Earth Radiation Management strategies as alternatives to SRM techniques

1. CEC14, Climate Engineering Conference 2014, Critical Global Discussions18-21 August, Berlin, Germany. Wednesday August 20th, 2014. Session: Novel SRM Techniques: Cirrus Clouds Thinning and Marine Sky Brightening Earth Radiation Management strategies as alternatives to SRM techniques Renaud de_RichterInstitut Charles Gerhardt MontpellierUMR5253 CNRS-UM2 ENSCM-UM1 Ecole Nationale Supérieure de Chimie de Montpellier, 8 rue de l’Ecole Normale34296 Montpellier Cedex 5, France

2. SRM (sunlight reflection methods) SRM aims to reduce incoming Shortwave radiation

3. Earth Radiation Management The notion of ERM was introduced in 2011 by Mitchell et al, with Modification of Cirrus Clouds to Reduce Global WarmingMitchell DL, Mishra S, & Lawson RP. Cirrus clouds and climate engineering: new findings on ice nucleation and theoretical basis. Planet Earth, 2011, 257-288. In (very) short: cirrus clouds trap Longwave radiation below them and contribute to warm the Earth by back radiation; dissipating cirrus clouds would increaseoutgoing longwave radiation, thus global warming is reduced.Same thing for CO2: if we reduce it’s concentration we allow more heat energy (IR radiation) to escape out to the space.=> Thus, for Mitchell et al, CDR belongs, together with Cirrus Clouds reduction, to ERM techniques which target to increase outgoing Longwave radiation

4. SRM aims to reduce incoming SW Lagrange L1 reflectors orbital mirrors CDR cloud whitening aerosols dissipating Cirrus clouds => reducing back radiation sea reflectivityland albedo ERM aims to increase outgoing LW For Mitchell et al, CDR belongs, together with Cirrus Clouds reduction, to ERM techniques which goal is to increase outgoing Longwave radiation + Night Sky radiative cooling GHGR Land Oceansurface radiation

5. Let us start with thermals By which mean can we enhance outgoing Earth LW radiation?

6. one possibility for generation of thermals Thermals: birds and sailplaners (gliders) know them well albedo change urban heat island

7. the hot air is transferred from the surface and released much higher, where it still rises high in the troposphere where some of the heat can escape out to the space Updrafts generated by solar chimneys Greenhouse effect+ Stack effect Cost-competitive energy if height > 700mArchitects say >1500m height no problem! A prototype with 200m high chimney built and fully tested 1982-1989 Aufwindkraftwerk described in 1931 by German author Hanns Günther.  The prototype was built under the direction of a German engineer, Jörg Schlaich in Manzanares, Ciudad Real, 150 km south of Madrid Spain. The project was funded by the German government and the power plant operated for 7 years.

8. CO2CDR Something else on which we can act to increase OLWR? Figure from NASA

9. DAC: CO2 direct capture in the Atmosphere All methods require energy to move air through the adsorption system EXCEPTED ONE! Adsorption on solids (similar to current methods being tested for Carbon Capture & Sequestration) Adsorption into alkaline solutions (or alkaline solid resins) Resulting material must be transported and sequestered Costs could be competitive since plants can be located near the sequestration location… The energy required to capture 4 CO2 emits 1 CO2(if done using FFPP)

10. http://www.sciencedirect.com/science/article/pii/S1364032112005680http://www.sciencedirect.com/science/article/pii/S1364032112005680 In 2013 we proposed to use artificial trees from Lackner, with his alkali solid resin, in synergy with a Solar Updraft Chimney • DAC +25% efficiencyusing renewable energy • no more fans (investment savings & more energy savings) • + other synergies (resin regeneration…)

11. other GHGsGHGR Do we forget something on which we can act to increase OLWR? Figure from NASA

12. http://www.sciencedirect.com/science/article/pii/S1389556711000281http://www.sciencedirect.com/science/article/pii/S1389556711000281 All other GHGs, can also be removed from the atmosphere… Carbon dioxide removal (CDR) techniques aim to remove CO2, a major greenhouse gas, from the atmosphere, allowing more outgoing long-wave to escape (less back radiation). by photocatalysis! But such approaches are still in development … photocatalysis may be applied successfully to eliminate or transform all major long-lived well mixed GHGs, but alsosoot, tropospheric ozone and other short-lived climate forcers.

