Proceedings, Sept. 2012
Carbon dioxide . . . it’s what makes our soft drinks zesty and champagne . . . well, champagne. It is also a major greenhouse gas. Absorbed into the sea it is an essential component for growth of plankton, the first stage of marine life. By contrast, excessive amounts can make some organisms sick and possibly extinct.
The beneficial role of CO2 is in the photosynthetic process that feeds phytoplankton, the microscopic plants of the sea. Carbon dioxide, solar energy and the chlorophyll pigment combine to make food for these organisms that are the first level of life in the sea. A critical byproduct of this chemistry is the respiration of oxygen by these tiny plants. The vast surface area of the World Ocean supplies 50–80 percent of Earth’s oxygen. Indeed, it is the lungs of our planet.
The sea has an enormous capacity to absorb CO2. Since the Industrial Revolution began about 1750, man’s activities have loaded the atmosphere with great quantities of it. However the oceans have been able to absorb about 50 percent of this anthropogenic CO2. Remarkably, this percentage has remained fairly constant over the past 250 years even as increasing amounts are injected into the Earth’s atmosphere. But this “carbon sequestration” comes at a price. When atmospheric CO2 dissolves in seawater there is a chemical reaction that forms carbonic acid, a very weak acid.
Scientists use the pH numerical scale to define the relative acidity or alkalinity of a solution using a range of 0–14. Distilled water is neutral at a value of 7.0. Numbers lower than this are acidic and those above are alkaline. At present the average pH for the oceans is 8.1, so it is slightly alkaline—but this number is decreasing steadily. To be clear, it is unlikely that the oceans’ pH will ever drop below 7.0, so the term “acidification” refers to relative acidity as seawater becomes less alkaline. The accompanying graph shows the relationship between dissolved CO2 and increasing acidity in the sea from the years 1850–2100 (estimated).
What should the carrier air wing of the future look like? The topic has taken on new significance as a consequence of an article in the July issue of Proceedings by the Chief of Naval Operations ADM Jonathan Greenert. The title of the article, “Payloads over Platforms: Charting a New Course,” its discussion of the diminishing value of stealth, and the positive mentions of both the F/A-18 Hornet and unmanned systems such as the Scan Eagle and Fire Scout led some observers to accuse the CNO of being secretly opposed to the carrier variant of the F-35 Joint Strike Fighter. In response, ADM Greenert and his staff have stressed that the article did not refer in any way to the F-35, but instead to stealth in the future.
The F-35 noncontroversy aside, Greenert made a profound statement that could have dramatic implications for the character of U.S. air power, in general, and the future carrier air wing, in particular. The CNO declared “we need to move from ‘luxury-car’ platforms—with their built-in capabilities—toward dependable ‘trucks’ that can handle a changing payload selection.” Why? Well, by definition “luxury car” platforms are expensive. A payload-centric approach allows for more rapid technological refresh at lower cost as well as the ability to tailor forces for the conflict du jour.
One conclusion to be drawn from the CNO’s assertion that the Navy needs to move toward “dependable trucks” is that the value of the performance characteristics associated with so-called “luxury car” platforms is declining Those characteristics include stealthiness, speed, maneuverability, perhaps even survivability. There are those who argue that the combination of advanced sensors, data fusion, high-performance missiles and directed-energy weapons will bring the era of manned fighters and penetrating bombers to an end. It is by no means certain that the U.S. aerospace industry will be able to design an affordable sixth generation manned aircraft with the combination of range, persistence, stealth, ISR, and payload required to operate in such an intensely hostile environment.
A wave strikes the side of to the Military Sealift Command fleet replenishment oiler USNS Henry J. Kaiser (T-AO 187) as it conducts a replenishment at sea with the aircraft carrier USS Nimitz (CVN 68) on July,7.
[U.S. Navy Photo]
The U.S. Navy kicked of its annual Rim of the Pacific (RIMPAC) exercises last Friday and will use the world’s largest naval exhibition to test its concept for powering expeditionary operations on biofuels. A carrier strike group, dubbed the Great Green Fleet, is the culmination of several years of testing in the biofuels arena and will serve as the Navy’s first top-to-bottom test of a force that could go to war powered by alternative energies. But parochial interests in Congress threaten to undo the Navy’s progress on biofuels and undermine efforts to build a cost-competitive biofuels market.
When the House Armed Services Committee took up its annual debate over the National Defense Authorization Act (NDAA) for fiscal year 2013, questions about the Navy’s biofuels program quickly came to the forefront. When the bill hit the House floor in May, two provisions had been added during markup of the bill by Rep. Mike Conaway (R-TX). Biofuels backers see the provisions as an attempt to undercut the Navy’s ambitious effort, which they contend hurts efforts to stabilize Defense Department fuel costs and offset DOD’s dependence on foreign fossil-based fuels.
The first provision, which is more symbolic than substantive, exempts DOD from the so-called Section 526 requirements contained in the Energy Independence and Security Act of 2007. The section requires government-purchased alternative fuels to have a lower greenhouse gas impact than current fossil fuels. DOD says it doesn’t need the waiver, but, within the biofuels industry, section 526 is seen as a levy holding back cheaper but more pollutant-intensive fuels like coal-to-liquid.