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www.tierra21.com.ar/PresentacionProblemasAmbientalesSoluciones.ppt -

Researchers Stephen Pacala and Robert Socolow at Princeton University have suggested one approach that they call "stabilization wedges." This means reducing GHG emissions from a variety of sources with technologies available in the next few decades. They suggest 7 wedges that could each reduce emissions, and all of them together could hold emissions at approximately current levels for the next 50 years, putting us on a potential path to stabilize around 500 ppm.

There is also the potential to capture the carbon dioxide emitted from fossil fuels and store it underground—a process called "carbon sequestration." In addition to reducing the gases we emit to the atmosphere, we can also increase the amount of gases we take out of the atmosphere. Plants and trees absorb CO2 as they grow, "sequestering" carbon naturally. Increasing forestlands and making changes to the way we farm could increase the amount of carbon we're storing.

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Coastal management strategies applicable to climate change to adapt to repeated sea-level rise or a change in the pattern of storms, would be: the rollback, adaptation and defense.

Rollback strategy: this strategy, as its name suggests, is to roll back human structures that may be affected by the effects of rising sea levels and other consequences of climate change. It requires, first,to provide space to relocate the uses and resources that support the coastal section. If available, this strategy is more consistent with climate change at regional scale, and it doesn't mortgage the area in the future.

For example, if the beaches are not confined the generally more advisable strategy is receding, as this is the natural behavior to expect in the beaches and associated dune fields. To make this strategy it would be necessary to enact a land use rules that prevent the installation of new components or activities in vulnerable areas.

In the case of soft cliffs on the rollback strategy, to let nature take its course would have similar implications to those described above for beaches. Also here you will have to define the potentially affected areas, making inventories and valuations of existing assets, limitations in use in certain areas and provide for the abandonment of buildings, etc..

For wetlands and similar areas the rollback strategy is the most appropriate in many cases because it will maintain the same total length. In other cases the inland migration of wetlands is impossible becuase of the presence of barriers of various kinds. In some cases there is no alternative and the final result is a reduction in the extent of wetlands, which will be totally or partially submerged. In other cases it is possible to eliminate the barriers (for example in areas that have simply been closed and dried), thereby facilitating migration and / or regeneration of areas previously occupied by wetlands.

Adaptation strategy: It requires a different approach to erosion and flooding.In the first case, the fighting strategy against erosion requires to relocate structures and to make a flexible use of the coastline. Currently the most common tendency consits in the use of a support vegetation and dissipation that reduces the risk of erosion. In the second case, the risks and costs associated to the process of flooding can be predicted. We can't forget that the flood defenses require continued thereby maintenance.

The defense strategy: It consists in building structures to defend or preserve certain human infraestructures from the rising sea level and other effects of climate change. Although this is the strategy that seems to prefer the society for its appearance “aparently” monolitic against erosion or flooding, implies high initial costs and a strong maintenance costs, as, for example, the history of defense and security structures illustrate the Maresme coast.

Also, we can't consider only one permanent solution to all the problems related with the climate change and its effects on the coast. Because of that, this defense strategy can only be considered for specific stretches of coast, and always reminding the time factor. The bes solution for any selectioned time scale consists in the combination of the three adaptation elements, and all within the framework of a comprehensive plan of the coastal zone.


A new method to optimize the reduction of the CO2 emissions is developed.

It is used to separate in a more eficiently way the carbon dioxide from the pollutant gases.

The carbon dioxide emissions to the atmosphere that are accomplished in the framework of some industrial activities, and which are a serious environmental problem, could be radically diminished if a new separation of the CO2 pollutant gases method is developed. This system guarantees a major effectiveness in the labour and it's more simple and accessible for the companies, according to its creators.

A new methodology developed recently by engineers and scientists of the Lawrence Livermore National Laboratory of California, United states, will allow the separation of the carbon dioxide from the pollutant sources, to, for example that the combustion gases of a coal-fired power central can be realized soon in a more efficient way and with better results for the environment.

The finding was published in a press release of the Lawrence Livermore National Laboratory. The results of the research have been published in the specialized magazine “ChemSusChem”.

The Lawrence Livermore National Laboratory team has created a way to detect the CO2 gases, in which they use ionic liquids, a special type of molten salt that becames liquid when the water gets to its boiling point. This allows to separate de carbon dioxide fron the initial source, but in a more efficient and stable way in comparison with the methods used nowadays.

Son conocidos hasta el hartazgo los riesgos que supone para el planeta una alta concentración de CO2 en la atmósfera, sin embargo aunque se registran grandes esfuerzos para reducir las emisiones de dióxido de carbono provenientes de la quema de combustibles fósiles, es imprescindible el paso que supone la captura del CO2, la separación de su fuente original. Gracias a esta nueva técnica podría mejorarse la eficiencia del proceso de captura de dióxido de carbono.

Las técnicas empleadas en la actualidad

¿Qué métodos se emplean actualmente?. Hoy, las plantas de carbón con procesos de captura de CO2, que evidentemente no son mayoría, emplean para la separación del dióxido de carbono procesos basados en el uso de absorción química con monoetanolamina (MEA).

En este mecanismo se utiliza un disolvente de uso general desarrollado por la ingeniería química hace 75 años. Esta solución posee desgraciadamente varios puntos en contra, como por ejemplo su escaso poder de selectividad, el uso de corrosivos, la necesidad de emplear grandes equipos y una disminución menor del CO2, que no resulta suficiente para detener el proceso negativo sobre la atmósfera.

Por el contrario, la nueva metodología desarrollada en el Lawrence Livermore National Laboratory permite superar varios de esos escollos. El uso de líquidos iónicos como disolventes para la separación del CO2 de la fuente primaria posee ventajas únicas con relación a los disolventes tradicionales.

Los beneficios son una alta estabilidad química, disminución de la corrosión, casi nula presión de vapor y una gran cantidad de opciones en cuanto a la versatilidad que pueden tener los iones para optimizar la captura del CO2. El trabajo de los ingenieros y científicos también contempla el diseño de una aplicación informática capaz de calcular con rapidez y precisión la mejor alternativa a aplicar para separar el dióxido de carbono.

Pruebas y estudios para optimizar el proceso

Es así que en los últimos años los responsables del proyecto han testeado distintos líquidos iónicos, con el objetivo de descubrir la opción más efectiva para la separación del dióxido de carbono. En cualquier caso, con lo logrado ya puede concluirse que el nuevo método estará más fácilmente al alcance de las empresas, tanto por cuestiones operativas como económicas.

Para poder llegar a contar con la herramienta informática capaz de seleccionar el mejor líquido iónico en cada ocasión, sin que sea necesario efectuar costosas y largas pruebas, el especialista Amitesh Maiti del Lawrence Livermore National Laboratory ha desarrollado junto a otros responsables de la investigación una ecuación capaz de hallar el potencial químico del CO2 en cualquier disolvente.

El desafío actual es trasladar esa ecuación al sistema informático mencionado, para que el mismo pueda producir los valores exactos de solubilidad en un gran número de disolventes, incluidos los líquidos iónicos que se emplean en este nuevo método de separación del dióxido de carbono.

Concretado este paso, y con la exactitud aportada por los métodos computacionales, los especialistas creen que la potencialidad del nuevo método de captura del CO2 es enorme, pudiendo incrementar en gran medida la eficiencia en la separación del dióxido de carbono con relación a los sistemas que se emplean en la actualidad.