*Global Economy B: Topic 8 - 'Climate Change: Science & Policy'

Question 1

Describe how new climate change is

Answer 1

• It is not something new, global average temperature has been flucuating from -6^C to +14^C over the last 540M years
• Stabilising temperature between the Pleistocene (2.5M BC - 12k BC) and Holocene (12k BC - present) facilitated the evolution of
  modern humans

Question 2

What are the 2 important concepts of climate change?

Answer 2

• 2 important concepts:
  1. Global Warming
  2. Greenhouse Gases (GHG)

Question 3

Describe the intuition behind global warming

Answer 3

• Certain gases in the earth’s atmosphere have the effect of blocking emissions of heat from
  the earth’s surface.
• Heat from the sun is allowed to pass through these gases to reach the earth but when it
  rebounds from the earth’s surface it is prevented from escaping back into space.
• In effect these gases form a glass screen above the earth -> greenhouse effect -> GHG gases

Question 4

Describe & explain greenhouse gases

Answer 4

• GHG all occur naturally, they regulate earth’s temperature
  -> without them the average temperature of the earth’s surface would be -19°C rather
  than +15°C -> there is a ~natural~ greenhouse effect.
• There is increasing evidence that there is an enhanced greenhouse effect caused by
  increasing emissions of these gases as a result of human activity (anthropogenic GHG
  emissions).
  ⇒ The scientific consensus is that human activity is influencing the climate
• There are 5 main greenhouse gases:
  1. Carbon dioxide (𝐶𝑂2): burning fossil fuels (coal, natural gas, and oil), solid
  waste, trees and other biological materials
  2. Methane (𝐶𝐻4): agriculture, fossil fuels, and decomposition of landfill
  waste
  3. Chlorofluorocarbons (𝐶𝐹𝐶-11 and 𝐶𝐹𝐶-12): Refrigerators, air
  conditioners, different types of sprays, fire extinguishers, and paints
  4. Nitrous oxide (𝑁2𝑂): agriculture, particularly fertilized soil and animal waste
• Current concentrations are considerably higher than pre-industrial concentrations
  -> especially CFCs concentrations which are man-made gases.
• Some of these gases have a very long atmospheric life
  -> Even if emissions start to fall, atmospheric concentrations will continue to increase
  for many years.
• Global Warming Potential (GWP)
  -> refers to the relative strength of one unit of each gas in contributing to global
  warming.
• These gases are all released by industrial and agricultural activity.
  Carbon dioxide is released when fossil fuels are burnt. The others come from a
  variety of sources

Question 5

Describe & explain the 3 main discussions related to global trends in GHG emissions

Answer 5

3 Main discussions:
I) Who emits the most?
* Asia is by far the largest emitter -> 53% of global emissions.
Who has contributed the most to global CO2 emissions?
* The United States has emitted more CO2 than any other country to date.
However, Asia is home to 60% of the world’s population.
Since 1751, the US is responsible for 25% of historical CO2 emissions
II) Who emits the most vs who is impacted the most
* Rich countries
have more
resources to
deal with the
CC effects
* While poor
countries are
facing serious
consequences
of CC like
droughts or
increasing sea
levels leading
to for example
migration
III) Who produces vs who consumes
Production based emissions:
* Considers emissions that take place within national territory and offshore areas over which
the country has jurisdiction -> A.k.a. territorial-based emissions.
Consumption based emissions:
* Considers emissions from domestic final consumption and those caused by the production
of imports -> Take into account the effects of trade

Question 6

Describe & explain the climate change uncertainty

Answer 6

• There is a great deal of uncertainty surrounding the exact effect that these gases have on global
  climate patterns
• Scenarios below e.g. based on changes in human life, governmental policy response,
  atmospheric changes etc
• Different sources of uncertainty: Accumulation of different layers of activities!:
• Change in technology
• Change in weather conditions and feedbacks in the atmosphere once warming starts
• Change in scientific thresholds
• Change in our adaptation policies

Question 7

What are the impacts & consequences of climate change?

