There are nine planetary boundaries that should be respected in order to reduce risking the self-regulating capacity of the planet. The environmental conference is only a first step.
Reaching a substantive global agreement in Copenhagen, Denmark, at the UN-sponsored climate-change conference this December on reducing greenhouse-gas emissions is a necessary step, but it is not sufficient. In order to avoid catastrophic tipping points, we need to effectively manage key Earth system processes, and we need to do it now.
In the run-up to the climate negotiations in Copenhagen, it is easy to get the impression that as long as we reduce emissions of greenhouse gases we will be safe from dangerous, or even disastrous, outcomes for humanity.
But mounting scientific evidence strongly suggests that is very unlikely.
For decades, we have lived with the predominant belief that environmental change occurs in an incremental, linear, and predictable fashion.
But growing evidence indicates that this may be the exception, not the rule, and that long periods of gradual change can eventually push us past thresholds that result in abrupt and potentially disastrous changes.
In fact, we can no longer exclude the possibility that we are crossing hard-wired thresholds at the planetary level, threatening the self-regulating capacity of the planet to remain in the stable and favorable state in which human civilizations and societies have developed during the past 10,000 years.
Compared with the 200,000 years or so that we humans have roamed around on Earth, this Holocene state has been extraordinarily stable from an environmental perspective, providing humanity with the precondition for human development as we know it, from the rise of agriculture to the modern industrial societies of today.
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