physics behind global warming stefan-boltzmann law total heat/energy emitted from a surface is...

Physics Behind Global Warming

Stefan-Boltzmann Law total heat/energy emitted from

a surface is proportional to the

fourth power of its absolute

temperature. (Applies to black

bodies).

Earth is receiving more energy than it is emitting.

From Sun to Earth: Energy flux at the sun’s surface = 63 x 10^6 W/m^2 (LOTS OF

ENERGY) Energy flux drops as it travels the square distance from the radiating

body. = 1360 W/m^2. Converted into heat then radiated (electromagnetic waves).

Physics…Continued Clouds play a large role when

determining how much solar radiation the earth will absorb. Cloud albedo ranges from 0 - 0.8

percent.

Earth’s average albedo is 0.3 0.3 of the radiated heat is being

reflected, while the other 0.7 is being absorbed.

Incoming radiation flux < out going = increase in temperature.

Eventually a radiation equilibrium / balance should be reached.

Physics Continued: Earths average temp is -18°C.

The average temp we experience is 15°C --> Greenhouses.

The many compositions that make up the atmosphere have different absorption levels. Water vapor & CO2 (most common greenhouse gases) = very

absorptive. Radiation that earth emits cannot escape freely. Gases warm = emit heat upwards & downwards. Like a blanket.

This causes the earth to warm & has many implications (rising sea level, etc). Ice = high albedo, keeps melting = very absorptive Earth.

Oceans low albedo = warming = water vapor = vicious cycle.

Argument: this is just a part of Earth’s natural cycle.

Biology (The aspects we see in everyday life):

Earth’s Natural Cycles: Before man there have been constant cycles of

warming and cooling periods.

Every 100,000 years, the planet appears to be alternating between these two climates.

Many believe that this justifies our present global heating It is apart of a natural cycle.

Counter Argument: Humans have exaggerated this cycle.

Biology: Continued

The CO2 in our Oceans

Oceans store CO2 in the form of bicarbonate and carbonate compounds. Balloon Experiment

Did we put CO2 in our atmosphere?

The heating of Earth may be releasing CO2 from Earth’s oceans.

88 tons of CO2 is released from our oceans yearly.

Biology Continued

Our Fault?

Burning of fossil fuels and coal is the #1 way humans contribute to Earth’s CO2 level.

Industrialization & New Technology

Scientists believe in order to combat global warming, people must control the use of fossil fuels.

Deforestation = less CO2 being converted into oxygen. Source of Greenhouse Gases.

Biology Continued The Effects of Global Warming Intimidates Our Ecosystems

Effect 1: Disease Spreads

When countries warm up, disease carrying insects migrate to the warmer regions.Scientists blame this for the persistence of Malaria.

Effect 2: Strong Storms

As the ocean's temperature rises, the probability of hurricanes rises.

Effect 3: Polar Ice Caps Melt

Ice Cube Lab Sea levels can rise by 230 feet if the ice caps melt Lower the salinity (saltiness) of the ocean waters. Oceans become uninhabitable to salt water fish. Ocean currents will also be knocked out of balance

Effect 4: Coral reefs

Due to warming of the oceans, many coral reefs have been destroyed. Coral reefs = major habitat for many marine species. Fish diversity has dropped significantly in many areas.

Chemistry Aspects of Climate Change

Oceans surface water acidity has increased.

As oceans continue to absorb CO2, pH level will drop.

Glaciers are melting.

pH experiment.

Chemistry Continued

Chemistry Continued

Chemistry Continued

Man-made vs. Natural

Natural Causes:Volcanic eruptions: emit CO2

Solar cycles and cosmic rays: responsible for more than 14%?

Water vapor: Water vapor is produced as feedback of increased CO2 emissions.

Man-made Causes: Driving your car

air conditioning or heat

Eating food that is out of season and shipped.

It is not Man-made: Water Vapor

makes up most of Earth’s greenhouse gases.

99% natrual

Humans only contribute by 0.001%

More Graphs Shows how

the amount of other gases in small compared to the 95% of water vapor.

The overall Co2 amount is 3.618%, and is not exaggerated like the 1st graph.

It is not Natural:

we cannot neglect the 65% of miscellaneous gases

Carbon Dioxide: 72% of gases produced in greenhouses are C02

Group Reflection:

Conflicting Ideas

Hard to keep Communication Far, time.

Working on own vs Working together

Hard Topic = Lack of Experiments