The Clathrate Gun Hypothesis posits that the release of methane from clathrates due to global warming could lead to a catastrophic acceleration of climate change.
Abstract
The Clathrate Gun Hypothesis suggests that the release of methane, a potent greenhouse gas, from clathrates on the ocean floor due to rising temperatures could trigger a rapid and irreversible increase in global temperatures. This hypothesis is supported by evidence of past climatic events, such as the Eocene hothouse period and the End-Permian Extinction, where significant methane releases likely played a role in drastic environmental changes. Although the exact scale of methane clathrate deposits remains uncertain, current research indicates that methane is gradually being released from permafrost regions, with the potential for more abrupt releases triggered by events like arctic cyclones. The hypothesis underscores the importance of understanding the stability of these deposits and the potential for a feedback loop that could exacerbate global warming, with implications for ocean acidification and atmospheric alteration.
Opinions
The author conveys a sense of urgency regarding the Clathrate Gun Hypothesis, emphasizing that the process, once started, may be unstoppable and could have severe impacts within a human lifetime.
There is a concern that even a modest temperature increase, as seen in past extinction events, could lead to significant environmental consequences, including the disruption of marine life and the loss of biodiversity.
The author suggests that while a runaway methane release might be unlikely according to some scientists, the potential for such an event warrants attention due to its severe implications for the global climate.
The article implies that the gradual release of methane, as observed in current research, should not lead to complacency, as the cumulative effect could still be significant, especially if destabilization accelerates.
The author posits that understanding the past, such as the Snowball Earth scenario, provides valuable insights into the potential future impacts of methane clathrate destabilization on Earth's climate.
There is an underlying message that the Clathrate Gun Hypothesis, despite being a hypothesis, is a critical concept to consider in the context of climate change and the evolution of Earth's environment.
Science, Theories
The Clathrate Gun Hypothesis or Why Methane “Burping” is Cause for Concern
The video below shows a lead researcher breaking down while reading out the results of her study which concludes that the Clathrate Gun has been already been fired.
So what is the hypothesis specifically?
The Clathrate Gun Hypothesis suggests that the release of methane from the earth due to warming could cause a massive increase in temperatures within a lifetime (‘gun’ because the process can’t be stopped, the process is irreversible).
Now let’s break it down.
Methane.
There are a couple of things to know about methane. It’s a colorless greenhouse gas 24 times more potent than carbon dioxide. That being said, methane can be a problem in the atmosphere, even in small quantities.
Alright, next: Clathrates.
For our situation, methane in ‘ice’ = clathrate. Now, clathrates are stable in cold temperatures or under high pressure. One cubic meter of clathrate could release 164 cubic meters of methane. It’s quite a bit. To put that in perspective, that’s 43,324.2 gallons.
Simple enough.
So Methane Clathrate is simply ice holding a lot of methane within its crystal structure.
Next. Where is this thing found?
Methane clathrate is found in seabed permafrost. Essentially, it’s mainly found on the ocean floor, however, there isn’t a consensus on just how large these deposits are.
We’ll jump back in history to grasp the scale of this theory. Apparently, some scientists theorize that the violent degassing may have affected the planet significantly. They suggest it could have resulted in the Eocene hothouse period. Eventually, the period of great warmth gave way for the cooling climate.
The large extinction occurred near the end of the Permian period about 250 million years ago. The damage to marine life was great; more than 94 percent of all species then abruptly disappeared as oxygen levels sank. It took at least 20 million years, and in special cases over 100 million years for environment diversity to recover. All of this happened simply from a temperature increase less than 6.5 degrees Celsius.
So how would methane clathrate figure into all of this?
The release of methane from the methane clathrate could increase global temperatures. An increase in global temperatures would release even more of the compound increasing temperatures further. An abrupt release could drastically impact the environment. Even if a runaway effect is unlikely, as postulated by few, it could still ocean acidification and alter the atmosphere. During a period of the Glacial Minimum, the temperatures went up 6 degrees Celsius.
Side note: The release of methane from the compound can be referred to as methane degassing or “burping.”
So, the trapped methane from the seabeds may have caused the End-Permian Extinction. Alright, that covers all the basics. We’ll delve further into the issue.
By using a process called ebullition, researchers could find the density of bubbles from the permafrost and found 100–630 mg of methane per square meter is released daily from the East Siberian Shelf into the water column. It basically suggests that methane release is gradual, not abrupt. However, events such as arctic cyclones could increase the rate of methane being released.
Another thing to consider is that clathrates can also exist not just in seabed permafrost. They can be found in water if the temperature is lower. Also, the methane could be contained by a ‘lid’ of permafrost.
Picture: Chris Butler/Science Source
In light of this info, let’s investigate Snowball Earth. About 630 million years ago, it’s believed the earth’s surface was almost entirely frozen. The frozen ice sheets of the planet would’ve had quite a bit of methane trapped within. However, because these sheets were unstable, they would collapse after growing big enough, releasing methane into the atmosphere. Temperatures increased, melting more sheets, releasing more methane, increasing temperatures further bringing the Snowball Earth to its end. It is thought that the last ice age was not brought to its end by methane-related warming.
Many of the methane clathrate deposits are in sediments that are too deep to be released suddenly. Furthermore, in the overall scheme of warming, the effect of methane would not be drastic. This is due to the fact that they destabilize from the deepest part of their stability zone, which is usually 100 meters below the seabed. It will surface eventually, but not as rapidly as previously thought.
Around 2008, there was research in the Siberian Arctic which claimed millions of tons of methane were escaping through breaches in the seabed permafrost. In certain areas, the concentrations of methane hit 100 times normal levels.
There’s a release of .5 metric tons of methane per year. Also, 50 gigatons of it are risked to be released at any moment. What if that happened? The amount of methane on the planet would increase by a factor of 12.
Miscellaneous:
There’s also a trapped gas deposit off Canada in the Beaufort sea. Considered to be the shallowest known deposit of methane, it lies 290 meters below sea level.
Along the eastern continental slope of the United States, destabilizing methane hydrate can be found, about 2.5 gigatons worth. It’s still unclear whether it would reach the atmosphere.
Although there isn’t exactly a consensus on the Clathrate Gun, after all, it is a hypothesis, it’s nonetheless good to be informed about the current state of our planet and how it’s evolved in the past and may change in the future.