Nature, 437, 681-686 (29 September 2005)
In a study done by Orr et al., the decreasing rate of free carbonate ion available for calcification for sea organisms will become undersaturated by 2050. Calcium ions in the ocean react with carbonate ions to form calcium carbonate which makes up exoskeletons of various sea organisms. The excess of dissolved carbon dioxide in the ocean has caused increasing amounts of carbonate to become tied up in bicarbonate ions which are unable to be used to form calcium carbonate. Pteropods have shown significant decreased calcification in water the same pH predicted with the “business-as-usual” projections. They are near the bottom on the food chain, and a change in their population could have a ripple effect throughout the entire ocean ecosystem. In higher altitude ocean ecosystems, this study has shown that acidification is increasing at a slower rate. This only means that these ecosystems will lag the lower altitude ones by 50-100 years. The only benefit to this is that these organisms have more time to possibly adapt to the new ocean chemistry.
Building and Environment, 46, 1081-1086 (2010)
When researching cost premiums for LEED certified buildings, Tatari and Kucukvar looked at buildings in terms of the various ratings and categories. The LEED rating system consists of four different ratings, Certified, Silver, Gold and Platinum. The cost premiums range from 1-8% depending on the rating. In general there is a premium of 0.66% for Certified buildings, 2.11% for Silver, 4.41% for Gold, and 6.5% for Platinum. The cost increases with a higher rating because higher performance sustainable building projects tend to require larger investments.
The LEED system is also broken up into eight different categories: sustainable sites (SS), water efficiency (WE), energy and atmosphere (EA), materials and resources (MR), indoor environmental quality (IEQ), innovation and design (ID), regional priority (RP), and building grade (BG). SS, EA, and BG demonstrated the most sensitivity and significance within these categories; therefore they have a higher influence on the cost of a LEED building.
Welladsen, H. M., Southgate, P. C. & Heimann, K., 2010. The effects of exposure to near-future levels of ocean acidification on shell characteristics of Pinctada fucata (Bivalvia: Pteriidae). Molluscan Research 30(3): 125-130.
Pearl Oysters of species Pinctada fucata produce pearls through building up nacre deposits between the shell and mantle of the oyster. Normally, these deposits are isolated from their surroundings, but it has been suggested that ocean acidification breaks down the protective shells and removes the isolation of the system.
The study serves to show that this breakdown of the oyster shell occurs, and has negative effects upon the nacre formations. The Pinctada fucata were exposed to water of pH 7.8 and 7.6 for 28 days, which resulted in shells 25.9% and 26.8% weaker, respectively, than the controls. As a result, the nacre formations showed signs of malformation and dissolution in comparison to the controls, as shown through scanning electron microscopy.
This degradation of shell strength and nacre formation could have serious effects on the cultured pearl industry, which relies heavily on the natural production of pearls within Pinctada fucata.
Coral Reefs Volume 29 Number 3, 637-648, DOI: 10.1007/s00338-009-0562-0
Bleaching occurs when corals eject zooxanthellae as a result of thermal stress. This causes changes in pigmentation, and corals then appear lighter or ‘bleached.’
Corals in the Great Barrier Reef near shore waters show high levels of bleaching with high water temperatures. Studies between 1985-2007 along the shoreline of the Great Barrier Reef, were done to predict if damage could be recovered in hard coral covering that is divided into two groups: Acropordae, and the rest of hard coral species. Hard cover coral increases faster than other families such as soft coral, with the median of 11% annum, and 4% for others.
Acroporidae showed recovery from cyclone damage. During periods of time with no disturbances, recovery was observed, but the impacts from bleaching were too severe and showed decline in hard coral covering. Coral will not withstand bleaching in the long run.
The Australian region surrounding the Great Barrier Reef, should make brood stock more available, and directly protect corals from rising temperatures.
Matthews DL, Cao L, Caldeira K. 2009. Sensitivity of ocean acidification to geoengineered climate stabilization. Geophysical Research Letters 36: L10706.
Although climate stabilization through geoengineering is a means of slowing climate changes, it is less viable for the other CO2 problem; climate engineering may increase the rate of ocean acidification.
In their study, Matthews and Caldeira from Concordia University and Carnegie Institution of Washington respectively, found that climate engineering modifies ocean chemistry through changes to CO2, temperature, salinity, DIC, and alkalinity. These effects were mediated by increased CO2 solubility, however, and changes in ocean pH were far less severe with equivalent atmospheric CO2 levels.
The notion that geoengineering will not mitigate ocean acidification was previously assumed, but this study confirmed the assumption. Second-order interactions between climate engineering, the global carbon budget, and ocean chemistry may slightly increase or decrease the rate of ocean acidification, depending on changes in future terrestrial carbon sinks. The study highlights the fact that changes in ocean chemistry are not only the direct result of pH influences, other factors play large roles in ocean acidification.
