Global Warming & Ocean Gas: An Interview with Rice University Professor Gerald Dickens
Welcome to Planet Earth: Our Loving Home.
In light of growing concerns about climate change and its effects on
the planet, Supreme Master Television visited with Dr. Gerald Dickens,
associate professor of Earth Science at the prestigious Rice University,
located in Houston, Texas, USA.
The private institution has earned respect as
a pioneer in the fields of nanotechnology, structural chemical
analysis, and space science.
As one of the most widely known and
highly regarded universities in the United States, it is often highly
ranked in numerous reports. Professor Dickens is a leading researcher
into the past history of the world’s oceans, with respect to the
changing patterns of their geology, chemistry and biology.
Currently,
he serves as the Paleoceanography Editor-in-Chief of the “American
Geophysical Union,” the most cited journal in the Earth Sciences field
throughout the world. Today, Professor Dickens shares his wealth of
knowledge and provides a neutral base for us to discern the relations
between global warming and marine geology,and how they affect the future
of our planet.
SupremeMasterTV: We are meeting with Professor
Gerald Dickens who is professor of Earth Science at Rice University here
in Houston, Texas, USA. It’s a pleasure to have you on the program
Professor Dickens and our topic of discussion is ocean gas and the
potential effect of global warming on this ocean gas.
Can you tell me firstly, what ocean gas are we talking about.
Professor Dickens: Most of it’s methane, and there will be methane that is stored in the sediments at the bottom of the ocean.
SupremeMasterTV: I understand that it’s stored in a crystal form. Can you explain that.
Professor Dickens: Yes. Methane can be both
dissolved in water, it can be as gas bubbles or it can be in an unusual
structure, what we call methane hydrate. That’s when we take methane
molecules and water molecules and then combine together to form a cage,
with the methane on the inside.It looks very much like ice.
SupremeMasterTV: And I understand that it’s called “fire in ice.” Can you explain that.
Professor Dickens: Well, because it looks very
much like ice, but as it melts it releases methane, which is the same
gas that’s used in natural gas for stoves and things like that.So you
can imagine if you put a match to it, it looks like a piece of ice with a
flame on top.
SupremeMasterTV: Now the next thing is, are we talking about any other gases particularly in the ocean, or is it mainly methane.
Professor Dickens: Well, there is certainly carbon
dioxide that’s dissolved in the ocean and that’s a major role, but we
don’t usually think of it as in the gas phase there. And so really, the
main gas that we’re thinking, in terms of the large amounts of gas in
the marine system, is methane.
SupremeMasterTV: Can you tell me how is that methane produced in the oceans. How is it actually produced.
Professor Dickens: Most of it occurs when organic
carbon lands on the sea floor. That means things, organisms, when they
die, as they fall through the water and land to the bottom of the ocean.
As they get buried, various microbes start consuming the organic
carbon. And one set of microbes is the Archaea, and a sub-set of the
Archaea are the ones that produce methane. So they take various
constituents from the original organic carbon and convert it to methane.
SupremeMasterTV: Very interesting, and I understand there’s a whole eco-system in these organisms down there on the ocean floor in the sediment.
Professor Dickens: Yes.
SupremeMasterTV: How does the methane stay in the ocean. What is keeping the methane there.
Professor Dickens: This one’s a little bit
complicated to explain. Essentially, it’s always there, but it’s always
been added to and it’s leaving. So in other words, as the methane’s
being produced, it’s also being consumed. So we end up with a steady
state system.
Perhaps the best analogy would be a forest. So, with
photosynthesis, we make new organic carbon in trees and as the trees
die, they release organic carbon.
The same thing happens in
marine sediments. So, as the organic carbon enters the sediment, the
Archaea turn it into methane. That methane is now in the sediment but,
at the same time, it’s slowly leaking out. And as it leaks out, it gets
either consumed by oxygen or another species that’s dissolved in water
which we call sulfate. So those are our sort of outputs.
SupremeMasterTV: And can you talk about temperature and water pressure in relationship to methane and hydrates of methane.
Professor Dickens: Sure. In this cycle that we’ve
just talked about, as we make methane, if a lot of methane is made and
we’re at relatively high pressure caused by the water, and at relatively
cold temperatures, such as the bottom of the ocean, then, as we start
making the methane, it will precipitate out in this solid clathrate
phase that we talked about earlier, where the water and the methane
combine to form this cage-like ice structure.
And that will precipitate and clog up the pores in the sediment. So
you can imagine a little bit of methane going in, a little bit of
methane coming out. But most of the methane in many parts of the world,
is stored in the solid phase in the sediment.
