Scientists recognize that Earth does have a “thermostat” of sorts:
Atmospheric carbon dioxide performs a role similar to that of the house thermostat in setting the equilibrium temperature of the Earth. It differs from the house thermostat, [however], in that carbon dioxide itself is a potent greenhouse gas (GHG) warming the ground [-level atmospheric] surface by means of the greenhouse effect. It is this sustained warming that enables water vapor and clouds to maintain their atmospheric distributions as the so-called feedback effects that amplify the initial warming provided by the non-condensing GHGs, and in the process, account for the bulk of the total terrestrial greenhouse effect. Since the radiative effects associated with the buildup of water vapor to near-saturation levels and the subsequent condensation into clouds are far stronger than the equilibrium level of radiative forcing by the non-condensing GHGs, this results in large local fluctuations in temperature about the global equilibrium value. Together with the similar non-linear responses involving the ocean heat capacity, the net effect is the “natural variability” that the climate system exhibits regionally, and on inter-annual and decadal time scales, whether the global equilibrium temperature of the Earth is being kept fixed, or is being forced to re-adjust in response to changes in the level of atmospheric GHGs.
Will, however, that “thermostat” save our species from extinction? Dr. Larry Vardiman, writing for the Institute for Creation Research would answer this question in the affirmative:
God has designed the atmosphere to maintain a uniform temperature, whether there is a cooling or a warming tendency. Only under catastrophic conditions will the atmosphere experience major changes. This type of catastrophic event occurred during the Genesis Flood, but this event involved unique conditions not applicable now. Under normal circumstances, God has designed the atmosphere with a built-in thermostat which maintains thermal equilibrium. This climate condition does not lead to a runaway greenhouse or a new ice age. The view of a climate with a built-in thermostat contrasts strongly with the conventional worldview that the atmosphere is unstable and a minor perturbation could lead to a natural catastrophe of either fire or ice.
Even if one does believe that (a) there is a “God” (however conceived) out there some place, and (b) the “Genesis Flood” actually occurred, one should ask oneself: Are we living now in a situation of “normal circumstances”? Vardiman’s statement suggests that he, at least, believes that we are. But are we actually?
I believe that the answer to this question can be easily inferred from the following NASA graph:
This graph shows, first, that it is “normal” for the CO2 level to fluctuate over time. During the past 400,000 years, in fact, that level has varied from a low of about 180 ppm to a high of just under 300 ppm—until recently: On May 9, 2013, it reached the 400 ppm level, and on March 9, 2015 reached 401.84 ppm!
If our time frame is limited to the past 400,000 years—or even 650,000 years (per the statement on the graph itself)—one must, second, admit that “normal” is now a thing of the past, and Dr. Vardiman has no basis for denying this fact.
The “jump” in CO2 level depicted on the above graph began, most scientists would argue, with the Industrial Revolution. And the significance of the increase that has been occurring is that it is correlated with temperature increase—with the former being the cause of the latter for the past 250 years. The pre-industrial level of CO2 has generally been thought of as around 280 ppm (one scientist, however, believes that it was closer to only 260 – 270 ppm), so that during the past 250 years the ppm level has increased between 120 and 140 ppm. Given the correlation between CO2 level and temperature, it should not, then, be surprising to learn that between 1880 and 2012—while the CO2 ppm level was increasing—earth’s atmospheric (surface) temperature increased by 0.85° C.
The variation in CO2 level in “normal” times was caused by a variety of factors, human activity not being one of them (in part because anatomically modern humans did not appear on the scene until 200,000 years ago). Human activities since the beginning of the Industrial Revolution, however, have resulted in a notable “pumping” of carbon dioxide into the atmosphere—the two major such activities being (a) the burning of fossil fuels and (b) deforestation. And the “pumping” that has occurred so far has increased the global mean by almost a degree C. This may not seem significant, but when one realizes that earth’s mean surface atmospheric temperature is 16°C, an increase of 1° C becomes more significant.
Given that there are no signs that our “pouring” of CO2 into the atmosphere will either cease or even level off soon, and that the warming that is (therefore) occurring is (in the Arctic especially) accelerating the release of methane gas into the atmosphere (which gas is 30 times more potent as a “greenhouse gas” than is CO2), there is the prospect that a “tipping point” will be reached soon.
