Tuesday, 12 January 2016

Coming to an end...

To all my loyal readers,

I have come to the end of my geoengineering blog-posts for the moment.  I have learnt a lot and have enjoyed writing about it.  I hope you have enjoyed reading them and I appreciate all the discussions and comments you have provided me with along the journey.   I intend, to be able to continue blogging in the near future, when I have more free time. But, for now, I wish to leave you with the below illustrations and a quote to think about.

“We must be the change we wish to see in the world”

Source for all 4 illustrations: Cartoon Movement

Monday, 11 January 2016

The Public Perception and COP21 Requirements

For the past few months this blog has analysed various geoengineering processes, including both SRM and CDR. This blog-post aims to discuss your thoughts and poll results, with a combination of academic literature, to assess people’s feelings on geoengineering.  I also wish to assess the COP21 agreement in reference to keep global temperatures lower than the 2oC threshold.

Uncertainty of geoengineering processes

The impacts that may be induced by geoengineering are unknown, leading to high levels of uncertainty for most people (Corner et al 2013).  Geoengineering is expected to decrease global temperatures and carbon dioxide levels, however, most processes have been experimented at only a laboratory scale or a small scale (as mentioned in previous blogs).  Although, climate change models are used to predict impacts of geoengineering processes, it is hard to ensure that these processes will perform exactly as expected.   Computational models tend to be unable to take into account all factors that may influence the atmosphere during geoengineering, as it is too complicated to process (Davies 2010).  Hence, creating a concern as to how geongineering may influence the environment and the water cycle.

Furthermore, people feel insecure to use geoengineering, as it may cause unexpected negative impacts, and there is no ‘undo button’.  Geoengineering processes may not work as expected and a malfunction may suddenly release large amounts of carbon dioxide in the atmosphere, at an alarmingly fast rate (Virgoe 2009).  Figure 1 highlights that a failure in geoengineering could increase temperatures 20 times faster than current rates of increased temperature (Bala 2009).  If this occurs, the impacts may be irreversible, leading to a large degradation of the atmosphere.  People may not have enough time to adapt against sudden plumes of carbon dioxide, causing health hazards.   Therefore, making people more sceptical to undertake geoengineering processes.

Figure 1: Implementation of SRM geoengineering and the failure scenario
Source: Baum et al 2013

Ethical and Moral Issues

A great concern occurs when regarding moral and ethical issues.  People fear that with adaptations of geoengineering methods, nations may assume that they do not have to mitigate their CO2 levels in the atmosphere (Davies 2010).  This may occur as geoengineering may be comprehended as a ‘quick fix’ and people may think that a sufficient solution has been found, creating a disincentive to further decrease fossil fuel emissions and increase renewable energy (Davies 2010).

Moreover, people may feel they do not need to be responsible for their actions, as scientists with improved technology, will always find a solution to problems they inflict on Earth (Davies 2010).   Therefore, encouraging people to not think of any negative influences induced on the environment, by their actions.  This behaviour may increase species extinction rates and negatively influence ecosystems (Bala 2009).

People are the main cause of climate change impacts.  Since the industrial revolution people have been increasing carbon dioxide levels in the atmosphere, leading to high temperatures and an increase in green house gases (Corner and Pidgeon 2010).  Therefore, Corner and Pidgeon (2010) suggest, since people play an important factor in negatively influencing the Earth, they should not try to ‘artificially fix’ the Earth through geoengineering, as they are likely to create further problems. 


Additionally, some geoengineering processes may have impacts at a global scale.  Therefore, questions arise regarding what organisation, nation or person should decide if geoengineering should be implemented and which type of geoengineering processes should be applied to reduce carbon dioxide levels.  Some countries may not want geoengineering to take place.  However due to global scale impacts, they may have no choice since other countries may be determined to promote this process (The Royal Society 2009).  Moreover, if all nations benefit from geoengineering, a question evolves to who should pay for the implementation (The Royal Society 2009).  Some nations argue that the developed countries should pay, as they are economically stable and have contributed greatly in increasing global carbon dioxide levels.  Controversially it is argued that developing countries are also using fossil fuels to a great degree and are also emitting carbon dioxide emissions, thus they should also pay for the installation of geoengineering. However, developing countries may be unable to do so, as they are not economically stable (The Royal Society 2009).

