Exploration of a novel geoengineering solution: lighting up tropical forests at night

[Geoeng Info]

https://esd.copernicus.org/preprints/esd-2021-85/

Exploration of a novel geoengineering solution: lighting up tropical forests at night

Xueyuan Gao, Shunlin Liang, Dongdong Wang, Yan Li, Bin He, Aolin Jia

Abstract. 

Plants primarily conduct photosynthesis in the daytime, offering an opportunity to increase photosynthesis and carbon sink by providing light at night. We used a fully coupled Earth System Model to quantify the carbon sequestration and climate effects of a novel carbon removal proposal: lighting up tropical forests at night via lamp networks above the forest canopy. Simulation results show that additional light increased tropical forest carbon sink by 10.4 ± 0.05 petagrams of carbon per year during a 16-year lighting experiment, resulting in a decrease in atmospheric CO2 and suppression of global warming. In addition, local temperature and precipitation increased. The energy requirement for capturing one ton of carbon is lower than that of Direct Air Carbon Capture. When the lighting experiment was terminated, tropical forests started to release carbon slowly. This study suggests that lighting up tropical forests at night could be an emergency solution to climate change, and carbon removal actions focused on enhancing ecosystem productivity by altering environmental factors in the short term could induce post-action CO2 outgassing.

[Maiken Winter]

Dear geoengineers,

I have been a quiet reader of this listserv for years. I am not an expert. And I am deeply concerned about the developments going on in our climate and natural systems.

But seriously? Are we now thinking about lightening up forests? What effects would that have on animals in those forests? Are there studies about that?

Are we willing to do anything to save humanity - which seems just to not want to be saved? Shouldn´t any geoengineering suggestions always be coupled with the demand to seriously step on the brakes, stop our believe in eternal growth and call for an immidiate moratorium in our collective overconsumption of about everything? Instead, we are happy that transcontinental flights are finally resuming, that new streets are being built to reduce traffic jams, that great big representative buildings are being built ... Most people are still in a completely wrong, self-destroying mindset. If we cannot change that, then I doubt that geoengineering can safe us, because we will destroy other life-supporting systems as well - such as intact ecosystems.

Thanks for your insights,

Best,

Maiken
www.wissenleben.de

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[Jessica Gurevitch]

This is a truly awful idea. These authors are apparently totally ignorant of, or uninterested in, the natural world of ecological communities and of biodiversity. Many, many organisms in tropical forests depend on nighttime darkness to survive and function. The "unintended (or uninformed) consequences" of this are horrifically mind blowing.

Jessica

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jessica Gurevitch 

Distinguished Professor and Co-Chair

Department of Ecology and Evolution
Stony Brook University
Stony Brook, NY 11794-5245 USA

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[Klaus Lackner]

The abstract is also wrong about energy consumption.  Photosynthesis is inefficient.  If one percent of the light goes into biomass it is doing well.   You also need to account for the  inefficiency of generating light.   So at best you need a hundred times as much energy as you would get out of carbon in the first place.  Even the worst of air capture is better than that.

 

All told this is a huge boondoggle.  It is bad for the environment, it consumes ridiculous amounts of energy, and as a result it is hugely expensive. 

 

Klaus

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[Renaud de RICHTER]

FYI, the article is still in the process of peer review and has not yet been accepted. You can create an account and comment it https://esd.copernicus.org/preprints/esd-2021-85/

I agree with Klauss and the energy requirements.

But I also welcome any new ideas to try to reduce global warming.

Even if the "proposals" made in this article seem awful to some, it can provide other researchers or entrepreneurs better ideas?

Maybe on a smaller scale, in some conditions and regions, it could be applicable without impacting the natural world of ecological communities and of biodiversity?

Let us imagine for instance that we can still enhance 5x the Miscanthus productivity (or another plant?) under an agricultural greenhouse, using artificial light at night, consuming 10x much less clear water or using slightly salted water in the Sahara, and produce biofuels with it, devoted to BECCS, then don't you think that lighting up at night, using excess electricity produced by wind energy, could be justified?

https://www.cleanenergywire.org/factsheets/why-power-prices-turn-negative

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[Daniele Visioni]

Dear all,

ESD is a journal that allows for community comments during peer review.

There’s one already: https://esd.copernicus.org/preprints/esd-2021-85/

I haven’t read the paper carefully (nor am I an ecologist) but I trust Jessica if she says it’s an awful idea! Possibly your direct feedback on the paper in the form of a comment on the ESD discussion could be helpful for everyone,

as it will be publicly accessible to everyone for ever, independently if the paper gets accepted or not.

