Flashcards in // lecture 34 Deck (36):
america's feelings about climate change
- princeton NJ - 55% of americans worry a great deal about climate change
americans and climate change
- 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
goals for fixing the problem
- 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
how to prevent higher CO2 concentrations
- higher CO2 levels mean higher temps eventually; emissions are increasing rapidly.
is stabilizing emissions enough?
- no! flattening out CO2 emissions still leads to large increases in CO2 concentrations.
- a constant rate still adds more CO2 into the air.
how to stabilize concentrations
- to stabilize at a certain concentration, it requires specific cuts in emissions
- 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.
Weighing the carbon blanket
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
adding to the CO2 blanket
- 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)
what happens to the CO2 emissions
- 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
countries by CO2 emissions
- 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%
our individual share: USA
- 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
individual share: world average
- per capita: 4.6 tonnes per year
the developing world
- 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
future of emissions for developing nations
- 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?
- world average per capita emissions is a little less than 5 tonnes
- world population 7 bill so total emissions are a little more than 30 billion gigatonnes.
countries per capita CO2 emissions
- wold avg is 4.6 tonnes per year
- highest are oil producing states
- US is rather high (11th): 4x word average (19 tonnes per person)
- australia and canada have similar emissions as US per capita (just smaller countries)
- many EU countries, Russia, Japan: 10 tonnes
- sweden, switzerland, china: 5 tonnes
- india: 1.1 tonnes
american per capita CO2 release
- 19 metric tonnes per person per year
- if you weight 115 lbs, you generate your weight in CO2 everyday.
- but for a 115 lb person in China, sweden, or switzerland, it takes about 5 days to accomplish the same feat.
unexpected changes in US CO2 release
- per capita CO2 release in the USA has declined because of weak economy, but also a strong shift from coal to natural gas that became very cheap
- natural gas releases less CO2 per unit of energy delivered than coal. also no sulfur dioxide, mercury produced etc.
fracking and the cost of us methane
- natural gas prices dropped by half in 2009 due to the increasing availability of shale gas (fracked).
coal production declines a little
- coal production in the east has been offset by increased domestic methane production in usa
coal trains from powder river, WY to cherry point, WA
- Plans are in place for 30 miles of coal trains to arrive
in Cherry Point, Washington terminal for shipment to China, each day.
coal train arguments
- for: jobs and local economy, cleaner coal for China (powder basin sulfur content less, but energy unit of CO2 also less)
- against: means we will burn more coal worldwide (more warming), train traffic a nuisance and danger (30 long ones per day), coal dust and diesel fumes a health hazard
clean power plan
- US EPA currently seeks to limit use of coal for electricity generation
- EPA clean power plan (CPP) rules would reduce CO2 emissions from coal plants to about 1550 MMT by 2030-40, reducing coal's share of electricity generation from 33% in 2015 to 18% in 2040
- Even without CPP it will be reduced to 1959 in 2040,
because of low natural gas prices, renewable tax credits and reductions in the cost of photovoltaic electricity generation.
how to prevent higher CO2 concentrations
CO2 emissions have actually sped up. 2000-2010
was the highest decadal rate of increase ever.
alternative energy sources
we already have the tech at generating CO2 -free electricity
- renewable energy: generated from natural sources such as solar, wind, tidal, geothermal, and hydroelectric
- nuclear is not renewable, but it also doesn't emit CO2
But Currently we’re not using much of it.
energy sources in china - 2011
- china, like much of the world, is a fossil fuel economy, mostly from coal
- 91% fossil carbon fueled as of 2011
- was 93% in 2011
useful facts about CO2
CO2 per unit energy emitted:
- Coal emits 67% more CO2 than natural gas
- Coal emits 30% more CO2 than oil
- Coal is a ‘dirty fuel’
US production of greenhouse gases
- CO2 is currently the largest and growing the most rapidly in comparison to other GHG's.
US energy sources
- renewable: 9%
why is US crude oil production going up?
- super fracking, back to the peak of 1970, in just about 5 years or so.
- oil forms from organic material trapped underground, makes oil. Pressure, heat and time make oil.
- if the shale is sufficiently fractured, the oil will start to flow towards the pools - traditional oil wells can get this
- typically only 20-30% of the oil in a shale field is available to traditional drilling. Most of it is still in porous rock.
introduces low viscosity fluid (e.g. water with some additives) into the bore hole at very high pressure. This fractures the rock and sends the trapped oil heading toward a production well.
more super fracking
- Drill horizontally in shale layer
- Make an explosion in the well casing
- Inject large volumes of low viscosity water under high pressure.
- Fractures occur.
- Wait for oil to flow to extraction well
is a tight shale, so oil only comes out if you use hydraulic fracturing More than 6000 wells were operating in July 2013, 300 million barrels a year. Most 80% of the extractable oil comes out in the first two years. 3.6Bbbl reservoir.