THOSE INCONVENIENT RISKS

THOSE INCONVENIENT RISKS

Do we know yet enough to embark on a world wide program of forced climate change? How soon can we learn enough to justify a massive alteration in the world energy economy?

My earlier article on this topic, posted at http://jaygaskill.com/InconvenientChoice.htm , raised a strong cautionary note: “As a species, we are not yet ready for the big time. Given the present level of incompetence, for the UN or a subgroup of nations to seriously engage in a program of global climate alteration is a little like allowing a group of hormone saturated teenagers to hack the source code and operating system of a major bank.”

Is there more we can learn? How might we go about it? What can we do in the meantime?

Climate Change and Public Policy:

Some Naïve Questions & One Careful Answer

Consider:

If water vapor is the overwhelmingly dominant greenhouse gas (and it is) —

NASA: Water Vapor is the most abundant greenhouse gas in the atmosphere…. However, changes in its concentration are also considered to be a result of climate feedbacks related to the warming of the atmosphere rather than a direct result of industrialization. The feedback loop in which water is involved is critically important to projecting future climate change, but as yet is still fairly poorly measured and understood. [My emphasis.]

As the temperature of the atmosphere rises, more water is evaporated from ground storage (rivers, oceans, reservoirs, soil). Because the air is warmer, the relative humidity can be higher (in essence, the air is able to ‘hold’ more water when it’s warmer), leading to more water vapor in the atmosphere. As a greenhouse gas, the higher concentration of water vapor is then able to absorb more thermal IR energy radiated from the Earth, thus further warming the atmosphere. The warmer atmosphere can then hold more water vapor and so on and so on. This is referred to as a ‘positive feedback loop’. However, huge scientific uncertainty exists in defining the extent and importance of this feedback loop… [Again, my emphasis.]

-and -if solar radiation increases, say by a factor {x}, over a significant period (as it has) –

(Mar. 21, 2003) — Since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, has increased by nearly .05 percent per decade, according to a NASA funded study.

‘This trend is important because, if sustained over many decades, it could cause significant climate change,’ said Richard Willson, a researcher affiliated with NASA’s Goddard Institute for Space Studies and Columbia University’s Earth Institute, New York. He is the lead author of the study recently published in Geophysical Research Letters.

‘Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years,’ he said.

NASA’s Earth Science Enterprise funded this research as part of its mission to understand and protect our home planet by studying the primary causes of climate variability, including trends in solar radiation that may be a factor in global climate change.

The solar cycle occurs approximately every 11 years when the sun undergoes a period of increased magnetic and sunspot activity called the ‘solar maximum,’ followed by a quiet period called the ‘solar minimum.’

Although the inferred increase of solar irradiance in 24 years, about 0.1 percent, is not enough to cause notable climate change, the trend would be important if maintained for a century or more. Satellite observations of total solar irradiance have obtained a long enough record (over 24 years) to begin looking for this effect.

Total Solar Irradiance (TSI) is the radiant energy received by the Earth from the sun, over all wavelengths, outside the atmosphere. TSI interaction with the Earth’s atmosphere, oceans and landmasses is the biggest factor determining our climate. To put it into perspective, decreases in TSI of 0.2 percent occur during the weeklong passage of large sunspot groups across our side of the sun. These changes are relatively insignificant compared to the sun’s total output of energy, yet equivalent to all the energy that mankind uses in a year. According to Willson, small variations, like the one found in this study, if sustained over many decades, could have significant climate effects.

-and- if the most powerful single impact of increased solar radiation entering the atmosphere from space is an increased generation of water vapor from the oceans (also true),

NASA: The ocean plays a key role in this vital cycle of water. The ocean holds 97% of the total water on the planet; 78% of global precipitation occur over the ocean, and it is the source of 86% of global evaporation.

-then- might not the climate-forcing effects of changes in the extra-atmosphere solar radiation flux {x} swamp those of trace gasses such as CO2[1] because of a water vapor “multiplier” effect?

Since we do not have, as yet, any reliable quantitative data about the fluctuation of atmospheric water vapor, and we have – as yet – failed to explain why changes in CO2 atmospheric concentrations appear to lag about 800 years behind ambient temperature changes[2], how can we persuasively rule out extra-atmosphere solar radiation as the largest single cause of the current warming trend?

One answer:

We simply don’t know enough to attribute the climate change in the last fifty years to human industrial activity. A brief correlation, however suggestive, falls short of demonstrating a causal link.

We need a better empirical model than the faux retro empiricism that uses (admittedly) approximate computer algorithms, massively applied, in an attempt to “prove” that we could have predicted prehistoric macro climate changes. The margin of error in these models is still embarrassing.

There are useful and potentially revealing experiments, still unperformed. The thermal trapping properties of various gas mixes on a reasonable macro scale – say a 500 meter column of air – could still be done. Side by side comparisons of the various greenhouse heat trapping properties of realistic gas mixes could be demonstrated, comparing water vapor variations to CO2 variations, for example. The radiation flux could be tightly controlled and the resulting thermal effect precisely measured.

Expensive, you say? Not compared with the cost of retooling the entire world economy on a quasi-emergency basis.

Consider that without water, the mean temperature of the earth at the surface would be about 67 degrees centigrade[3] or 152 degrees Fahrenheit!

We are as cool as we are because of the heat mediating effects of the oceans, including the complicated thermal transfers that involve the poorly measured effects of water vapor (crudely speaking, clouds cool by reflecting solar radiation back into space while “invisible’ water vapor is a potent greenhouse gas”).

If, as I strongly suspect, both CO2 and water vapor can function as heat amplifiers, potentially taking a “minor” increase in solar radiation and ramping up the effect, it is very plausible that water vapor is both more potent in that respect and more immediate. CO2 may actually be a trailing indicator instead of a climate driver because, after warming as taken place – due, say to other causes – precipitation increases, water vapor increases, plant respiration increases, and the ocean uptake of dissolved CO2 diminishes[4], all of which can be expected to drive up the CO2 atmospheric load. Without denying that human activity may have strongly contributed to the current CO2 atmospheric load, it probably is the case that most increases in atmospheric CO2 track the effects, not the causes of global warming periods.

Politics Again

On the political stage there is a temporary convergence between the global warming skeptics who see a national security advantage in pursuing alternate energy sources and the global warming evangelists. The meaningful point of potential correspondence, however, is a touchy area: nuclear energy. Sane environmentalists, including Patrick Moore, an original founder of Greenpeace, are on board.[5] Generation Four fission reactors, now in development, are safe and – if standardized and quasi-mass produced – ultimately economical over the long haul. Moments like these, where sanity and hysteria combine to support reasonable public policy, are as rare as an honest politician…

[1] CO2 concentrations in the atmosphere are still measured in parts per million.

[2] http://www.sciencemag.org/cgi/content/abstract/299/5613/1728

[3] NASA GSFC Water and Energy Cycle web site

[4] CO2 solubility decreases with increasing temperature at constant pressure. See http://www.kgs.ku.edu/PRS/publication/2003/ofr2003-33/P1-05.html .

[5] Patrick Moore, co-founder of Greenpeace, now chairman and chief scientist of Greenspirit Strategies Ltd, has advocated nuclear energy in a piece in The Washington Post. Go to at http://www.washingtonpost.com/wp-dyn/content/article/2006/04/14/AR2006041401209.html .

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