To Open The Sky
Earth's climate has changed a great deal since I began these Web pages ten years ago — not, it is true, as much as it changed in prehistoric times, but in ways that are easily noticed. Spring comes earlier in the year; rainstorms are wetter; animals, birds and fish are moving out of their traditional ranges; coastal cities are flooding during high tides. Other things have changed too. Some of these changes were good, others were bad. One good thing is that there is far less doubt about the reality that our climate is changing and that we are mainly responsible for the change.
Accordingly, there is less need to explain the science behind the changes. I can turn to what can be done, or should be done, to respond to them. How can we cut our carbon dioxide emissions, and how much will it cost? Is it feasible to remove carbon dioxide already in the atmosphere? Will we be able to convince other nations to do their part? Is holding back sea-level rise affordable? Will geoengineering save us?
I'm preserving the old pages on global warming, and may do some updating on them. A link to them is below. And I'm keeping the link to the federal government's Global Change Research Program here as well as there, because those pages document the ongoing impacts in the U.S. But it is time to get pragmatic about policies of mitigation and adaptation.
Origin and background
All original fuels were biofuels. Animal dung, dry leaves or brush, fallen limbs of trees, up through tallow rendered from animal fats for candles and whale oil for lamps. All of these released carbon dioxide (and soot) when burned, but these waste products did not change the atmospheric balance since they came from the biosphere and returned to it.
More recently, wood alcohol (methanol) and grain alcohol (ethanol) distilled into pure form from fermented mixtures have been used as fuels — as have the more complex alcohols like isopropyl, often used in laboratory alcohol lamps because it produced no soot. In modern times, ethanol made from corn and biodiesel produced from oils or fats using transesterification are increasingly used for transportation.
Swamp gas (methane) might have been used in preindustrial times, but the difficulty of capturing it makes this unlikely.
Upside
The major benefit of biofuels in today's world is that they slow the increase of fossil carbon dioxide entering Earth's atmosphere by substituting for traditional propane, gasoline, or diesel fuel used in ships, airplanes, and the billions of ground vehicles. Transportation currently makes up [40%] of total CO2 emissions and in 2018 amounted to x gigtons.
Downside
The major downside is that producing biofuels in quantities needed to replace traditional fuels is not yet economically feasible.
Corn ethanol, specifically, is not sustainable because iverting substantial amounts of the grain from food production raises the price of foods made from corn, which often puts them out of reach in developing countries. For example, during 2007 prices for corn tortillas tripled in some parts of Mexico1 because the U.S. began a government-mandated program of supplementing gasoline with ethanol made from corn.
