Data sets: Climate Change: How Do We Know? NASA - CLEAN
This static graph of changes in CO2 concentrations is going back 400,000 years, showing the dramatic spike in recent years.
To demonstrate the evidence of climate change.
ACTIVITY DESCRIPTION AND TEACHING MATERIALS
View >> Climate Change: How Do We Know?
TEACHING NOTES / CONTEXT FOR USE
The following comments are from CLEAN Reviewers.
- Visualization could be used as an motivational introduction to the main cause of climate change namely CO2 emissions.
- Other versions of this exist, but this high quality graphic has "added value" with additional information on the evidence for human impacts,and sources to relevant data.
- This graphic/image could also be used to discuss the importance of time series data and the nature of science.
- With a focus on the evidence that human activities are the reason for the recent increase in CO2, the webpage also includes summaries of the evidence and observations of recent change, plus links to the sources of the information.
About the Science
- A static visualization demonstrating evidence that atmospheric CO2 has increased since the Industrial Revolution.
- The page provides the key sources of data and information contained on the page with a brief explanation of the graphic.
- CO2 concentrations in ice cores have been measured back to 800,000 years as of 2008 but still show the same pattern.
- Comment from expert scientist: The subject is discussed in a scientifically valid and clear way.
About the Pedagogy
- Static image on CO2 increases is a compelling illustration.
- This image/illustration summarizes past climate fluctuations over the past 400,000 years.
- Students could be encouraged to go to the cited references and go beyond the image to discuss the significance of the increase being human induced.
Technical Details/Ease of Use
The image can be saved to the desktop or viewed online which would provide the ability to research the additional resources and for students to gather more information independently.
REFERENCES AND RESOURCES
References from the original resource at www.nasa.gov
1 IPCC Fourth Assessment Report, Summary for Policymakers, p. 5
B.D. Santer et.al., “A search for human influences on the thermal structure of the atmosphere,” Nature vol 382, 4 July 1996, 39-46
Gabriele C. Hegerl, “Detecting Greenhouse-Gas-Induced Climate Change with an Optimal Fingerprint Method,” Journal of Climate, v. 9, October 1996, 2281-2306
V. Ramaswamy et.al., “Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling,” Science 311 (24 February 2006), 1138-1141
B.D. Santer et.al., “Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes,” Science vol. 301 (25 July 2003), 479-483.
2 In the 1860s, physicist John Tyndall recognized the Earth's natural greenhouse effect and suggested that slight changes in the atmospheric composition could bring about climatic variations. In 1896, a seminal paper by Swedish scientist Svante Arrhenius first speculated that changes in the levels of carbon dioxide in the atmosphere could substantially alter the surface temperature through the greenhouse effect.
3 National Research Council (NRC), 2006. Surface Temperature Reconstructions For the Last 2,000 Years. National Academy Press, Washington, DC.
4 Church, J. A. and N.J. White (2006), A 20th century acceleration in global sea level rise, Geophysical Research Letters, 33, L01602, doi:10.1029/2005GL024826.
The global sea level estimate described in this work can be downloaded
from the CSIRO website.
6 T.C. Peterson et.al., "State of the Climate in 2008," Special Supplement to the Bulletin of the American Meteorological Society, v. 90, no. 8, August 2009, pp. S17-S18.
7 I. Allison et.al., The Copenhagen Diagnosis: Updating the World on the Latest Climate Science, UNSW Climate Change Research Center, Sydney, Australia, 2009, p. 11
8 Levitus, et al, "Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems," Geophys. Res. Lett. 36, L07608 (2009).
9 L. Polyak, et.al., “History of Sea Ice in the Arctic,” in Past Climate Variability and Change in the Arctic and at High Latitudes, U.S. Geological Survey, Climate Change Science Program Synthesis and Assessment Product 1.2, January 2009, chapter 7
R. Kwok and D. A. Rothrock, “Decline in Arctic sea ice thickness from submarine and ICESAT records: 1958-2008,” Geophysical Research Letters, v. 36, paper no. L15501, 2009
(Note: The pH of surface ocean waters has fallen by 0.1 pH units. Since the pH scale is logarithmic, this change represents approximately a 30 percent increase in acidity.)
14 C. L. Sabine et.al., “The Oceanic Sink for Anthropogenic CO2,” Science vol. 305 (16 July 2004), 367-371
The following description is by the developers of the orginial resource at www.nasa.gov
The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.
The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years.1
Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. Studying these climate data collected over many years reveal the signals of a changing climate.
Certain facts about Earth's climate are not in dispute:
- The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.2 Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many JPL-designed instruments, such as AIRS. Increased levels of greenhouse gases must cause the Earth to warm in response.
- Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate responds to changes in solar output, in the Earth’s orbit, and in greenhouse gas levels. They also show that in the past, large changes in climate have happened very quickly, geologically-speaking: in tens of years, not in millions or even thousands.3