And to respond to Maiken, I don’t think there’s a “we” here (in the sense of “we geoengineers”, and probably nobody considers themselves one). 6 academics have submitted a paper of their own free volition and probably without asking anyone else (at least no ecologists, as far as I can see). If the response from the community is that it’s an incredibly awful idea, the thing will probably die down on its own, and everyone will have learned something useful (maybe!).

Best,

Dan

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[Oliver]

Do you not think this is rather a kneejerk reaction? Is it as awful an idea as injecting thousands of tons of silver dioxide or similar materials into the stratosphere? An action which will influence the global weather for a minimum of 4 years if done at the equator. Now that is a truly awful idea. On the other hand, I would say that the consequences of lighting forests are more predictable, and the idea is scalable and can be stopped easily.

In any case perhaps with some adjustment the idea may have merit. How about lighting desert plantations in marginal areas, not in pristine forest where delicate flora and fauna exist. Solar power can recharge batteries or lighting. Or extreme northern boreal forest, where few other animal forest species exist in large numbers. In areas of low radiation such a light boost may be just what it takes to increase productivity.

Oliver

-- 
Dr. Oliver Branch
Inst. for Physics and Meteorology (120)
University of Hohenheim
Garbenstr. 30
D-70599 Stuttgart

phone: 0711 - 459 -23132

[Ernie Rogers]

I am sure you are right, Jessica.  I would be interested in hearing your ideas on how to increase productivity on a global scale, or otherwise absorb large amounts of CO2.  /Ernie

To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/5b2789a6-3faa-af9a-11d0-fa565c15e3ee%40uni-hohenheim.de.

[Michael Kleeman]

Irrespective of the benefits or risks of solar radiation management the ecosystem impacts are real.  

And for reference deserts have a rich life and are sensitive to light, pressure, vibration and general disruption.   Different from forested area but no less alive in their own way

We need to be humble in the face of complex systems and not propose simplistic interventions that make assumptions based on too little data.  

On Nov 10, 2021, at 12:55 PM, Oliver <oliver...@uni-hohenheim.de> wrote:

 Do you not think this is rather a kneejerk reaction? Is it as awful an idea as injecting thousands of tons of silver dioxide or similar materials into the stratosphere? An action which will influence the global weather for a minimum of 4 years if done at the equator. Now that is a truly awful idea. On the other hand, I would say that the consequences of lighting forests are more predictable, and the idea is scalable and can be stopped easily.

To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/5b2789a6-3faa-af9a-11d0-fa565c15e3ee%40uni-hohenheim.de.

[Jessica Gurevitch]

We hardly know what the impacts of SAI would be on ecological systems and we really need to learn more. My best guess (and it’s just an evidence-free guess at this point) is that some organisms and systems would benefit from SAI, perhaps greatly, and others would be harmed, maybe by a lot.  Much of that depends on the details, like how much we reduce emissions at the same time. We need a lot more information.  Certainly what we’re doing now to the atmosphere and biosphere is harming many systems and organisms, and causing extinctions and displacements.  Some are thriving, though—unfortunately many of those doing well are cosmopolitan invasives. 

In my opinion the benefits and risks to ecological systems are inextricably bound to the fate, well being and suffering of humans and human systems. 

Sent from my iPhone

On Nov 10, 2021, at 6:07 PM, Michael Kleeman <mkle...@well.com> wrote:



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[Ernie Rogers]

Jessica said,

" Maybe the thing to concentrate on is what would increase long lived soil carbon rather than photosynthesis."

Thanks, Jessica, great idea.  How about this?  How to do long-lived storage in the sea, using natural processes?

To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/F417A37C-AC85-4E6D-9F24-1E1910B509C3%40stonybrook.edu.

[Oliver]

Hello Michael,

Absolutely agreed on your point about rich desert ecology, and that we need to be humble in the face of the complex earth system. In all likelihood, all goeengineering methods are in some way 'simplistic' because they intervene in processes which have evolved over time, in symbiosis with the Earth system's changing state, as driven from the outside by Milankovich cycles and tectonic processes.

However, we are at the point now where we are looking for 'least worst' solutions rather than magic bullets which moderate global forcing with little impact on important ecosystem services, as they probably don't exist. Hence, there is a risk calculation where we may need to accept a limited amount of damage to achive the greater good, i.e.,  a reduction in glocal forcing to preserve as many ecosystems as possible. Saving every desert ecosystem with little biomass may be a luxury we cannot afford.

Furthermore, I would argue that we need to shift away from a 'magic bullet' geoengineering paradigm to one which advocates a diverse mix or 'package' of smaller scale solutions which all together have a synergetic impact on forcing, e.g., a mixture of regional aforestation, white roofs, marine cloud brightening, cirrus thinning, enhanced weathering, CCS and so on (these must be scaleable, sustainable and quickly reversible). By doing this, we retain the option to assess these pathways and then emphasize or deemphasize individual options over time as their impacts on society and environment become apparent.

