Final Study Guide 11 Flashcards
Anthropocene
1
Q
Why do we think that the late twentieth-century global warming is due to human activity?
A
- We believe that global warming is created by the carbon gases released by burning fossil fuels. The carbon gases are green house gasses that absorb heat from the sun and trap it in Earths atmosphere.
- temp has risen with industrialization
2
Q
Why is the ocean conveyor belt important?
A
- Responsible for moving warm, relatively fresh surface water around until it cools down. It accumulates salt and sinks because it’s now colder and is more dense.
- Warm surface waters are depleted of nutrients and carbon dioxide, but enriched again as travels through conveyor belt as deep or bottom layer. Base of world food chain (algae and seaweed) rely on nutrients from deep water
- The great ocean conveyor is the circulation system of the ocean. The conveyor transports both energy and matter around the world in an identifiable circulatory pattern. This system is conceptualized as acting like a giant conveyor belt taking heat energy across immense ocean distances in the air-driven currents of the oceans as well as any material substances that happen to have found their way in there. The conveyor is of great importance to the climate and may be linked to carbon dioxide levels in the air.
3
Q
What are the major effects of global warming?
A
- Sea level rise
- Shoreline decrease
- Retreating glaciers
- Warmer
- increase in atmospheric CO2
- Arctic ocean melting
- Loss of sea and land ice
4
Q
Carbon Dioxide
A
- A driver of Global Warming is CO2 in the Atmopshere
- Greenhouse gas
- Earth inhales CO2 in the summer, exhales in the winter
> Correlated to growth of plants – live in summer, die in winter - C02 in Glacial deposits – record of C02 levels –
- Prior 500 years decrease, dramatic increase in 1900’s industrial revolution
- Exists as gas (CO2), solute (carbonate, ions), and solid (organic carbon)
5
Q
Carbon Cycle
A
- the series of processes by which carbon compounds are interconverted in the environment, chiefly involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels
- regulates climate over long time scales
- CO2 in atmosphere from volcanic eruptions → CO2 in rain weathers continental rocks and carries HCO3 to oceans → HCO3 forms CaCO3 in ocean → goes to seafloor → subduction and CaCO3 converted to CO2
- Planetary C Cycle: can only happen on a planet with tectonic recycling
- changes in CO2 levels → changes in rate of weathering
- CO2 increase → temp increases → rate of weathering increases → CO2 levels decrease
> weathering impact is more important and more efficient at higher temps
> negative feedback loop: earth can never get too hot or cold
6
Q
Methane
A
atmospheric methane is a greenhouse gas, simplest alkane, main component of natural gas
7
Q
Global Warming
A
Warming of the earths atmosphere due to greenhouse gasses
8
Q
Heat Content
A
- The amount of heat stored in the oceans.
- If oceans warming up, earth is absorbing more energy.
- Can lead to worse storms
- Ocean releases heat in El Nino events
9
Q
Glaciers
A
- Slowing moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles
- Have been receding in years
10
Q
Antarctic
A
- Antarctica sits on a land mass (north pole ice), the dynamics of which our understanding is incomplete.
> Ice streams (which are under the top ice) move down, can cause crevices.
> The entire ice shelf can move - Antarctica has increased motion in ice streams, ice on land will make the sea level rise when it melts where-as ice bergs melting will not affect sea levels much.
11
Q
Arctic
A
- polar region at northernmost part of earth
- negatively affected by climate change
12
Q
Ice Loss
A
- Greenland arctic has been losing ice for over 50 years
- Ice loss can lead to rising sea levels (Glacier melting but not ice berg melting)
13
Q
Glacier Retreat
A
- Due to the increase of greenhouse gases, glaciers have been shrinking due to the melting of the freshwater
- Effect of global warming.
- Arctic glaciers have become smaller since 1953
- Ex from slides: Effects glacier national park, Austria’s Pasterze Glacier
14
Q
Sea Level Rise
A
- Effect of Warming of climate system – since 1950s sea level has risen
- Caused By: Thermal Expansion (molecules spread out as temperature rises )50% and Melting 50%
- Sea level will rise from melting of glaciers
> Though not of just ice: Icebergs will not affect it much. - Will flood the continents
- Opens new shipping routes - Not all effects of global warming are negative.
- Effects wildlife
- Can increase El Nino effects – El Nino comes with high sea levels
- Sea level change has been larger than mean rate during past two milienia, over 1901-2010 the mean rate was 0.19 m.
15
Q
Thermal Expansion
A
- the tendency of objects to change in volume in response to a change of temperature
- Warming of the oceans – 50% responsible for expansion of water molecules = rise of sea level
> If you heat a material, it will expand and will have less density and will rise. - Correlation between sea level and thermal expansion
16
Q
Temperature Proxy
A
?
