Re:Greenland ice has shrunk beyond return, study finds
by ivalm on Friday August 14, 2020 @11:50PM
(#24165754)
Earth survived way higher co2 levels and we don’t emit nearly enough sulfides. There is essentially zero chance of Venus event happening. I’m more inclined that climate change can cause catastrophic war than runaway to ultra high temperatures.
Re:Greenland ice has shrunk beyond return, study finds
by imtringued on Saturday August 15, 2020 @10:58AM
(#24169333)
Past CO2 levels aren't relevant because over time things like solar irradiance change as well. The amount of CO2 needed to maintain a certain global temperature shrinks over long time frames (hundreds of millions of years) as the sun gets hotter and hotter until it finally dies.
Re:Greenland ice has shrunk beyond return, study finds
by ivalm on Saturday August 15, 2020 @01:40PM
(#24170656)
Except sun hasn’t become meaningful hotter in the past hundred mil years. Also, we would need lots of sulfer dioxides to get emited, which isn’t happening.
Will earth suffer over the next billion years and lose atmosphere? Sure, but that’s not what’s happening now.
Re:Greenland ice has shrunk beyond return, study finds
by neckardt on Saturday August 15, 2020 @01:02AM
(#24166102)
> but a runaway green house effect is certainly possible
Could you go into detail about how this could happen? My understanding is that this would require lots of greenhouse gasses getting pumped into the atmosphere somehow (Something like all the forests in the world burning down). I remember hearing one theory regarding methane calthrate [1] causing this effect, however I haven't read any studies going into the specifics of how large this effect could be.
[1]: https://en.wikipedia.org/wiki/Methane_clathrate#Methane_clat...
If a positive temperature feedback loop happened to the earth’s atmosphere we could definitely end up like Venus, where no living thing can survive.
And as engineers we understand that positive feedback loops cause changes in exponential progression. It can be “almost fine” for a while and then suddenly “there’s nothing we can do” even in human timescales.
And it could happen fast enough that humans don’t develop tech robust enough to survive other planets unsupported, so game over for humanity, better luck next time.
I personally don’t think thats going to happen, but to be honest I wouldn’t want to risk it.