CO2 apparently helps—but even that is uncertain. I would want to see a very convincing case that we are far enough from the edge for the risk of reglaciation to be over before advocating hanging around on the reglaciation cliff-edge. Short of eliminating the ice caps, it is difficult to imagine what would be convincing. Those ice caps are potentially major bad news for life on the planet—and some industrial CO2 is little reassurance—since that could relatively quickly become trapped inside plants and then buried.
The global ice caps have been around for millions of years now. Life on earth is adapted to climates that sustain them. They do not constitute “major bad news for life on this planet.” Reglaciation would pose problems for human civilization, but the onset of glaciation occurs at a much slower rate than the warming we’re already subjecting the planet to, and as such even if raising CO2 levels above what they’ve been since before the glaciations began in the Pleistocene were not enough to prevent the next round, it would still be a less pressing issue.
On a geological time scale, the amount of CO2 we’ve released could quickly be trapped in plants and buried, but with the state of human civilization as it is, how do you suppose that would actually happen quickly enough to be meaningful for the purposes of this discussion?
The global ice caps have been around for millions of years now. Life on earth is adapted to climates that sustain them. They do not constitute “major bad news for life on this planet.”
The ice age is a pretty major problem for the planet. Huge ice sheets obliterate most life on the northern hemisphere continents every 100 thousand years or so.
Re: reglaciation being slow—the last reglaciation looked slower than the last melt. The one before that happened at about the same speed. However, they both look like runaway positive feedback processes. Once the process has started it may not be easy to stop it.
Thinking of reglaciation as “not pressing” seems like a quick way to get reglaciated. Humans have got to intervene in the planet’s climate and warm it up in order to avoid this disaster. Leaving the climate alone would be a recipe for reglaciation. Pumping CO2 into the atmosphere may have saved us from disaster already, may save us from disaster in the future, may merely be a step in the right direction—or may be pretty ineffectual. However, it is important to realise that humans have got to take steps to warm the planet up—otherwise our whole civilisation may be quickly screwed.
We don’t know that industrial CO2 will protect us from reglaciation—since we don’t yet fully understand the latter process—though we do know that it devastates the planet like clockwork, and so has an astronomical origin.
The atmosphere has a CO2 decay function with an estimated half-life time of somwhere between 20-100 years. It wouldn’t vanish overnight—but a lot of it could go pretty quickly if civilisation problems resulted in a cessation of production.
Hopefully—if we have enough of a civilisation at the time. Reglaciation seems likely to only really be a threat after a major disaster or setback—I figure. Otherwise, we can just adjust the climate controls. The chances of such a major setback may seem slender—but perhaps are not so small that we can afford to be blazee about the matter. What we don’t want is to fall down the stairs—and then be kicked in the teeth.
We don’t know great many things, but what to do right now, we must decide right now, based on whatever we happen to know. (To address the reason for Desrtopa’s comment, if not any problem with your comment on this topic I’m completely ignorant about.)
We don’t know that. The science of this isn’t settled. The Milankovitch hypothesis of glaciation is more band-aid than theory. See:
http://en.wikipedia.org/wiki/Milankovitch_cycles#Problems
CO2 apparently helps—but even that is uncertain. I would want to see a very convincing case that we are far enough from the edge for the risk of reglaciation to be over before advocating hanging around on the reglaciation cliff-edge. Short of eliminating the ice caps, it is difficult to imagine what would be convincing. Those ice caps are potentially major bad news for life on the planet—and some industrial CO2 is little reassurance—since that could relatively quickly become trapped inside plants and then buried.
The global ice caps have been around for millions of years now. Life on earth is adapted to climates that sustain them. They do not constitute “major bad news for life on this planet.” Reglaciation would pose problems for human civilization, but the onset of glaciation occurs at a much slower rate than the warming we’re already subjecting the planet to, and as such even if raising CO2 levels above what they’ve been since before the glaciations began in the Pleistocene were not enough to prevent the next round, it would still be a less pressing issue.
On a geological time scale, the amount of CO2 we’ve released could quickly be trapped in plants and buried, but with the state of human civilization as it is, how do you suppose that would actually happen quickly enough to be meaningful for the purposes of this discussion?
The ice age is a pretty major problem for the planet. Huge ice sheets obliterate most life on the northern hemisphere continents every 100 thousand years or so.
Re: reglaciation being slow—the last reglaciation looked slower than the last melt. The one before that happened at about the same speed. However, they both look like runaway positive feedback processes. Once the process has started it may not be easy to stop it.
Thinking of reglaciation as “not pressing” seems like a quick way to get reglaciated. Humans have got to intervene in the planet’s climate and warm it up in order to avoid this disaster. Leaving the climate alone would be a recipe for reglaciation. Pumping CO2 into the atmosphere may have saved us from disaster already, may save us from disaster in the future, may merely be a step in the right direction—or may be pretty ineffectual. However, it is important to realise that humans have got to take steps to warm the planet up—otherwise our whole civilisation may be quickly screwed.
We don’t know that industrial CO2 will protect us from reglaciation—since we don’t yet fully understand the latter process—though we do know that it devastates the planet like clockwork, and so has an astronomical origin.
The atmosphere has a CO2 decay function with an estimated half-life time of somwhere between 20-100 years. It wouldn’t vanish overnight—but a lot of it could go pretty quickly if civilisation problems resulted in a cessation of production.
If reglaciation starts, could it be stopped by sprinkling coal dust on some of the ice?
Hopefully—if we have enough of a civilisation at the time. Reglaciation seems likely to only really be a threat after a major disaster or setback—I figure. Otherwise, we can just adjust the climate controls. The chances of such a major setback may seem slender—but perhaps are not so small that we can afford to be blazee about the matter. What we don’t want is to fall down the stairs—and then be kicked in the teeth.
I discuss possible theraputic interventions on: http://timtyler.org/tundra_reclamation/
The main ones listed are planting northerly trees and black ground sheets.
We don’t know great many things, but what to do right now, we must decide right now, based on whatever we happen to know. (To address the reason for Desrtopa’s comment, if not any problem with your comment on this topic I’m completely ignorant about.)