Cont: Global warming discussion V

[lomiller]

 

[Trakar]

These Scientists Did More Than Tell Us We Were Doomed

The authors of the IPBES report also gave us a road map out

IPBES Report Link: https://www.ipbes.net/sites/default/files/downloads/spm_unedited_advance_for_posting_htn.pdf

IPBES - The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services
The intergovernmental body which assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision makers.

Table SPM.1. Approaches for sustainability and possible actions and pathways for achieving them: pages 32-35

Key Messages (document sections)

1. Nature and its vital contributions to people, which together embody biodiversity and ecosystem functions and services, are deteriorating worldwide.
2. Direct and indirect drivers of change have accelerated during the past 50 years.
3. Goals for conserving and sustainably using nature and achieving sustainability cannot be met by current trajectories, and goals for 2030 and beyond may only be achieved through transformative³changes across economic, social, political and technological factors.
4. Nature can be conserved, restored and used sustainably while simultaneously meeting other global societal goals through urgent and concerted efforts fostering transformative change

Sobering read, at the least.

 

[Red Baron Farms]

Sobering read, at the least.

Agreed and not at all unexpected either.

Once I saw this:
Farming Claims Almost Half Earth's Land, New Maps Show

I began to realize if almost 1/2 the land is already in agriculture, and the vast majority of the rest of it is mountain peaks, glaciers, and deserts unsuitable for all life but the extremophiles. Then added to that thought my experience in agricultural methods and knowledge of what the conventional does to the life on that land. I knew this will crack and collapse catastrophically soon.

I mean seriously. You cant literally kill off 1/2 the planet with biocides every single year on purpose and expect a good outcome. D'oh

 

[JeanTate]

This is, I hope, a good place to ask about net CO₂ emissions (for want of a better word) that end up in the atmosphere.

A lot of such is obviously directly anthropogenic: burning fossil fuels, say.

Some is (only just) indirectly anthropogenic: clearing forests, say, for palm plantations or cattle ranches.

Some more indirect, such as methane leaks (methane becomes atmospheric CO₂, after a delay).

How much, though, is due to "natural" effects of climate change? For example, warmer weather in boreal forests leads to massive die-offs of trees which leads to net atmospheric CO₂; or more severe droughts lead to more ferocious and widespread forest fires (with much slower re-growth as the fires really do kill much more of the flora).

 

[lomiller]

This is, I hope, a good place to ask about net CO₂ emissions (for want of a better word) that end up in the atmosphere.

A lot of such is obviously directly anthropogenic: burning fossil fuels, say.

Some is (only just) indirectly anthropogenic: clearing forests, say, for palm plantations or cattle ranches.

Some more indirect, such as methane leaks (methane becomes atmospheric CO₂, after a delay).

How much, though, is due to "natural" effects of climate change? For example, warmer weather in boreal forests leads to massive die-offs of trees which leads to net atmospheric CO₂; or more severe droughts lead to more ferocious and widespread forest fires (with much slower re-growth as the fires really do kill much more of the flora).

The airborne fraction has remained at ~45% since the industrial revolution. IOW the land and ocean carbon sinks absorb all the carbon released naturally and more than half the CO2 we release by burning fossil fuels.

It’s widely recognised that this cannot continue indefinitely and indeed that at the earth warms, it will slowly release naturally sequestered CO2. These slow feedbacks are a key player in glacial cycles for example, and provide the long term amplification required to turn small orbital wobbles into big climate chances.


These are slow effects however, and thus far have been swamped by our rapid release of fossil carbon. Of note, however, is that while we know these slow feedbacks exist and have powerful long term effects, they are not factored into current climate models or scenarios. Basically all IPCC projections ignore any and all effects that are not currently occurring, which means they are as conservative as reasonably possible with almost all risk on the side of them underestimating long term warming.

 

[JeanTate]

The airborne fraction has remained at ~45% since the industrial revolution. IOW the land and ocean carbon sinks absorb all the carbon released naturally and more than half the CO2 we release by burning fossil fuels.

It’s widely recognised that this cannot continue indefinitely and indeed that at the earth warms, it will slowly release naturally sequestered CO2. These slow feedbacks are a key player in glacial cycles for example, and provide the long term amplification required to turn small orbital wobbles into big climate chances.


These are slow effects however, and thus far have been swamped by our rapid release of fossil carbon. Of note, however, is that while we know these slow feedbacks exist and have powerful long term effects, they are not factored into current climate models or scenarios. Basically all IPCC projections ignore any and all effects that are not currently occurring, which means they are as conservative as reasonably possible with almost all risk on the side of them underestimating long term warming.

Thanks!

