The Relationship between Arctic Sea Ice and Carbon Dioxide in the Atmosphere

Greenhouse gases, carbon dioxide in particular, have led to global warming, which have affected people’s lives significantly: the temperature in summer keeps increasing, cities at middle latitudes have less and less snow, and glaciers, snow cover and permafrost keep decreasing in the two poles. Global warming is not something that people can ignore anymore. Increasing emissions of carbon dioxide can aggravate ozone hole; as a result, more sunlight will get to the earth, which causes the temperature to increase; therefore, Arctic sea ice melts more during summer. Now, the difference of the extent of sea ice gets to 30% between summer and winter time. The thinner of the sea ice is, the less carbon dioxide will be removed, according to a recent study.

The article (source from University of Southern Denmark) published in ScienceDaily discusses their study of how sea ice can help remove carbon dioxide from the atmosphere. In the article, Dorte Haubjerg Sogaard’s group states that not only oceans can absorb a huge amount of CO2, but also the ice. They claim that “the chemical removal of CO2 in sea ice occurs in two phases”. First, CO2 is formed into calcium carbonate in winter, which is stored deep down in the ocean. When it gets to summer, CO2 is also needed for the process of calcium carbonate to dissolve. The key point in this article is talking about both forming and dissolving sea ice have impacts on the carbon dioxide in the atmosphere.

Overall, I thought this article brings up a new idea of the relationship between sea ice and carbon dioxide. The shortcomings in this article, I think, would be it does not specifically talk about the process of how calcium carbonate forms and why CO2 would be necessary to the dissolving process of calcium carbonate. I know the formation of calcium carbonate needs CO2, but it made me confused that why when sea ice melts and calcium carbonate dissolves, CO2 is needed. In addition, a new term “frost flowers” appears in the article. It is defined as “flower-like ice”, which was formed on the surface of newly formed sea ice in winter. It states that there is a higher concentration of calcium carbonate in frost flowers. It would be better if there were more information provided regarding the reasons.

In the article “The Impact of Lower Sea-ice Extent on Artic Greenhouse-gas Exchange” from Nature Climate Change, there is more information about the temperature on Arctic and CO2 fluxes, as well as methane. Nature Climate Change did provide the information and data in terms of how CO2 moves around the ocean. However, it does not mention that dissolving sea ice would help remove CO2 in the atmosphere. I personally think this article is more creditable.

ScienceDaily article Link:

http://www.sciencedaily.com/releases/2014/09/140922110424.htm

Nature Climate Change article Link:

http://www.lib.umich.edu/articles/details/FETCH-LOGICAL-e771-e2928c3e686390c7efbdfc8a091a1a5b41bf15b6072933431122c405ad91e77a1

(Click “MGet It-Full Text Online” on the up right)

Reducing Greenhouse-Gas Emissions: Concrete

Greenhouse-gas emissions, largely responsible for increases in temperature globally, may happen in a multitude of ways. The combustion of hydrocarbons will release carbon dioxide, a prominent greenhouse-gas, as will the reactions of molecular oxygen to chemicals such as formaldehyde and carbon monoxide. Additionally, use of a chemical solvent in the form of carbon tetrachloride, which may also be used in other functions, is considered a greenhouse-gas emission. Though these are all methods of greenhouse-gas emission, a perhaps less familiar method of greenhouse-gas emission is through concrete production, which could benefit from a decrease in associated greenhouse-gas emission.

                                                           Credit: © sframe / Fotolia

An article on sciencedaily.org, an American scientific news website, not only quantified the greenhouse-gas emission of concrete production with a “5-10 percent of industrial greenhouse- gas emissions” estimate, but also described a method of producing concrete that will hopefully result in a decrease of greenhouse-gas emissions as one consequence. The article was based off a publication in Nature Communications by Pellenq, et al. and the method involved making the calcium to silica ratio 1.5 in cement, a component of concrete. This ratio was determined from analyzing atomic structures and was proclaimed to decrease carbon emissions by up to 60 percent and strengthen the concrete.

