In Production (today): 180 GW (1% of world’s total)
Present growth: 38% global growth (in 2014), China & India to
increase by 400% by 2019
Strengths: developing countries around tropics, low life-cycle
emissions, 80% drop prices since 2000,
Challenges: public initiative, intermittent supply,
A wedge could be achieved by adding 20,000 km2
PV-panels to
today’s capacity.
..energy of electrons excited by photons.

12. 5. Nuclear Electricity
In Production (today): 17% of world’s total
Present growth: 10% per annum (New Policy Scenario). China, India, Russia, South Korea
to have highest expansion while US & Europe to move away.
Strengths: fuel cost (30% of coal), second lowest life-cycle emissions (3.3% of coal),
untapped potential of five-sixth of today, employs many (260% of coal)
Challenges: nuclear fusion, operation & maintenance (210% of coal), structural resistant to
disasters, hazard risks (earthquake, flood), waste disposal
A wedge can be achieved by tripling the present nuclear production.
..energy stored in nucleus of an atom.

13. 4. Building Efficiency
Consumption (residential & commercial): 10,380 TWh (~56% world’s total)
Population (world): 7.4 b (2015, UN) ... growth: 83m/yr
Asia + Africa: 5.6 b (~75% of total)
Key Driver: increasing indoor activity, access to transport
Challenges: improve lighting (20-30% of building’s energy), sustainable design (HVAC:
30-40% of building’s energy)
Switching to CFL saves up to 70% energy - an easier way to vie 15% tariff increase by 2035.
A wedge can be achieved by cutting 25% energy in residential and commercial buildings.
..energy leaks from building enclosures.

14. 3. CCS - Electricity
Today’s coal-burning power plants produce about one fourth of
the world’s carbon emissions and are large point-sources of
CO2 to the atmosphere.
The most economical way to pursue this is to capture CO2 at
large electricity or fuels plants, then store it underground.
A wedge of emissions savings would be achieved if
● Applying CCS to 800 large (1 billion watt) baseload coal power plants or 1600 large baseload
natural gas power plants in 50 years. As with all CCS strategies , to provide low-carbon energy
the captured CO2 would need to be stored for centuries.
Challenges:
● Risks due to the leakage; cost

15. 2. Efficiency in Electricity Production
Today’s coal-burning power plants produce about one-fourth of the world’s carbon emissions, so
increases in efficiency at these plants offer an important opportunity to reduce emissions.
A wedge of emissions savings would be achieved if
● Producing the world’s current coal-based electricity with doubled efficiency
● More efficient conversion results at the plant level from better turbines, from using
high-temperature fuel cells, and from combining fuel cells and turbines.
● Cogeneration (the co-production of electricity and useful heat) and from polygeneration (the
co-production of chemicals and electricity).
Challenges:
● Limitation of the technology.

16. 1. Transport Efficiency
A typical 30 miles per gallon (30 mpg) car driving 10,000 miles per year emits a ton of carbon into
the air annually.
There are about about 600 million cars in the world now, and it’s predicted that there will be about
2 billion passenger vehicles in 2060.
A wedge of emissions savings would be achieved if
● The fuel efficiency were doubled from 30 mpg to 60mpg.
● Efficiency improvements by using hybrid and diesel engine technologies, as well as making
vehicles out of strong but lighter materials.
● Cutting carbon emissions from trucks and planes by making these engines more efficient.
● Aviation is the fastest growing component of transportation.
Challenge:
● Public transportation is not convenient.

17. Stakeholder Perspective ..1/3
As an auto-industry:
As transportation is driving force for mobility and dynamism, auto-industry
supports your enlistment of top-priority to Transport Efficiency.
However with the advent of electric and PV cars, we can have better transport with
less emissions.
As an industrial/developing country:
Although alternative energy seems like a brilliant choice for zero-emissions,
improving the present reliable and wide-spread source is quintessential. As such,
your enlistment of Energy Efficiency as second most important is a smart choice.

18. Stakeholder Perspective ..2/3
As an auto-industry:
Another way to reduce transportation emissions is to improve urban infrastructure,
which is solely a government initiative.
In addition, use of vehicles effectively such as car-pooling practices can not only
reduce emissions, but also reduce traffic congestion: a societal initiative.
As an industrial/developing country:
As developing countries are faced by financial deficits for R&D, frontier nations
can subsidize technology sharing. For instance PV cells are expensive in India as
much of it is imported from Germany.

19. Stakeholder Perspective ..3/3
As an auto-industry:
Efficiency of transportation can be significantly improved by changing driving
practices such as gradual acceleration, constant speeds etc. which is solely an
individual habits.
As an industrial/developing country:
An immediate solution for an alternative energy could be nuclear power. So far
only three accidents have occurred world-wide. Robust structural designs and
intelligent risk mechanisms can help overcome the present challenges. Listing
nuclear power in No.5 seems an acceptable move.

20. Conclusion
The goal of climate mitigation essentially involves cooperation and consensus
between three forces:
Government policies for existing scenarios and new establishments.
Business corporates promoting and implementing new technologies.
Non-governmental organizations emphasizing the importance to people.
Public and societal awareness through journalism and social media.

21. Sources
International Energy Agency
Intergovernmental Panel on Climate Change, UNEP & WMO
United Nations Population Division
US Energy Information Administration
Department of Energy, US

22. Team “From Lands Far Far Away”
Dawid Scierka
Kalaivanan Murthy
Maohua Pan

23. Credentials
Acknowledgement
Prof. Dr. Henderson
Thank You