"For our purposes, there are two major categories of climate feedback loops: positive and negative.
Negative feedback is a process that causes a decrease in function, often in an effort to stabilize the system.
A positive feedback loop, however, “
accelerates a response.”
Using the water vapor cycle as an example, it goes a little something like this:
1. As more and more heat-trapping greenhouse gases are emitted, the atmosphere warms up.
2. This warmer air leads to more water evaporating from our oceans, rivers, lakes, and land, and entering the atmosphere.
3. Warmer air also holds more water vapor, and water vapor itself traps heat.
4. The extra water vapor in the already warmer air retains
even more heat, amplifying the initial warming.
5. Even more warming leads to even more water evaporating, starting the cycle over again. And again.
And again.
It’s a vicious cycle – climate change causing a cascade of effects that result in even more climate change. A problem we created taking on a life of its own… to potentially devastating effect.
Without the regulating action of the negative feedback loop,
a positive loop can eventually spiral out of control, creating changes in the climate system we cannot ever undo. This is called a “tipping point.”
According to NOAA, “The accelerating effects of positive feedback loops can be at risk to irreversible tipping points, which are changes to the climate that are not steady and predictable.
Basically, tipping points are small changes within the climate system that can change a fairly stable system to a very different state. Similar to a wine glass tipping over, wine is spilt from the glass as the tipping event occurs and standing up the glass will not put the wine back; the state of a full wine glass becomes a new state of an empty glass.”
