By Bryan Carter
Over 700 million gallons of oil end up in the ocean each year! While immediate physical impacts of oil on ecosystems are obvious, chemical components of oil spills receive less publicity than they deserve (3). About a quarter of the oil that is spilled vaporizes into the atmosphere in the form of volatile organic carbons (3).
Volatile organic carbons (VOCs) are a wide variety of chemical compounds that vaporize into gas easily due to low boiling points. VOCs are naturally released by plants, deposited into soils, and eventually carried by rivers into the oceans. This is part of the global carbon cycle, a circuit of inputs and outputs of carbon into different regions of the biosphere.
Human-caused sources of VOCs can disrupt the carbon cycle. They are responsible for human health concerns as well as negative biological influences (3). A major source of these VOCs is from oil spills (3). Oil is composed primarily of carbon that has been stored deep in rocks out of the carbon cycle for millions of years. Re-introducing oil into the environment alters the carbon cycle, which is crucial to understanding climate change.
Once in the atmosphere, VOCs can disrupt traditional chemical reactions, directly affecting ozone concentrations (2) (5). This can lead to increased amounts of dangerous UV rays reaching the earth’s surface, making VOCs directly responsible for changes in global climate.
Oceans hold the key to our planet’s natural defense against human inputs of VOCs. Carbon naturally fluxes between the ocean and atmosphere. This transference represents an attempt to balance the concentrations between each medium, or achieve equilibrium (1). Human inputs of VOCs result in an over abundance in the atmosphere, compared to the ocean. This leaves the potential for VOCs to flux into the ocean.
Studies have shown that the infamous chlorofluorocarbons, a non-natural VOC used as a refrigerant up until the 1970s is now currently fluxing into the ocean (2). Chlorofluorocarbons destroy ozone in the atmosphere but are harmless in the ocean (2). Acetone, a commonly used household-cleaning agent has been found to be fluxing into the ocean as well (4) (5).
VOCs released from oil spills will eventually flux into the ocean. Bryan Carter, a graduate student at the University of North Carolina Wilmington was recently interviewed on the subject of oil spill impacts on climate change.
“VOCs will naturally flux into the ocean. The key is will this process be able to keep up with the amount of oil we release into the environment? The ocean will do its part to contest climate change, but it’s important that humans do ours as well,” said Carter.
Oil spills dramatically and quickly damage ocean environments. However, the ability of the ocean to remove VOCs from the atmosphere where they directly promote climate change, to the ocean where they are harmless is critical to the long-term health of the environment.
(1) Cen-Lin, HE, May-Tzung, FU. Air-Sea Exchange of Volatile Organic Compounds: A New Model with
Microlayer Effects, Atmospheric and Ocean Science Letters. 6: 97-102 (2013).
(2) Fine, Rana A. Observations of CFCs and SF6 as Ocean Tracers, The Annual Review of Marine
Science. 3: 173-195 (2011).
(3) Hanna, Steven R., Drivas, Peter J. Modeling VOC Emissions and Air Concentrations from the Exxon
Valdez Oil Spill, Air & Waste. 43:6 298-309 (1993, 2012).
(4) Marandino, C.A., De Bruyn, W.J., Miller, S.D., Prather, M.J., Saltzman, E.S. Oceanic Uptake and the
Global Atmospheric Acetone Budget, Geophysical Research Letters. 32: 5806 (2005).
(5) Sinha, V., Williams, J., Meyerhöfer, M., Riebesell, U., Paulino, A.I., Larsen, A. Air-sea Fluxes of methanol, acetone, acetaldehyde, isoprene, and DMS from a Norwegian fjord following a phytoplankton bloom in a mesocosm experiment, Atmospheric Chemistry and Physics. 7: 739-755 (2007).
By Claire Robinson
A recently discovered biological process involving global oceanic dimethyl sulfide (DMS) can reverse the anthropogenic warming of the Earth’s atmosphere.
Known as the CLAW hypothesis, DMS has been linked to production of cloud-condensation nuclei (CCN) in the atmosphere, which produce clouds and reflect the Sun’s radiation back into space.1 The CLAW acronym stands for the 4 authors’ last names who developed this hypothesis: Charlson, Lovelock, Andreae, and Warren. The underlying theme of the CLAW hypothesis is that organisms are able to biologically alleviate stressors in their living environment. This negative feedback process could potentially stabilize atmospheric temperatures.
