-Global Average Temperatures have risen 1 degree since 1960, whereas natural variation in the past was only .2 degrees C
-Sea level has been rising, and the process has been accelerating since 1860
Describe the Greenhouse Effect
Short wave radiation hits the atmosphere. Some bounces back, some passes through to the planet where it is converted to long wave radiation and felt as heat. The earth absorb some, and reflects some back into the atmosphere. Greenhouse gasses absorb energy (mostly infrared) and reemit it in all directions, so some goes back to the earth. These gasses keep the planet 33% warmer than it would otherwise be.
Name the four major carbon reserves in decreasing order of carbon conent
sediments ocean atmosphere biota
Natural Causes of Climate Change
-Volcanic Aerosols -Air-Sea interactions -such as El Nino -Ocean Circulation -Solar Output
The Coriolis effect causes water moving in the Northern Hemisphere to flow to the right, creating ekhman spirals and building up water in gyres near the equator that flow in a circle as water tries to move to the right with the coriolis effect and “downhill” due to gravity
Describe the 3 wind cells, their latitudes, and their winds
How did scientists determine the composition of the inside of the earth?
-discontinuities in seismic waves
-composition of meteorites -same elements present in meteorites as we predict are at the center of the earth
-If you drill into the earth, it gets warmer as you go down
At convergent plate boundaries, one plate sinks under another, creating a thick lake for crust (50 k or more below the surface). Crust is less dense than mantle, so to equal out the force of gravity mountains rise
Formation of Ocean Islands
At high pressure points in the lithosphere called hostpots, part of the mantle emerges through the sea floor and forms islands. As the plates move, the hotspot stays in the place, so a series of islands made from mantle material form
Wagener’s Evidence for Pangea + Continental Drift
-continents/plates fit together like puzzle pieces
-fossils of the same species found on seperate continents, but occupy adjacent areas when supercontinental theoty
-fossil evidence of certain land areas being at different latitudes in the past than they are now
-Mountain belts – Caledonia Mountains and Appalachian Mountains were one mountain range on Pangea
5 main factors that define a soil
-topography -biotic activities -parents material -time -climate
tommy’s bitches pay (for) tommy’s crack
Antarctic Bottom Water
Water in the Antarctic is cold, and therefore dense, and therefore sinks and spreads north. It is colder but fresher than North Atlantic Deep Water, so it is less dense.
North Atlantic Deep Water
Forms in the North Atlantic, very salty and cold, very dense
Salty in North Atlantic because the glaciers freeze with less salt than the ocean normally has, so more is left in the North Atlantic. Also, the North Atlantic doesn’t get a lot of precipitation.
Antarctic Intermediate Water
Cool fresh water formed in Southern ocean, not as dense as Atlantic Bottom Water and North Atlantic Deep Water
Typical Year in Pacific Ocean (Not El Nino Year)
WALKER CIRCULATION CELL: trade winds blow from America west to Indonesia, so the WESTERN PACIFIC WARM POOL forms on the western side of the Pacific Ocean where warm water blown by the winds piles up
The Warm pool heats the air above it, causing it to rise and create a low pressure zone, intensifying the trade winds.
Water piles up, the thermocline sinks in the west. Condensation of warm air on the Western side makes Indonesia wet, whereas lack of condensation on the eastern side makes California dry
El Nino Year
Westerly Wind bursts occur more often when the Westerly Warm Pool is large and they counteract the trade winds.
When the trade winds stop, gravity pulls the warm pool east forming a giant KELVIN WAVE
The redistribution of warm water further decreases the pressure gradient and slows the trade winds.
There is less rain in Indonesia, more in America The thermocline levels out, so upwelling in America doesn’t reach the thermocline to pull up the nutrients.
An exagerated normal state: even more warm water is in the West and cold in the East
Kelvin Wave from El Nino bounces of Eastern Coast, bounces back and moves arm pool farther to the West than it normally goes.
Makes Indonesia even hotter than normal, America’s even dryer
How does Coral Bleaching occur?
