Geoengineering

Question 1

What is the keeling curve?

Answer 1

The Keeling Curve is a graph that plots the ongoing change in concentration of carbon dioxide in Earth’s atmosphere since the 1950s.
Seasonal variation- peak April, drop October

Question 2

What is geoengineering?

Answer 2

Large scale efforts to diminish climate change resulting from greenhouse gases that have already been released to the atmosphere

Question 3

What are the two types of geoengineering?

Answer 3

Solar geoengineering (solar radiation management = SRM)
Carbon dioxide removal (CDR)

Question 4

SRM

Answer 4

Solar radiation management

Diminish the amount of climate change produced by high greenhouse gas concentrations.

Question 5

CDR

Answer 5

Removing CO2 and other greenhouse gases from the atmosphere

Question 6

Why is geoengineering such an issue?

Solar radiation management

Answer 6

Risk…

Raises novel global scale governance and environmental issues
Some SRM approaches are thought to be low in cost.
Scale of SRM deployment will likely depend on considerations of risk

Question 7

Why is geoengineering such an issue?

Carbon dioxide removal (CDR)

Answer 7

Cost…

Raises issues related so scale, cost, effectiveness, and local environmental consequences
Scale of CDR deployment will likely depend primarily on cost.

Question 8

What is the termination effect?

Answer 8

Refers to the consequence of a sudden halt or failure of the geoengineering system.

Question 9

What could a termination effect/ failure in an SRM approach mean?

Answer 9

Relatively rapid warming which would be more difficult to adapt to than the climate change that would have occurrence in its absence.

SRM methods that produce the largest negative forcing and which rely on advanced technology are most risky.

Question 10

Compared with a climate that has a higher temperature and high co2 level, much more carbon would be stored in the oceans and land in a climate with low solar irradiance, low temperature and high co2.

In the case of a halt or failure of the solar geoengineering processes a sudden warming could mean what…?

Answer 10

Carbon stored in the land and ocean reservoir to be released in the atmosphere, triggering further warming.

Question 11

Different ways of removing carbon from the atmosphere?

Answer 11

Ocean fertilisation 
Ocean alkalinity addition 
Accelerated chemical weathering of rocks
Manufacturing carbonate minerals using silicate rocks and CO2 from air.
Direct air CO2 capture 
Biomass with carbon capture/storage 
Afforestation/reforestation

Question 12

CDR trade offs

Answer 12

Huge physical areas in play with these approaches for relatively minor effects on global CO2 -> exaggerates land use conflicts as much as anything
Some paired wins: ocean weathering slows acidification, but…
Cost limited.