SupremeMasterTV: And whereabouts is it distributed. Whereabouts in the ocean floor do we find this methane.
Professor Dickens: Well, in general we sort of
need a couple of places. First we need, to get these very large methane
deposits where the methane is in the solid phase, we need both cold
temperatures and relatively high pressures. We’re talking generally 500
meters or so water depth.
Professor Dickens: For example, if we go out in
the middle of the ocean, we have very cold temperatures at the sea
floor. The waters are very deep. But there is very little organic carbon
reaching the ocean there.
So we don’t see very much methane. In fact, in the middle of parts
of the ocean, there is really no methane. However, as we get closer to
the continents, we have both organic carbon coming off rivers, as well
as we have fairly productive regions.
So you can imagine where this puts it, is on a sort of slope of
continental margins, where we have both the input and supply of organic
carbon, plus the pressure, plus the temperature.
SupremeMasterTV:The organic carbon is things like what, decomposing organisms or plants or….
Professor Dickens: The simplest way for the
average person to think of it is, a fish dies and it falls to the
bottom. But in terms of overall mass, most of it is phytoplankton. So
single celled organisms, algae, diatoms, various phytoplankton that live
and die and fall down to the bottom of the ocean.
SupremeMasterTV: Is the methane fairly evenly
distributed around the world on these continental slopes, or is there
more concentration in various areas of the world.
Professor Dickens: It’s clearly distributed in
some places more than others. It’s in particular in areas where we’ve
had a lot of organic carbon land on the sea floor for quite some time.
None of these systems are new. So they take a long time to accumulate
very large amounts of methane, we are talking millions of years. So you
need a supply of organic carbon for a long time.
There are certain areas where we’ve had this supply, and those are
the areas we really find a lot of methane. It’s a little more
complicated than that. Part of it is, there are areas around the world
that we haven’t really looked, so we don’t know the full distribution.
But I think it’s fair to say that it is unevenly distributed. But, in
general, we have found it around all continents.
SupremeMasterTV: What are the beneficial effects of methane.
Professor Dickens: Well, I guess it depends who’s
benefiting. I mean, certainly, for humans, we like to use methane as
natural gas. It’s now a large fraction of the energy, in many countries,
is derived off natural gas. And certainly, as we talked about before,
you can light methane hydrates or the methane that comes off these
materials.So it can be used as an energy source. Certainly, it’s part of
the large eco-system that we have just scratched the surface. We don’t
really understand this. But this very large, what we call the deep
biosphere, this methane’s crucial to that eco-system.
SupremeMasterTV: Coming back now, so the fact that
the methane stays sequestered in the ocean as long as the temperatures
are cold enough and the depth of the ocean, and there’s enough pressure.
So what about warming. How does global warming have the potential
effect on this methane sequestered in the oceans.
Professor Dickens: We always have a little bit of
methane being formed and a little bit of methane leaving in this large
body of methane that's sitting there. However, that large body is
sensitive to pressure and temperature and so, what we know, at least in
the laboratory, is if we take the solid phase and we either increase the
temperature or decrease the pressure, that solid phase goes from the
ice-like crystal structure into its constituents, so into water plus
gas.
And so what we think happens, and it certainly potentially can
happen, is as you warm up marine sediment or decrease the pressure, the
solid phase can convert to gas and then you have an over-pressured
system, and we think that a lot of gas can come out very fast.
SupremeMasterTV: Coming back now, so the fact that
the methane stays sequestered in the ocean as long as the temperatures
are cold enough and the depth of the ocean, and there’s enough pressure.
So what about warming. How does global warming have the potential
effect on this methane sequestered in the oceans.
Professor Dickens:
We always have a little bit of methane being formed and a little bit of
methane leaving in this large body of methane that's sitting there.
However, that large body is sensitive to pressure and temperature and
so, what we know, at least in the laboratory, is if we take the solid
phase and we either increase the temperature
or decrease the
pressure, that solid phase goes from the ice-like crystal structure into
its constituents, so into water plus gas.And so what we think happens,
and it certainly potentially can happen, is as you warm up marine
sediment or decrease the pressure, the solid phase can convert to gas
and then you have an over-pressured system, and we think that a lot of
gas can come out very fast.
SupremeMasterTV: So what would that do to the
world. To the plant life, the human life the planet itself, if a lot of
methane gas was released as a result of global warming heating up the
oceans. What are the potentials.
Prof. Dickens: Well, the first thing to think
about is, where does the methane go. So, if the methane comes out of the
sediment there's really sort of two possibilities.
One is it
would go into the ocean and be oxidized in the ocean, in which case the
methane would be converted to carbon dioxide in the ocean. And probably
the most significant effect right off the bat, is acidification. So you
drop the pH.
