What I am confused about is why you seem to insist that bifurcations are inconsistent with constantly changing systems? It is well known that systems exhibiting complex, sometimes unstable oscillations are capable of rapid unpredictable shifts. (Depending on the situation, the switching can be between attractors and in other circumstances a bifurcation occurring when a driver is gradually changed.) There seems to be little confusion about this among mathematical modelers.

I encountered your site indirectly via your WSJ article. I found that piece frankly muddled and bit misleading (although I think I’m getting a clearer idea of where you’re coming from after reading some of this site). The analogy between “balance of nature” and current climate models seems misplaced. What specifically are you proposing as an alternative to current modeling approaches?

There’s no excuse why every south-facing, unshaded structure shouldn’t be sporting some kind of solar collector(s). We have the technology, and we have the means to mass-produce and install it. So it makes other energy sources obsolete, who cares? Either the energy monopolies need to get on board with renewable, CLEAN energy or they go out of business. Isn’t that how the free market is supposed to work?

Saying that something is going to undergo a “tipping point” makes things sound much worse than simply saying that things are going to change, and the use taints a discussion in a way that is unscientific and inappropriate in scientific papers about natural ecological systems, and leads us away from, rather than toward, better understanding.

Also, the term “tipping point” is used in a more specific way to mean a sudden shift from one steady-state to some other state-steady condition of the entire system. Since populations, species, ecosystems, and the entire biosphere are non-steady-state systems, this way of thinking just doesn’t fit. Non-steady-state systems are always changing and do not have neat, specific fixed conditions.

People who had difficulty with what I have written about tipping points here, where I have to be very brief, would be best helped if they take the time to read my book Discordant Harmonies, where I took the time, and much effort, to explain the nature of nature as best understood by modern science, and to explore the history of the idea, especially the idea of nature in steady state. These ideas are not the easiest or simplest, and can’t be explained in a slogan or phrase. But if we really want to solve environmental problems, we have to understand how nature really works, and that takes time and effort. The term “tipping points” is being used in a way that suggests the answers are simple, which they are not.

Other essays on my website pursue these ideas in other ways, and could help those of you who are having trouble understanding the concepts.

Over the next weeks, I will be adding more material to this website to go deeper into the ideas and expand upon them. I hope readers like this one will join me in that pursuit. I’ve spent 4 decades trying to understand nature and help solve environmental problems, and I can tell you that the path is difficult, but fascinating, and also important.

Dan Botkin

Although “Life” may be highly resilient, individual species are much less so, and individual organisms even less so. Take human life for example. We require an environment within a certain temperature range (natural or artificially maintained), a steady supply of food and water, oxygen to breathe, and protection from predation and disease. If any of these are disrupted sufficiently from a range (using suitable measures), we die. If they are disrupted for enough of us, the whole species dies. These are real thresholds, and they hold for all species. Logically, there is also a threshold for the possible extinction of all life on Earth; say from a large asteroid impact or the eventual death of the sun.

The whooping crane example just proves the point that environments have to be carefully regulated, by natural processes or human intervention, in order to maintain species with fairly specific requirements.

Here are a few examples from possible global warming scenarios. If sea levels rise and tropical storms become more fierce, millions will die in Bangladesh. For them, this is a pretty big tipping point. More generally, if the climate warms and dries to the point where we can’t produce enough food for support human populations, millions more may die, including us. Ocean warming and increasing acidity are threatening the ecosystems of coral reefs, pelagic micro-organisms, and food chains. Contrary to the authors, I look ahead and see many cliffs on the near and far horizon.

There’s obviously some sophisticated math and ecology behind the author’s work, and the explanation is clear for ecosysems that vary within a range that’s compatible with the requirements of life for specific organisms. Isn’t the argument all about human-induced changes that may be large enough to disrupt those requirements?