The characteristic smell of the sea is very distinctive. That salty, beachy, unique scent is actually DMS. DMS is a biologically produced compound, produced from multiple species of microscopic plants that photosynthesize, called phytoplankton. DMS is formed by the decomposition of dimethylsulfoniopropionate (DMSP); in other words, when DMSP is broken down, DMS is produced.1,3 DMSP is broken down either by bacterial metabolism or in phytoplankton by enzymes called DMSP-lyases.3
The application of this process can be monumental. If we can understand and harness this particular feedback process to our advantage, we might be able to say in the future: “DMS saved the world.”
Recent papers have found that there are multiple pathways for DMS in the environment. In reality, most DMS produced is redeposited back into the ocean, leaving only 3% to exit into the atmosphere.3 Other pathways for DMS include photooxidation and microbial consumption.3 However, this isn’t stopping some researchers who are using alternative theories and methods to use DMS to our advantage.
An example is the Southern Ocean Iron Enrichment Experiment (SOFeX) that occurred in 2002. Biogeochemist Oliver Wingenter and others fertilized portions of the Southern Ocean with iron sulfate (FeSO4) and observed changes in concentrations of trace gases, including DMS. DMS was observed at five times normal concentrations during the experiment.4 Other scientists disagree with the idea of iron fertilization, or nutrient fertilization altogether.5,6
Climate change is one of the hottest topics in the media right now. President Barack Obama recently released his final version of the Clean Power Plan, which will hopefully begin to address the threat of climate change on our planet. “There is such a thing as being too late when it comes to climate change,” says Obama.7 The reality is that climate change is real, it’s happening now, and we need to educate ourselves about it. A good place to start is our ocean.
Seventy percent of the Earth’s surface is ocean, and the oceans have been regulating climate on a global scale through coupled interactions throughout history. DMS is a perfect example of an oceanic-atmospheric coupled interaction.
Dr. Rob Condon, an oceanographer from the University of North Carolina Wilmington, states: “Everyone has an opinion; thus the issue of climate change is debated and denied based on perception, not the evidence.” What most scientists can agree on is that climate change is happening in our generation, and the oceans are affecting climate tremendously. The data speaks for itself, and action on climate change requires trusting scientists and also trusting the media’s communication of that data.
Further studies must be done to understand in full detail the role of DMS in the oceans and also in the atmosphere. What has been discovered so far about DMS is astounding, and it has easily become one of the most influential compounds in the ocean.
1Charlson, R. J., J. E. Lovelock, M. O. Andreae, and S. G Warren. 1987. Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature 326: 655-661.
2Trenberth, K. E. The Role of the Oceans and Climate. Oco.noaa.gov. Accessed 15 September 2015.
3Gypens, N., A. V. Borges, G. Speeckaert, and C. Lancelot. 2014. The dimethylsulfide cycle in the eutrophied southern North Sea: A model study integrating phytoplankton and bacterial processes. PLoS ONE 9(1): e85862.
4Wingenter, O. W., K. B. Haase, P. Strutton, G. Friederich, S. Meinardi, D. R. Blake, and F. S. Rowland. 2004. Changing concentrations of CO, CH4, C5H8, CH3Br, CH3I, and dimethyl sulfide during the Southern Ocean iron enrichment experiments. PNAS 101(23): 8537-8541.
5Chisholm, S. W., P. G. Falkowski, and J. T. Cullen. 2001. Dis-crediting ocean fertilization. Science 294(5542): 309-310.
6Fuhrman, J. A. and D. G. Capone. 1991. Possible biogeochemical consequences of ocean fertilization. Association for the Sciences of Limnology and Oceanography 36(8): 1951-1959.
7The White House. “President Obama Announces the Clean Power Plan.” Online video clip. Youtube.com. 3 August 2015. Web. Accessed 16 September 2015.
By Meg McConville
“Every year in Australia skin cancers account for around 80% of all newly diagnosed cancers, [and] 95-99% of skin cancers are caused by exposure to the sun4.” Although ultraviolet (UV) radiation is a natural form of light, its high energy easily causes DNA damage.
In the oceans, DNA damage leads to increased mortality rate and decreased photosynthesis of phytoplankton3,5. “Phytoplankton are so numerous that they account for approximately fifty percent of all photosynthesis on earth and fifty percent of the oxygen in the air we breathe2.” These microscopic organisms also contribute greatly to ocean productivity as the basis of most food webs. It is therefore important to understand the effects elevated UV levels can have on phytoplankton populations. Yet, the topic of ultraviolet radiation is often overlooked and consequently under researched.