SupremeMasterTV: Yeah, the oceans would become acidic, wouldn’t they.
Prof. Dickens: The second possibility is, of
course, you could bubble methane up to the atmosphere. Or, it turns out
an interesting phenomenon that we have discovered is that sometimes
pieces of hydrate will float, and so they can float up very shallow and
then dissociate near the ocean surface.
So, there's ways to get methane into the atmosphere.
Now,
there, it turns out, what's interesting with methane, is it's a very
potent greenhouse gas, much more potent than CO2. So the net effect of
that is to essentially contribute to warming.
SupremeMasterTV: So we're talking about volumes
here. How much volume of methane. I've read estimates of anything up to
10 trillion tons of methane in the ocean.
Prof. Dickens: Let's just think about this. I usually think in gigatons and so a gigaton is 1 trillion tons.
SupremeMasterTV: 1 trillion tons.
Prof. Dickens: And so we usually think somewhere
on the order of 2,000 to 20,000 gigatons are the sort of estimates for
how much methane is stored in the crystal phase, of which again there
will be also gas bubbles and dissolved. And so the total system,
we're talking on the order of somewhere on that range of 2,000 to 20,000 gigatons of methane.
SupremeMasterTV: And if that was released into the atmosphere.
Prof. Dickens: Well, I don't think it would be
ever possible to release it all, but even if a fraction of
thathttp://suprememastertv.tvhttp://suprememastertv.tv We can think
about, for example, what humans are doing today. So probably, you know,
if we burned all the fossil fuels that are available today, somewhere on
the order of 4,000 gigatons of carbon that will be added to the
atmosphere.
So you can imagine that if 10,000 gigatons of methane - an average
number for estimates that people have made…If one-tenth of that goes,
you know, we are on the order of magnitude of what we are doing today,
in terms of adding carbon dioxide.
SupremeMasterTV: So is methane toxic to humans.
Prof. Dickens: Certainly, if the entire atmosphere around you is methane, it is toxic.
SupremeMasterTV: There's no oxygen to breathe.
Prof. Dickens: But small amounts of methane are
not going to be toxic, but certainly it's flammable so it's not a good
idea to have lots of methane.
SupremeMasterTV: Has this ever happened in the past, where a lot of methane gas has been released into the atmosphere on Earth.
Prof. Dickens: We think so. We are very confident
that there are times in the past where large amounts of carbon dioxide
go into the ocean and / or atmosphere very quickly. We think that the
source of that carbon dioxide is oxidized methane. So that methane has
come into the system and either by mixing with oxygen in the ocean or
through various reactions in the atmosphere, it converted to CO2.
SupremeMasterTV: And when did this happen.
Prof. Dickens: Probably the best studied of these
times is about 55 million years ago, right after the Paleocene-Eocene
boundary. And it's an interesting time, in that we see all sorts of
environmental consequences. So something clearly happened.
In fact, that's why we have a boundary there, because the organisms
on life changed quite dramatically across this time period. And we see
things such as over 6, 7 degree warming around the world, including the
high latitudes. We see changes in the hydrologic cycle, so some places
become very dry, some places become very wet. We see ocean
acidification. We see changes in oxygen content in the ocean. So many,
many different environmental changes occurred during this time.
SupremeMasterTV: Has this ever happened in the past, where a lot of methane gas has
been released into the atmosphere on Earth.
Prof. Dickens: We think so. We are very confident
that there are times in the past where large amounts of carbon dioxide
go into the ocean and / or atmosphere very quickly. We think that the
source of that carbon dioxide is oxidized methane.
So that methane has come into the system and either by mixing with
oxygen in the ocean or through various reactions in the atmosphere, it
converted to CO2.
SupremeMasterTV: And when did this happen.
Prof. Dickens: Probably the best studied of these
times is about 55 million years ago, right after the Paleocene-Eocene
boundary. And it's an interesting time, in that we see all sorts of
environmental consequences. So something clearly happened. In fact,
that's why we have a boundary there, because the organisms on life
changed quite dramatically across this time period.
And we see
things such as over 6, 7 degree warming around the world, including the
high latitudes. We see changes in the hydrologic cycle, so some places
become very dry, some places become very wet. We see ocean
acidification. We see changes in oxygen content in the ocean. So many,
many different environmental changes occurred during this time.
SupremeMasterTV: What happened to the animal life then. What happened to the plant life. Is there evidence what happened to them.