This raises at least three questions: Will the various effects of the warming that is now occurring:
(1) Be such that at some point in the near future warming itself will accelerate?
(2) With that acceleration creating climate chaos—i.e., (a) more storms, (b) more severe storms, and (c) more weather variability—which, combined with an increasing mean temperature, will reduce food availability drastically?
(3) With that reduction (combined with increased disease and violence) resulting in mass starvation—to the point that our species becomes extinct?
There is:
the tantalizing possibility that a natural regulatory mechanism could set a ceiling on the global warming that scientists say will result from emissions of heat-trapping gases like carbon dioxide. At present rates of emission, they calculate, atmospheric concentrations of these greenhouse gases will double by the middle of the 21st century, eventually raising the average surface temperature of the earth by 2 to 9 degrees Fahrenheit. They say that a warming in the upper end of that range would have catastrophic results for the world’s climate.
It is not yet known whether the effects of the predicted warming would be mitigated by the thermostatic effect that scientists say they have now demonstrated. But the new findings may rule out the direst scenarios about the greenhouse effect, in which global warming would escalate until it ultimately makes the earth inhospitable to life. Scientists and environmentalists who fear this possibility point out that this is precisely what happened on Venus.
In fact, regarding the possibility of earth’s self-regulation, Dr. Veeradhabran Ramanathan (a climatologist at the Scripps Institution of Oceanography in La Jolla, California) has made this provocative comment:
“I cannot see how the planet can have a runaway greenhouse effect.” (given the findings reported in the article in question).
Is Dr. Ramanathan right about this? I am not a climate scientist, but the first point that I would make here is that the term “climate change” is an unfortunate term for what is occurring now, climate disintegration being a more accurate term.
The very concept of “climate” is based on the assumptions that (a) the pattern of weather phenomena at a given location during a year will repeated year after year rather closely, with (b) different locations exhibiting different such patterns. This assumption has realism, of course: The discipline of Climatology could not exist if it did not!
Because there are an infinite number of locations, there are an infinite number of climates, but climatologists—being reasonable people!—have identified groups of climates; i.e., they have created climate classifications. These classifications have been meaningful until recently, but are losing their value because of the second of the three points I made above (the subpoints in that point constituting climate disintegration).
The climate disintegration that has begun to occur is likely not only to (a) continue to occur, but to (b) accelerate. The atmospheric processes that we humans have set in motion are likely to continue into an indefinite future—with no prospect that I, at least, can see that earth’s ability to regulate itself will “kick in” in time to save us from eventual extinction. In fact, John B. Davies has stated (in 2013):
The world is probably at the start of a runaway Greenhouse Event which will end most human life on Earth before 2040.
Note that Davies said “most” not “all,” but if “most” humans are gone by 2040, one wonders how the rest will survive—given the interdependence that exists in the modern world! Also note that although Dr. Ramanathan is unable to believe that runaway can occur, Davies asserts that it now is occurring!
What’s difficult for me, at least, to believe is that our species will not be extinct within a few decades, if not years. I find this plausible not only because of the research findings by climate scientists that have been accumulating over the past few years, but because of the geological record:
- “It is estimated that over 99.9% of all species that ever lived are extinct.”
- It’s known that there have been five mass extinctions in the geological past.
- Extinctions are now occurring at a rapid rate; “current extinction rates are up to a thousand times higher than they would be if people weren’t in the picture.” In fact, we humans are now living in The Sixth Extinction (2014) period!
What makes us think that we humans will not be a part of the current mass extinction now occurring?!
As one with three children and five grandchildren, this is not something that I want to believe, by any means! But it seems to me that (a) “runaway”—with all that that implies (warming, per se, and the second of the three points that I made above)—is now underway, (b) that it will accelerate, (c) has already passed a point that reversing, or even halting, it is not now possible, so that (d) it’s just a matter of time before our species joins the dinosaurs (but for a different set of reasons, of course).
How, then, should one respond to this (very strong) possibility? Each person must make his or her own decisions regarding this. Of course, few in this country—in this world—are even aware of the “pickle” that we humans are in!