Oil depletion and climate change will create an entirely new context in which political struggles will be played out. Within that context, it is not just freedom, democracy, and equality that are at stake, but the survival of billions of humans and of whole ecosystems.

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.

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 real problem is that we use too much oil. It's that simple and that difficult. If we truly want to reduce our vulnerability to high prices, the best way to do so is to reduce consumption.

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.

...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

If we aim for what is no longer possible, we will achieve only delusion and frustration. But if we aim for genuinely worthwhile goals that can be attained, then even if we have less energy at our command and fewer material goods available, we might nevertheless still increase our satisfaction in life.