// lecture 34 Flashcards
1
Q
america’s feelings about climate change
A
- princeton NJ - 55% of americans worry a great deal about climate change
2
Q
americans and climate change
A
- worry follows ideological lines - Liberals more worried about climate change than conservatives.
- most people do not consider it a serious threat in their lifetime, esp. older people
3
Q
goals for fixing the problem
A
- one goal: minimize temp increase
- but recall that some warming is locked in even if we keep CO2 concentrations exactly at today’s levels
- temps still increase by 0.5 C because the oceans take time to warm up
4
Q
how to prevent higher CO2 concentrations
A
- higher CO2 levels mean higher temps eventually; emissions are increasing rapidly.
5
Q
is stabilizing emissions enough?
A
- no! flattening out CO2 emissions still leads to large increases in CO2 concentrations.
- a constant rate still adds more CO2 into the air.
6
Q
how to stabilize concentrations
A
- to stabilize at a certain concentration, it requires specific cuts in emissions
7
Q
James Hansen
A
- wants to bring CO2 emissions down to 350 ppm, but it’s really drastic from 400 ppm
- NASA scientist and activist
- part of 350.org, trying to reduce emissions
- very drastic pathway to reduce to 350ppm, you would have to cut emissions so drastically you would have to TAKE CO2 out of the atmosphere and not add anymore.
8
Q
Weighing the carbon blanket
A
the atmosphere contains about 3,000 Gtonnes of CO2 3 x 10^15 kilograms
- the surface of the earth is about 5 x 10^14 square meters
- so there’s about 6 kilograms of CO2 for every square meter of earth, or about 13.2 pounds
- there were about 9.3 pounds before the industrial revolution, so industrial humans have added about 4 pounds so far
- there are 10,000 kg of air per square meter
9
Q
adding to the CO2 blanket
A
- each yer we emit about 1% of the total CO2, or about 2 ounces per square meter, but only about half of that stays in the atmosphere, so we add one ounce per year to the atmosphere per square meter.
- 5% increase per decade, 10 ounces added to the total 13.2 pounds
- 2ppm/year out of 400 ppm total (0.5 % increase)
10
Q
what happens to the CO2 emissions
A
- not all of the emissions go into the atmosphere, a little less than 50% actually
- 25% goes into the ocean, but leads to ocean acidification
- 30% goes into land ecosystems
11
Q
countries by CO2 emissions
A
- china: 25%
- US: 18%
- india: 5.5%
- russia: 5.2
- japan: 3.6
- all other less than 3% each
- European union: 14%
- north america: 21%
- asia and oceania: 44%
12
Q
our individual share: USA
A
- per capita matters (how much per person?)
- some of these countries are so large because they have large populations
- USA per capita: 19 tonnes per year
13
Q
individual share: world average
A
- per capita: 4.6 tonnes per year
14
Q
the developing world
A
- half of the people in the world live on less than 2.50/day
- 2.1 billion live without access to electricity
- they should and will get more electricity
15
Q
future of emissions for developing nations
A
- in around 20 years, the developing world will surpass developed countries in CO2 emissions
- developing nations will be a massive energy market in the future, what fuels will they use?