Coral has a symbiotic relationship with a bacteria called zooxanthellae. Zoox provide energy through photosynthesis, coral provides nutrients
When the water is too warm, the zoox perform too much photosynthesis and create too much oxygen, making the zoox poisonous to the coral so the coral expells them and turns white
If temperature rise short lived, zoox come back, but if it lasts too long, the coral dies (if there are enough larvae present when the water decreases in temperature again the coral may recover from death in 10 years)
Why do cholera outbreaks occur right after the end of the monsoon season?
-monsoon rains create runoff that carries nitrogen-rich chemical fertilizers and human/animal wastes into equatic habitats. Once the monsoon clouds leave: sunlight + nitrogen + algae = algal bloom Cholera bacteria forms a symbiotic relationship with the algae, using the algae’s photosynthesis for energy
How do copepods contribute to the spread of cholera?
copepods have an exoskeleton made of chitin. cholera bacteria gather on the chitin and eat it. while growing on the chitin, they can acquire new DNA from the environment, allowing new strands of cholera to form that people aren’t immune to
How have humans contributed to cholera epidemics?
The Green Revolution in the 1960’s transformed the agriculture of Southeast Asia. Irrigation and deforestation increased runoff and algal bloom. Chemical fertilizers supply nitrogen for the algae
Global warming also increases the intensity of the monsoons, increasing transport of nitrogen through runoff.
How does CO2 effect the pH of the ocean?
lowers it (makes it more acidic)
How can we know CO2 levels of the past?
-glaciers captured air pockets stratified by each years’ summer melting and winter freezing, so very accurate
What effect does Albedo have on global temperatures?
Why do some “good” policies get rejected by the political process?
-Lack of information/voter education -Lack of representation -Political mobilization bias
what is the largest sink for anthroprogenic carbon?
Describe the mechanisms of sinking carbon into the ocean
solubility pump: Ocean dissolves carbon and it sinks into deep water, doesn’t reemerge for thousands of years
biota pump: Organisms like plankton use CO2 to grow, sink to the bottom of the ocean and the carbon becomes sediment
Why would planting trees at high latitudes increase global temperatures?
Now, they are fields of ice and snow that have a high albedo. Planting trees would greatly decrease the albedo because areas that were open snow fields would not have vegetation, which has a lower albedo.
Order of Scientist’s Presentation Style
-Caveats -Data -Facts -Methods -Results -Recommendations -Outside Reviews and Rethinking -Scientists get last word
Order of Journalists’ Presentation Style
-Reccomendations -Results -Methods -leave out the rest because not enough space
Professional Biases of Scientists
-Favored theory -Familiarity with a certain model or technique -A crony -An institution
Double-Ethical Bind of putting science in the media
you need to provide full disclosure, but how can you do that in a 20 second soundbite? You need to reach people effectively, for which you need a 20 second soundbite.
best way is to use metaphors about probability of outcomes “just like people buy insurance”
What are two challenges to international climate change policies?
-need for voluntary acceptance -Climate change not affecting all nations equally e.g. canada and northern europe’s agriculture may benefit from global warming
What are the “flexibility mechanisms” in capping of CO2 emissions?
-international emissions trading -credit for carbon sinks -“offsets” – credit for technology transfers to developing countries – Clean Development Mechanisms
what are three ways of determining how many emission permits each country gets? (proportional to…)
-proportional to current emission rates -proportional to population -proportional to GDP
How did Kyoto determine the distribution of the permits?
-developed nations, proportional to historic emissions -developing nations, stay on projected emissions track
Name 6 impacts we already
-surface melting on Greenland increasing -Heat waves such as Europe 2003 -Number of floods per decade increasing since 1950 -stronger hurricanes -wildfires -diminishing sierra snowpack in California
Name 3 impacts of climate change on ecosystems
timing shifts – change the timing of their lifecycle (eg migrate earlier in the year)
range shifts – geographical shifts (organisms go farther north or higher in elevation)
Population split by geographic barrier, differentiate to adapt to different ciccumstances
No geographic separation, a species diverges into two species
e.g. you have an apple orchard with flies. Pears are introduced, some of the flies prefer pears. They stop interbreeding and become separate species.
