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Journal of Creation 25(2):17–19, August 2011

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Is the faint young sun paradox solved?



Scientists who believe in evolution find themselves confronted with many paradoxes. One of those paradoxes is the existence of males and females within each kind. Logically, reproduction in evolution should be asexual; it is a very difficult problem to figure out why there should be a male and female in evolution. This conundrum was one of the top 18 science mysteries showcased in the Aug 18–25, 1997, issue of U.S. News & World Report, under the title of ‘Why should males exist?’1 This is really a problem of their own making because they’ve chosen to believe in evolution. This is where Bible believing Christians have the evidence hands down in this area, since it says in Genesis 1:27 that God created man in His own image and “male and female He created them”. Another paradox of their own making is the faint young sun paradox.2

What is the faint young sun paradox?

It was discovered about 40 years ago that in the evolutionary origin of the solar system the sun would have been significantly less luminous with the earth receiving about 20 to 30% less sunlight than today.3 This difference is believed to have been caused by a higher ratio of hydrogen to helium in the sun’s core at that time. Even in the late Precambrian, solar luminosity is estimated to still be about 6% less than today.4 On this basis, the earth should have been totally glaciated from near its beginning, after it cooled down from its initially hot state within evolutionary scenarios. This is because a slight decrease in solar luminosity is enough to cause an ice age:

“Simple energy-balance climate models of the Budyko/Sellers type predict that a small (2–5%) decrease in solar output could result in a runaway glaciation on the Earth. But solar fluxes 25–30% lower early in the Earth’s history apparently did not lead to this result.”5

So the early earth should have been easily glaciated from the poles to the equator.

This glaciation should have continued indefinitely to this day with no possible biological evolution, unless something drastic occurred to warm the earth:

“Without any change in atmospheric pCO2 [CO2 partial pressure], an increase in solar flux by ~27% above the present value would be needed to melt the equatorial ice (emphasis mine).”6

A 27% increase over the present solar luminosity seems like an impossible task.

So, the evolutionary scientists have a major paradox since most of the Precambrian, except for several global and near global ‘ice ages’,7 shows evidence of relatively warm temperatures:

“One of the major puzzles of the Earth’s history is that the global-average surface temperature has been fairly constant over geological time scales (within about 10 deg of the current value) even though solar luminosity was as much as 20–30% lower 4 × 109 years ago, according to established knowledge about stellar evolution.”8

A further problem is that evolutionary scientists need the earth relatively warm for the evolution of life, which would be impossible within their paradigm if the earth is totally frozen over. The issue is even more of a puzzle since some evolutionary scientists believe that the ocean water, which would heat the atmosphere, was extremely hot back then, around 55–85°C!9

Attempted resolution of the paradox

The faint young sun paradox has generated a lot of hypotheses that attempt to explain it. To counter the much lower solar luminosity and keep Earth temperatures relatively warm, researchers have suggested two differences, either separate or in combination, between the early earth and today: more greenhouse gases and a lower planetary albedo (reflectivity). Water vapor is the strongest greenhouse gas today, accounting for around 95% of the greenhouse effect. It would be an obvious choice, except it does not help, because when water vapor condenses to clouds, it makes the problem worse by increasing the albedo from the cloud tops.10 So, the other minor greenhouse gases, namely carbon dioxide, methane, and ammonia, have been evoked to solve the problem.

A typical solution in the past has been to suggest a whopping increase in carbon dioxide on the early earth, resulting in a super greenhouse effect.11 However, it is unknown exactly how much carbon dioxide would have been needed to counter the faint young sun and keep Earth temperatures somewhat like today. One estimate is that Precambrian CO2 concentrations would have to be in the range of 1,500 to 2,500 times the present atmospheric level!12 Other estimates are significantly lower than these values. Such a radical increase in CO2 does not seem very likely in any evolutionary scenario. Besides, new information from ‘ancient soils’ indicates that Archaean carbon dioxide levels were much too low to counteract the faint young sun.10 All these old solutions using CO2 and other greenhouse gases have been rebutted, but two new solutions have recently been proposed and are believed to show promise.13

The new solutions

One of the new ‘solutions’ to the faint young sun paradox proposes that a lower planetary albedo with slightly higher greenhouse gases solves the problem.14 The researchers ‘solve’ the problem by postulating smaller continents, a higher methane concentration, and a lower planetary albedo because the cloud condensation nuclei (CCN) were much fewer and larger. Fewer CCN translate into larger cloud droplets that are less reflective, so planetary albedo is reduced.