There's another indirect contributor I'm interested in: increased natural methane emissions, e.g. due to thawing permafrost. I think I read, upthread, that the direct effects of this (i.e. more warming) are not (or not well?) modeled (maybe I didn't read carefully enough). The indirect effect is yet more atmospheric CO₂.

Also, as the oceans become more acidic, will their ability to absorb atmospheric CO₂ decrease? IOW, more generally, what's the expected trend for the "~45%"?

 

[lomiller]

Thanks!

There's another indirect contributor I'm interested in: increased natural methane emissions, e.g. due to thawing permafrost. I think I read, upthread, that the direct effects of this (i.e. more warming) are not (or not well?) modeled (maybe I didn't read carefully enough). The indirect effect is yet more atmospheric CO₂.

Also, as the oceans become more acidic, will their ability to absorb atmospheric CO₂ decrease? IOW, more generally, what's the expected trend for the "~45%"?

Realclimate has covered it a dew times but Methane probably isn't an issue long term, at least not directly.

http://www.realclimate.org/index.php/archives/2012/01/much-ado-about-methane/

http://www.realclimate.org/index.ph...of-methane-in-our-climate-in-five-pie-charts/

The thing to remember is that Methane only stays in the atmosphere for a decade or so. CO2 on the other hand stays in the atmosphere for centuries. CO2 also has a long tail, so ~10% of the CO2 we are releasing will still be in the atmosphere 100K years from now.

If you increase the amount of Methane you release there is a corresponding 1 time increase in atmospheric methane, and radiative forcing. OTOH if you increase the amount of CO2 you release, atmospheric CO2 and radiative forcing will rise for several centuries, so in spite of Methane nominally being a stronger greenhouse gas CO2 has a larger climate impact. IF Methane were released fast enough it could cause very rapid warming, but only for a couple decades before the Methane decomposed to CO2.


While such a release could be possible at the very least it's unlikely, and rates at which methane is release would need to be many orders of magnitude faster than what's currently observed.

This isn't to say arctic soils and permafrost are not an issue, they contain enormousness amounts of carbon, but even if this carbon is initially released as methane is becomes CO2 rather quickly. However, there is enough carbon stored there that the CO2 itself is a big problem.

Also, as the oceans become more acidic, will their ability to absorb atmospheric CO₂ decrease? IOW, more generally, what's the expected trend for the "~45%"?

It's generally agreed that the oceans ability to hold CO2 drops as temperature increases. At the oceans continue to warm, therefor, at some point the worlds oceans will stop absorbing CO2 from the atmosphere and begin releasing CO2 into the atmosphere. All the anthropogenic ic carbon they have already absorbed and more could ultimately be released into the atmosphere.

Again though, exactly when or how much extra carbon is an unknown so this is not something built into current climate change scenarios.

 

[The Atheist]

Congratulations, humans - CO2 has passed 415 ppm!

C'mon, fire up those cars, we can do 500, easy.

 

[Trakar]

Realclimate has covered it a dew times but Methane probably isn't an issue long term, at least not directly.

http://www.realclimate.org/index.php/archives/2012/01/much-ado-about-methane/

http://www.realclimate.org/index.ph...of-methane-in-our-climate-in-five-pie-charts/

The thing to remember is that Methane only stays in the atmosphere for a decade or so. CO2 on the other hand stays in the atmosphere for centuries. CO2 also has a long tail, so ~10% of the CO2 we are releasing will still be in the atmosphere 100K years from now...

Not saying you are wrong, but you may be missing some qualification and nuance in what you appear to be saying. This isn't, strictly speaking, in accord with what the geologic record demonstrates. The problem with large scale, rapid releases of CH4 is that they overwhelm the mechanisms of atmospheric degradation of CH4 to CO2, meaning that large releases of methane into the atmosphere, have the potential to linger for tens to hundreds of thousands of years, and all the methane that is degraded is merely degraded to the longer potential persistence problem of atmospheric CO2 all the while exasperating the background warming.

(Note I'm speaking more to Clathrate devolution than peat/tundra soil emissions.)

BTW, I see the science is still dragging toward the scenarios many of us understood and found well supported 2 decades or so ago.

