Inquiry in the classroomErik Froburg, Education Coordinator

Carbon Cycle: Global to local

Ruth Varner, PhD

Agenda• Introduction to Inquiry• Carbon Cycle Content• Case study: Carbon Cycle game • Lunch• Carbon Cycle Content cont’d• Case Study: Photosynthesis• Using Cores to Observe the Earth

System

Inquiry-based instruction derives from scientific

inquiryScientific inquiry refers to the diverse ways in which scientists study the natural world and propose explanations based on the evidence derived from their work.

National Science Education Standards

Students are asked to:

•Observe and describe objects and events

•Create explanations for their observations

•Manipulate objects and events to test various explanations

•Communicate ideas and findings to others

National Research Council, (2000). Inquiry and the National Science Education Standards: A guide for teaching and learning. Washington, D.C.: National Academy Press.

Student Knowledge and Skills

School Context

Teacher Knowledge and Skills

State/National AssessmentsGoals of the Lesson

Your choice of inquiry must balance the needs of:

A curriculum should employ methods from all parts of the inquiry spectrum. The appropriate level of inquiry is dependent upon many things, such as:

•Subject matter

•Time available

•Teaching objectives

However, highly student-directed inquiry is most often neglected, so we tend to focus on it.

There is no “right” level of inquiry

Inquiry needs to be scaffoldedscaffolded to meet the needs of both students

and and teachers

Students Teachers

May not have sufficient content background.

May be uncomfortable not knowing results in advance.

May not be comfortable with open-ended questions.

May not feel that they have control over the content being learned.

May not have the autonomy for self-directed work yet.

May feel pressured by time constraints.

May not know what is expected of them.

May not like the unpredictability of inquiry.

It is good practice to occasionally analyze our own

use of inquiry

•Where does this lesson fit into the inquiry continuum?

•Can I modify this lesson to make it more inquiry-based?

•Does my curriculum adequately represent all aspects of inquiry?

•Using a common yardstick (i.e. the Essential Features table) allows you to discuss and promote the use of inquiry amongst colleagues.

Summary

•Inquiry-based instruction follows the model of scientific inquiry employed by scientists.

•Inquiry in the classroom falls on a continuum from student-driven (more inquiry) to teacher-directed (less inquiry).

•Challenges to inquiry prevent (full) student-driven inquiry all of the time.

•Optimal rather than maximal solutions should be sought for introducing inquiry.

•Understanding and conducting inquiry is a part of the NC Science Competencies.

Atmospheric CO2 at Mauna Loa

Keeling, C.D. and T.P. Whorf. 2004. Atmospheric CO2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.

An Impeccable Record of our AtmosphereAn Impeccable Record of our Atmosphere

The Earth System

• The Earth is a system made up of components.

• There are feedbacks between these components.

• These relationships can be used to predict past and future changes in the environment.

• The Carbon cycle is an important Earth System.

Formation of Fossil Carbon

• Coal: from the remains of plants (mainly from Carboniferous period)

• Oil: from marine organisms that were buried under ocean or river sediments

• Natural Gas: was originally oil; higher temperature and pressure converted it to primarily methane

Combustion

Burning hydrocarbons produces CO2 and CO:

CxHx + O2 CO2 + H2O(if enough O2) Complete combustion

 Hydrocarbon + oxygen = carbon dioxide and water

CxHx + O2 CO2 + CO + H2O(if not enough O2) incomplete combustion

 Hydrocarbon + oxygen = carbon dioxide and carbon monoxide and water

Photosynthesis – carbon fixed from inorganic CO2 to organic molecules (sugars)

6 CO2 + 6 H2O C6H12O6 + 6 O2

chlorophyll, sunlight

Respiration – sugar is “burned” as part of a metabolic process that consumes oxygen and produces energy (ATP) – decomposition results in respiration