Poll Results

When looking at both polls (Figure 2), it is evident that most votes are similar to the beliefs found in academic literature.  At present, there are 13 votes for SRM methods and 16 votes for CDR methods.  Although the number of votes may not be large enough to draw academic conclusions, it can be compared to academic papers.  The results draw the conclusion that a high proportion of people feel that no geoengineering methods should be implemented, as they are unsafe and risky towards people and the environment.  This is highlighted, as it is the most popular selected option, with 46% of SRM votes and 37% of CDR votes.  In the case of SRM methods two other options, both gained 23% of the votes, these were white roofs; and green and PV roofs.  These options are considered soft geoengineering methods, as the technology used is simple and more natural, hence people may feel content that side effects may not drastically impact the Earth like other SRM methods (Corner et al 2013).  This observation is also seen in CDR methods as Enhanced Weathering and Afforestation/Reforestation both gained 19% of the votes. 


Figure 2: SRM and CDR Poll Results

However, to my surprise, when regarding CDR methods, Carbon Dioxide Capture also gained 25% of votes, even though it can be perceived as a technologically advanced method.  By looking at people’s comments on previous blog-posts, it can be deduced that this process, implementing Carbon Dioxide Capture, may be more effective than other processes with minimal environmental impacts.  Therefore, people may be more comfortable to use this process, even though it is costly and requires large amounts of water.

Furthermore, it is evident through the polls people are more content using CDR methods rather than SRM methods (Corner et al 2013).  This may be because most CDR methods are an enhancement of natural processes to reduce CO2, whereas SRM uses mechanical ways to change global temperatures.  Furthermore, the main aim of SRM is to increase sun reflection to reduce global temperatures and does not reduce CO2 levels, which is the main reason climate change impacts are occurring (Davies 2010).  Nevertheless, this is controversial as the immediately feasible and most researched geoengineering methods are SRM methods rather than CDR methods (Brogan 2015)

COP21 Agreement

The recent United Nations Framework Convention on Climate Change (COP21) took place in Paris in December.  The nations that participated agreed that global temperatures should only increase by a maximum of 2oC, with a main aim to only reach a 1.5oC increase in average global temperatures when compared to pre-industrial levels (UNFCCC 2015).  A very ambitious aim that gives false hope of a solution to mitigate climate change impacts (Bawden 2016).  However, this aim is very hard to achieve, as it requires fast rates of COreduction, which are highly unlikely to be achieved by 2030 by cutting fossil fuels (Bawden 2016).  Many scientists feel that renewable energy is not technologically advanced to reduce climate change impacts to the desired degree (Upton 2015).  Hence, for the COP21 agreement to be successful, it is likely that geoengineering methods will have to be applied.  It can also be argued that the COP21 agreement indirectly suggests the implementation of geoengineering, as it requests the safe use of carbon sinks (see previous blogs) and suggests sufficient technological advancement should be implemented to mitigate climate change impacts (UNFCCC 2015).  The positive aspect of the COP21, is the agreement to have no negative impacts inflicted on ecosystems, the environment, people and food security (UNFCCC 2015).

Many scientists feel that actions against climate change need to be taken now, to avoid catastrophic impacts (Bawden 2016). The COP21 agreement was fundamental in emphasising that actions needed to be taken immediately (UNFCCC 2015).  Hence, many scientists are against geoengineering but feel that this process needs to be implemented, as it may be the only solution to delay climate change impacts (Upton 2015).  Scientists believe there has not been a substantial change when trying to mitigate climate change impacts through renewable energy and a reduction of fossil fuels.  They also feel, geoengineering should be a temporary solution until renewable energy develops further and replaces fossil fuels (Upton 2015).