Most people know the oceans cover seventy percent of the earth’s surface but do not realize that the ocean helps moderate global climate. Megan McConville, a Masters student at UNCW who is currently learning about the effects of UV, explained, “The composition of the atmosphere is largely influenced by the oceans; different gases are continuously passed from ocean to atmosphere and vice versa.” In order to protect our oceans and understand global climate, scientists must study not only vital processes involving the atmosphere and the ocean, but also the sun.
Most of life on earth is dependent on solar radiation. “The different types of radiation are determined by their wavelengths, which effect their energy,” Megan explained. “UV has a smaller wavelength than visible light, or the light we see with our eyes,” she continued. “This means that the small decrease in wavelength causes a larger increase in energy, which makes UV radiation more harmful and is the reason why UV causes skin cancer.”
What does this mean for our oceans? Because oceans cover most of the earth’s surface, UV is more likely to come in contact with seawater than land. The surface waters where UV is most likely to penetrate are also where phytoplankton live. Therefore, increasing UV levels would make phytoplankton more susceptible to DNA damage, increased mortality, and decreased photosynthetic ability3,5.
Phytoplankton have some defensive strategies against elevated UV, such as DNA repair and photo-protective pigments. However, the overall efficiency of such mechanisms is uncertain. Megan added, “If phytoplankton populations die, higher trophic levels that rely on them for food will suffer. And if phytoplankton cannot convert carbon dioxide to oxygen through photosynthesis, carbon dioxide levels will increase.”
Despite the harmful effects of elevated UV levels, the Intergovernmental Panel on Climate Change admit to only a medium understanding of solar irradiance and its effects on global climate1. Megan concluded, “Excess ultraviolet radiation can cause immense damage to phytoplankton on a cellular level, but has the potential to impact global processes.” Therefore, an increased focus on ultraviolet light and its effects on climate change is essential for the future of our oceans and our planet.
By Nick Iraola
Volcanic eruptions are one of the most vivid and awestruck natural phenomena on Earth. Their powerful impact on climate change is clear, as their catastrophic volumes of ash and minerals descend chaos into our atmosphere and alter our climate cycles.
If climate impacts of terrestrial volcanoes are that clear, then why haven’t we been paying more attention to the climactic impacts of underwater volcanoes? Is it possible that we have been missing a significant player in climate change, and that underwater volcanoes could have been the straw that broke the Ice Ages’ back?
A recent paper published in March of 2015 by Dr. Maya Tolstoy of Columbia University took a look into what types of impacts Mid-Ocean Ridge volcanoes had on climate change and what we could have been missing. She claims that undersea volcanoes could be, “…acting as a climatic valve that causes the flow of greenhouse gases to fluctuate.”1 This fluctuation may even have been the catalyst that drove the abrupt end of the ice ages.
If underwater volcanoes are that influential, why has it taken science this long to notice? Tolstoy explains that little has been known about the Mid-Ocean ridge eruptions because, “…most occur far from land, at seismicity levels below the detection capabilities of global seismic networks.”
The current understanding is that underwater volcanoes erupt at a fairly constant rate, emitting small amounts of CO2 over a cycle of about 100,000 years. These emission amounts are significant, but not enough to raise any alarms about impacting climate due to their occurrence over a long time scale.
With newly available technology in seafloor hydroacoustics, Tolstoy argues that our current understanding is a misconception. She boasts that underwater volcanoes are moderately dormant over this 100,000-year time scale, and actually erupt in short, consecutive pulses during ideal conditions. This releases carbon dioxide in a condensed time span versus spacing it out over a 100,000-year cycle.
Her theory is supported by data that reveals a direct correlation among CO2 emissions, production of seafloor crust, and high orbital eccentricities. At high orbital eccentricities (when the moon is furthest from the sun) magma in the oceanic crust experiences increased pressure of being forced out of its chamber. When sea level is low during Ice Ages because of glacial formation, this pressure exceeds the strength of the crust and an eruption occurs. Carbon dioxide is emitted into the ocean, equilibrates with the atmosphere, and increases the greenhouse effect.
So could these volcanoes really have spelled the abrupt end for the Ice Ages? The key in Tolstoy’s study is the pulsing frequency compared to spacing out eruptions over time. Oceanographic scientist, Dr. Iraola of UNC at Wilmington’s Center for Marine Science, comments that: “Underwater volcanic high frequency events over a small time scale would result in rapid increases in atmospheric COs levels, thereby quickly warming the planet, and plausibly ending an Ice Age.”