Causes of endangerment
Habitat-loss Over-exploitation Invasive species
Describe the case study of butterflies at jasper ridge
-non-native european grasses invaded the grasslands and outcompeted all the plants the the butterfly eats, butterfly went extinct at jasper ridge -butterflies lay eggs, hatch to larvae, have to grow big enough to go into hybernation as older larvae until next rainy season. too much or too little rain will kill them -J ridge has gotten the same amount of rain since the 40s, but more extreme rainstorms and droughts, killing the young larvae -three populations in the bay area, used to have exchange among zones, woodside colony paved over, less genetic diversity
Name 6 types of diversity ( XXX diversity within XXX)
-Genetic diversity within a population -Population diversity within a species -Species diversity within a community -Community diversity within an ecosystem -Diversity of functional groups (different species act differently, fill different ecological niches) -agrobiodiversity (if you diversify the kind of banana you eat one fungus can’t wipe them all out)
Why is most biodiversity in the tropics? (5)
-lots of isolated islands -lots of rain and lots of sunlight -not as much seasonal variability -increased competitiveness drives further speciation – find ecological niches to fill -In periods of glaciation, the tropics were the only places not covered with ice, all species driven there.
Name, describe, and give examples of four types of ecosystem services
Provisioning Services: things you consumer directly e.g. seafood Regulating serves e.g. fire prevention, flood control, pest control, polination Cultural services e.g. ecotourism, spiritual values supporting services + preservation of options -things you don’t know the value of til their gone -pharmaceutical drugs – things that support the bees who do the pollination
Case Study: ecosystem services in Costa Rica
-pays US $20/acre for climate stabilization, water purification, biodiversity, resources, scenic beauty -everyone who buys gasoline pays into the fund -Costa Rica went from having the highest deforestation rate in the world to the lowest
Define these three terms: Ground Water Saturated Zone Aquifers
Ground Water: water below the earth’s surface at greater than atmospheric pressure Saturated Zone: pore space filled with water Aquifers: where ground water is moving
graph of stream flow v. date
list the purposes of dams in decreasing order
recreation flood control fire and farm ponds irrigation
name and describe two food demand shifters
income (increasing demand for meat and biofuels)
How did the green revolution increase the supply of food?
from 1970, we have nearly double the production of grain while barely increasing the amount of land used
negative effects of green revolution
-too many crop rotations in a year — nutrient depletion -too much nitrogen from fertilizers — dead zones -fertilizers cause greenhouse gas emissions, especiallly methand -some poor people can’t afford fertlizer
Pacala + Socolow Wedge Model
right now we emit 7 billions tons of carbon a year. If we continue at Business as Usual, we’ll emit 14 billion tons by 2050. In order to stay at 7 billion, they developed “wedges”describing things we can do to approach that massive amount of carbon one wedge at a time. wedges include: -Agriculure and Forestry -stop all deforestation -Alternative energy sources -Carbon capture and storge -Power Generation -raise efficiency at 1600 coal-fired plants and replace some with gas-fired -End-user efficiency and conservation -cute electricity use in homes, offices, stores -drive less -increase fuel economy of cars
what are some TECHNICAL issues you have to consider when looking at energy policy?
-Scale – how much energy can this resource produce -Infrastructure – do we have the capability of building it? -Variability over space and time
what are some ECONOMIC issues you have to consider when looking at energy policy?
Cost to consumer – cents/kwh upfront costs of overhauling system job loss
what are some SOCIAL issues you have to consider when looking at energy policy?
grain ethanol, you grow grain traditionally and use it to make fuel
cellulosic, you take marginal lands and use whatever was growing on it to make ethanol
what are the bennefits of electric cars?
-reduces demand for oil (stops sending money to our enemies, reduces demand which reduces prices) -multiple fuel sources for electricity (fossil fuels, nuclear, renewables) -Cleaner (no tailpipe emissions – mitigates health effects, especially in cities) -Lower CO2 emissions -Cheaper