Nominated for 4 PPTA awards including: “PPTA of the Year”, “Best Use of Scientific Comedy”, and “Best Original Screenplay”

What is Carbon? Carbon is an element that is in all living things. Molecules containing carbon are called Organic.

Carbon Cycle The movement of carbon from the environment into living things and then back again is the Carbon Cycle. You already know how carbon dioxide cycles between photosynthesis and cellular respiration.

Carbon Cycle Carbon dioxide in the air enters into living things through photosynthesis. Oxygen and glucose produced from photosynthesis are then used by plants and animals for cellular respiration. Cellular respiration produces carbon dioxide to be released again.

Carbon Cycle Keep in mind all living things have carbon in them, so when they die, decomposers help return that carbon to the environment and soil.

Carbon Cycle That carbon makes up coal, oil, and natural gas (fossil fuels). Fossil fuels are burned in a process called Combustion. Combustion releases carbon dioxide back into the air. What do you think the largest natural release of carbon stored in the ground is?

How many of you have heard that… Climate change is due to human activities. or… Climate change is due to human and natural causes. Nearly all climate scientists agree on causes of climate change. or… Many scientists do not agree on causes of climate change.

Science Science is a way of knowing about the natural and material world. – Hypothesis – Data – Evidence – Conclusions

Research Thousands of studies dealing with different aspects of climate change have been conducted and published So… how do we make sense of all this?

Intergovernmental Panel on Climate Change (IPCC) Who is it? – Governments Members of the UN Participate by naming experts and reviewing the reports before they’re published – Scientists Close to 1000 scientists Climatologists, ecologists, atmospheric physicists, and others Dr. Susan Solomon, a NOAA atmospheric chemist, an IPCC member and one author of IPCC summary

Intergovernmental Panel on Climate Change (IPCC) What do they do? – Review current scientific and technical literature relevant to global climate change – Provide reports on their findings at regular intervals – Reports are designed to be politically neutral and of high scientific and technical standards

Weather vs. Climate Weather describes the atmospheric conditions at a specific place at a specific point in time. Climate is determined by long term trends in weather.

Evidence of Climate Change Will not be the same everywhere Evidence found in: 1.Ice core sampling 2.Tree rings 3.Earth’s average temperature 4.Patterns and amounts of precipitation 5.Ice and snow cover 6.Sea level 7.Extreme weather events

1. Ice Core Sampling Direct atmosphere measurements date back to the 1950’s The oldest continuous ice core dates back 800,000 years in Antarctica The ice encloses bubbles of air that contain a sample of the atmosphere

2. Tree Rings (Dendrochronology) Tree ring data lets us look as far back as 2,000 years Tree rings provide direct evidence of droughts, heavy precipitation, and length of the growing season.

3. Temperature ( ) Image Credit:

3. Temperature ( ) Image Credit: IPCC.

4. Precipitation Observed Precipitation Changes: Image Credit: Data Source: Regional Climate Trends and Scenarios for the U.S. National Climate Assessment

5. Sea Ice Coverage Image Credit: National Snow and Ice Data Center

6. Sea Level Data source: Coastal tide gauge records. Credit: CSIRO Data source: Satellite sea level observations. Credit: CLS/Cnes/Legos. 2012

7. Extreme Weather Events Image Credit:

Climate is Affected by Several Factors Historical (Natural) Changes Milankovitch Cycles Solar fluctuations Plate Tectonics Volcanic eruptions Greenhouse effect Recent (Human) Changes Greenhouse effect Fossil fuel combustion Land-use change from human activities

Natural Factors Affecting Earth’s Climate

Milankovitch Cycles Named after a Serbain mathematician, Milutin Milankovitch EXTREMELY long term effects that scientists think may be the cause of the ice ages. These are movements of the Earth that affect the amount of solar radiation that it gets.

Milankovitch Cycles Eccentricity Obliquity Precession Earth’s wobble, tilt, and orbit

Milankovitch Cycles Precession Direction of the Earth’s axis changes over time The Earth wobbles like a top on its axis 26,000 year cycle

Milankovitch Cycles Obliquity The tilt angle of the Earth’s axis changes over time The greater the tilt the greater the differences in the seasons. 40,000 year cycle

Milankovitch Cycles Eccentricity Varying shape of Earth’s orbit, e.g. how elliptical it is 100,000 year long cycle Animation

Solar Cycles Sunspots are storms on the surface of the sun and are associated with extremely strong magnetic activity, solar flares hot gaseous emissions These follow an 11 year cycle. Scientific research estimates that normal fluctuations due to Solar Cycles increase or decrease solar radiation reaching Earth by only 0.1% - 0.2%.