The article agreed well with the Nature Communications publication at certain major points. In terms of making concrete stronger, clarity in qualifying concrete strength using terms such as “tightly ordered crystalline structure” and “disordered glassy structure” helped in tying the article to the atomic models described in the Nature Communications publication. Additionally, the article did acknowledge that the study was done on an atomic scale with a goal of eventually applying it to a larger scale, which was reminiscent of the Nature Communications publication yet a good alternative to fully describing its dense methodological details.  

The article did fall short in a few regards though. What I could not understand from the article was the link, scientific or not, between a chemical ratio and lower carbon emissions; the article just mentioned that the “decarbonation of limestone, and the heating of cement” contributed greatly to greenhouse-gas emissions. The article could have included some additional information from the Nature Communications publication, such as the mention of a good calcium to silica ratio in reducing production waste and therefore carbon emissions, to help with this. Additionally, I thought the article used some emotion to upgrade the importance of cement by including phrases such as “no other solution” and “magic” to describe it.  

Overall, the article did a good job of communicating the findings in the Nature Communications publication succinctly to an audience reading the environment section of a news website. This was definitely not easy given the ten pages of the Nature Communications publication along with its dense methodologies. However, I thought the article left out a bit of important information and had an emotional component as described previously. For these reasons, I would give the article a score of 7/10. 

Links:

Sciencedaily.org article: 

http://www.sciencedaily.com/releases/2014/09/140925141236.htm

Original Journal (Nature Communications) article: 

http://www.nature.com/ncomms/2014/140924/ncomms5960/full/ncomms5960.html

 

Ozone Kills Crops in India

Increasing levels of ozone in the lower atmosphere have been a topic of study and have been linked to a decline in agricultural yields around the world. Most of these studies use modeling to predict lower products in the future, but one recent study examined data from 2005 to determine damage done to crops by ozone. This study was described in a recent article by RT.com titled “India Ozone Pollution Kills Enough Crops to Feed Nearly 100mn Poor aYear – Study”. The article describes the loss of $1.29 billion in agricultural products (wheat, cotton, rice and soybeans) in 2005 that has been attributed to ozone. It is also possible that this new study could influence policies to put pollution standards in place.

AFP Photo/Narinder Nanu

While the news article does properly cite the scientific study,
it falls short in some aspects. The authors of the news article did not explain any of the possible shortcomings of the research that are clearly outlined in the study. There are possible shortcomings such as a lack of an accurate “AOT40 exposure-response function”. The article also did not mention other issues that have reduced agricultural output, such as the $1 billion in damages that was caused by flooding. It is likely that this was not mentioned because it would have subtracted from the importance of the ozone pollution. Another issue with the article is that it did not use any of the error calculations that were used in the study. Those errors could significantly change the meaning of the data. The economic impact may actually be less that $1 billion, which could mean that flooding has a larger impact on crop production in India than ozone pollution.

Average O₃ - induced crop production loss from AOT40 metrics for cotton, soybean, rice, and wheat during 2005. The production loss numbers are given in kilotons/grid box. 

In the research study, Sachin, et al. explain how this loss in crop production could have an impact on India’s new program to subsidize food for roughly two thirds of its population (1.2 billion). The researchers calculated that the amount of crops destroyed by ozone pollution in 2005 are enough to provide that subsidy to 94 million citizens, and this was the same figure used by the article in its attention grabbing headline. This article could have explained how this number was calculated and this would have provided more meaning to the number. 

All in all, I believe the article accurately represented the basics of the study, but fell short in some areas. It could have provided more information about the data that it gave, as well as the possible shortcomings of the article. But, all things considered, the article seemed free of hyperbole and political influence. Because of this, I would give the article an 8/10.

Link to RT.com article

Link to study in Geophysical Research Letters

Link to study in Geophysical Research Letters (With MGet It)