Global Warming and Hydrogen as Clean Energy
If your top priority is feeling secure in the belief that global warming (if it's actually happening, and if human activities are responsible for it) is necessarily a bad thing, or you believe that hydrogen represents a clean energy source that is "environmentally friendly" — then don't read any further.
Here's an article, in the Quaternary Science Reviews, that suggests global warming is occurring, it is caused by humans, and that that is a good thing, since the warming has retarded the advance of ice-age glaciers.
Abstract
According to a new hypothesis, greenhouse-gas concentrations in the atmosphere should have fallen throughout the last several thousand years and caused a significant cooling of Earth's climate, but early anthropogenic emissions of carbon dioxide and methane kept temperatures relatively warm. A further prediction is that ice should have begun accumulating in northeast Canada several thousand years ago. We carry out a preliminary test of this hypothesis by reducing atmospheric CO2 and CH4 concentrations to their estimated ‘natural’ levels in an experiment with the GENESIS climate model. In the absence of anthropogenic contributions, global climate is almost 2 °C cooler than today and roughly one third of the way toward full-glacial temperatures. The hypothesis of an overdue glaciation is confirmed, but at a small scale: parts of Baffin Island retain snow cover year-round, and snow cover persists on high terrain in Labrador for 11 months of the year.
1. IntroductionThe relative temperature stability of the last 10,000 years has long been viewed as the result of natural climatic causes. Orbital variations are seen as having permitted a brief interglacial break between the previous glaciation and the next one, each encompassing 90% of the duration of a 100,000-year cycle. An accompanying view has persisted that humans played no significant role in altering atmospheric greenhouse-gas concentrations or affecting global climate until the 1800s, when byproducts of the industrial revolution begin to add measurably to the natural greenhouse-gas levels already in the atmosphere and to contribute to the warming trend of the last century (IPCC, 2001).
Both of these concepts have been challenged (Ruddiman, 2003). Ice-core evidence from previous interglaciations indicates that forcing by orbital-scale changes in solar radiation and greenhouse-gas concentrations should have driven Earth's climate significantly toward glacial conditions during the last several thousand years. The hypothesized reason that most of this cooling did not occur is that humans intervened in the natural operation of the climate system by adding significant amounts of CO2 and CH4 to the atmosphere, thereby offsetting most of the natural cooling and fortuitously producing the climatic stability of the last several thousand years. One prediction of this hypothesis is that early anthropogenic greenhouse-gas emissions stopped a glaciation that otherwise would have begun several millennia ago.
2. Experiment [ . . . ]
3. Discussion
The 2 °C mean-annual cooling simulated by removing anthropogenic greeenhouse gases (Fig. 3a) is equivalent to roughly one third of the global-mean difference between full-interglacial and full-glacial climates (CLIMAP, 1981; Mix et al., 2001). It also represents 80% of the warming simulated by the GENESIS 2 model in response to a doubling of modern CO2 (Thompson and Pollard, 1997). Without any anthropogenic warming, Earth's climate would no longer be in a full-interglacial state but well on its way toward the colder temperatures typical of glaciations.
[ . . . ]
In the northern hemisphere, these experiments indicate that high terrain on Baffin Island would today be in a condition of ‘incipient glaciation” (Fig. 3) and that portions of Labrador and Hudson Bay would also have moved very close to such a state (Fig. 4), had greenhouse-gas concentrations followed natural trends. Our results thus provide support on a limited scale for the hypothesis that an ice sheet would now be present in northeast Canada, had humans not interfered with the climate system.
The longer persistence of snow cover in Baffin and Labrador can be compared against the pattern of retreat and final disappearance of Laurentide ice at the end of the most recent deglaciation (Fig. 6). The last place from which Laurentide ice melted—Baffin Island—is the first (and only) place it reappears in our simulation. The next-to-last place the ice sheet melted—the high terrain in central Labrador—is the region poised very near a state of incipient glaciation in this experiment.