400 Years of Sunspot Activity

Plate Tectonics Plate Tectonics and associated Continental drift Have been exerting their effect on the Earth’s geography over billions of years Have shaped the continents as we know them The impact on climate (very long term, and in the past) was: – by changing land mass and ice caps (size & location) and – changing ocean circulation patterns which transport heat around the Earth and in turn – influences atmospheric circulation processes.

Volcanic Eruptions / Albedo Volcanic eruptions of ash and gases into the troposphere and above cause SHORT TERM cooling (few years). The gases released are mainly water (H 2 O), carbon dioxide (CO 2 ) and sulfur dioxide (SO 2 ). The 1 st 2 do not change ambient levels by much. But the SO 2 reacts with H 2 O to form sulfates. Sulfates increase the brightness (albedo) of clouds, reducing the solar radiation reaching Earth. The large volumes of ash also block some incoming solar radiation but the effect is less significant and more short lived.

Volcanic Eruptions Do Volcanic eruptions cause long term climate change? Apparently not. There is evidence of slight warming at some times, and slight cooling at other times. In these cases any temperature changes are minimal and short lived. Interesting point: During the time before and at the beginning of the Little Ice Age, there was an increased incidence of volcanic activity – enhancing the effect of the Sun Spot minimum.

Forest Fires Forest fires produce a lot of smoke – made up of particulates and gases. Based on what you learned about volcanic activity, what impact could large forest fires have on climate? – Will this impact be local? Global?

Greenhouse Effect

Solar Radiation – What does this data tell you? Image Credit:

Anthropogenic Factors Affecting Earth’s Climate

Land-Use Change In the Southeast U.S., land use changes from bare soil in cotton and other row crops to forests (currently 70 percent of the region) may have contributed to the negative trend in temperature over the past 100 years.

We Have Altered the Atmosphere Greenhouse Gas Pre-1750 Tropospheric Concentration Recent Tropospheric Concentration Change in Tropospheric Concentration Carbon dioxide (CO 2 ) 280 ppm400 ppm43% Methane (CH 4 ) 700 ppb1874 ppb168% Nitrous oxide (N 2 O) 270 ppb324 ppb20% Chlorofluorocarbons (CFCs) ppb (different for each CFC) NA Ozone (O 3 ) 25 ppb34 ppb36% Data Source:

Atmosphere Gases Image Credit:

Focus on CO2 It has changed a lot It stays in the atmosphere a long time The US emits more CO 2 than other greenhouse gases We can do something about it Image Credits:

Global and Continental Temperature Change Natural forces alone do not explain the changes in temperature

What does all this mean? 97% of climate scientists combine this and other evidence to draw conclusions: – Earth’s climate is currently changing. – Changes are not the same at all locations on Earth. – Future changes may be more rapid than historical changes. – Human activities are responsible for most of the climate change being observed.

What will happen in the future? Scientists use models to project temperature changes with different assumptions for emissions. Image Credit:

Forest Habitat Changing Current Modeled Forest Future Model – Low Emissions Future Model – High Emissions

Sea Level Rise 1-5 meters in Bangladesh 7-8 meters in Florida PCC slide no. 037

It’s a Challenge A very complex system Regional variation Changes are hard to see No firm predictions; models have limitations Not just about the science - Political, Ethical, Economic - As policies are made concerning climate change, what are some economic sectors that would be affected? - What are some ethical factors involved?

The US Public Has Many Beliefs about Climate Change

But why disagreement? People see and remember information that matches what they know – So it is hard to change someone’s mind People have partial information and leap to conclusions – And then when presented with complete information, it doesn’t match People listen to influential leaders – Rather than figuring it out for themselves

Solutions to Climate Change Lots of options; no single solution – Adaptation – Mitigation Policies and actions implemented by – Governments: international, national, state, local – Industry and business – Individuals – all of us!

Air Pollution: Other Human Impacts on the Atmosphere Photochemical Smog – Air pollution caused by automobile exhaust in the presence of sunlight. – Solar radiation turns the nitrogen and carbon compounds into ozone.

Ozone Depletion CFCs (chlorofluorocarbons) – Gas released by cleaning agents, old refrigerators, and aerosol cans. Ozone Hole – Seasonal decrease in ozone over Earth’s polar regions.

Acid Precipitation Occurs when sulfur dioxide and nitrogen oxides act as condensation nuclei, making precipitation acidic – 90% of sulfur emissions in the US are human caused