Ice sheet contributions to future sea-level rise from structured expert judgment
https://www.pnas.org/content/early/2019/05/14/1817205116

Conclusions.
This study suggests that experts’ judgments of uncertainties in projections of the ice sheet contribution to SLR have grown during the last 6 y and since publication of the AR5. This is likely a consequence of a focused effort by the glaciological community to refine process understanding and improve process representation in numerical ice sheet models. It may also be related to the observational record, which indicates continued increase in mass loss from both the AIS and GrIS during this time. This negative learning (36, 37) may appear a counter intuitive conclusion, but is not an uncommon outcome: as understanding of the complexity of a problem improves, so can uncertainty bounds grow. We note that for risk management applications, consideration of the upper tail behavior of our SLR estimates is crucial for robust decision making. Limiting attention to the likely range, as was the case in the Intergovernmental Panel on Climate Change AR5, may be misleading and will likely lead to a poor evaluation of the true risks. We find it plausible that SLR could exceed 2 m by 2100 for our high-temperature scenario, roughly equivalent to business as usual. This could result in land loss of 1.79 M km2, including critical regions of food production, and displacement of up to 187 million people (38). A SLR of this magnitude would clearly have profound consequences for humanity.

 

[lomiller]

Not saying you are wrong, but you may be missing some qualification and nuance in what you appear to be saying. This isn't, strictly speaking, in accord with what the geologic record demonstrates. The problem with large scale, rapid releases of CH4 is that they overwhelm the mechanisms of atmospheric degradation of CH4 to CO2, meaning that large releases of methane into the atmosphere, have the potential to linger for tens to hundreds of thousands of years, and all the methane that is degraded is merely degraded to the longer potential persistence problem of atmospheric CO2 all the while exasperating the background warming.

(Note I'm speaking more to Clathrate devolution than peat/tundra soil emissions.)

BTW, I see the science is still dragging toward the scenarios many of us understood and found well supported 2 decades or so ago.

Ice sheet contributions to future sea-level rise from structured expert judgment
https://www.pnas.org/content/early/2019/05/14/1817205116

David Archer, a climate scientist at the university of Chicago and one of the Realclimate contributors write this simulation where you can play around with this type of scenario.

http://www.realclimate.org/index.php/archives/2012/01/an-online-model-of-methane-in-the-atmosphere/
http://climatemodels.uchicago.edu/methane/


Here is the result for a really big Methane pulse (100Gt) occurring over a 5-year span (Much more rapid release than the one he’s looking at in hos blog post). This pulse is ~100X our current anthropogenic Methane emission and nominally ~100-200 years worth of equivalent CO2 at current emission rates. (Yearly CO2 emission is around 38Gt, CO2-eq is either 34X or 86X depending on what time horizon you select)

Notice that even the peak radiative forcing for such a pulse isn’t ridiculously high and CO2 once again dominates changes radiative forcing within 30 years and within 50 it’s almost as if the pulse never even occurred. Also note that there is no evidence such a large pulse and rapid is even possible in the foreseeable future. Basically we are talking about a 100000% increase in Methane emissions in the artic and nothing like that is occurring or immanent.

 

[lomiller]

I’m not entirely sure the model in my last post works for negative numbers, but here is what it shows if we were to immediately cut anthropogenic Methane emissions in half but keep emitting CO2 our current rate. The difference in radiative forcing is negligible in comparison to CO2.

 

[carlosy]

Industrial methane emissions are 100 times higher than reported, researchers say

Using a Google Street View car equipped with a high-precision methane sensor, the researchers discovered that methane emissions from ammonia fertilizer plants were 100 times higher than the fertilizer industry’s self-reported estimate. They also were substantially higher than the Environmental Protection Agency (EPA) estimate for all industrial processes in the United States.

...

The team discovered that, on average, 0.34% of the gas used in the plants is emitted to the atmosphere. Scaling this emission rate from the six plants to the entire industry suggests total annual methane emissions of 28 gigagrams – 100 times higher than the fertilizer industry’s self-reported estimate of 0.2 gigagrams per year.

In addition, this figure far exceeds the EPA’s estimate that all industrial processes in the United States produce only 8 gigagrams of methane emissions per year.

“Even though a small percentage is being leaked, the fact that methane is such a powerful greenhouse gas makes the small leaks very important,” said Joseph Rudek, co-author and lead senior scientist at Environmental Defense Fund. “In a 20-year timeframe, methane’s global warming potential is 84 times that of carbon dioxide.”
...

http://news.cornell.edu/stories/201...are-100-times-higher-reported-researchers-say


I suppose this is not helping.

 

[The Atheist]

I suppose this is not helping.

I'll tell you what else isn't helping: the deceitful way the idiotic term "gigagrams" is used. We already have a long-established term for weights of that size - the universally-known "tonne", 1000 kg. A gigagram is 1000 tonnes, so why use a term that makes the total sound and look much scarier than it actually is? The only time I've ever seen the term used is for methane or CFC emissions.

Global CO2 emissions are ~35 gigatonnes, 35 million tonnes.

The methane emission mentioned are 8 gigagrams, of 8,000 tonnes. Whilst indeed not helping, it's a drop in the ocean at 1/500th of a percentage point of the CO2 released worldwide.

