Arguments
What climate change is happening to other planets in the solar system?
What the science says...
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There are three fundamental flaws in the 'other planets are warming' argument. Not all planets in the solar system are warming. The sun has shown no long term trend since 1950 and in fact has shown a slight cooling trend in recent decades. There are explanations for why other planets are warming. |
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Climate Myth...
Other planets are warming
"[E]vidence that CO2 is not the principle driver of warming on this planet is provided by the simultaneous warming of other planets and moons in our solar system, despite the fact that they obviously have no anthropogenic emissions of greenhouse gases.
Mars, Triton, Pluto and Jupiter all show global warming, pointing to the Sun as the dominating influence in determining climate throughout the solar system." (Ian McClintock - PDF, page 8)
The basis of this argument is that the sun must be causing global warming and in fact, warming throughout the solar system. There are several flaws in this line of thought. Firstly, the characterisation that the whole solar system is warming is erroneous. Around 6 planets or moons out of the more than 100 bodies in the solar system have been observed to be warming. On the other hand, Uranus is cooling (Young 2001).
Secondly, the theory that a brightening sun is causing global warming falls apart when you consider the sun has shown little to no trend since the 1950s. A variety of independent measurements of solar activity including satellite data, sunspot numbers, UV levels and solar magnetograms all paint a consistent picture. Over the last 35 years of global warming, sun and climate have been moving in opposite directions.
That begs the question - what is causing warming on other planets? With the exception of Pluto, climate change on other planets are fairly understood:
- Martian climate is primarily driven by dust and albedo. Global dust storms increase the surface albedo by settling brighter dust on dark surfaces. Higher albedo leads to more sunlight being reflected which has a cooling effect. Snapshots of Mars' surface in 1977 and 1999 find that the surface was brighter in 1977 and darker in 1999. However, this doesn't necessarily point to a long term warming trend - the 1977 snapshot was made shortly after a global dust storm while the 1999 snapshot occured before a dust storm. Consequently, there is little empirical evidence that long term global warming on Mars is occuring (Richardson & Vasavada 2007). More on Mars...
- Neptune's orbit is 164 years so observations (1950 to present day) span less than a third of a Neptunian year. Climate modelling of Neptune suggests its brightening is a seasonal response (Sromovsky et al. 2003). Eg - Neptune's southern hemisphere is heading into summer. More on Neptune...
- Neptune's largest moon, Triton, has warmed since the Voyager space probe visited it in 1989. The moon is approaching an extreme southern summer, a season that occurs every few hundred years. During this special time, the moon's southern hemisphere receives more direct sunlight (Elliot et al. 1998).
- Jupiter's storms are fueled by the planet's own internal heat (sunlight is 4% the level of solar energy at Earth). When several storms merge into one large storm (eg - Red Spot Jr), the planet loses its ability to mix heat, causing warming at the equator and cooling at the poles (Marcus et al. 2006). More on Jupiter...
- Pluto's warming is not clearly understood. Pluto's orbit is much more elliptical than that of the other planets, and its rotational axis is tipped by a large angle relative to its orbit. Both factors could contribute to drastic seasonal changes. As Pluto's orbit is equivalent to 248 Earth years and observed warming spans only 14 years, it is likely this is a seasonal response (Sromovsky et al. 2003).
Last updated on 21 October 2016 by John Cook. View Archives
This defense of position is particularly poor and can be refuted by a simple 5th grade-level experiment. Take a brisket and put it in your oven, setting the oven at 175 degrees Fahrenheit. After an hour check the brisket's temperature. Put it back in the oven and raise the oven's temperature to 350 degrees Fahrenheit for twenty minutes. After twenty minutes, take it out and check the brisket's temperature. It went up right? Now put the brisket back on the oven and lower the oven's temperature slightly to 325 degrees Fahrenhiet for a half hour. Take the brisket out and check it's temperature. The temperature of the brisket will have continued to rise! "How is that?", you seem to say, "How could the temperature of the brisket continue to rise when the temperature of the oven went down by 25 degrees?" Your "defense" is that the oven couldn't be warming the brisket because the brisket didn't cool when the oven's temperature was slightly lowered -- even though the oven's temperature was still well above the brisket's point of stasis. Seriously???
mkuske, the only way your analogy is valid is if the brisket has not yet reached the oven's temperature of 325 when you lower the oven's temperature from 350 to 325. The oven is still warmer than the brisket, so of course the brisket continues to warm toward that temperature of 325. If instead the brisket has reached the equilibrium temperature of 350 before you lower the oven's temperature to 325, then the brisket will start to cool down from 350. (And it will cool slower than the oven does, because the brisket has greater thermal mass than the oven's air.)