Answer 7

• IPCC 5th Assessment Report 2014:
  Anthropogenic GHG emissions “are extremely likely to have been the dominant cause of the
  observed warming since the mid-20th century”.
• “Surface temperature is projected to risk over the 21st century under all assessed emission
  scenarios. It is very likely that heat waves will occur more often and last longer, and that
  extreme precipitation events will become more intense and frequent in many regions. The
  ocean will continue to warm and acidify, and global mean sea level to rise”.
  Consequences:
  ⇒ Likely to be complex and far reaching:
• Sea level increase will cause major problems for low lying areas (e.g. Bangladesh,
  Netherlands, East Anglia) and will necessitate the construction of large scale sea defences
  (where?).
• Rising temperatures will have serious implications for ecology and agriculture.
• Occurrence of storms and hurricanes will increase and new areas will start to experience
  tropical storms.

Question 8

Describe & explain the method for implementing policies related to climate change

Answer 8

There are several points to bear in mind when it comes to formulating policy responses:
1. There is a long time lag between our current actions and the effect of them on the climate
(Climate change is an intergenerational issue: do we act now or save money for the future?).
2. For the main GHG (CO2 ) there is no end of pipe technology, i.e. we cannot use new
technology to reduce emissions, in the same way that we can for other air pollutants.
3. Since the effect of emissions is felt globally, it is no good if one or two countries reduce
emissions, if others do not -> Any action has to be implemented globally

Question 9

State & explain the potential policy responses for climate change

Answer 9

Potential policy responses:
* Mitigation: Actions to limit the magnitude or rate of long-term climate change, i.e. actions
that reduce the amount of GHG released into the atmosphere.
* Policies that concentrate on the reduction of energy use and encouraging the switch to
cleaner fuels since this provides the greatest scope for emissions reduction.
* CO2 mitigation policies:
- Use energy more efficiently and switch to less carbon intensive fuel (gas and
renewables), i.e. to prevent emissions (How?)
- Increase the amount of carbon that is absorbed by trees by increasing forested areas
and preventing deforestation.

• Adaptation: Actions to reduce the vulnerability of social and biological systems to climate
  change, i.e. actions that lower the risks caused by climate change.
• Policies that concentrate on the reduction of local or regional vulnerabilities (e.g. urban
  planning, construction of flood defences, thermal insulation, etc.).

Question 10

Describe & explain the challenges for the design of climate policies

Include citations

Answer 10

• (Hallegatte, 2009; Fankhauser and Burton, 2011)

Challenges for the design of climate policies:
* Policy makers will select policies that yield the greatest net benefits (benefits minus costs).
* Costs of climate policies (e.g. building a flood defence):
Uncertainty of cost -> Low
Time scale of benefit -> Short term

• Benefits of climate policies:
  Mitigation: Reduction of future CC damages due
  to the decrease in GHG.
  Adaptation: Reduction of future CC damages
  due to the implementation of policies to reduce
  the vulnerability of social and biological systems
• Benefits of adaptation and mitigation policies depend on future climate
  (what is the future climate? We don’t know, depends on future climate!)
  Uncertainty of cost -> High
• Furthermore, uncertainty might lead to regret in the design of climate policies
• The different time scale of costs and benefits of climate policies means that projects to
  tackle climate change are not likely to be favoured.
• Cost Benefit Analysis:
  The cost-benefit rule: Politicians will focus on Net Present Value (NPV)
  NPV = (SIGMAt(Bt - Ct))/(1+r)^t > 0
  This equation calculates the difference between PV benefits and PV costs of the project -> NPV
• Therefore there is a dual objective for the design of climate policies (Mayrhofer and Gupta, 2016; Hallegatte, 2009):
• Maximise the net benefits
• Minimise the regret
  How?
• Focus on co-benefits of climate policy:
  Uncertainty -> Low
  Time scale -> Short term

Question 11

Summarise the main challenges for the design of climate policies

Answer 11

• The three main challenges for the design of climate policies:
  1. Global phenomenon (local actions are not enough)
  2. Long term phenomenon (intergenerational nature)
  3. Uncertainty (benefits are long-term, mostly)
  Climate Change: Science & Policy (III)
  The Global Economy