17
Q
Nitrous Oxide
A
- Major greenhouse gas and air pollutant
- A driver of Climate Change
- Along with CO2, and methane, Nitrous Oxide levels have reached levels that are unprecedented in the last 800,000 years
- Greenhouse gas
18
Q
Greenhouse Gases
A
- gases in the atmosphere that absorb and emit heat and radiation (ozone, carbon dioxide, water vapor, nitrous oxide)
> CO2 – Carbon Dioxide – most significant
> CH4 – Methane – decay or organic materials in landfills, wetlands…
> N2O – Nitrous Oixide – fertilizer use, animal waste management, fossil fuel combustion
> Hydroflurocarbons (HFCs) – synthetic chemical in industrial use
> Perfluorocarbons (PFCS) - synthetic chemical in industrial use
19
Q
Ocean acidity
A
- The constant increase of acidity in oceans because of carbon dioxide
- Ocean acidity has been increasing in last 50 years
- Acidic oceans kill coral reefs that NEVER return.
- Effects the lithosphere
20
Q
pH
A
unit of measure that tells the acidity or basicness of something (scale 1-14)
21
Q
Atmospheric CO2
A
- Earth takes in CO2 during the summer, exhales CO2 during winter
- Contributes to greenhouse effect
- has increased a lot recently
22
Q
Oceanic Reservoir
A
?
23
Q
Land Use
A
Changes in land use such as deforestation or agriculture is partly responsible for over 8.0 Gt of carbon into the atmosphere each year.
24
Q
GDP
A
Gross domestic product - the amount of product a country produces within its borders
25
Forcing
- Perturbation in Earth’s natural balance that causes a change in earth’s climate systems
- A way to compare different causes of perturbations in a climate system
26
Aerosol
- fine solid particles or liquid droplets microscopically dispersed in air or another gas
> ex: haze, dust, particulate air pollutants, and smoke
> atmospheric particulate matter
27
Radiative Forcing
- When there’s more energy radiating down on the planet than there is radiating back out to space, something’s going to have to heat up
- Energy is constantly flowing into the atmosphere in the form of sunlight that always shines on half of the Earth’s surface. Some of this sunlight (about 30 percent) is reflected back to space and the rest is absorbed by the planet. And like any warm object sitting in cold surroundings — and space is a very cold place — some energy is always radiating back out into space as invisible infrared light. Subtract the energy flowing out from the energy flowing in, and if the number is anything other than zero, there has to be some warming (or cooling, if the number is negative) going on.
- Total radiative forcing is a possibility, and has led to an uptake of energy by the climate system
28
Ozone Forcing
Reduction of ozone from the upper layers of the atmosphere causes more radiation to hit Earth
29
Aerosol Forcing
- Aerosols can cool the Earth's surface because they reflect sunlight and make cloud formation, possibly mitigating warming caused by greenhouse gases.
- However, some aerosols, such as black carbon from coal emissions, absorb sunlight and can cause atmospheric warming. Because aerosols comprise such a broad collection of particles, with vastly different properties, the degree to which each absorbs or deflects sunlight and assists in cloud and precipitation formation varies greatly, making it difficult to gauge their impact on Earth's temperature and spatial distribution of rain and snow.
30
Solar forcing
change in solar intensity
31
Anthropogenic Forcing
Forcing due to human, rather than natural, factors. Such factors include increased greenhouse gas concentrations associated with fossil fuel burning, sulphate aerosols produced as an industrial by-product, human-induced changes in land surface properties among other things.
32
Black Carbon
Climate forcing agent caused by incomplete combustion of fossil fuels and emitted in both anthropogenic soot and natural ways, pure carbon in several linked forms
33
Aerosol-cloud interactions
- Aerosols → can increase clouds →
| - Increased clouds → increased albedo → a cooler earth
34
Climate Models
- See scenarios and Projection
- The IPCC puts together climate models.
- Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate. ...
- One issue is that they take the earth and make it into pixel squares that retain so much data in each square / grid, that it takes MONTHS to YEARS for climate models to be completed by supercomputers
35
Volcanic forcing
- Volcanoes, for example, eject huge columns of ash into the air, as well as sulfur dioxide and other gases, yielding sulfates.
- Volcanoes emit Aerosols, dust, and gasses
36
Climate scenarios
?
37
Representative concentration pathways
- Scenarios on the effects of emissions put together by the Intergovernmental Panel on Climate Change - IPCC
- From Google: Representative Concentration Pathways are four greenhouse gas concentration trajectories adopted by the IPCC for its fifth Assessment Report. The pathways are used for climate modeling and research
- The new IPCC RCPs describe four scenarios how the planet might change in the future, for climate research and modeling
- So what are these Representative Concentration Pathways? There are four: RCP8.5, RCP6, RCP4.5, and RCP2.6 (the latter also referred to as RCP3PD, where 'PD' stands for Peak and Decline). The numbers refer to radiative forcings (global energy imbalances), measured in watts per square metre, by the year 2100.
38
Time lag
time difference between projection and actual occurrence
39
Shorelines
- With global warming comes glacial melting and thermal expansion of oceans, meaning that sea levels will rise.
- If the sea levels rise, the shore line will recede.
- Projections of shoreline at 2070 show that Washington D.C, Baltimore, Philidelphia and New York City will be under water
40
Projection
The tools of climate models are used with future scenarios of forcing agents (e.g., greenhouse gases and aerosols) as input to make a suite of projected future climate changes that illustrates the possibilities that could lie ahead
41
Sea level change
the constant increase of sea level which is about 3 mm/year
