Lecture 33: Mitigation to Climate Change

Question 1

What is the main driver of climate change?

Answer 1

excessive addition of GHGs to the atmosphere through anthropocentric activities

Question 2

What are the two main approaches to climate change responses?

Answer 2

1. mitigation: addressing the cause
2. adaptation: responding to the effects

Question 3

What is a climate stabilization wedge?

Answer 3

A “wedge” is a strategy to reduce carbon emissions. S wedge redirects the flow of 25 GtC in its first 50 years.

Question 4

What are the four categories of wedges?

Answer 4

• efficiency and conservation
• nuclear energy
• fossil-fuel based strategies
• renewable energy & biostorage

Question 5

What is stratospheric aerosol injection?

Answer 5

Intentionally injecting molecules (like SO2 from volcanos), which reflect solar radiation, into the atmosphere

Question 6

How does stratospheric aerosol injection work?

Answer 6

SO2 reacts with hydroxyl, water, and oxygen to form sulfuric acid which reflects shortwave radiation –> eventually falls as acid rain 2-3 years later

Question 7

What is marine cloud brightening?

Answer 7

Generating longer lasting high altitude clouds over oceans through injection of sea salt particles into the air (clouds = lower albedo = more energy reflected)

Question 8

How does refreezing sea ice affect climate change mitigation?

Answer 8

water from the arctic is pumped onto thin arctic ice and refreezes, thickening the ice and ensuring low albedo is maintained.

Question 9

How does ocean fertilization affect carbon sequestering?

Answer 9

By fertilizing oceans, algae and plankton growth is stimulated and they uptake dissolved carbon, which ends up as sediment in the ocean. (still largely theoretical)

Question 10

What is direct carbon capture (and storage)?

Answer 10

Atmospheric carbon is removed and incorporated into long term storage in commercial products or rocks.