Prof. Dickens: Well, it’s interesting. So if you
look at organisms in the bottom of the ocean, many of them seem to go
extinct. So life was not too good at the bottom of the ocean. On land,
it's a much different sort of response and, you know, looks like
organisms migrate. And so we see just the distribution of organisms
change very, very fast.
Prof. Dickens: If we go into the north pole and
drill a hole there and collect the sediment that was deposited there 55
million years ago, it looks like temperatures somewhere in the 70
degrees, although we're not totally sure whether those are summer
temperatures or annual temperatures. Nonetheless it's still quite warm.
SupremeMasterTV: Very interesting. And we are thinking that methane was probably the reason at that time, is that right.
Prof. Dickens: Somehow… we think that methane is
some component of this. And what we're not sure is whether it's
essentially the trigger or a feedback.
SupremeMasterTV: We were talking also about what can we do to help with global warming.
Prof. Dickens: As far as methane, in terms of
global warming, probably, certainly over the next 100 or 200 years these
methane reservoirs in the deep ocean are probably not responsive at
that sort of time scale. On the other hand, if we go to up to permafrost
regions, yes, we can get methane coming out from the permafrost, which
may act as a feedback.
So as we start melting permafrost we release extra methane As far
global warming, that is just a huge problem. I can give you my own
personal opinions. I think it’s going to take a radical view of a change
in lifestyle, as well as new technologies. And it’s really going to
take a combination of both.
There are all sorts of these
feedbacks, and many of them we don’t really fully understand. So, for
example, there’s a paper, just a couple weeks ago, summarizing recent
evidence that as you start warming things up, the biosphere, the plants
start releasing more carbon than they take in.
So when you start doing things, they start taking in carbon, but
then they start kicking it back out. So it’s like, gosh! That’s a
feedback that’s really problematic. That’s not in our models. And there
are many of these things that we just really don’t understand right now.
SupremeMasterTV: I remember, in reading the
papers, you were saying that the carbon in the methane is actually like a
huge capacitor that people haven’t really worked into their thinking,
and to do with the carbon cycle.
Prof. Dickens: The carbon cycle. If you think of
three boxes, it’s the easiest way to think of the carbon cycle. You have
an atmosphere, a biosphere and the ocean.
Prof. Dickens: Biosphere, trees, plants; so the terrestrial biosphere. And all of these
are
connected. So you think of three boxes, much like, I like to think of
it as a swimming pool and 2 hot tubs. And so between each one of these
boxes there are inputs and outputs. In the analogy between the swimming
pool and the hot tub, it’s essentially the ocean is the big box. And
it’s a common misconception for the average person, they think that all
the carbon is in trees.
But it turns out that most of the
carbon, about 93% of it, is in the ocean, not in trees or in the
atmosphere. So what’s happening right now is we’re adding a lot of
carbon to the atmosphere. It’s coming in much faster than it can go into
the biosphere or into the ocean. So that’s why the CO2 is going up
very, very quickly.But it turns out, that if you suddenly realize there
is a lot of methane on the planet, somewhere there is now a 4th box.
So you can’t have an ocean that’s nominally 35,000 gigatons and
then suddenly talk about methane being 10 or 20,000 gigatons. There’s
another box in the system. So the simplest way to think about it is a
capacitor. You have organic carbon. The normal way people think of the
carbon cycle is, you have a little bit of carbon coming into the system,
through volcanoes or through weathering, and a little bit of carbon
coming out of the system. So you have this large box, a little bit of
input and a little bit of output and the carbon cycle in between all
this. And then, essentially by adding methane, what you have to say is,
some portion of the organic carbon leaving the system then gets
converted to methane, so you add a new box. Then a little bit leaks out
and it goes back into the ocean.
The idea for the capacitor is that output can change dramatically
in the time frame. Sometimes we can have a lot of methane come out very
quickly.
SupremeMasterTV: With the temperature change.
Prof. Dickens: With the temperature change.
SupremeMasterTV: And the pressure change.
Prof. Dickens: Yeah.
SupremeMasterTV: Is there any other comments, anything else that you think the general public should know.
Prof. Dickens: The fantastic thing is, I think I
mentioned to you earlier today, is that 15 years ago, I don’t think
anyone would have even asked me. I just sort of did my own thing and
studied methane and climate change. Now people are actually interested.
SupremeMasterTV: That’s a very important topic,
very important. Well it’s been an absolute pleasure having you on the
program, Professor Dickens. Thank you so very much for granting us this
interview.
Prof. Dickens: Well thank you for having me.
We sincerely thank Dr. Dickens for sharing
this discussion on the current studies of links between ocean gas and
global warming. We sincerely wish you all the best in your endeavors to
further our understanding in this very important area of research.