We are about to enter a new era in which, each year, less net energy will be available to humankind, regardless of our efforts or choices. The only significant choice we will have will be how we adjust to this new regime. That choice - not whether, but how to reduce energy usage and make a transition to renewable alternatives - will have profound ethical and political ramifications.
Richard Heinberg...the era of cheap oil and natural gas is coming to a crashing end, with global oil production projected to peak in 2010 and North American natural gas extraction rates already in decline. These events will have enormous implications for America's petroleum-dependent food system
Richard HeinbergSurveying the available alternative energy sources for criteria such as energy density, environmental impacts, reliance on depleting raw materials, intermittency versus constancy of supply, and the percentage of energy returned on the energy invested in energy production, none currently appears capable of perpetuating this kind of society.
Richard HeinbergWhen a caterpillar eats a leaf, then a thrush eats the caterpillar, or when a hawk eats the thrush only 5 to 20% of usable energy is transferred from one level to the next. ... Thus herbivores will account for a much smaller fraction of the biomass [than plants] and the carnivores for a still smaller fraction.
Richard Heinberg