The science is in: either we go cold turkey on our coal, oil, and gas addictions, or we risk raising the planet's temperature to a level incompatible with the continued existence of civilization.

Surveying 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.

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.

...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

When 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.

The idea that we industrialized humans are immune to the natural laws that have restrained growth in other species-and humans in past social regimes-is to me so self-servingly blind as to be morally reprehensible.

Early ecologists soon realised that, since humans are organisms, ecology should include the study of the relationship between humans and the rest of the biosphere. ... We don't often tend to think about the social sciences (history, economics and politics) as subcategories of ecology. But since people are organisms, it is apparent that we must first understand the principles of ecology if we are to make sense of the events in the human world.