The principal causes of the global crisis are unsustainable conditions in society, the economy, and in the ecology.
Unsustainability in society. The contemporary world is polarized; there is a large and still growing gap between rich and poor, powerful and marginalized. The gap is expressed in economic terms, but it’s a social reality. It depresses the quality of life, and even the chances of survival of vast populations.
Unsustainability in the economy. In the six decades since World War II, more of the planet’s resources have been consumed than in all of history before then. Global consumption is nearing, and in some cases has already surpassed, planetary maxima. The production of oil, fish, lumber, and other major resources has already peaked; forty percent of the world’s coral reefs are gone, and annually about 23 million acres of forest are lost. Ecologists also speak of “peak water,” since henceforth the quantity of water suited for human use is bound to diminish.
Unsustainability in the ecology. Social and economic unsustainability is exacerbated by the conditions human activity is creating in the environment. The planet’s wealth is being progressively overexploited and exhausted. Today about one-third of the world’s population doesn’t have access to adequate supplies of clean water, and by 2025 two-thirds of the population will live under conditions of critical water scarcity. 12 to 17 million acres of cropland are lost per year. At this rate 741 million acres will be lost by mid-century, leaving 6.67 billion acres to support 8 to 9 billion people. This would be catastrophic, as the remaining 0.74 acres of productive land could only produce a bare subsistence level of food. During the 20th century human activity has injected one terraton of CO2 into the atmosphere. Currently it’s injecting another terraton in less than two decades. The rapid injection of carbon dioxide makes it impossible for the Earth’s ecosystems to adjust.
Biologist James Lovelock’s assessment of the planet’s ecological condition has an ominous ring of truth. “I now take an apocalyptic view of the future,” he wrote, “because I see 6 to 8 billions of humans faced with ever diminishing supplies of food and water in an increasingly intolerable climate.”