13. Latent heat release Next way of enhancing outgoing heat radiation

14. Equatorial Solar chimney (Denis Bonnelle) with piece of cake collector (initial Drawing: Janning Petersen) sea water is pumped, warmed and spayed Arabic peninsula Salt deposit Africa Red Sea averagesurface temperaturein August >30°C A solar chimney variant at the equator Outside air temperature 35°C, 85% relative humidity. Sea water at 30°C is warmed to 85°C by the sun in black tubing and sprayed at the chimney entrance so has to obtain hot air 60°C / 95% RH The excess water is directed to a saline (salt deposit). At some height inside the tower, an efficient heat exchanger with the outside air temperature cools the air => clear water condensates(20-30%, useful byproduct?) and the heat of condensation releases heat, warming the air above, making the air lighter… This warmed airin the tower rises and sucks the air column below by increased buoyancy. After the exit out of the tower, the warm and humid air still rises until the condensation releases morelatent heat that escapes to the outer space.

15. Latent heat release Next way of enhancing outgoing heat radiation

16. Image from Aqua CERES Artificial tornadoes Hurricane Heat Engine close of a Carnot cycle (image from Emmanuel) atmospheric vortex engine concept from Louis Michaud (figure by Charles Floyd) http://vortexengine.ca

17. Are there other methods to help thermal infrared radiation to escape more easilyto the outer space? YES ! There are many devices able to enhance atmospheric convection

18. Anymore things to enhance thermal IR out to space? Figure from NASA

19. 0IL Heat Pipes or Thermosyphons Half million thermosyphons are already used to prevent permafrost melting

20. Half million heat pipes are used to prevent permafrost melting along roads, railways, oil pipelines… in Siberia, Tibet, Alaska…

21. Are there credible proposals against the vicious cycle due to loss of polar reflectivity (albedo)? A melting glacier surface cannot raise its temperature and thus not increase outgoing longwave radiation; any surplus of radiation is thus used for additional meltingOerlemans, J. A projection of future sea level. Climatic change,  1989, 15(1-2), 151-174.

22. Both a SRM technique by ALBEDO effect and a ERM method by heat transfer from the ocean to the atmosphere D. Bonnelle has proposed a device transferring sea water in altitude where chilling air makes ice, which is returned to the ocean. The latent heat of freezing warms the air inside a tall tower anddrives turbines to produce renewable electricity. The hot air coming out of the chimney enhances atmospheric convection…and the humidity released will produce high albedo fresh snowhttp://data.solar-tower.org.uk/thesis/2004-Denis-BONNELLE_Solar-chimneys_Energy-towers_etc.pdf

23. SNOW CANONS top ofa hill Proposal by: S. Zhou, P.C. Flynn; Geoengineering downwelling ocean currents: a cost assessment. Clim Change 2005, 71(1-2), 203–220Both aSRM: by ALBEDO effect andERM: by heat transfer from the ocean to the atmosphere D.Bonnelle also proposed a giant closed heat pipe thermosyphon(book ISBN: 978-2729854072)

24. Emitted by surface and preferably by the atmospheric window Other ways of enhancing outgoing IR radiation? by the atmospheric window8-13 µm

25. Complementarity between cool roofs… SRM reflective coatings on top of buildings => .

26. Improved by cold water storage tank=> reduces even more the cooling costs …and night sky radiative cooling radiant materials on top of buildings =>ERM University of Central Florida Parker, D. S., Sherwin, J. R., Hermelink, A. H., & Center, F. S. E. (2008). NightCool: A Nocturnal Radiation Cooling Concept. 2008 ACEEE Summer Study on Energy Efficiency in Buildings, 209-222.

