Insulation: first the body, then the home. Photo credit: Woolpower. Over the last decades, both the insulation of homes and the energy efficiency of heating appliances have improved considerably. These efforts have led to substantial energy savings in fuel consumption. In spite of population growth, higher comfort levels, and a trend towards building larger homes, total energy consumption for space heating by American households came down from 5.32 quadrillion Btu in 1993 to 4.30 quadrillion Btu in 2005 (source). Similar trends can be seen in other industrialized countries. Nevertheless, space heating still consumes a huge amount of energy, which comes almost exclusively from fossil fuels.
Further improvements in energy-efficient buildings and heating systems can be expected, but apart from the embodied energy required to make the housing stock more efficient, there is an additional problem that prevents a fast and steep reduction in energy consumption: cost. Room temperature The body as a heating system Maintaining thermal comfort. My Neighbors Use Too Much Energy. From www.christmasvacationcollectibles.com I have described in a series of posts the efforts my wife and I have made to reduce our energy footprint on a number of fronts. The motivation stems from our perception that the path we are on is not sustainable. Our response has been to pluck the low-hanging fruit, demonstrating to ourselves that we can live a “normal” life using far less energy than we once did.
We are by no means gold medalists in this effort, but our savings have nonetheless been substantial. Now we shift the burden off of ourselves, and onto our neighbors. You don’t have to run faster than the bear—just faster than the other guy. Setting the Scale The U.S. energy budget—accounting for nearly a quarter of the energy consumption of the entire world—is about 100 quadrillion Btu (“Quads”, or QBtu) per year. The 100 QBtu number refers to primary energy—before accounting for substantial efficiency losses in power plants, car engines, etc. Household Savings Electricity Natural Gas. Can Economic Growth Last? [slimstat f='count' w='ip' lf='resource contains can-economic'] views this month; [slimstat f='count' w='ip' lf='strtotime equals 2011-07-01 | interval equals -1'] overall As we saw in the previous post, the U.S. has expanded its use of energy at a typical rate of 2.9% per year since 1650.
We learned that continuation of this energy growth rate in any form of technology leads to a thermal reckoning in just a few hundred years (not the tepid global warming, but boiling skin!). What does this say about the long-term prospects for economic growth, if anything? World economic growth for the previous century, expressed in constant 1990 dollars. For the first half of the century, the economy tracked the 2.9% energy growth rate very well, but has since increased to a 5% growth rate, outstripping the energy growth rate.
The figure at left shows the rate of global economic growth over the last century, as reconstructed by J. Exponential vs. First, let’s address what I mean when I say growth. The Real Population Problem. Sometimes considered a taboo subject, the issue of population runs as an undercurrent in virtually all discussions of modern challenges. Naturally, resource use, environmental pressures, climate change, food and water supply, and the health of the world’s fish and wildlife populations would all be non-issues if Earth enjoyed a human population of 100 million or less. The subject is taboo for a few reasons. The suggestion that a smaller number would be nice begs the question of who we should eliminate, and who gets to decide such things.
Also, the vast majority of people bring children into the world, and perhaps feel a personal sting when it is implied that such actions are part of the problem. I myself come from a long line of breeders, and perhaps you do too. Recently, participating in a panel discussion in front of a room full of physics educators, I made the simple statement that “surplus energy grows babies.” A Brief Look at Population History Does Energy Grow Babies?
The Energy Trap. Many Do the Math posts have touched on the inevitable cessation of growth and on the challenge we will face in developing a replacement energy infrastructure once our fossil fuel inheritance is spent. The focus has been on long-term physical constraints, and not on the messy details of our response in the short-term. But our reaction to a diminishing flow of fossil fuel energy in the short-term will determine whether we transition to a sustainable but technological existence or allow ourselves to collapse. One stumbling block in particular has me worried. I call it The Energy Trap . In brief, the idea is that once we enter a decline phase in fossil fuel availability—first in petroleum—our growth-based economic system will struggle to cope with a contraction of its very lifeblood. Fuel prices will skyrocket, some individuals and exporting nations will react by hoarding, and energy scarcity will quickly become the new norm.
Energy Return on Energy Invested Arresting the Decline: Take 1.