[ . . . ]
The GENESIS 2 experiment reported here probably underestimates the amount of ice that would exist today in northeast Canada without anthropogenic gases. We have intentionally limited the number of potential feedbacks in this initial test of the early anthropogenic hypothesis in order to identify the primary atmospheric effect of lowered greenhouse gases on climate. This simulation did not include the positive albedo feedback effect produced by changes in the tundra/forest boundary at high latitudes (Bonan et al., 1992). The much colder climate simulated in this initial run would have increased the area of tundra relative to forest. Because snow-covered tundra has a higher albedo than forest (when snow is present), the change in albedo should have caused further cooling. Previous sensitivity experiments with GENESIS 1 have shown that vegetation/albedo feedback increases the initial climatic impact of prescribed changes in (orbital) forcing at high latitudes (Foley et al., 1994). The imposed changes in tundra limits had the largest effect on temperature and snow cover in the spring season. For the simulation reported here, this kind of feedback would result in colder temperatures and thicker snow cover in late spring, longer-lasting snow cover in summer, and the possibility of more extensive regions of incipient glaciation.
Dynamical ocean processes may also provide positive feedback through changes in wind-driven and thermohaline circulations. Both observational evidence and model simulations indicate that cooling of the Nordic Seas and weakening of the thermohaline circulation were factors in the glacial inception near 115,000 years ago (Cortijo et al., 1994; Khodri et al., 2001; Yoshimori et al. 2002). In addition, a simulation for 6000 years ago using a model with both interactive vegetation and interactive ocean/sea-ice showed considerably enhanced climate sensitivity to orbital forcing compared to simulations with only one of these two components (Ganopolski et al., 1998).
Finally, our ‘snapshot’ experiment only indicates regions where overall mass-balance conditions would permit ice growth, but it does not address how growing ice sheets might have evolved through time. Growing ice sheets have positive feedback effects on local climate, including the elevation/temperature feedback from vertical ice growth, and the albedo feedback from gradually expanding snowfields and lateral ice flow (Andrews and Mahaffy, 1976). Future simulations that incorporate ice, vegetation, and ocean feedbacks, now underway and planned, are likely to enhance the climatic responses to removal of anthropogenic greenhouse gases and enable ice sheets to expand beyond their regions of inception.
My jury is still out on whether or not global warming is happening . . . but even if you buy that it is a reality (and it may well be), and that global warming is the product of human activity (again, certainly possible), it may not be altogether as destructive as the environmental industry would have us believe. (Keep in mind that defining and addressing environmental issues has become big business, and with big business come lots of opportunities for honest and dishonest people. And, as with all industries, there actually are a lot of self-serving people doing bad work who make it difficult for us guppies to separate the good scientists and their good science from the charlatons and their junk science.)
But I guess whether or not you are relieved that we aren't well on our way into another ice age depends on what your priorities are: if you believe that Man is solely a despoiler of nature and her other-worldly spirits, you would surely find reason to deplore a prolonged inter-glacial period marked by human proliferation, and human cultural and scientific progress.
If you are blissfully comfortable with the notion that hydrogen is an easy solution to our energy problems while at the same time saving the environment, the second article you may not want to read is this:
LOS ANGELES — Hydrogen-fueled cars have been hailed as the future of transportation — clean, safe and propelled by a power source whose only by-products are air and water.
"Your main three drivers for developing hydrogen are energy independence, economic growth and environmental sustainability," said Patrick Serfass, technical and program development coordinator of the National Hydrogen Association.
The problem, critics say, is that the technology that makes the fuel of the future generates just as much pollution as the gasoline-powered vehicles we drive right now.
"We need to understand where it's going to come from," says Dr. Michael J. Prather, earth-systems science professor at the University of California at Irvine.
Extracting useful quantities of hydrogen from water requires a massive amount of energy — energy that typically comes from burning oil or coal.
You can also get hydrogen from methane — but once again, it takes a "dirty" fuel to create a "clean" one.
Another possible problem: Scientists call hydrogen a "leaky gas" that easily escapes from any container you put it in, potentially harming the environment.
"It is not a neutral gas," Prather said. "It actually does interact in the atmosphere. And in some sense it needs a better evaluation."
Well, there you have it: no free lunch. You gotta use dirty energy to get clean energy, and hydrogen does interact with in the atmosphere.
Just food for thought, a dose of reality, something to curb unbridled enthusiasm . . .
Brian
