Can't we just make the clouds brighter?

The next solar radiation proposal under scrutiny will be marine cloud brightening. This idea has been up in the air (get it?) since 1999 when it was first proposed by James Latham, a climatologist at the National Centre of Atmospheric Research. He proposed seeding marine stratocumulus clouds with seawater aerosols generated at the ocean surface (Latham et al. 2012) to result in additional cloud condensation nuclei within the cloud. These generated particles are held 1000 metres into the air, to help increase cloud reflectivity. Marine stratocumulus clouds cover over a quarter of the ocean surface and are hundreds of metres cubed in volume with albedos ranging between 0.3 and 0.7 (Hanson, 1991). Therefore by increasing the reflectivity of these clouds, it reduces a large proportion of incoming solar radiation to Earth and prevents excess warming induced by anthropogenic greenhouse gases.

In fact - did you know that clouds are already reflecting more than the amount of solar radiation which has been captured by anthropogenic carbon dioxide (Mims, 2009)? Ergo, Latham's idea utilises and optimises the current functionality of clouds to our advantage to reduce the induced impacts of climate change, and encourage a greater reflectivity of sunlight through the artificial generation of a seawater mist to the clouds in our atmosphere.

Source: Giphy

So how can we generate this additional seawater mist?

Many have debated different ideas; from collisions between air-saturated jets of water, a hydraulic equivalent of a photomultiplier, vibrating piezoelectric vapourisers, or to simply forcing water through 0.8 micron diameter holes in a wafer-thin sheet of Silicon. Over 1.5 billion holes would be required for a silicon slice only 20cm in width (Mims, 2009). This is an obstacle in itself- what is the most appropriate method? Silicon was suggested as the material of choice but its ability to withstand high pressure in experiments has been discouraging. There is also a need for uniformity in size of the water droplets, as to not run the risk of larger heavier droplets falling as rain prior to elevation of the mist (Mims, 2009).

Let's say hypothetically that the ability to generate a seawater mist is achieved- how are we to elevate it to 1000 metres high into the air?

Well, Stephen Salter from Edinburgh University has been engineering a concept of wind-powered, remote-controlled, unmanned Flettner vessels (Salter et al. 2008), otherwise known as 'albedo yachts' (see image below). The Flettner motors can transform wind energy into thrust to generate lift of the seawater particles upwards (Mims, 2009). Over 1500 of these vessels would need to be deployed worldwide and transforming 30 litres of saltwater per second in order to correspond to the rate of increasing carbon dioxide concentrations, but not without a hefty construction cost of between $3.2-4.8 billion (Mims, 2009)!

Source: UCAR

However, this idea has caused concerns, particularly with regards to changes in precipitation patterns. Plenty of General Circulation Models (GCMs) have been produced - including that by Latham himself, which all suggest that deployment of marine cloud brightening will cause a dramatic decrease of precipitation in the Amazonian Basin, and both the Hadley Centre and the UK MET Office in particular, suggested that desertification could result in the Amazon rainforest, as cooler temperatures, as a consequence of less incoming solar radiation, in the South Atlantic will result in less evaporation and therefore a reduction in excess of 1mm per day (Latham et al. 2012) of precipitation in the Amazon (Mims, 2009). If this were to occur, this would have huge implications on biodiversity- the rainforest is home to 40,000 plant species alone (WWF, 2014) and that's not even including birds, mammals, reptiles, fish, or amphibians! As well as social and economic consequences of livelihood and loss of homes.

Models have similarly suggested that under conditions of double the current carbon dioxide levels in the atmosphere, full seeding of marine cloud brightening would reduce precipitation in the Amazon, North America and South East Asia, but would however increase precipitation in Africa and Australia (Latham et al. 2012)! Is this a fair compromise to make? The influence of marine cloud brightening will definitely result in a global environmental change and affect the entirety of the global population.

Source: Eating jellyfish

So should maritime cloud brightening be given the go ahead? A complexity (as always) resolves in its application on the large scale- can we ensure success? Can we ever be certain that it will work? What if there are unintended consequences? Another trouble with this proposal is that it meddles with the dynamics of clouds, of which the microphysical processes are not yet even fully understandable within science. With so much uncertainty, how can we trust that the generated seawater mist will add to cloud condensation nuclei concentrations without a glitch? The problem of rainfall patterns similarly suggests corrections and certainty before deployment.

Rasch et al. (2009) have similarly suggested that an increase in planetary albedo cannot and will not compensate for increasing greenhouse gases especially in relation to consequences such as ocean acidification which could destroy many marine ecosystems. It merely provides extra time for us to ponder over future uncertainties and hopefully come up with an appropriate mitigation response.

However, the problem of time is that it always runs out.

Till next time!

S xx

Time to put your sun shades on...

So our first solar radiation method is: Sun shades- and no I'm not referring to these:

Source: Wry smiles

However, the concept does have the same effect!

