Circuloscompensadores y reforzadores

Caso 1.
Este caso es un post de un sitio de internet llamado “The economist” que contiene por lo menos 4 círculos de realimentación.

Why don't Americans believe in global warming?

FIRST of all, I apologize for the slightly inflammatory headline of this post. The fact is that a majority of Americans (58%) do think climate change is a serious problem, according to the January 2011Rasmussen Energy Update, and fully one-third, 33%, "see it as a Very Serious problem." Still, the United States is less exercised about climate change than a lot of countries, and it's one of the few places where you can turn on the television and catch a debate between mainstream figures about whether climate change is even real. Over the weekend, for example, Charles Krauthammer suggested that a beliefin global warming has the same epistemological status as a religious belief.
I've been wanting to take a step back and think about why America is a laggard in the fight against climate change. I would pos it a handful of explanations:
Psychological: The consequences of climate change are too awful to contemplate. Therefore, we're denying the issue, as we used to deny monsters in the room byhiding under the blanket. If you don't look at it, it can't look at you.
Economic: The costs of a large-scale effort to fight global warming are too steep to bear. Therefore, we're trying to ignore the issue, or pretending it doesn't exist, or we believe that the economy (including development) is more important.
Political: The fact that Democrats are always hammering on about climate change andRepublicans aren't suggests that this is a political issue, not a scientific one. This creates a feedback loop: if climate change were real, why is it so polarising? Because it's so polarising, it must be slightly suspicious.
Epistemological: Why should we believe in climate change? Where's the evidence? All we know is what scientists say, and scientists are sometimes wrong. And don't even get mestarted on Al Gore.
Metaphysical: God isn't going to let millions of people die in an epic drought.
I suspect the metaphysical denial is quite rare—but given the comparative religiosity of American culture and the stereotypes thereof, it gets a lot of air time. It is also the least valid of the reasons for denial (partly because in the given system, God obviously does let people die). The otherexplanations are more common. In the Rasmussen poll, for example, a plurality of respondents said that "there is a conflict between environmental protection and economic growth."
I would add here that America's recalcitrance The first is that America consumes a lot of the world's resources. That means America would incur heavier costs than a small European state from a large-scale effort to fightclimate change; disproportionate to its size, but proportionate to its (disproportionate) energy use. The second is that America is big enough that its agreement is probably necessary and perhaps even sufficient for a serious climate fight. In a sense, some international environmental rhetoric could be free riding on American inaction. Neither of these are excuses, just explanatory factors.
Thepolitical and epistemological reasons are pronounced in America and are interrelated. Again, in keeping with the perception that a lot of Americans are religious whackos, there is a perception that this is a country that doesn't believe in science. But the R&D spending would suggest otherwise. It may be that Americans are unusually willing to break rank with scientific authority—as seen in theoccasional flare-ups of vaccine scepticism—but it's not a thoroughgoing animus. (Have dinner with a pregnant woman sometime, and see what I mean.) Similarly, there's not some kind of secret American campaign against the environment. In the 1960s the United States played a leading role in starting the modern environmental movement. It was America, in fact, that saved a lot of whales.
Today, however,...