25.07.2017

# New Publications

0 Comments

Cao, Long; et al. (2017): Simultaneous stabilization of global temperature and precipitation through cocktail geoengineering

Cao, Long; Duan, Lei; Bala, Govindasamy; Caldeira, Ken (2017): Simultaneous stabilization of global temperature and precipitation through cocktail geoengineering. In Geophys. Res. Lett. 37 (D6), p. 117. DOI: 10.1002/2017GL074281.

"Here we investigate the possibility of stabilizing both global mean temperature and precipitation simultaneously by combining two geoengineering approaches: stratospheric sulfate aerosol increase (SAI) that deflects sunlight to space and cirrus cloud thinning (CCT) that enables more longwave radiation to escape to space."

LINK


Read more »

24.07.2017

# Media

0 Comments

Newsweek: Climate Change and Geoengineering: Artificially Cooling Planet Earth by Thinning Cirrus Clouds

"Over recent decades, scientists from across the globe have been discussing the potential of geoengineering—the deliberate manipulation of the environment that could, in theory, cool the planet and help stabilize the climate."

LINK


Read more »

24.07.2017

# Media

0 Comments

Live Science: Cool the Planet? Geoengineering Is Easier Said Than Done

""If cirrus clouds behave like a blanket around the Earth, you're trying to get rid of that blanket," Lohmann, a professor of experimental atmospheric physics at ETH Zurich, told Live Science."

LINK


Read more »

22.07.2017

# New Publications

0 Comments

Lohmann, Ulrike; Gasparini, Blaž (2017): A cirrus cloud climate dial?

Lohmann, Ulrike; Gasparini, Blaž (2017): A cirrus cloud climate dial? In: Science (New York, N.Y.) 357 (6348), S. 248–249. DOI: 10.1126/science.aan3325.

"Climate engineering through cirrus cloud thinning, in contrast, mainly targets the long-wave radiation that is emitted from Earth."

LINK


Read more »

14.06.2017

# New Publications

0 Comments

Lauvset, Siv K.; et al. (2017): Climate engineering and the ocean. Effects on biogeochemistry and primary production

Lauvset, Siv K.; Tjiputra, Jerry; Muri, Helene (2017): Climate engineering and the ocean. Effects on biogeochemistry and primary production. In: Biogeosciences Discuss., S. 1–36. DOI: 10.5194/bg-2017-235

"Here we use an Earth System Model with interactive biogeochemistry to project future ocean biogeochemistry impacts from large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences."

LINK


Read more »

02.02.2017

# New Publications

0 Comments

Kärcher, Bernd (2017): Cirrus Clouds and Their Response to Anthropogenic Activities

Kärcher, Bernd (2017): Cirrus Clouds and Their Response to Anthropogenic Activities. In: Curr Clim Change Rep. DOI: 10.1007/s40641-017-0060-3.

"This review assesses recent observational and modeling evidence of how anthropogenic activities might affect cirrus. Changes in physical properties and chemical composition of liquid aerosol particles will unlikely affect cirrus significantly, but anthropogenic influences may occur through changes in heterogeneous ice nuclei."

Link


Read more »

19.11.2016

# New Publications

0 Comments

Quaas, Johannes; et al. (2016): Regional climate engineering by radiation management: Prerequisites and prospects

Quaas, Johannes; Quaas, Martin F.; Boucher, Olivier; Rickels, Wilfried (2016): Regional climate engineering by radiation management: Prerequisites and prospects. In Earth’s Future. DOI 10.1002/2016EF000440.

"In this paper, we discuss the idea that RM can be differentiated and scaled in several dimensions with potential objectives being to influence a certain climate parameter in a specific region. Some short-lived climate forcers (e.g., tropospheric aerosols) exhibit strong geographical and temporal variability, potentially leading to limited- area climate responses. Marine cloud brightening and thinning or dissolution of cirrus clouds could be operated at a rather local scale."

Link


Read more »

11.07.2016

# Media

0 Comments

CSCS: Can cirrus cloud seeding help to “save” the climate? (press release)

Press release on Gasparini, Blaž; Lohmann, Ulrike (2016). "The interaction of cirrus clouds with radiation is a complex one, which depends on the concentration of ice crystals, their size, as well as on properties such as the temperature of the cloud and the underlying surface, and solar insolation.  Model calculations indicate their radiative effect accounts for about 5 Watts per square meter in global average. “Were one to eliminate all cirrus clouds, that would immediately counteract a CO2 doubling which adds a ‘warming’ impact of 3.7 Watts per square meter”, says atmospheric physicist Ulrike Lohmann of ETH Zurich. This is what makes cirrus clouds a potential target for geoengineering methods."

Link


Read more »

11.07.2016

# New Publications

0 Comments

Gasparini, Blaž; Lohmann, Ulrike (2016): Why cirrus cloud seeding cannot substantially cool the planet

Gasparini, Blaž; Lohmann, Ulrike (2016): Why cirrus cloud seeding cannot substantially cool the planet. In J. Geophys. Res. Atmos. 121 (9), pp. 4877–4893. DOI 10.1002/2015JD024666.

"The net warming effect of cirrus clouds has driven part of the geoengineering research toward the idea of decreasing their occurrence frequency by seeding them with efficient ice nucleating particles. We study responses of cirrus clouds to simplified global seeding strategies in terms of their radiative fluxes with the help of the ECHAM-HAM general circulation model. Our cirrus scheme takes into account the competition between homogeneous and heterogeneous freezing, preexisting ice crystals, and the full spectrum of updraft velocities."

Link


Read more »

27.05.2016

# Media

0 Comments

Inverse: The Crazy Plan to Zap Clouds with Lasers to Stop Climate Change

Media response to Matthews, M.; et al. (2016). "With the right kind of technology, it's possible."

Link


Read more »