Climate Change: Science And Policy

Question 1

During what timespan stabilised temperature facilitating the evolution of modern humans?

Answer 1

Pleistocene and Holocene

Question 2

The science of global warming

Answer 2

Some gases block emissions of heat from earth’s surface.

So heat rebounds and is preventing from escaping back into space.

I.e forming a glass screen above the earth like a greenhouse> greenhouse effect> GHG gases

Question 3

Do GHG occur naturally

Answer 3

Yes

Question 4

Without them what would the average temperature of earth surface be?

Answer 4

-19C compared to 15C with them

Question 5

Link between human activity and emission of GHG gases

Answer 5

Enhanced greenhouse effect (activity increases emissions)

Human activity is influencing climate

Question 6

5 main GHG

Answer 6

Carbon dioxide
Methane
Chlorofluorocarbons (CFC-11 and CFC-12)
Nitrous oxide

Question 7

Current concentrations of GHGs compared to pre-industrial concentrations

Answer 7

Current concentrations are considerably higher, especially CFCs as man-made gases

Question 8

Significance of gases having long atmospheric life

Answer 8

It means even if emissions fall, atmospheric concentrations continue to increase for many years

Question 9

Global warming potential (GWP)

Answer 9

The relative strength of one unit of each gas in contributing to global warming

Question 10

What has the highest GWP

Answer 10

CFCs

CFC-11 4500
CFC-12 7100
So worst for global warming per unit wise.

Question 11

What gas has the largest share of warming effect

Answer 11

CO2-61%

So despite CFCs having biggest GWP, it is not the biggest contributor overall.

Question 12

Where do the release of these gases come from?

Answer 12

Industrial and agricultural activity

Question 13

Biggest annual GHG emission by sector 2010

Answer 13

Electric power stations-25.6%

Question 14

How is CO2 released?

Answer 14

Burning fossil fuels

Question 15

What country emits the most

Answer 15

Asia 53% of global emissions

However Asia is home to 60% of world’s population

Question 16

Who has contributed the most to global CO2 emissions (cumulative)

Answer 16

US- 25% of historical emissions

Question 17

Production based emissions

Answer 17

Emissions that occur domestically and offshore where country has jurisdiction

Question 18

Consumption based emissions

Answer 18

Emissions from domestic final consumption and those caused by the production of imports. (Account for effects of trade

Question 19

So who has the most production emissions (territorial based)

Answer 19

China-9.8bn
US-5.3bn

Question 20

Who has the most consumption emissions (domestic consumption and emissions from import production to account for trade)

Answer 20

China 8.4bn (less than their production emissions)
US 5.7bn (more than their production emissions)

Question 21

Climate change: uncertainty

Question 22

Climate change impacts

Answer 22

Heat waves occur more often and longer
Extreme precipitation events more intense and frequent.
Ocean warming and acidify
Global mean sea level rise

Question 23

Consequences of sea level rising

Answer 23

Problems for low lying areas e.g Netherlands.

Requires construction of large scale sea defences

Question 24

Consequence of rising temperatures

Answer 24

Serious implications for ecology and architecture

Question 25

3 main challenges with policy responses to climate change

Answer 25

Time lag between actions and effect on climate (uncertainty)

Technology

Global phenomenon

Question 26

Other problem with climate change policy (regarding CO2)

Answer 26

No end of pipe technology for CO2

I.e cannot reduce CO2 emissions in the same way we can for other air pollutants

Question 27

Another problem with policy to climate change

Answer 27

Has to implemented on a global scale, as effect is felt globally. No good if one or 2 reduce.

Question 28

2 types of policy response

Answer 28

Mitigation-limit magnitude of climate change i.e lower amount of GHG released

Adaptation-reduce vulnerability of social/biological systems i.e Lower risks caused by climate change

Question 29

Mitigation

Answer 29

Policies that focus on reducing energy use and substituting to cleaner fuels

Question 30

Examples of mitigating policy

Answer 30

Increase forested areas or preventing deforestation to increase amount of carbon absorbed by trees.

Question 31

Adaptation and examples

Answer 31

Policies that focus on reducing local/regional vulnerabilities e.g flood defences, urban planning, thermal insulation etc.

Question 32

Aim in policy design for climate change

Answer 32

Select policies yielding greatest net benefit (benefits-costs)

Question 33

Challenges in policy design for climate change

Answer 33

Uncertainty
Time scale- often short term

Question 34

Benefits of climate polices

Answer 34

Mitigation-reduce future damage due to reduction in GHG

Adaptation-reduce future damages to social/biological systems

Question 35

Policy regret- uncertainty

Answer 35

Uncertainty can lead to regret.

Uncertainty can lead to under-adaptation leading to regret

Question 36

Policy regret- time scale

Answer 36

Different time scale of costs and benefits of policy.

Costs of climate policy as short term
Benefits of policy are seen long term (remember time lag)

So projects to tackle CC are not likely to be favoured.

Question 37

How they calculate cost benefit

Answer 37

NPV (net present value)

Question 38

Note: graph shows present value at different years.

If benefits/costs are received far into future, present value will be lower.

Question 39

So, overall duel objective of climate policies

Answer 39

Maximise net benefit

Minimise regret (by considering uncertainty and time scale)