Environ. Sci. Technol., 2009, 43 (20), pp 7985–7991
With the implementation of the Energy Independence and Security Act of 2007 there has been an increase of additional crops for biofuel production. With the increased demand for agricultural products there has been concern about the negative aspects resulting. For instance “agriculture is currently responsible for 76% of the nitrous oxide,” a lot of which ends up in the oceans as a result of water runoff. In this study Costello et al., from the Department of Civil and Environmental Engineering at Carnegie Mellon University, examine the impact of nitrogen loading in the Gulf of Mexico as a result of increased use of biofuel. They assesses the NO3- output from different crops used to create biofuel and it is determined that corn production for biofuel creates the highest output of NO3- in comparison to other biofuel crops. This study is relevant to the affect of biofuel on hypoxia because it relates the amount of runoff created from biofuel crops to the hypoxia in the Gulf of Mexio.
Impact of Elevated CO2 on Shellfish Calcification
Geophysical Research Letters, Vol. 34 L07603, doi:10.1029/2006GL028554, 2007
Many marine organisms produce shells made of calcium carbonate, or CaCO3. Two calcifying oyster species, namely Mytilus edulis (mussel) and Crassostrea giga (Pacific), were subjected to both CO2 free air and normal air. A simple formula was used to calculate the calcification rates. The overall conclusion was that the calcification rates of both species went down sharply as both pH decreased, CO2 increased, and CO32- increased. It is noted that global shellfish production rose last year to 11.7 million tons and that Crassostrea gigas was the most cultivated species of them all. This study is therefore relevant to the economics of the shellfish industry because it shows significant danger to one of the most prominent species in the industry. This study by F. Gazeaus and his associates took place in the Easter Schelt estuary in Zeeland, Netherlands. Other sources are cited to juxtapose this research with previous research on similar species.
GEOPHYSICAL RESEARCH LETTERS, VOL. 37, L15704, 5 PP., 2010
As changes in the pH are becoming apparent from ocean acidification, it is important for scientists, and the public, to understand how these numbers will drop over the coming decades. Using a simple ocean carbon cycle model (SCM), Bernie and his team examine how pH levels will fall by 2100. The SCM in the study incorporates terrestrial carbon cycle models, climate models, and characteristics of the ocean, such as alkalinity, and nitrate availability. Bernie then examines different mitigation scenarios, looking at when the mitigation efforts begin and how strong the efforts are. Bernie and colleagues find that with current rates, pH levels would decrease to between values of 7.67 and 7.81 by 2100, however an aggressive mitigation approach starting by the year 2016 would only cause a decrease to 8.02. These results are significant as they tell scientists and the public that mitigation efforts will prove effective compared to not taking any action against ocean acidification.
The Comparative Politics of Carbon Taxation 10.1146/annurev.lawsocsci.093008.131545 (2010)
Kathryn Harrison, a professor of political science at the University of British Columbia, believes carbon taxes offer significant advantages compared to a cap-and-trade system to reduce carbon dioxide emissions. She looked at the experience of Finland, Denmark, Germany and Canada to determine the conditions where carbon taxes are politically practical. In her opinion, carbon taxes’ advantages include transparency, predictability of costs, ease of implementation, and application to small and large sources. The price certainty of carbon taxes can encourage business investment to develop and adopt low carbon technologies. Recycled revenue carbon taxes are the most economically efficient. Revenues can be used to reduce payroll or income taxes that usually discourage productivity. The carbon tax is more effective than just an energy tax because the level of taxes depends on the amount of carbon in the fuel whereas an energy tax taxes all fuels at the same rate. Overall, Kathryn Harrison thinks the carbon tax is more beneficial to the goal of reducing carbon emissions, but only if it is applied to all types of fossil fuels without exemptions.
Global Change Biology Volume 17, pages 2980-2986 (2011)
Under lead author Maud C.O. Ferrari, a group of scientists performed experiments on the effects of increased ocean acidity on the antipredatory responses of four species of damselfish (Pomacentrus amboinensis, Pomacentrus chrysurus, Pomacentrus nagasakiensis, and Pomacentrus moluccensis). All four species showed decreased antipredatory responses in acidified waters, but the range of loss of responses varied greatly, from 30% to 95%. Additional testing on P. chrysurus showed an increase of five to seven times normal in fatality by predation of larvae raised in predicted future acidified environments. All experiments occurred in November and December, 2009, at the Lizard Island Research Station on the Great Barrier Reef off the coast of Australia. The seawater used for the experiment was pumped directly from the ocean, and the fish used for the experiment were all freshly-caught juveniles.