In consequence, one must redefine 'geoengineering' in a way that removes the requirement that any one single method needs to have a measurable impact on global forcing. An example of this is instead is to call methods 'regional geoengineering'. We would also need to refine our notion of what success is for these solution. In other words, a reduction in forcing of 0.01 W m-2 might be called a success, instead of requiring 0.2 W m-2 or similar as a benchmark (arbitrary numbers).  Research would need to reflect this complex mix instead of writing paper after paper on the impacts of e.g. global reforestation alone, or global SAI alone, and so on.

However, in my opinion SAI should be thought of in a different catgory to geoengineering. Recreating Pinatubo or Krakatoa is neither scaleable, or easily reversible and hence gives the rest of geoengineering proposals a bad name. On the other hand, marine or cirrus cloud seeding and its meteorological impacts can be stopped much more rapidly (of course, feedbacks with vegetation may be much slower).      

Regards

Oliver

-- 
Dr. Oliver Branch
Inst. for Physics and Meteorology (120)
University of Hohenheim
Garbenstr. 30
D-70599 Stuttgart

phone: 0711 - 459 -23132

To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/7834B502-DA81-477D-9BD3-EFC3CCFF2320%40well.com.

[Jessica Gurevitch]

Sadly, I know almost nothing about the benthos—we need marine ecologists to tell us about that! I’m strictly terrestrial and prefer dry upland systems myself. I even avoid fens, marshes, bogs and the like. 

Sent from my iPhone

On Nov 10, 2021, at 10:52 PM, Ernie Rogers <ernie.e...@gmail.com> wrote:



[Douglas MacMartin]

Any option involves pros and cons, but it is curious to refer to SAI as neither scalable nor reversible.  For scalability, it is essentially the only option we know for sure can scale (as your own email suggests by choice of defining success).  For reversibility, if you stop putting aerosols in, the effect goes away.  Note that if you’ve been doing it long enough for it to matter, then the time constant of the effect going away is going to be mostly dominated by the response times of the climate system, not by the residence time of the aerosols.  So it’s true that the termination shock would be a bit more abrupt for MCB than for SAI, but that’s probably not that big a deal.  It would seem to me that if one wants to do a comparison between methods, then one ought to actually evaluate their impacts rather than arbitrarily dismissing them by throwing incorrect adjectives around.

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[Claudia Wieners]

Original idea, but apart from worrying about unwanted side effects for the ecosystem and technical questions about the maintenance of all these lamps, cables etc, I wonder whether 16 years is on the short side. Would it not take longer than that for the forest to equilibrate, i.e. reach a state where the extra uptake is compensated by an extra emission of CO2 from rotting biomass? I.e. maybe negative feedbacks kick in only after the 16 years? 

Of course, the new forest would have a bigger reservoir of carbon, but in equilibrium it would maybe stop being a sink. Yet one would have to continue lighting the forest forever or at least a long time to keep the carbon in the forest because after termination the carbon is released again. So some form of direct air capture might have the advantage of storing the carbon more safely without constant energy input (for a ton already stored). 

Finally, note that Keller et al 2015 did an experiment - admittedly in an intermediate complexity model - where they assumed they could afforest the whole Sahara (let's just assume for a moment that it could be done somehow...). They found significant carbon uptake during the growth of the forest but after about 50 years the forest equilibrated, acting as a storage but no longer as a sink. And the storage thus created was far, far smaller than anthropogenic emissions till now, though of course one might argue that there is no silver bullet and one shouldn't dismiss any carbon-reducing measure purely on the ground that it alone cannot fully solve the problem. 

Are there any biosphere experts here who can confirm or contradict my concerns? Am I mistaken? 

Op wo 10 nov. 2021 om 07:54 schreef Geoeng Info <infog...@gmail.com>:

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[Jessica Gurevitch]

You are raising very valid points. Also, if the trees run out of nitrogen, water, etc., which seems very possible, they will stop photosynthesizing and taking up carbon. It is an interesting idea, but the authors have not considered many of the limitations and unwanted effects of this idea, which are very large.

There has been some work on using solar panels to light crops at night to increase production, which is also interesting, but doesn't do much for reducing carbon (the crops are harvested after each growing season and used, so the carbon cycles back to the atmosphere almost immediately).  

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jessica Gurevitch 

Distinguished Professor and Co-Chair

Department of Ecology and Evolution
Stony Brook University
Stony Brook, NY 11794-5245 USA

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAJUUK5cAzC0F%3D%3DhBEjWRomu9WUz3dp7WSEmsa66jS7HQ4p7AoA%40mail.gmail.com.