27. SRM Remark: SRM is only possible 12 h/day… or on one half of the planet at the same time

28. …meanwhile outgoing Longwave radiation is permanent Outgoing longwave radiation, March 18, 2011 from Aqua CERES data

29. Some recent progress done by researchers in Stanford and Harvard universities

30. Pros and Cons of SRM and ERM ERM SRM • Geoengineering SRM diverts sunlight radiation back into space by increasing albedo, increasing short wave radiation reflection (parasol effect): thus less light reaches the Earth surface. • But blocking the sun will not help the humans to stop spewing billions of tons of CO2 into the atmosphere • ERM consists to increase longwave outgoing radiation, by the use of atmospheric convection devices, which are a full set of unusual renewable energies, which allow more heat to leave the Earth surface and at the same timecool the Planet,provide humans with all their energy needsandprogressively de-carbonize the energy sector

31. Q3: are there complementarities between: ERM SRM ? & FAQ Science fiction??? what about orbital mirrors? and reflector arrays at the Lagrange (L1) point? and millions of artificial trees? …and… and … • Q1: isn’t it like science fiction? Behind “atmospheric convection devices”,the science is strong and they are proven technologies!They are worth being studied to help cool the Earth by ERM • Q2: if so perfect and so good, … why aren’t they already built and in operation? Answer later, after the talk… Yes! Some examples, after the talk…

32. More information on Open Access: http://www.sciencedirect.com/science/article/pii/S1364032113008460

33. Thank you for your attention QUESTIONS?

34. Additionnal slides

36. Comments on SRM SRM Advantages: • It can be cheap • Rapid deployment is possible • It allows to “buy time” • It is often presented as a “last resort”, in case of climate emergency SRM Drawbacks: • Imperfectly compensates for CO2 driven warming • Doesn’t stop ocean acidification, nor CO2 emissions • May introduce new environmental risks like affecting precipitation patterns and volumes... • Treats the symptoms rather than cure the illness

37. Future ERM prospects • Solar updraft towerand downdraft energy tower are under industrial development in the US (Texas & Arizona) • Atmospheric vortex engine found funding for the next prototypes in Canada. The development plan is going on. • Heat pipes are widely used in several industrial sectors and prevent permafrost melting on the Trans Alaska Pipeline and the Qinghai-Tibet Railway. • Radiative cooling technologies and new materials are available for heat transfer by the atmospheric window during clear sky nights.

38. How can we cool the Earth surface? There exist many convection devices are able to break the GHGs insulating envelope surrounding the Earth and create thermal bridging, thus increase outgoing longwave radiation Some examples of convection towers and devices: • http://en.wikipedia.org/wiki/Energy_tower_(downdraft)http://www.solarwindenergytower.com/the-tower.html • http://en.wikipedia.org/wiki/Solar_updraft_towerhttp://www.solar-updraft-tower.com/en#commercial_sut/index http://www.theengineer.co.uk/energy-and-environment/news/per-lindstrand-plans-1km-high-inflatable-solar-energy-chimney/1017508.article • http://en.wikipedia.org/wiki/Vortex_engine http://www.fmrl.gatech.edu/drupal/projects/solarvortexGeorgia Institute of Technology http://phys.org/news/2012-12-entrepreneur-funding-tornado-power.html • http://en.wikipedia.org/wiki/Radiative_coolingHarvard University, Cambridge http://www.pnas.org/content/early/2014/02/26/1402036111.short • http://en.wikipedia.org/wiki/Heat_pipe

39. Conclusion: by progressively replacing fossil fuel power plants, these unusual renewable energies will produce electricity with no CO2 emissions and thus will reduce global warming, cool the Planet, stop sea level rise, stop ocean acidification…