Typical Greenmunist tactic. "8000 tonnes doesn't sound like much - that's a very small ship, and less than 10% of the heaviest trains. Gigagrams sounds like a lot, though!"

At a time when the world struggles with understanding the problem, using emotive terms doesn't help.

Keep it real, people. (not blaming the poster - you're just posting what's written)

 

[Reality Check]

I'll tell you what else isn't helping: the deceitful way the idiotic term "gigagrams" is used. ...

Papers try to use units that reduce redundant zeros and reflect the uncertainty. Writing 29000 ((±18000) tonnes per year as 29 (±18) Gigagram per year is basic scientific scholarship. Well known scientific scholarship is not deceitful or idiotic. The results are the same whatever units that are used - fertilizers plans emit ~100 times the self-reported amounts of methane. You even suggest that that these are standard unis used for methane emissions!

Industrial methane emissions are underreported, study finds

Estimation of methane emissions from the U.S. ammonia fertilizer industry using a mobile sensing approach

 

[lomiller]

I'll tell you what else isn't helping: the deceitful way the idiotic term "gigagrams" is used. We already have a long-established term for weights of that size - the universally-known "tonne", 1000 kg. A gigagram is 1000 tonnes, so why use a term that makes the total sound and look much scarier than it actually is? The only time I've ever seen the term used is for methane or CFC emissions.

Global CO2 emissions are ~35 gigatonnes, 35 million tonnes.

The methane emission mentioned are 8 gigagrams, of 8,000 tonnes. Whilst indeed not helping, it's a drop in the ocean at 1/500th of a percentage point of the CO2 released worldwide.

Typical Greenmunist tactic. "8000 tonnes doesn't sound like much - that's a very small ship, and less than 10% of the heaviest trains. Gigagrams sounds like a lot, though!"

At a time when the world struggles with understanding the problem, using emotive terms doesn't help.

Keep it real, people. (not blaming the poster - you're just posting what's written)

In the literature Petagrams is the most common unit I see used for CO2 emission. Tonnes seems more common when reporting to the public. In either case you probably need some context to tell you how significant some new source is, especially when it comes to Methane where people tend not to know what is normal.

I generally follow climate science and I couldn’t tell you off the top of my head if this was a truly meaningful new emission. As a general rule though, As I’ve said previously, the risks associated with Methane are overblown. The real problem scenarios are either CO2 driven or unlikely to occur given out best current understanding.

 

[The Atheist]

In the literature Petagrams is the most common unit I see used for CO2 emission. Tonnes seems more common when reporting to the public. In either case you probably need some context to tell you how significant some new source is, especially when it comes to Methane where people tend not to know what is normal.

I'm at least slightly happy they haven't resorted to the present idiotic way of giving measures like "eight football fields long" or "as much as ten elephants".

I generally follow climate science and I couldn’t tell you off the top of my head if this was a truly meaningful new emission.

Pretty ho-hum overall, which is why I suspect they went with the scary number rather than tonnes.

Methane looks like about 5 gT/yr, so another 0.2% won't make a huge difference.

Mind you, there's an old saying about straws and camels' backs as I recall.

 

[Reality Check]

...I suspect they went with the scary number rather than tonnes.

Suspicion does not make scholarship wrong. A paper about methane emissions went with units that are used in methane emissions as you mentioned (The only time I've ever seen the term used is for methane or CFC emissions) and the units make sense when writing the numbers involved: Writing 29000 (±18000) tonnes per year as 29 (±18) Gigagram per year is basic scientific scholarship

 

[Reality Check]

Methane looks like about 5 gT/yr, so another 0.2% won't make a huge difference.

Not a huge numerical difference. But climate science tells us that small changes in greenhouse gases can have large changes in climate. Methane is a more powerful greenhouse gas than CO2.

Industrial methane emissions are 100 times higher than reported, researchers say

“Even though a small percentage is being leaked, the fact that methane is such a powerful greenhouse gas makes the small leaks very important,” said Joseph Rudek, co-author and lead senior scientist at Environmental Defense Fund. “In a 20-year timeframe, methane’s global warming potential is 84 times that of carbon dioxide.”

 

[The Atheist]

Suspicion does not make scholarship wrong.

Is there a prize for lying about posts?

If so, you'd win it in perpetuity.

I did not say anywhere it was wrong.

For god's sake, read the posts you think you're discussing. You are as dishonest as any antivaxer or 1080 protestor.

 

[The Atheist]

Meanwhile, another feedback loop comes to fruition: more extreme weather = more use of fossil fuels to warm up/cool down, with energy emissions rising the fastest since 2011.

https://www.theguardian.com/busines...ustry-carbon-emissions-bp-report-fossil-fuels