By Dr. Robert Thorson
I’m dreading the 112th Congress, which begins next January. New members of the House and Senate are dominated by those who are either publicly skeptical of human-caused climate change, or who have derided those who believe that “the reduction and control of atmospheric CO(-2) [is] a serious and pressing issue, worthy of real-time attention.”
That pre-election quote comes from the final sentence of a report published in the Oct. 15 journal Science written by four climate scientists from NASA’s Goddard Institute for Space Studies. They have what the author Tom Wolfe called the “right stuff”: the training, vision and guts to do their work well and stand by its results.
This raises the question: If we can trust NASA engineers and astronauts to build space stations and orbiting shuttles, then why can’t we also trust NASA scientists and computer programmers to make useful predictions about climate change?
The answer that works for me is one I learned in kindergarten: that imagining adventures in outer space was much more fun than imagining cleaning up my room. Spending my allowance on toy rockets made sense. Spending it on cleaning supplies was unthinkable.
I’m afraid that my view from kindergarten is the one that will be seen by the 112th Congress. Cleaning up our atmospheric room with policies that supply carbon benefits is less fun to think about than other parts of the national agenda.
To help visualize the invisible aspects of climate change, I’ve decided to share an analogy from the article cited above, “Atmospheric CO(-2): Principal Control Knob Governing Earth’s Temperature.”
Open your refrigerator. Inside you will find a knob that adjusts the internal temperature above or below normal. Your oven probably also has a knob, one that adjusts the internal temperature from warm to broiling.
Moving the knobs on either of these kitchen appliances does not change the temperature directly. What happens is that these small mechanical movements send electronic signals to their respective thermal units, which then follow through with more or less cold or heat.
Though the climate system of planet Earth is much more complex than those of appliances, the carbon content of earth’s atmosphere is crudely analogous to the knob positions on your kitchen appliances. Any change sends a signal to the main thermal unit of earth’s greenhouse system, its water cycle, where condensation, precipitation, sublimation, freezing, melting and other transfers of matter take place.
Though carbon gases do contribute directly to the greenhouse effect (about 25 percent of the total) their primary role is to message the water cycle, which amplifies the signal by about 75 percent through various feedback mechanisms, with vapor and clouds accounting for about 50 percent and 25 percent of the total greenhouse response, respectfully.
The external sun and subsurface volcanism are separate, smaller control knobs that force the atmosphere’s water-based thermal unit to react. Solar radiation varies about 0.1 percent due to the 11-year sunspot cycle, and to other, more erratic processes at longer time intervals. Volcanic aerosols from large eruptions force short-term coolings that last several years. Thermal oscillations within the ocean basins at time scales ranging from a year to millennia are not control knobs, but are mass transfers within the water feedback cycle.
Regardless of what the 112th Congress thinks, these NASA authors know that the “atmospheric CO(-2) control knob is now being turned faster than at any time in the geological record,” despite the fact that the present CO(-2) level in the Earth’s atmosphere (390 parts per million) is already far higher than the maximum for recent interglacial epochs (280 parts per million).
No one will deny the physical feel of a knob being turned, even if their eyes are closed. Why, then, would they deny the turning of a gaseous knob that can’t be seen, but which can easily be measured?