Overall, people feel that geoengineering is a process of high uncertainty and many unpredicted negative impacts may take place.  However, climate change impacts are becoming more apparent and global temperatures are increasing.  Although geoengineering is not the ideal solution, I feel that it could delay climate change impacts allowing renewable energy to advance to an efficient level where fossil fuels are not needed.  I believe that some geoengineering processes may be more beneficial than others; and with an increase of research and technological advancement, some processes may have limited or no impacts on ecosystems, the hydrological cycle or food security.  I believe we are at a stage that geoengineering may have to be a temporary solution to delay further increases of global temperatures.  I personally, will feel more reassured if nations implement geoengineering processes that will be further researched and have minimal impacts.  I look forward to hearing your thoughts on the matter.

Sunday, 10 January 2016

CDR Poll!

To all my fellow readers,

Thank you for following my journey of analysing geoengineering processes and articulating your opinions.

I am running another poll, this time regarding CDR methods of geoengineering.  I am curious to know if you believe any of the CDR processes mentioned, should be implemented in the future to mitigate climate change impacts.  Please feel free to voice your opinion in the comment section; it would be highly appreciated.

Furthermore, the ‘Other-please comment’ option is for any other CDR process that I have not included in my blog-posts.  Please let me know in the comment section what other CDR geoengineering process you have in mind and why it should be implemented.

I will leave you with some illustrations I though were entertaining regarding CDR. I look forward to hearing your thoughts.

Source: Cartoon Movement

Source: Quark Soup by David Apel

Carbon Sequestration

To all my fellow readers,

I found this video that analyses another CDR geoengineering process known as carbon sequestration and I thought I would share it with you.

This process aims to pump CO2 deep underground in a carbon pool and store it there for 10,000 or more years (Lorenz and Lal 2014).  There are two types of carbon sequestration, biotic and abiotic (Figure 1).  Biotic Carbon sequestration involves an enhancement of the natural processes of absorbing carbon.  Carbon dioxide naturally dissolves in the soil through combustion and decomposition (Lal 2004).  Therefore, forming soil organic carbon (SOC) and soil inorganic carbon (SIC), which absorbs carbon down the soil profile.  The enhancement of this process can increase the absorption of CO2 at faster rates and can be undertaken through land use, biofuels and an increase in organic biomass known as biochar (Lorenz and Lal 2014).  Biochar is the burning of organic material to form a charcoal, which can sink underground (Lorenz and Lal 2014).  This blog aims to analyse biochar as an example of biotic carbon sequestration.  Furthermore, Abiotic Carbon sequestration is a human engineering process, where CO2 is artificially injected deep in the soil surface (usually in saline aquifers to form carbonates) or deep in ocean sinks (Lal 2008). 

Figure 1: Representation of Carbon Sequestration
Source: Carboncycle 

Biotic Implications

The biotic sequestration of carbon through biochar may be very beneficial for crops and trees as it improves the quality of the soil due to more nutrients (Lal 2004).  The soil pH increases, due to the biochar process, leading to a reduction of acidic soil, which may be induced by Aluminium toxicity (Lorenz and Lal 2014).  The biochar reduces Aluminium toxicity and the soil gains the ability to hold moisture, leading to plants growing faster and stronger (Lal 2008). Therefore, there may be a decrease in the need of fertilisers and water, leading to a reduction of agricultural costs (Lorenz and Lal 2014).  Additionally, in the case of crops, agricultural yield may increase, leading to more economic benefits for people, as studies through experiments, show that crop productivity increases by 11% (Lorenz and Lal 2014).  Nonetheless, various types of soil and biochar react differently and some may be more effective than others (Lorenz and Lal 2014).  Thus, it may be deduced, that this geoengineering process not only reduces global CO2 levels, it is also beneficial for plant growth.