For now, continued monitoring and data collection is needed to further robust Tolstoy’s theory. One thing is for certain: with the startling results from Tolstoy’s work, we’d be hard-pressed to continue ignoring underwater volcanoes as significant climate change players.
By Ethan Simpson
With the 2015 hurricane season upon us, it is more important than ever to understand how the most important greenhouse gas, water vapor, effects global climatological processes.
The last forty years have seen a marked rise in public and scientific interest in the global phenomenon known as climate change. Specifically, much research effort has focused on the increasing role of greenhouse gases as drivers of the change. These greenhouse gases (GHG’s) act in the atmosphere to absorb and trap heat in Earth’s atmosphere, thus keeping our planet warm. While some of the minor contributing GHG’s can be traced to human sources, the largest contributors are all found naturally in the atmosphere. Water vapor, and by extension clouds, account for the majority of the greenhouse effect, but seem to receive the least amount of attention in the public sphere. Recent work, however has attempted to rectify this by evaluating the proportional contribution of water vapor and clouds to the overall Greenhouse effect.
According to Gavin Schmidt and colleagues, the three largest contributors to the greenhouse effect are water vapor, clouds, and CO2, in decreasing order. Their environmental models reveal that water vapor contributes half of the total greenhouse effect globally, with cloud cover contributing another quarter and CO2 roughly one fifth. This revelation makes it apparent that to truly understand climate change, a better understanding of how water vapor functions in the atmosphere will be necessary. The true effect water vapor has on global temperature rise is difficult to imagine on its own, but when the other minor GHG’s are included, the picture becomes much clearer. As Schmidt points out in his paper, even marginal increases in global temperature due to the other GHG’s such as CO2, would lead to increased evaporative processes and add more water vapor to atmosphere, further increasing the overall greenhouse effect.1 However, one confounding effect of increased water vapor would be an increase in cloud production. Clouds are known to both reflect sunlight, decreasing global temperatures, and to in other circumstances retain heat in the atmosphere by absorbing heat. Complex processes such as these are difficult to accurately predict and may play very large, yet currently unknown roles in climate change.
What are the major sources of water vapor in our atmosphere? Well, the largest shouldn’t surprise you. Evaporative processes from the Oceans contribute the majority of atmospheric water vapor, and the production of this water vapor is a major driver of Earth’s weather systems and deep oceanic currents. While we understand some of the major effects water vapor has on a global scale, future studies must strive to disentangle the complex relationships water vapor has with other greenhouse gases in the atmosphere. So as we enter the peak of hurricane season, which is itself driven by the condensation of water vapor into storm clouds, take a moment to appreciate the immense power contained in atmospheric water vapor.
Schmidt, G. A., R. A. Ruedy, R. L. Miller, and A. A. Lacis (2010), Attribution of the present‐day total greenhouse effect, J. Geophys. Res., 115, D20106, doi:10.1029/2010JD014287.
By Katie Reed
The ozone layer acts as the earth’s natural sunscreen by blocking harmful, high energy UV light. Without it, UV light would be able to reach earth’s surface and damage plants, animals, and humans. Unfortunately, the ozone layer is depleted when human-made substances called CFCs are released into the atmosphere. One ingredient of CFCs is chlorine which can react with ozone, breaking up the ozone molecules, and depleting the layer. This process has created an ozone hole in Antarctica, which is credited with causing shifts in spring ice coverage.
In 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer was held. Since then, these chlorine containing substances have slowly been phased out of use, but are still present in the atmosphere. The Antarctic ozone hole is expected to be observed for at least the next 35 – 50 years.
Dr. H. Nagase and his colleagues in Japan, Germany, and the United States have a radical idea to remove some of the chlorine from the stratosphere: inject ice particles into the atmosphere.
“The ozone destruction in Antarctica could be significantly reduced if a systematic method was established that would reduce HCl.” said the study, published in May. They propose a geo-engineering approach which involves injecting ice at an altitude of about 25 km. This process would work, they say, because HCl dissolves in ice particles. These particles can then fall to earth, effectively removing the chlorine before it can react with ozone.
The study found that five conditions had to be adjusted in order to optimize chlorine removal. Size and concentration of the particles, along with altitude, latitude, and seasonality of injection, all affect the efficacy of ice injection.
