Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stop emitting CO2 or geoengineering could be our only hope

02.09.2009
The future of the Earth could rest on potentially dangerous and unproven geoengineering technologies unless emissions of carbon dioxide can be greatly reduced, the latest Royal Society report has found.

The report (published today,1st September, by the Royal Society(1), the UK’s national academy of science) found that unless future efforts to reduce greenhouse gas emissions are much more successful than they have been so far, additional action in the form of geoengineering will be necessary if we are to cool the planet.

Geoengineering technologies were found to be very likely to be technically possible and some were considered to be potentially useful to augment the continuing efforts to mitigate climate change by reducing emissions. However, the report identified major uncertainties regarding their effectiveness, costs and environmental impacts.

Professor John Shepherd, who chaired the Royal Society’s geoengineering study(2), said, “It is an unpalatable truth that unless we can succeed in greatly reducing CO2 emissions we are headed for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases. Our research found that some geoengineering techniques could have serious unintended and detrimental effects on many people and ecosystems - yet we are still failing to take the only action that will prevent us from having to rely on them. Geoengineering and its consequences are the price we may have to pay for failure to act on climate change.”

The report assesses the two main kinds of geoengineering techniques – Carbon Dioxide Removal (CDR) and Solar Radiation Management (SRM). CDR techniques address the root of the problem – rising CO2 – and so have fewer uncertainties and risks, as they work to return the Earth to a more normal state. They are therefore considered preferable to SRM techniques, but none has yet been demonstrated to be effective at an affordable cost, with acceptable environmental impacts, and they only work to reduce temperatures over very long timescales.

SRM techniques act by reflecting the sun’s energy away from Earth, meaning they lower temperatures rapidly, but do not affect CO2 levels. They therefore fail to address the wider effects of rising CO2, such as ocean acidification, and would need to be deployed for a very long time. Although they are relatively cheap to deploy, there are considerable uncertainties about their regional consequences, and they only reduce some, but not all, of the effects of climate change, while possibly creating other problems. The report concludes that SRM techniques could be useful if a threshold is reached where action to reduce temperatures must be taken rapidly, but that they are not an alternative to emissions reductions or CDR techniques.

Professor Shepherd added, “None of the geoengineering technologies so far suggested is a magic bullet, and all have risks and uncertainties associated with them. It is essential that we strive to cut emissions now, but we must also face the very real possibility that we will fail. If “Plan B” is to be an option in the future, considerable research and development of the different methods, their environmental impacts and governance issues must be undertaken now. Used irresponsibly or without regard for possible side effects, geoengineering could have catastrophic consequences similar to those of climate change itself. We must ensure that a governance framework is in place to prevent this.”

Of the CDR techniques assessed, the following were considered to have most useful potential:

CO2 capture from ambient air – this would be the preferred method of geoengineering, as it effectively reverses the cause of climate change. At this stage no cost-effective methods have yet been demonstrated and much more research and development is needed.

Enhanced weathering – this technique, which utilises naturally occurring reactions of CO2 from the air with rocks and minerals, was identified as a prospective longer-term option. However more research is needed to find cost-effective methods and to understand the wider environmental implications.

Land use and afforestation – the report found that land use management could and should play a small but significant role in reducing the growth of atmospheric CO2 concentrations. However the scope for applying this technique would be limited by land use conflicts, and all the competing demands for land must be considered when assessing the potential for afforestation and reforestation. Should temperatures rise to such a level where more rapid action needs to be taken, the following SRM techniques were considered to have most potential:

Stratospheric aerosols – these were found to be feasible, and previous volcanic eruptions have effectively provided short-term preliminary case studies of the potential effectiveness of this method. The cost was assessed as likely to be relatively low and the timescale of action short. However, there are some serious questions over adverse effects, particularly depletion of stratospheric ozone.

Space-based methods – these were considered to be a potential SRM technique for long-term use, if the major problems of implementation and maintenance could be solved. At present the techniques remain prohibitively expensive, complex and would be slow to implement.

Cloud albedo approaches (eg. cloud ships) – the effects would be localised and the impacts on regional weather patterns and ocean currents are of considerable concern but are not well understood. The feasibility and effectiveness of the technique is uncertain. A great deal more research would be needed before this technique could be seriously considered.

The following techniques were considered to have lower potential:

Biochar (CDR technique) – the report identified significant doubts relating to the potential scope, effectiveness and safety of this technique and recommended that substantial research would be required before it could be considered for eligibility for UN carbon credits.

Ocean fertilisation (CDR technique) – the report found that this technique had not been proved to be effective and had high potential for unintended and undesirable ecological side effects.

Surface albedo approaches (SRM technique, including white roof methods, reflective crops and desert reflectors) – these were found to be ineffective, expensive and, in some cases, likely to have serious impacts on local and regional weather patterns.

Catherine de Lange | alfa
Further information:
http://www.royalsociety.org/geoengineeringclimate

More articles from Ecology, The Environment and Conservation:

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Big data approach to predict protein structure

27.03.2017 | Life Sciences

Parallel computation provides deeper insight into brain function

27.03.2017 | Life Sciences

Weather extremes: Humans likely influence giant airstreams

27.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>