However, although there may be some positive impacts with an increase in biochar activities, it may lead to a change in microorganisms found in plants (Lorenz and Lal 2014). In the long-run microorganisms may adapt to biochar implications.  Consequently, this may influence plant growth thus making this process less beneficial forcing some plant species to shift their populations elsewhere or forcing species to adapt to this environment (Lorenz and Lal 2014).  However, there is little research on long-term impacts of biochar as a geoengineering process and it is hard to assess to what degree plants and crop yield may be affected in the long-run, compared to short-term impacts (Lorenz and Lal 2014).  Therefore, it is questionable to what degree biotic carbon sequestration may be affective.

Another negative impact may be that an increase in biochar activities may reduce the surface albedo due to the charcoal produced (Lorenz and Lal 2014).  A decrease in surface albedo may increase temperatures and reduce SOC absorption due to higher decomposition rates.  Thus questioning to what degree this geoengineering process will be affective.

Furthermore, to form biochar, burning takes place, thus CO2 is expected to slightly increase during this burning process (Lorenz and Lal 2014).  Once the process is complete and biochar is formed, the soil begins to absorb carbon. This questions to what degree CO2 levels will be absorbed due to the initial CO2 release.  The undertaken studies regarding biotic carbon sequestration occupy a time frame of 1-4 years (Lorenz and Lal 2014).  Therefore, there is high uncertainty if this process will be as effective and efficient as desired in the long-run.  Additionally, methane (CH4) may increase due to by-products created by biochar, thus increasing atmospheric green house gases (Lorenz and Lal 2014).  With an increase in green house gases, climate change impacts may not be mitigated.  Therefore, it is questionable to what degree this process may be successful to reduce global temperatures.

Abiotic Implications

When undertaking abiotic carbon sequestration, it is very hard to predict any impacts induced on ecosystems and the hydrological cycle, as it is very hard to process computationally (Lal 2008).  Nonetheless, a main concern is to develop an efficient process of injecting carbon deep in the soil or ocean and avoiding any leakages back to the surface (Lal 2008).  These leakages may reduce the effectiveness of this geoengineering process and may even pollute freshwater aquifers or make oceans more acidic (Lal 2008).  Moreover, costs may be relatively high as it is hard to inject CO2 deep underground efficiently and technological advancements may be essential to undertake this process effectively (Lal 2008).

Overarching Disadvantage

Lastly, an overarching concern is to ensure that CO2 is injected deep in the soil and it stays there for a very long time (Lal 2008).  For this process to be successful, the CO2 must stay in the carbon sink for a minimum of 5,000-10,000 years (Lorenz and Lal 2014).  If it stays stored for just 100 years, this may not be enough to reduce climate change impacts efficiently (Lorenz and Lal 2014).


Overall, carbon sequestration is a risky process and of high uncertainty.  I believe for it to be a viable process a lot more research and technological advancements may be necessary to reduce negative implications.  I think although it sounds very plausible, induced, carbon sequestration may not be worth undertaking, as it may not be as effective as desired and may not work as efficiently as needed.  What is your opinion on this process?

Monday, 4 January 2016

Afforestation and Reforestation: a mitigation of climate change impacts?

Deforestation has occurred for thousands of years, forests have been cut down for industries, homes, wood fire, logging, cattle and ship building (Brown et al 2014).  Deforestation releases CO2 in the atmosphere and stops CO2 absorption, leading to an increase in climate change impacts.  However, the restoration of trees could be used as a CDR geoengineering method to reduce CO2 emissions, as urged by COP21 agreements to reduce carbon sinks (Bailey 2015).  This can be undertaken by afforestation and reforestation.  Afforestation is the human growth of trees on land, which has not been forested in the past.  Reforestation is the human growth of trees on land, which was previously forested (Figure 1) (Caldeira et al 2013).  The natural absorption of CO2 is stored in trees and reduces atmospheric CO2, hence this geoengineering process could reduce climate change impacts. 