C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

Biological uptake/release of CO2

From the Atmosphere: Inorganic C in the Ocean

CO2 (atm) ↔ CO2 (aq) ↔ HCO3- + H+ ↔ CO32- + H+ ↔ CaCO3 ↔ seds

Carbon dioxide in the oceans

Calcareous skeleton carbon – can be dissolved or deposited

Figure 7.10

UNH/NOAA-PMEL CO2 Buoy in Gulf of Maine

In sea water

In overlying atmosphere

Case study: Carbon Cycle game

Terrestrial Carbon

• Soil carbon is released through respiration : root and microbial (decomposition)

• Plants respire CO2

• Plants also fix carbon through photosynthesis

Terrestrial Carbon

Biological uptake/release of CO2

Photosynthesis – carbon fixed from inorganic CO2 to organic molecules (sugars)

6 CO2 + 6 H2O C6H12O6 + 6 O2

chlorophyll, sunlight

Respiration – sugar is “burned” as part of a metabolic process that consumes oxygen and produces energy– decomposition

results in respiration

C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

•Global network of flux towers used to measure COGlobal network of flux towers used to measure CO22 exchange between exchange between ecosystems and the atmosphereecosystems and the atmosphere•Sites also include measurements on vegetation, soils, hydrology and Sites also include measurements on vegetation, soils, hydrology and meteorology. meteorology. •Information available to researchers, students and educators.Information available to researchers, students and educators.

FLUXNET

Wind direction

Turbulent eddiesWind direction

Turbulent eddies

http://www.fluxnet.ornl.gov/fluxnet/index.cfm

Total ecosystem respiration =Rsoil + Rleaf + Rstem + Rcwd

Rsoil

Rstem

Rleaf

Rcwd

Rsoil = Rroot + Rdecomp

Soil CO2 efflux is a measurement of the Rsoil that reaches the atmosphere

Measuring Soil CO2 EffluxManual chamber measurements

Autochamber measurements

Volcanos

Subduction of limestone at plate boundariesCarbonotype: watery low temperature lava

Oceans +2 Pg yr-1

Atmosphere +2 Pg yr-1

FACE Duke Forest, Chapel Hill, NC

Carbon Fertilization ?

FACE site locations

Case Study: Photosynthesis

Using cores to analyze the Earth System

To determine the ecosystem history of the area and the impacts of changes in riverine flow. An understanding of natural cycles of change prior to significant human disturbance allows land managers to set realistic performance measures and targets for salinity and other water quality and quantity measures.

Sediment Cores from the Southwest Coastal Area, Everglades National Park, Florida

~1900 years old

http://oceanworld.tamu.edu/resources/oceanography-book/evidenceforwarming.htm

The oxygen isotope ratio and the hydrogen isotope ratios give the temperature at which H2O condensed as water or snow on the surface of the ice sheet. Air bubbles trapped in the ice gives atmospheric gas content, especially the concentration of carbon dioxide (CO2)Dust content in the ice indicates windiness over land upwind of the ice sheet.Salt content in the ice indicates windiness over the ocean upwind of the ice sheet. Sulphuric acid (H2SO4) content of the ice depends on volcanic activity. Learn more about evidence collected from ice cores by reading Deciphering Mysteries of Past Climate From Antarctic Ice Cores. (http://www.globalchange.umich.edu/globalchange1/current/labs/Lab9/Vostok.htm)

Ice Cores

Radial/cross section from a giant sequoia log (Sequoiadendron giganteum)

http://www.koshland-science-museum.org/exhibitgcc/historical08.jsp

Long-term, quantitative temperature and precipitation records can be determined from tree rings.

http://www.yale.edu/fes519b/saltonstall/trmmdata.htm

http://lh5.ggpht.com/_86eqKXBZMaw/RsPNBLX1BCI/AAAAAAAAADs/enILirRyRT4/APE1_D1.jpg

Little Ice Age: 1400-1800 A.D.

LIA

European Settlement in Canada

The Great Dismal Swamp: Carbon cycle history

Role of peatlands in global carbon cycle

CARBON EMISSION

CARBON SINK

Modified from Brown, 1998; and Moore et al, 1998

PLANTS

PEAT

anaerobic decomposition

aerobic decomposition

oxidation

CO2

CH4

CH4

CO2

DOC

photosynthesisCO2