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OKIsItJustMe

(19,938 posts)
Sat Feb 13, 2016, 01:16 PM Feb 2016

Scientists say window to reduce carbon emissions is small

http://oregonstate.edu/ua/ncs/archives/2016/feb/scientists-say-window-reduce-carbon-emissions-small
[font face=Serif][font size=5]Scientists say window to reduce carbon emissions is small[/font]

02/08/2016

[font size=3]CORVALLIS, Ore. – At the rate humans are emitting carbon into the atmosphere, the Earth may suffer irreparable damage that could last tens of thousands of years, according to a new analysis published this week.

Too much of the climate change policy debate has focused on observations of the past 150 years and their impact on global warming and sea level rise by the end of this century, the authors say. Instead, policy-makers and the public should also be considering the longer-term impacts of climate change.

“Much of the carbon we are putting in the air from burning fossil fuels will stay there for thousands of years – and some of it will be there for more than 100,000 years,” said Peter Clark, an Oregon State University paleoclimatologist and lead author on the article. “People need to understand that the effects of climate change on the planet won’t go away, at least not for thousands of generations.”

The researchers’ analysis is being published this week in the journal Nature Climate Change.

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9 replies = new reply since forum marked as read
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Scientists say window to reduce carbon emissions is small (Original Post) OKIsItJustMe Feb 2016 OP
And the rigtwing terrorists on the SC owned by the GOP have stopped what little Obama randys1 Feb 2016 #1
I don’t think they’re trying to kill the human race OKIsItJustMe Feb 2016 #2
I agree JFKDem62 Feb 2016 #4
Natural processes can remove 1 ppm in ~800 years. GliderGuider Feb 2016 #3
I usually go for 1 ppm per 1,000 years (it’s a nice round number) OKIsItJustMe Feb 2016 #5
What “non-natural” processes pscot Feb 2016 #6
The only effective ones will be some form of carbon capture and sequestration OKIsItJustMe Feb 2016 #7
+1 nt GliderGuider Feb 2016 #8
Thank you pscot Feb 2016 #9

randys1

(16,286 posts)
1. And the rigtwing terrorists on the SC owned by the GOP have stopped what little Obama
Sat Feb 13, 2016, 01:19 PM
Feb 2016

could do.

The GOP is trying to kill the human race.

I have said that for a long time, waiting for everyone to catch up.

OKIsItJustMe

(19,938 posts)
2. I don’t think they’re trying to kill the human race
Sat Feb 13, 2016, 01:27 PM
Feb 2016

That (of course) would be suicide.

I think they just want to be as rich as possible.

 

GliderGuider

(21,088 posts)
3. Natural processes can remove 1 ppm in ~800 years.
Sat Feb 13, 2016, 01:28 PM
Feb 2016

If we stop emitting CO2 completely today, it will take 100,000 years to return to pre-industrial levels. Every year we delay costs the planet another 2500 years of recovery time.

OKIsItJustMe

(19,938 posts)
5. I usually go for 1 ppm per 1,000 years (it’s a nice round number)
Sat Feb 13, 2016, 01:39 PM
Feb 2016

My conclusion, based on the analysis of James Hansen (et al.) is that we will need to resort to “non-natural” processes.
http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf

… If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO₂ will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that. …

pscot

(21,024 posts)
6. What “non-natural” processes
Sat Feb 13, 2016, 09:09 PM
Feb 2016

do you envision? At some point the powers that be will decide to pull out all the stops. What forms might that take.

OKIsItJustMe

(19,938 posts)
7. The only effective ones will be some form of carbon capture and sequestration
Sat Feb 13, 2016, 10:40 PM
Feb 2016
Biochar is one approach which may be employed. Hansen et al suggested that if we acted immediately, the combination of biochar and reforestation (combined with a moratorium on coal) might bring CO₂ levels down at an acceptable rate.


Carbon sequestration in soil also has significant potential. Biochar, produced in pyrolysis of residues from crops, forestry, and animal wastes, can be used to restore soil fertility while storing carbon for centuries to millennia (82). Biochar helps soil retain nutrients and fertilizers, reducing emissions of GHGs such as N₂O (83). Replacing slash-and-burn agriculture with slash-and-char and use of agricultural and forestry wastes for biochar production could provide a CO₂ drawdown of ~8 ppm in half a century (83).

In Supplementary Material we define a forest/soil drawdown scenario that reaches 50 ppm by 2150 (Fig. 6B). This scenario returns CO₂ below 350 ppm late this century, after about 100 years above that level.

Unfortunately, that call for immediate action was in 2008.



Assumptions yielding the Forestry & Soil wedge in Figure 6B are as follows. It is assumed that current net deforestation will decline linearly to zero between 2010 and 2015. It is assumed that uptake of carbon via reforestation will increase linearly until 2030, by which time reforestation will achieve a maximum potential sequestration rate of 1.6 GtC per year (S34). Waste-derived biochar application will be phased in linearly over the period 2010-2020, by which time it will reach a maximum uptake rate of 0.16 GtC/yr (83). Thus after 2030 there will be an annual uptake of 1.6 + 0.16 = 1.76 GtC per year, based on the two processes described.



Even then, it was a bit of a stretch…


Various chemical reactions may be used to capture carbon from ambient air. I expect these will be attempted.

The thing that haunts me is this: We’ve been burning coal to produce energy. If we wanted to capture the CO₂ we released and convert it into… say… a solid chunk of carbon (like coal) we would need to supply every bit of energy that was released by burning the coal in the first place and then some (due to thermodynamic inefficiencies.) Kinda like paying a loan back with interest.

That’s a lot of energy to get from somewhere, in a hurry…


As a result, I think we will probably attempt to sequester CO₂ itself. (Perhaps deep ocean sequestration.)
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