User:Delparastan/sandbox

Article Evaluation:
This article is well written and informative. I especially like the use of citations, background information and cross links to other wikipedia articles. I agree with the earlier reviewer, the information is solid and well researched. My suggestions to improve include breaking the article into a few more sub-headings to allow people to see at a glance what is discussed in the article.

Wiki Article Evaluation:
I have chosen the article "Materials Science" which is of interest to a number of WikiProjects including Materials and Engineering. Follow is my evaluation of the article:

The article is very well written and has a neutral language and is easy to read for people that are not expert in the field. It covers the main disciplines in the materials science and provides a general perspective to the reader. I do not think that the article or any information is out of date. However, the field of materials science is growing with a fast pace and it is important to keep the article up-to-date. This job has been done quite well and I can see that however there’s still room for improvement. Some of the most recent discoveries in the field can be highlighted, possibly with adding some pictures. These can include, but not be limited to, biomimetic and bioinspired materials, energy harvesting materials, smart materials, flexible electronics, and etc. To my opinion, the article has a neutral language and none of the information presented is heavily biased towards a particular position. The references used in this article are mostly reliable sources including peer review research journals. I checked a few of them and the links are working and redirecting to the source. The article does need more citations to my opinion.

The talk page of the article mostly contains discussions about adding/removing citations or improving the article by adding some of the important journals in the field. I believed there is room for improvement and there are few ideas that can be discussed in the Talk page.

Peer Review:
For the peer review I chose to write about Direct Air Capture of Carbon Dioxide draft (as of Tuesday November 27th) that has been selected by another group in class.

I think the topic is really interesting and has the potential to become a great article. Having said that, however, it should be noted that there is currently a somewhat thorough section on the topic in the Carbon Dioxide Removal page in Wikipedia. The article starts with an introduction on Direct Air Capture of CO2; however, the passage is extremely brief and does not provide the general reader with the necessary background in order to have a transition into the main paragraphs. In my opinion the article can significantly benefit from having a more coherent introduction paragraph. Moreover, the section on capture methods is too concise which makes it difficult to follow the arguments for a reader who does not have enough knowledge about the field. Adding a few lines on describing the process and what happens in the separation techniques can be quite helpful to readers. Also, for this section the article can benefit from incorporating some schematics that can help visualizing the differences.Also, it would be nice to have some numbers about the total carbon dioxide emissions as well as the capacity for capture using other technologies in order to make a fair comparison with DAC. For instance, when it is mentioned that “to capture 3.3 Gigatonnes of carbon dioxide a year, the water requirements would be 300km3 a year, or 4% of the water used for irrigation,” the numbers can be much more meaningful if they are compared with total CO2 emissions per year. Same goes for the argument about energy consumption; it would be nice to more directly compare it to other technologies in terms of carbon dioxide concentration and/or energy use.I believe when talking about financial cost of the process, both capital and operational costs should be taken into account. Some information on the availability and cost of employing DAC units would be helpful. The section on DAC projects around the world possibly needs more citations. Also, since the companies that are mentioned in this passage have Wikipedia pages (at least some of them) it would be nice to have them linked to this page when they are mentioned so readers can refer to those pages if are interested to know more about the companies and the technologies that they are using.

In general, I think if these points are being taken care of, the article can be a good contribution to the Wikipedia on the subject of Carbon Dioxide Capture.

Wikipedia Final Project for UC Berkeley CCS Course (C195/236):
Group 7: Wilson Chan // Amir Peyman Delparastan // Robin Wollesen de Jonge // Gerald Sng // Glendon Chong

Blue Carbon Capture in Ocean
Ocean storage refers to the use of large water bodies and marine lifeforms to capture carbon by exploiting natural and geological mechanisms. Oceans cover slightly more than 70% of the total surface area of the Earth, and plays a major role in helping to stabilize Earth’s climate. This presents itself as a readily available carbon sink to store and capture atmospheric carbon dioxide. Due to the solubility of carbon dioxide in water, CO2 naturally dissolves in oceanic waters to form an equilibrium. With an increase in the concentration of carbon dioxide in the atmosphere, the position of equilibrium pushes the equilibrium in the direction such that more CO2 dissolves into the water. Utilizing this mechanism, more than 500 Gtons of carbon dioxide (amounting to a total of 140 Gtons of carbon) of anthropogenic carbon dioxide emissions released over the past 2 centuries have been absorbed by the oceans. With increasing atmospheric CO2 concentrations released due to human activities as compared to levels before the Industrialization, oceans are currently absorbing 7 Gt carbon dioxide per annum. To enhance the natural mechanism of CO2 dissolving in water, several methods have been proposed by the scientific community. These include the use of iron fertilization, urea fertilization, mixing layers, seaweed as well as direct carbon injection into the sea floor.