The most important parameter was size of the ice particle. For this process to be effective, ice particles have to be small to provide adequate surface area, but large enough for gravity to quickly remove it from the stratosphere, away from the ozone layer.
Altitude, latitude, and timing of injection all affect how long the particles can remain ice, and also how much ozone is present. The researchers limited the injection to a 10-day period, and found injection to be most effective in Antarctic fall because of seasonality conditions.
Finally, concentration is important. High concentrations may be more effective, but also more expensive.
Overall, the models determined that 40µm ice particles injected at about 25 km, between 70-80 degrees south, at a concentration of 3x1014 molecules/cm3, in May-July would remove the most HCl.
The researchers stress this was an initial presentation of a possible solution, and that more information needs to be collected before this can be considered a feasible process. Factors like evaporation, other particle interactions and, of course, cost need to be further investigated.
The biggest challenge, Nagase and his colleagues say, will be designing an effective and successful method to inject the ice.
 Nagase, H., Nagase, H., Kinnison, D., Petersen, A., & Vitt, F. (2015). Earth's future: Effects of injected ice particles in the lower stratosphere on the Antarctic ozone hole. American Geophysical Union Publications. 3(5):143-158.
By John Roberts
Nitrous Oxide, or Laughing Gas as it is commonly known, is a naturally occurring greenhouse gas that has approximately 300 times more impact on atmospheric warming than carbon dioxide pound for pound.¹ What makes nitrous oxide even more problematic is that the molecules stay in the atmosphere for an average of 114 years before being removed or destroyed by chemical means, where as carbon dioxide tends to constantly cycle within the Carbon Cycle.
The thing about N2O is that it is a naturally occurring gas that among other processes, is generally created from agricultural methods by the process of nitrification and denitrification from microorganisms in soil (or salt marsh muck, which we will get into…). Incidentally, nitrate (NO3-) is a very common commercial fertilizer used all over the world and when used for commercial farming or domestic landscaping it can run off into coastal waterways many issues can arise due to the increased nutrient flow into the aquatic ecosystem.
According to a long term study (9 years) of whole ecosystem dynamics of salt marshes that undergo nutrient enrichment, the effects of increasing nitrogen have profound impacts on coastal ecosystems.² These impacts range from erosion of creek banks to increased microbial decomposition of organic matter. It was proven that the increased nitrogen caused an increase in above ground biomass and a decrease in the belowground biomass which caused the banks to be less stable which in turn caused the erosion. While this was a study on relatively small patches of land, it equates with many coastal locations and ecosystems globally that receive an anthropogenic increase in nitrogen from industrial practices.
Microbes are not only found in the soil of farms, they are also prevalent in the muck and mud of estuaries and other coastal environments. If we continue to release excess nitrogen into coastal systems there will only be an increase in N2O production from these systems as well as a decrease in stability of the land and plant material to offset this production.
We know that a natural part of the nitrogen cycle is nitrous oxide, and we know that addition of nitrogen into aquatic ecosystems increases the production of nitrous oxide which in turn has an effect on atmospheric heating of several hundred times that of carbon dioxide. The Intergovernmental Panel of Climate (IPPC) Change estimated at 3.5 teragrams (7.7 Billion lbs.) of N2O from agricultural soils in 2006. Compare this number to the 20.0 billion pounds of anthropogenic CO2 in 2009 and the fact that only 74% of total anthropogenic N2O comes from agriculture and the numbers become quite formidable, especially if you multiply the comparative impact of nitrous oxide by 300. With something as potent and long lasting as N2O we cannot afford to wait any longer to start working on the problem.
New Research Links Increase in Global Methane Flux to Potentially Massive Leak of Methane Gas From World-Wide Marine Sediments
By Robbie O'Donnell
(Wilmington, North Carolina) – Methane gas is one most prevalent greenhouse gases released into the Earth’s atmosphere by humans around the globe, and it also happens to be extremely damaging to global climate. In a 2010 study the EPA stated that, pound for pound, Methane has a 25 times greater effect on climate change then CO2 over a 100 year period. And now, a recent study shows that there is a potentially new, natural, source of methane being released at alarming rates around the globe; and its coming from almost 1,000 meters beneath the sea.