But let's skip your analogy and use the real Earth. You are implying there is a lag between the increased incoming energy from the Sun and the Earth's heating. You are quite correct. Assuming the Earth initially was in thermal equilibrium (same energy coming in as going out to space), an increase in the energy coming in from the Sun will cause energy immediately to start accumulating in the Earth (by which I mean the atmosphere, surface land, surface water, deep oceans--the whole shebang). But that extra energy is distributed among all the components of "the Earth," which takes time. So although parts of the Earth immediately start heating, there is a lag before the entire Earth system reaches a new temperature. If the Sun's input stops increasing--flattens out--then the Earth's energy indeed will continue to increase, but only until it reaches equilibrium.
But simultaneously, as the Earth's temperature increases, the Earth emits more energy to space. So as soon as the Sun's input to the Earth flattens, the energy imbalance in the Earth (energy in minus energy out) instantly starts decreasing. That makes the rate of temperature increase slow down. But that is not what has been happening. Instead the energy imbalance has continued to increase, and the rate of temperature increase has not slowed. Also, we have a large amount of empirical evidence of the length of the lag between a change in the Sun's input to the Earth and the resulting temperature change (e.g., the Sun's 11-year cycle and volcanic eruptions of large amounts of reflective aerosols). The lag is not nearly as long as the time in which the Sun's radiance has been flat.
For more details, and for a more proper place to put your comments on this topic, see the post "Climate time lag."
mkuske, also see the post "It's the Sun." Be sure to read the Basic tabbed pane, then the Intermediate one, then the Advanced one.
Tom Dayton, First I'll acknowledge that this is a simplistic analogy. However, you're assuming that the Earth has in fact reached the equilibrial state for the amount of increased activity from the Solar Grand Maximum (Modern Maximum), likewise assuming that the equiibrial state would be met almost instantly (in the larger picture of time).
Just like the temperature of the brisket doesn't instantly jump to 350 degrees just because the oven around it did, neither does the Earth when irradiated by the Sun. In fact the oven could heat to 350 degrees in minutes but it would take hours for the brisket to reach that temperature.
In this analogy the brisket only increases in temperature if affected relatively constantly by the heat input of the oven over an extended period of time. Also when the brisket is cooked, it doesn't immediately express it's stored heat and become room temperature, it releases it over time. After all you don't have to heat it back up 5 minutes after it comes out of the oven. Likewise if it's been out of the oven for 30 minutes and you do want it a little warmer, you don't have to cook it for an hour again, starting from scratch. It has stored some of that heat radiation and gets to temperature much more quickly. Likewise the Earth would not immediately express its stored energy especially considering it -- until very, very recently -- has been exposed to a fairly constant and atypical excess of irradiation from the Sun.You're assuming that the Earth -- and rest of the solar system -- has reached the temperature that it would if the Solar Grand Maximum were the typical constant state.
In this analogy, what is typical for the brisket is the 175 degrees worth of heat radiation from the oven. What's typical for the Earth is a normal non-Solar Grand Maximum fluctuation of radiation from the Sun. The brisket only heats because it is exposed to a constant yet atypical 350 degrees of heat radiation from the oven before the oven drops slightly to 325 degrees, as the Earth has been exposed to an atypical and constant amount of the Sun's increased energy, even though there has been the slightest dip in activity -- which is still being atypical.
And the constancy is important. After all if you turn the stove on for 15 minutes, then turn the stove off for fifteen minutes, then turn the stove on for fifteen minutes, then turn it off for fifteen minutes and continue on that way, you won't get very far at cooking your meat as the brisket will barely have time to absorb more enegy than it expresses. Keep that oven on for 45 minutes though, with the meat continuing to absorb more and more heat and what happens? Your brisket gets cooked. As for Earth -- and the rest of the solar system -- because of the extended Solar Grand Maximum, the Earth has been in the "oven" and constantly asborbing a hightened level of radiation for an extended period of time (since approximately 1900). That doesn't mean it met its equilirial temperature for that heightened state of solar activity.
Tom Dayton, I also find it interesting and somewhat amusing the differing standards that are applied. For instance, the reason given for solar activity not causing global warming is that solar activity has retreated ever so slightly (while still being at an atypically much higher rate over an extended period of time). Meanwhile the Earth's temperature virtually flat-lining over a period of time in which CO2 has been released into the atmosphere at the highest rate ever is in fact accepted.
[DB] This thread is about other planets' warming, or not. If you wish to discuss whether global warming has continued over the recent decade+ period, go to this thread where they explain why you are very, very wrong:
Global warming since 1997 more than twice as fast as previously estimated, new study shows
Further, you should also review this post:
Global warming is being caused by humans, not the sun, and is highly sensitive to CO2, new research shows