Figure 1: Afforestation and Reforestation Processes

Afforestation and Reforestation Impacts

The increase in tree plantation may be very beneficial as large amounts of CO2 will be absorbed from the atmosphere, provided trees are planted in the correct areas.  Albeit reforestation and afforestation absorb large amounts of CO2  they may negatively impact aquifers, due to high demands of water for tree growth.  Large amounts of trees require large amounts of water consumption for irrigation.  Moreover, evapotranspiration levels will increase leading to an increase in aquifer discharge (Heck et al 2015).  Hence although atmospheric CO2 may be absorbed and reduce climate change impacts, aquifers may deplete due to not enough recharge occurring in arid areas.  Moreover, ecosystems may change due to changes in water availability.  In China, there were abrupt changes in ecosystems due to a high level of tree planting and a low rainfall occurrence of 400-500mm per year (Brown et al 2014).  This lead to a degradation of ecosystems due to not enough water being supplied, questioning the degree of benefits of afforestation and reforestation.  Controversially, precipitation levels should increase by 1-2%, as bare soil will be replaced by trees, for instance in Nigeria.  Abiodum et al (2013) suggest that extreme rainfall events may increase in Nigeria due to a slower monsoon occurrence created by afforestation.  It is suggested that an increase in afforestation may have regional positive impacts of increased rainfall events, yet global warming may increase in regions around the afforested area.  Additionally, there may be an increase in droughts in semi-arid regions, as monsoons decrease and delays in air moisture occur in the region, hence delaying rainfall events.  It is evident that precipitation events will change due to afforestation and reforestation.  However, it is unclear to what degree this may be beneficial or disadvantageous for the hydrological cycle.

Although afforestation and reforestation can reduce atmospheric CO2  a large supply of trees will also demand a high supply of nutrients.  As afforestation and reforestation will occur at large scales, soil depletion will take place (Heck et al 2015).  It is estimated that 50-150kg N/ha/yr will be required for herbaceous plants (Heck et al 2015).  Thus a Nitrogen(N) fixation will be required to replenish the soils.  It is likely that fertiliser use will increase due to an increase in nutrient demand for soil replenishment, hence increasing the costs of afforestation and reforestation (Heck et al 2015). Therefore, questioning the degree of this geoengineering process being advantageous.

Moreover, another negative impact that may occur with afforestation and reforestation may be a decrease in albedo (i.e. solar reflectance) and an increase in roughness to a higher coverage of land with trees (Heck et al 2015).  Hence, if afforestation and reforestation occur on a large-scale, this may increase global temperatures at a local and global scale.  Thus, it may not be as influential as desired as a geoengineering process due to not reducing climate change impacts . 

Furthermore, there may be shifts in biodiversity, a main concern regarding environmental sustainability issues.  To minimise this impact it is essential when planting trees in an area to maintain the local species (Heck et al 2015).  Therefore plantation management is essential to ensure an equal growth of all species in a habitat (Heck et al 2015).  It is very difficult to ensure that no species outcompetes another species causing a shift in food webs or the natural biodiversity of an area.

Lastly, there may be an issue when regarding space.  If trees are planted at large scales for afforestation and reforestation, this creates an opportunity cost which enables the growth of agriculture or urban areas (Heck et al 2015).  Hence, this may lead to a degradation of economic growth and food security (Caldeira et al 2013).  Thus questioning to what degree people and governments would be willing to ‘sacrifice’ land for this geoengineering process to reduce CO2 levels.


Afforestation and reforestation can be considered an easy process to implement, with low costs and relatively low risks due to less technology being required and being such a familiar process.  However, this process may occur at a fast rate and may degrade ecosystems and the water cycle.  Hence it is questionable to what degree this process would be beneficial as a CDR method.  I believe the growth of trees is always beneficial.  However, I think the human induced growth of trees (especially in large-scales) would be very difficult to implement successfully, due to water and biodiversity management issues.  I look forward to you opinion on this CDR method.