Dr. Adam Skarke of Mississippi State University and an interdisciplinary team of scientists recently published a paper in Nature Geosciences analyzing methane emissions in the US Atlantic Margin off the eastern coast of the United States. Skarke’s research team was made up of several geologists from the United States Geological Survey (USGS) and Mali’o Kodis, a National Oceanic and Atmospheric Sciences (NOAA) Hollings Scholar and student at Brown University.
Using multi-beam water column backscatter data Dr. Skarke and his team were able to identify almost 570 methane plumes over a 94,000 km2 area off the eastern coast of the United States. These plumes come from a “frozen”, solid form of methane referred to as a gas hydrate, that is solid and stable at a small range of temperatures and pressures beneath the sea. These gas hydrates can be found in marine sediments from all around the world and are actually a vital source of life for organisms who rely on the methane for their life processes.
Skarke and his team estimated that the total yield for methane gas hydrates in this margin was close to 614 trillion cubic meters2. This represents a massive, and detrimental, source of further methane gas emissions to the Earth’s atmosphere, on top of the already huge inputs from other methane emitters like melting permafrost and agricultural production. With increased global atmospheric and oceanic temperatures these hydrates will only continue to destabilize, increasing greenhouse gas concentrations and even adding to the acidification of the oceans. “Such seeps would represent a source of global seabed emissions that have not been fully accounted for in global carbon budgets”, say Skarke; making these hydrates especially hazardous moving into the future.
Humans could potentially further the release of these hydrates, especially here off the coast of North Carolina, by disturbing these sediments for oil and natural gas drilling. Because these hydrates are only stable at specific temperatures and pressures any change in the two, like the disruption of sediments due to drilling, would substantially increase the release of methane from the seafloor.
However, there is a silver lining. These hydrates represent a massive sink and storage resource for global carbon; and because they are not fully understood, could be a potential savior. With decreased average atmospheric and oceanic temperatures these hydrates would become stable and act as a virtual “prison” for methane in the oceans as it would be locked and stored in this solid hydrate form.
Robert O’Donnell (firstname.lastname@example.org)
UNCW Center for Marine Science
By Rachel Lucas
According to current global estimates, the rate of heat building up on Earth over the past decade is equivalent to detonating about four Hiroshima atomic bombs worth of energy per second[i]. That means, to current date, we have accumulated a near 2.5 billion atomic bombs of heat since 1998.[ii]
This heat is transferring itself into our oceans and (now) melting glaciers. In the face of this, denial of human-caused climate change still manages to persist.[iii] And yet, when we look to the science behind it, we find that 99.9% of climate scientists agree: accelerated climate change is happening, and this acceleration is human caused.[iv] Climate change denial is a serious issue that endorses political inaction and ultimately procures long-term negative ecological and economic impacts, and the root of this denial starts with a misunderstanding of what is a natural cause, and what isn’t.
One common argument provided by deniers is, “Earth’s climate is designed to change. It’s a completely natural cycle”. Now, this claim isn’t wrong per se, but it is, however, inapplicable to the climate change we are currently witnessing. To understand this inconsistency, it helps to have a basic grasp of the main component controlling these natural climate cycles, what are known as the Milankovitch cycles. In short, the Milankovitch cycles are recurrent changes in the positioning of the Earth in relation to the sun caused by fluctuations in the actual shape of the Earth's orbit, the degree of Earth’s axial tilt towards or away from the sun; and the circular “wobble” on its axis as it circles around the sun in its gravitational orbit. These changes occur across large time scales, roughly 100,000 years, and bring the Earth, overall, closer to or farther away from the sun.
As the Earth's orbit changes, so too does the amount of sunlight Earth receives at different latitudes in different seasons. The amount of sunlight received in the summer at high northern latitudes over the North Atlantic and Arctic Oceans appears to be especially important to determining whether the Earth is in an ice age or not. When the northern summer sun is strong (i.e., Earth has an ellipsoid orbit bringing closer to the sun with increased axial tilt bringing more direct heat and light to the N. Hemisphere) the Earth tends to be in a warm period that lasts about 10,000 y. This melts away glacial ice (e.g., melting of Greenland ice sheet) causing massive freshwater release into the ocean followed by a 400 ft. sea level rise. When the northern summer sun is weak (i.e., Earth has a circular orbit and decreased axial tilt limiting the amount of light and heat in the N. hemisphere) ice sheets formed over winter in the N. Atlantic and Arctic Ocean don’t melt in the summer and slowly amass over time forming massive glaciers; this brings about the next ice age that lasts for about 100,000 y. In short, that’s the natural cycle: brief warm periods (about 10,000 y) followed by the slow build of an ice age that lasts for about 100,000 y.
