CO2 Absorption of IR Radiated by the Earth

Abstract

Global warming and the rise in concentration of greenhouse gases are important topics in environmental chemistry and have been studied since the turn of the century (1, 2). Quite often, students are informed that methane, carbon dioxide, and other greenhouse gases absorb infrared (IR) radiation of certain frequencies. However, students tend to have only a vague quantitative sense of the efficiency with which greenhouse gases absorb IR light. In this work, we derive a model using Beer's law and describe an experiment that illustrates the effectiveness of IR absorption by CO 2 . The experiment may be useful for environmental, physical, or instrumental chemistry courses.

A Simple, Student-Built Spectrometer To Explore Infrared Radiation and Greenhouse Gases

“…A “thematic” course on the chemistry and controversy of climate change for upper-level non-STEM students has recently been developed, a tested classroom demonstration to illustrate the greenhouse effect is available, and integrated lab-lecture case studies for nonscience majors have been developed . There has also been a significant number of laboratory experiments developed to understand absorption of infrared radiation by small molecules, carbon dioxide absorption of infrared radiated by the earth, the use of photoacoustics to confirm the infrared absorption by greenhouse gases, the use of calorimetry to explore heat retention and global warming, and an experiment that uses vibrational spectroscopy and a simple spreadsheet analysis to estimate the greenhouse warming potentials of greenhouse gases . Finally, a study to investigate general chemistry students’ understanding of the chemistry underlying climate change was recently reported …”

A Comparison of Carbon Dioxide Emissions from Electric Vehicles to Emissions from Internal Combustion Vehicles

“…It is well-known that carbon dioxide is a greenhouse gas, − and the most recent report of the Intergovernmental Panel on Climate Change states that it is almost certain that human greenhouse gas emissions are largely responsible for the significant rise in global average temperatures during the past 60 years:It is [a 95% probability] that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period …”

“…Previously published student exercises have explored carbon dioxide emissions primarily to teach stoichiometry, , as a tie-in to infrared spectroscopy , or through more general discussions of the atmospheric greenhouse effect. ,, …”

Photoacoustic Experimental System To Confirm Infrared Absorption Due to Greenhouse Gases

“…Global warming is one of the most serious issues of today and detailed analyses have been carried out on this issue . Many efforts have been made in chemical education to stimulate the interest of students in this serious environmental problem − . The atmosphere’s transparency to visible light and semiopacity to infrared (IR) light owing to the absorption by greenhouse gases (GHGs) are the key points for understanding the mechanism of global warming.…”

“…We have been involved in a project that helps high-school students understand the IR-absorbing property of GHGs by conducting simple experiments. Although the Fourier-transform infrared (FTIR) spectrometer is useful for obtaining detailed information about the characteristics of GHGs , , we did not use this technique because the mechanism of an FTIR spectrometer is too complicated for high-school students to understand and the students are unfamiliar with interpreting information from an IR chart. Also because of its price, it is difficult to provide an FTIR spectrometer to each group of students.…”