As long as it is taught factually and not proselytized, what’s the problem?
Tips for teachers:
Regrettably there is a lot of disinformation about climate change – here’s some IPCC-recognized and approved points that demonstrate model-driven hype in the media is baseless and that enhanced greenhouse effect, while true is not a significant problem.
Unchanged since the Third Assessment Report (TAR) is the formula for calculating increased forcing from increasing carbon dioxide: ΔF = αln(C/C0)
α = 5.35; C is CO2 in ppm and; the subscript 0 denotes the unperturbed concentration. ΔF is expressed in Watts per meter squared.
Thus any doubling from any initial concentration delivers 3.7W/m2 additional forcing: 5.35ln(2/1) = 3.7W/m2.
Given that a doubling series is simply exponents of 2 it is fairly simple to calculate CO2‘s forcing contribution from a first single ppm in the atmosphere (21 = 2 ppm and 1 x 3.7 W/m2 … 28 = 256 [approximating pre industrial revolution levels] and 8 x 3.7 = 29.6W/m2; 29 = 512 ppm and 9 x 3.7 = 33.3W/m2).
So how do we equate that to surface temperature change?
Easy, we introduce Trenberth’s graphic from Trenberth, K. E., J. T. Fasullo, and J. Kiehl, 2008: Earth’s global energy budget. Bull. Amer. Meteor. Soc., in press:
Note the “Back Radiation” figure – that’s greenhouse effect including all the positive and negative feedbacks in the climate system and anyone who’s done their homework knows that’s generally reckoned on being 33 °C (the difference between earth’s calculated absolute temperature of 255 kelvins (K) without greenhouse and the 288 K we find with it).
Surely it doesn’t take a rocket scientist to realize that if about 330 W/m2 is required to raise the planet’s temperature about 33 °C then about 10 W/m2 is required for 1 °C or 1W/m2 is approximately equal to 0.1 °C.
Doubling CO2 then delivers 0.37 °C warming accounting for earth’s natural feedbacks.
Conclusion: enhanced greenhouse is real but trivial.
That isn’t how PBS is pitching it, however:
For the first time, new national educational standards for grades K-12 will link global warming trends to manmade emissions. Part of our Coping With Climate Change series, Hari Sreenivasan looks at the challenges teachers face when covering the topic of climate science in their classrooms.
(Not sure of this will embed here – if not go to http://www.pbs.org/newshour/bb/climate-change/jan-june12/teachclimate_05-02.html )
Watch Teachers Endure Balancing Act Over Climate Change Curriculum on PBS. See more from PBS NewsHour.