Role of Iron in Carbon Sequestration
Ocean iron fertilization is an example of a geoengineering technique that involves intentional introduction of iron-rich deposits into oceans and is aimed to enhance biological productivity of organisms in ocean waters in order to increase carbon dioxide (CO2) uptake from the atmosphere, possibly resulting in mitigating its global warming effects. Iron is a trace element in ocean and its presence is vital for photosynthesis in plants, and in particular phytoplanktons, as It has been shown that iron deficiency can limit ocean productivity and phytoplankton growth. For this reason, “iron hypothesis” was put forward by Martin in late 1980s where he suggested that changes in iron supply in iron-deficient ocean-waters can bloom plankton growth and have a significant effect on the concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration.

In fact, fertilization is an important process that occurs naturally in the ocean waters. For instance, upwellings of ocean currents can bring nutrient-rich sediments to the surface. Another example is through transfer of iron-rich minerals, dust, and volcanic ash over long distances by rivers, glaciers, or wind. Moreover, it has been suggested that whales can transfer iron-rich ocean dust to the surface, where planktons can take it up to grow. It has been showed that reduction in the number of sperm whales in the Southern Ocean has resulted in a 200,000 tonnes/yr decrease in the atmospheric carbon uptake, possibly due to limited phytoplankton growth.

Carbon Sequestration by Phytoplanktons
Phytoplankton is photosynthetic, needing sunlight and nutrients to grow, taking up CO2 in the process. Planktons can take up and sequester atmospheric carbon through generating calcium or silicon-carbonate skeletons. When these organisms die they sink to the ocean floor where their carbonate skeletons can form a major component of the carbon-rich deep sea precipitation, thousands of meters below plankton blooms, known as marine snow. Nonetheless, based on the definition, carbon is only considered "sequestered" when it is deposited in the ocean floor where it can be retained for millions of years. However, most of the carbon-rich biomass generated from planktons is generally consumed by other organisms (small fish, zooplankton, etc.) and substantial part of rest of the deposits that sink beneath plankton blooms may be re-dissolved in the water and gets transferred to the surface where it eventually returns to the atmosphere, thus, nullifying any possible intended effects regarding carbon sequestration. Nevertheless, supporters of the idea of iron fertilization believe that carbon sequestration should be re-defined over much shorter time frames and claim that since the carbon is suspended in the deep ocean it is effectively isolated from the atmosphere for hundreds of years, and thus, carbon can be effectively sequestered.

Efficiency and Concerns
Assuming the ideal conditions, the upper estimates for possible effects of iron fertilization in slowing down global warming is about 0.3W/m2 of averaged negative forcing which can offset roughly 15-20% of the current anthropogenic emissions. However, although this approach could be looked upon as an alternative, easy route, to solving our carbon emission crisis and lower concentration of in the atmosphere, ocean iron fertilization is still quite controversial and highly debated due to possible negative consequences on the marine ecosystem. Research on this area has suggested that fertilization through deposition of large quantities of iron-rich dust into the ocean floor can significantly disrupt ocean’s nutrient balance and cause major complications in the food cycle for other marine organisms. Since 1990, 13 major large scale experiments have been carried out to evaluate efficiency and possible consequences of the iron fertilization in ocean waters. A recent research conducted on these experiments determined that the method is unproven; sequestering efficiency is low and sometimes no effect was seen and the amount of iron deposits that is needed to make a small cut in the carbon emissions is in the million tons per year.