Earth left its most recent ice age 11,000 y ago which means our warming period (should have) ended about 1,000 y ago. It is now in a phase with a more circular orbit and decreasing tilt that’s slowly decreasing light in the N. hemisphere in the summer time. With less light in N during summer, this means the Earth should be very slowly cooling again, not warming, which means current warming trends are completely off track from the natural cycle. Furthermore, the kind of heat build-up brought about by the Milankovitch cycles would occur over about 100,000 y; instead, we have increased this rate of occurrence to such an accelerated pace (about 4 atomic bombs detonated every second) that we have reduced this 100,000 y time span to about a century. This reduction in timescale is massive, and the only thing that could account for its acceleration is, unfortunately, us. But accepting this truth doesn’t have to mean the end of the world! Instead, it is pivotal to delving deeper into understand all of the variables affecting current climate change, especially oceanic processes, and to start making the changes necessary to mitigate its effects.
NASA/GISS graph combining positive and negative forcing and temperature for a clear picture of the natural cycle in comparison to the current anthropogenic forcing due to industrial processes. Source: http://ossfoundation.us
[i] Nuccitelli D, Way R, Painting R, Cook J, Church J, 2012 analyzing global heat data global heat data created by combining pentadal (5-year average) ocean heat content data to a depth of 2,000 meters from Levitus et al. (2012), and land, atmosphere, and ice heating data from Church et al. (2011).
[iii] Estimated 52% of Americans in 2014 believe that scientists don’t agree on climate change or its cause. Conducted by the Yale Project on Climate Change Communication. Source: http://environment.yale.edu/poe/v2014/
[iv] Poll reviewed more than 24,000 peer-reviewed articles on global warming published in 2013 and 2014 surveying over 70,000 scientists. Source: http://www.msnbc.com/msnbc/how-climate-change-deniers-got-it-very-wrong
Could Hydrogen Peroxide production by UV-B in Planktonic Microorganisms Cause Sea Warming and Ice Melting?
By Jordan Smith
Hydrogen Peroxide is an extremely common household item that most people recognize and possibly have used before. But what most people do not know is that hydrogen peroxide can be produced inside marine planktonic microorganisms and as a result affect marine ecosystems, decrease ice thickness, and alter climate!
Is this really something we should be worried about? Under ultraviolent-B radiation (UV-B) oxidation of water (H2O) by dioxygen (O2) yields hydrogen peroxide (H2O2) but hydrogen peroxide is a potent microbicide so as soon as it is produced inside the cell it must be removed through catalase activity. This decomposition of hydrogen peroxide produces an extreme amount of heat that is 13 times greater than that which is produced in ATP hydrolysis. Making this reaction by far the most exothermic in nature1.
All this heat must go somewhere! A paper published by Dr. Cosme Moreno in 2012 showed the importance of this heat produced from over activated hydrogen peroxide catalase. Dr. Moreno estimated that with a 0.07 W/m2 increase (which is 30% of the UV-B increase of the Arctic) being transformed to heat at the water-ice interface, in an area the size of a spherical 8 km in diameter during a week could produce a little more than a megaton of energy. Which is 80 times larger than the atomic bomb used in the Second World War.
With an increasing amount of UV-B radiation reaching the earth and penetrating deeper through the ice, the radiation will reach more organisms. This will create a negative feedback loop. For instance, in high latitude regions, marine microorganisms, which have been encased in floating ice during winter, are released in spring to the interface between the water and ice. There they absorb UV-B radiation, produce hydrogen peroxide, use catalase to remove the hydrogen peroxide, and in turn produce heat which causes them to become less dense and rise. This density effect from the heat produced inside the cell will lead to the accumulation of these organisms at the water-air or water-ice interfaces leading to increased absorption, heat production, and sea ice melting.
The heat produced at the water-air interface is largely transferred to the air and contributes to the heat flux to the atmosphere. Though this flux has largely been ignored it has the capacity to significantly change atmospheric circulation and sea surface warming when viewed on a time scale of a decade. Moving forward more research needs to be conducted on this biogeochemical process, which has been shown to cause significant effects on marine ecosystems and climate.
Moreno. C. M. (2012). Hydrogen peroxide production driven by UV-B in planktonic microorganisms: a photocatalytic factor in sea warming and ice melting in regions with ozone depletion. Biogeochemistry. 107:1-8.