Figure 1. Change in solar luminosity with time. Two different vertical scales are used that represent uncertainties in the initial luminosity that in turn depends on estimates of the original composition of the sun’s core. The beginning luminosity can vary from 25% to 40% less than at present. Note that even in the late Precambrian, solar luminosity is still 4.7 to 6% less than today. (From ref. 4, p. 16724.)
Figure 1. Change in solar luminosity with time. Two different vertical scales are used that represent uncertainties in the initial luminosity that in turn depends on estimates of the original composition of the suns core. The beginning luminosity can vary from 25% to 40% less than at present. Note that even in the late Precambrian, solar luminosity is still 4.7 to 6% less than today. (From ref. 4, p. 16724.)

One problem with a high concentration of methane in the atmosphere is that it combines with nitrogen to form an organic haze. Although methane is a greenhouse gas that results in a warmer atmosphere, the organic haze increases the planetary albedo, more than offsetting the greenhouse effect of increased methane.

This is where the second mechanism enters in to ‘solve’ the problem, claiming that the organic haze will have clumped aggregates.15 Such an organic haze lowers the planetary albedo for visible light, and has the added benefit that it shields the early earth from ultraviolet light, thus allowing the origin of life from chemicals. Such a scheme will also increase the amount of ammonia in the atmosphere, which will give an added heating to the atmosphere. With ammonia and methane back in the early atmosphere, the researchers are coming back to the rejected early atmosphere postulated in the mid-1950s by Miller and Urey.

The paradox is not solved

As a result of this new research, some people are thinking the faint young sun paradox is finally solved. Even the title of the first research paper is: “No Climate paradox under the faint early Sun”.16

However, it does not take much analysis to realize the two new solutions are an ad hoc house of cards. The first set of researchers has the gall to state that the problem is solved by using a one-dimensional (vertical) climate model. This is amazing since any climate model, other than a three-dimensional general circulation model with a realistic ocean, biosphere, and cryosphere (the snow/ice component), is inaccurate. For example, such a one-dimensional model ignores important feedbacks, such as the powerful ice albedo feedback. As snow and ice increase, the albedo increases to cause further cooling.

Furthermore, comments on the two recent proposals from the main science journals are not very positive. James Kasting stated in Nature: “Despite all these proposed warming mechanisms, there are still reasons to think that the faint young Sun problem is not yet solved.”17 Alicia Newton writes in Nature Geoscience: “Challenges for each hypothesis remain, and are likely to remain for some time.”13

Of course, creationists do not have a paradox with a faint young sun because the solar system is young. Moreover, the failed solutions to the paradox provide one more reason why the solar system is young.2

Posted on homepage: 28 December 2012


  1. Ridley, M., Why should males exist? U.S. News & World Report 123(7):52, 54, 1997. Return to text.
  2. Faulkner, D., The young faint Sun paradox and the age of the solar system, Journal of Creation 15(2):3–4, 2001. Return to text.
  3. Molnar, G.I. and Gutowski, Jr., W.J., The ‘faint young sun paradox’: further exploration of the role of dynamical heat-flux feed backs in maintaining global climate stability, Journal of Glaciology 41(137):87–90, 1995. Return to text.
  4. Crowley, T.J. and Baum, S.K., Effects of decreased solar luminosity on Late Precambrian ice extent, Journal of Geophysical Research 98(D9):16723–16732, 1993. Return to text.
  5. Caldiera, K. and Kasting, J.F., Susceptibility of the early Earth to irreversible glaciation caused by carbon dioxide clouds, Nature 359:226–228, 1992. Return to text.
  6. Caldeira and Kasting, Ref. 5, pp. 226–227. Return to text.
  7. Oard, M.J., Ancient Ice Ages Or Gigantic Submarine Landslides? Creation Research Society Monograph No. 6, Chinoa Valley, AZ, 1997. Return to text.
  8. Molnar and Gutowski, ref. 3, p. 87. Return to text.
  9. Oard, M.J., Evolutionary origin of life even more difficult, Journal of Creation 21(3):15–16, 2007. Return to text.
  10. Kasting, J.F., Faint young sun redux, Nature 464:687–689, 2010. Return to text.
  11. Kuhn, W.R. and Kasting, J.F., Effects of increased CO2 concentrations on surface temperatures of the early Earth, Nature 301:53–55, 1983. Return to text.
  12. Graedel, T.E., Sackmann, I.-J. and Boothroyd, A.I., Early solar mass loss: a potential solution to the weak sun paradox, Geophysical Research Letters 18(10):1881–1884, 1991. Return to text.
  13. Newton, A., Warming the early Earth, Nature Geoscience 3:458, 2010. Return to text.
  14. Rosing, M.T., Bird, D.K., Sleep, N.H. and Bjerrum C.J., No climate paradox under the faint early Sun, Nature 464:744–747, 2010. Return to text.
  15. Wolf, E.T. and Toon, O.B., Fractal organic hazes provided an ultraviolet shield for early Earth, Science 328:1266–1268, 2010. Return to text.
  16. Rosing et al., ref. 14, p. 744. Return to text.
  17. Kasting, ref. 10, p. 688. Return to text.

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