Urea fertilization
In waters with sufficient iron micro nutrients, but a deficit of nitrogen, urea fertilization is the better choice for algae growth. Urea is the most used fertilizer in the world, due to its high content of nitrogen, low cost and high reactivity towards water. When exposed to ocean waters, urea is metabolized by phytoplankton via urease enzymes to produce ammonia.

The intermediate product carbamate also reacts with water to produce a total of two ammonia molecules. In 2007 the 'Ocean Nourishment Corporation of Sydney' initiated an experiment in the Sulu sea (southwest of the Philippines), were 1000 tons of urea was injected into the ocean. The goal was to prove that urea fertilization would enrich the algae growth in the ocean, and thereby capture $$CO_2$$from the atmosphere. This project was criticized by many institutions, including the European commission, due to lack of knowledge of side effects on the marine ecosystem. Results from this project are still to be published in literature.

Another cause of concern is the sheer amount of urea needed to caption the same amount of carbon as eq. iron fertilization. The nitrogen to iron ratio in a typical algae cell is 16:0.0001, meaning that for every iron atom added to the ocean a substantial larger amount of carbon is captured compared to adding one atom of nitrogen.

Scientist also emphasize that adding urea to ocean waters could reduce oxygen content and result in a rise of toxic marine algae. This could potentially have devastating effects on fish populations, which other argue would be benefiting from the urea fertilization (the argument being that fish populations would feed on healthy phytoplankton.

Seaweed Fertilization
In order to mitigate global warming, seaweed farming is both a possible and plausible way. This method was adopted in early ocean algae proposals to mitigate global warming. This is done through commercial kelp farms designed to take up tens of thousands of square kilometres of the open ocean. Through this method, seaweed beds will perform as an effective sinks by decreasing the level of dissolved inorganic carbon (DIC) in the ocean.

Seaweeds do the above by removing carbon through the process of photosynthesis, taking in excess CO2 and producing O2. Facts and figures have shown that 0.7 million tonnes of carbon are removed from the sea each year by commercially harvested seaweeds. Even though seaweed biomass is small as compared to the coastal region. They remain essential due to their biotic components, the ability to provide valuable ecosystem services and high primary productivity. Seaweeds are different from mangroves and seagrasses, they are photosynthetic algal organisms and non-flowering. Even so, they are primary producers that grows in the same way as their terrestrial counterparts, both of which assimilate carbon by the process of photosynthesis and generates new biomass by taking up phosphorus, nitrogen, and other minerals.

The attractiveness of large-scale seaweed cultivation is proven over the years, with low-cost technologies and the multiple uses that can be made of its products. Today, seaweed farming made up approximately 25% of the world's aquaculture production and its maximum potential has not been utilised.

Currently in the world,seaweeds contributes approximately 16–18.7% of the total marine-vegetation sink. In 2010 there are 19.2 × $$10^6$$ tons of aquatic plants worldwide, 6.8 × $$10^6$$ tons for brown seaweeds; 9.0 × $$10^6$$ tons for red seaweeds; 0.2 × $$10^6$$ tons of green seaweeds; and 3.2 × $$10^6$$ tons of miscellaneous aquatic plants.There is an estimations of 1000 tons of carbon is temporarily sequestered in the ocean, making the sea as an important carbon sink.

Mixing Layers
Mixing layers involve transporting the denser and colder deep ocean water to the surface mixed layer. As the temperature of water in the ocean decreases with depth, more CO2 and other compounds are able to dissolve in the deeper layers. This method relies on the oceanic carbon cycle, and aims to speed up the natural process of upwelling through the use of large vertical pipes serving as ocean pumps, or a mixer array. When the nutrient rich deep ocean water is moved to the surface, algae bloom occurs, resulting in a decrease in CO2 due to carbon intake from Phytoplankton and other photosynthetic eukaryotic organisms. The transfer of heat between the layers will also cause ocean water from the mixed layer to sink and absorb more CO2.

This method has not gained much traction as algae bloom harms marine ecosystems by blocking sunlight and releasing harmful toxins into the ocean. The sudden increase in CO2 on the surface level will also temporarily decrease the pH of the seawater, impairing the growth of coral reefs.The production of carbonic acid through the dissolution of CO2 in seawater hinders marine biogenic calcification and causes major disruptions to the oceanic food chain