Decarbonising the economy and reducing climate change

Question 1

Emissions by geographical region - rich and poor countries

Answer 1

Global pop of Rich countries is 19.7% compared to 80.3% with average per capita emissions at 16.1tCO2eq in rich compared to 4.2tCO2eq in poor countries

Question 2

Fossil fuel combustion 1900-1999 of industrialised countries figures for the US and Europe

Answer 2

Of the industrialized countries and regions, the US and Europe contributed the most to the world’s CO2 emissions from fossil fuels during this time period (30.3% and 27.7% respectively).

Question 3

& of emissions responsible for yearly Co2 emissions worldwide

Answer 3

Emissions from the burning of fossil fuels are responsible for roughly 80% of yearly CO2 emissions worldwide

Question 4

Emissions based on overall scale of activity and efficiency

Answer 4

Question 5

Choice between action and delay

Answer 5

‘Choice today is between action and delay’ – Pacala and Socolow in 2004.
The choice was delay – present emissions 9-9.5 GtC per year rather than 7 GtC in 2000.

Question 6

Davis’s analysis of wedges needed

Answer 6

Davis new analysis of wedges – stabilization requires near complete decarbonisation
Davis (2013) – need for 31 wedges

Possible need 12 hidden wedges (assumed rate of technological improvement in previous scenarios)
Nine stabilization wedges
Ten phase-out wedges

Question 7

Stabilization and mitigation wedges

Answer 7

stabilization wedges (green) of emissions avoided through mitigation efforts that hold emissions constant at 9.6 GtC y-1 beginning in 2010, phase out wedges of emissions avoided through complete transition of technologies and practices that emit Co2 to the atmosphere to ones that do not, and allowed emissions

Davis et al (2013)

Question 8

Economic costs and benefits of GHG abatement - MAC curve

Answer 8

Question 9

Stern Review - costs of climate change compared to costs of reducing emissions

Answer 9

Climate change impacts have significant economic costs – 5-20% of GDP by 2100
The costs of reducing emissions are significant but smaller – 1-2% GDP

Question 10

Political and scientific problems with the 2 degree C warming goal

Answer 10

Politically and scientifically, the 2 degree C goal is wrong-headed.
Politically, it has allowed some governments to pretend that they are taking serious action to mitigate global warming, when in reality they have achieved almost nothing.
Scientifically, there are better ways to measure the stress that humans are placing on the climate system that the growth of average global surface temperature – which has stalled since 1998 and is poorly coupled to entities that governments and companies can control directly.

(Victor and Kennel, 2014)

Question 11

New warming goal is needed

Answer 11

New goals are needed – such as changes in the ocean heat content – that are better rooted in the scientific understanding of climate drivers and risk.

(Victor and Kennel, 2014)

Question 12

Two nasty political problems

Answer 12

First, the goal is effectively unachievable – owing to continued failures to mitigate emissions globally, rising emissions are on track to blow through this limit eventually.
Second the 2 degree goal is impractical – it is related only probablistically to emissions and policies, so it does not tell particular governments and people what to do.

Victor and Kennel, 2014

Question 13

The tenuous 2 degree goal

Answer 13

The scientific basis for the 2 degree C goal is tenuous. – the plant’s average temp has barely risen in the past 16 years. But other measures show that radiative forcing – the amount by which accumulating GHGs in the atmosphere are perturbating the planet’s balance – is accelerating.

Victor and Kennel, 2014

Question 14

The Copenhagen Accord

Answer 14

The Copenhagen Accord reiterates the international’s commitment to ‘hold the increase in global temperature below 2 degrees C.
Its preferred focus on global emission peak dates and longer-term reduction targets, without recourse to cumulative emission budgets, belies seriously the scale and scope of mitigation necessary to meet such a commitment.

Anderson & Bows (2011)

Question 15

Chances of meeting the 2 degree warming target

Answer 15

Analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2 degrees C.

2 degrees C now more appropriately represents the threshold between ‘dangerous’ and ‘extremely dangerous’ climate change.

Anderson and Bows, 2011

Question 16

Technologies available to meet world’s energy need

Answer 16

A portfolio of technologies now exists to meet the world’s energy needs over the next 50 years and limit atmospheric Co2 to a trajectory that avoids a doubling of the preindustrial concentration.

Pacala and Socolow, 2004

Question 17

Stabilization at 500ppm

Answer 17

Stablilization at 500ppm requires that emissions be held near the present level of 7 billion tons of carbon per year for the next 50 years, even though they are on course to more than double

Pacala and Socolow, 2004

Question 18

Carbon emission wedges

Answer 18

If carbon emission were to grow 2% per year, then about 10 wedges would be needed instead of 7, and if carbon emissions grew at 3% per year, then around 18 wedges would be required.

Pacala and Socolow, 2004

Question 19

Wedge created from efficiency and conservation

Answer 19

Improvements in efficiency and conservation probably offer the greatest potential to provide wedges – an entire wedge would be created if the US were to reset its carbon intensity goal to a decrease of 2.11% per year and extend it to 50 years.

Pacala and Socolow, 2004

Question 20

Wedge from fuel economy

Answer 20

Improved fuel economy – One wedge would be achieved if, instead of average 30 mpg on conventional fuel, cars in 2054 averaged 60mpg, with fuel type and distance traveled unchanged.

Pacala and Socolow, 2004

Question 21

Wedge from power plant effficiency

Answer 21

Improved power plant efficiency – One wedge would be created if twice todays quantity of coal-based electricity in 2054 were produced at 60% instead of 40% efficiency

Pacala and Socolow, 2004

Question 22

Stabilization of Co2 emissions consistent with Co2 concentration

Answer 22

Stabilizing Co2 emissions at current levels for 50 years is not consistent with either an atmospheric Co2 concentration below 500ppm or global temperature increase below 2 degrees C

Davis et al, 2013

Question 23

Claim against Pacala and Socolow, 2004

Answer 23

Claims that Pacala And Socolow make the solutions seem easy – since 2004 annual emissions have increased and their growth rate has accelerated. – more than 7 wedges would now be necessary to stabilize emissions and stabilizing emissions at current levels for 50 years does not appear compatiable with P&S’s target of an atmospheric CO2 concentration below 500ppm nor the international community’s goal of limiting increase to 2 degrees C more.

Davis et al, 2013

Question 24

Wedges to eliminate emissions

Answer 24

Eliminating emissions over 50 years would require 19 wedges: 9 to stabilize and an additional 10 to phase-out emissions

This many wedges would mean deploying tens of terawatts of carbon-free enrgy in the next few decades.

Davis et al, 2013

Question 25

Integrated and aggressive set of policies needed

Answer 25

An integrated and aggressive set of policies and programs is urgently needed to support energy technology innovation across all stages of research, development, demonstration and commercialization.

Davis et al, 2013