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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ On Mon, Nov 15, 2021 at 6:59 PM Claudia Wieners <[email protected]> wrote: > 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 <[email protected]>: > >> 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. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/geoengineering/CAKSzgpY%2BwsJV%2BoDydH9fcXOdgPX5UEheUqkpZ5io2MfLozoQDw%40mail.gmail.com >> <https://groups.google.com/d/msgid/geoengineering/CAKSzgpY%2BwsJV%2BoDydH9fcXOdgPX5UEheUqkpZ5io2MfLozoQDw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAJUUK5cAzC0F%3D%3DhBEjWRomu9WUz3dp7WSEmsa66jS7HQ4p7AoA%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAJUUK5cAzC0F%3D%3DhBEjWRomu9WUz3dp7WSEmsa66jS7HQ4p7AoA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CA%2BPtSAN5dizmQJwNNxONiCc_5P3K0P5XxBfHGNDWLez8Q5U7QA%40mail.gmail.com.
