Energy and the Environment
- Posted on February 14, 2014
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As is all too often currently presented, energy and the environment need not be an either/or proposition.
One cannot refute the fact that an abundance of energy, primarily from fossil fuels, has been a boon to mankind over the past 250 years. For about the last 35 years however, it has been abundantly clear those benefits have been attended by a significant and mounting environmental cost.
Were it clear we could produce energy without environmental costs, maintenance of the status quo would be tantamount to committing planetary vandalism and homicide.
The World Health Organization reports that over 150,000 deaths annually can be currently attributed to climate change and climate related property damage has averaged in the vicinity of $200 billion/year most recently.
The latest study by Matthew England et al., Temperatures blown off course, published in the journal nature climate change, presents evidence of how we can do better than produce damage-free energy. We can match current fossil fuel outputs with environmentally beneficial production.
Notwithstanding an earlier study by British and Canadian researchers that suggested global warming has not actually slowed, measurements simply haven’t been taken where it is occurring, the England study shows how unusually strong trade winds in the Pacific Ocean have buried surface ocean heat in deeper water and offers this burial as a rationale for why the rise in measured surface temperatures has significantly slowed since 2001.
Taking the British/Canadian study into account however; an alternative explanation would be the planet is warming faster than anyone has previously anticipated and thus the need to act is all the more urgent.
These studies are significant in that they address the so called global warming “pause” or “hiatus” that became fodder for climate science skeptics and critics subsequent to the presentation of the UN’s Intergovernmental Panel on Climate Change report in September of 2013.
John Church, one of the lead authors of the IPCC report said in an interview with the Toronto Star at that time, “The only place that can store heat in the climate system are the oceans. In the past 40 years, oceans have stored 90 per cent of the heat and much of that is in upper part of the oceans. But now there is indication that in the past decade, the heat is going deeper into the oceans and so even though the surface has not warmed as much, the deep ocean has continued to warm up. Oceans can trap huge amounts of heat over hundreds of decades and maybe even hundreds of centuries. But how much and for how long is unclear. As oceans continue to warm and expand, the sea levels rise and push against ice sheets. That is a concern in the long-term.”
Indicative of the amount of heat the oceans can store, while accumulating energy at a rate of between 4 and 12 Hiroshima bombs equivalents every second, is the 2012 paper of Levitus et al, World Ocean Heat Content and Thermosteric Sea Level change (0-2000 m),1955-2010, which shows that to a depth of 2000 meters and over the study’s span the oceans have only warmed an average of 0.09°C.
In an interview with the Guardian Dr. England stated,: “Global warming has not stopped. People should understand that the planet is a closed system. As we increase our emissions of greenhouse gases, the fundamental thermal dynamics tells us we have added heat into the system. Once it’s trapped, it can go to a myriad of places – land surface, oceans, ice shelves, ice sheets, glaciers for example.” Further he explained how the winds help the ocean to absorb heat into the thermocline – that’s roughly the area between 100 metres and 300 metres deep. He says once the trade winds drop – which is likely to come within years rather than decades – then the averaged surface temperatures will rise sharply again.
While acknowledging that it can not happen that way, Levitus et al. points out that if all of the heat the oceans have absorbed between 1955 and 2010 was instantly transferred to the lower 10 km of the atmosphere it would warm by approximately 36 C.
The planet is a closed system. Of all the myriad places trapped heat can go however the deep ocean is the largest heat sink, where it can be most diluted and do the least damage, the only place where its movement from the surface is an opportunity to produce power in accordance with the second law of thermodynamics and the only place where it would be less of an environmental threat than in its current location. On the surface it drives tropical storms that cause death and destruction and move heat towards the poles and per the following diagram the coefficient of expansion of ocean water at a depth of 1000 meters is half that of the tropical surface.
The estimation of Krishnakumar Rajagopalan and Gérard C. Nihous, in their paper An Assessment of Global Ocean Thermal Energy Conversion Resources With a High-Resolution Ocean General Circulation Model is that the global maximum steady-state OTEC electrical power potential is about 14 Terawatts, which is more than all of the energy derived from fossil fuels in 2006 according to the United States Energy Information Administration.
The production of this power with a deep water condenser design would require the constant movement of heat, about 20 times more than the quantity of energy produced, into the oceans at least three times deeper than where it is currently being shifted by the trade winds. This would perpetuate the existing pause concurrently to the generation of sufficient power to replace all we are currently generating from fossil fuels.
The Guardian article shows the following Australia’s CSIRO science agency chart of sea level rise in recent decades and points to the fact that the 2011 decline was due to water being temporarily stored on the Australian land mass following the major flooding and rainfall event of that year.
To a lesser extent this effect would be replicated by the conversion of ocean volume to hydrogen by electrolysis, in order to bring offshore generated power to market, and then the reconstitution of this hydrogen back into water on land either in a fuel cell or a combustion engine that produces power.
If we are not taking any practical lessons from studies such as the ones referenced in this piece, one has to wonder what is the point of them?
To my mind, they point to the fact that the solution to our most significant problem is staring us in the face even as we do nothing about it, least of all for the 150,000 dying each year.