Just like sunglasses, the purpose of the sunshade is to reduce incoming solar radiation, but instead from the top of the atmosphere to counterbalance warming induced by increasing greenhouse gases! Thin refractive mirrors reflect incoming solar radiation away from Earth, reducing the amount of radiation reaching Earth and warming the climate.

The 'Sun Shade World' was an idea proposed by Early in 1989. He proposed the implementation of a sunshade, composed of tens of thousands of metre-sized small spacecrafts, comprised of a thin refractive screen,  at the Lagrange Point (L1) between Earth and the Sun, which would be designed to reduce incoming solar radiation to Earth (Lunt et al. 2008). Lagrange points are "positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them" (NASA, 2012). L1 in particular is the point directly between the Sun and the Earth, and is approximately 1.5km away from Earth (Washington University) with the same annual orbit of Earth- 365 days.

Source: NASA

However, ultimately, does a solar reduced world solve any of our climate problems? Firstly, yes! By reducing incoming solar radiation, the sunshade would successfully reduce annual global mean temperatures to mirror that of the pre-industrialised world prior to 1750. This has been one of the main goals of mitigation strategies thus far, and scientific research has always encouraged attempts to return to pre-industrial levels, to re-stabilise our climate. A sunshade world can do this!

Interestingly, the world has been in a reduced solar radiation and high carbon dioxide level environment before in our geological past of the Cambrian era! This means the Earth has been in a similar climatic situation before, and it was actually an era of an evolution boom, with a warming climate and rising sea level (National Geographic, 2014).

However, reducing solar radiation does not dampen the effects of increased carbon concentrations in the atmosphere, and the forcings of radiation from increased carbon dioxide differs from solar forcings (Govindasamy & Caldeira, 2000). Firstly, carbon dioxide, and other greenhouse gases trap heat all day, all night, and all year round. Solar radiation, in contrast, is more attributed to daylight hours and is expected seasonally, and most abundantly towards the equator (Govindasamy & Caldeira, 2000), so it cannot completely characterise our pre-industrial world.

A Community Climate Model was produced by National Centre of Atmospheric Research (NCAR) which simulated three different global scenarios: pre-industrial, doubled carbon dioxide emissions, and finally, doubled carbon dioxide emissions with reduced solar radiation- i.e. geoengineering. From the three scenarios, the sunshade geoengineered response, cooled the climate the greatest by 1.88 Kelvin and particularly in the equatorial regions, but could intensify carbon dioxide's impact on stratospheric temperatures through enhancing stratospheric cooling (Murphy & Mitchell, 1995) which could lead to damage of the ozone layer (Houghton et al. 1990)!

Other issues of the Sunshade world, is it causes a reduction of intensity in the hydrological cycle such as a decrease in precipitation- particularly in the tropics, which has a web of social and economic issues attached, and in the Arctic sea ice melt would increase (Lunt et al. 2008). However most importantly, a dominant issue, and this has been highlighted above, is that carbon concentrations in the atmosphere will continue to increase. Therefore any atmospheric carbon effects will not be mitigated through the adoption of a Sunshade world. For example, ocean acidification will not be stopped, and the impacts this has for marine ecosystems is humongous, and has a domino effect on the ocean's future capabilities as a carbon store.

Also, lastly and foremost, is should this 'World' be adopted, what if a) it fails or b) we decide it needs replacing or no longer want to use it; this will cause a rapid increase in global warming, and as carbon concentrations were still increasing during the geoengineered time, this could have hugely adverse effects on the world, in terms of re-adapting to an anthropogenically intensified climate.

The 'Sunshade World' remains a proposal for the time being, and the list of uncertainties suggest if or when it is deployed, is a long way off, as does the economic expense of a few trillion dollars to spare. The only way this scheme could work effectively, is if carbon mitigation strategies are employed harmoniously, which could help reduce the rapid climate change potential, should the Sunshade be removed.

What do you think?

S xx

Solar Power!

Having assessed the opportunities that carbon reduction methods uphold in response to the ever increasing global warming... I think it is safe to assume that proposals so far are still very much hypotheses, and none are yet ready to be deployed across the globe (at least on the large scale in the case of biochar)- not to mention the fact that some responses cannot resist against rapid changes in climate, and lets face it, we need emergency answers and pronto.

Luckily, carbon reduction methods aren't the only answer; solar reduction methods are a second category of geoengineering proposals, aimed to respond to recent anthropogenic climate changes.

Solar radiation methods differ from carbon reduction methods as they are not designed to remove any atmospheric carbon concentrations but instead reduce the amount of solar radiation reaching the Earth, which is enhancing global warming.

Source: The Economist

The following posts will explore the different proposed methods of solar radiation management to ultimately allow us to draw a comparison against carbon reduction methods!

Here's a teaser trailer of what is yet to come! (As you can see there still remains controversy regarding the issues of climate change and global warming!)

Sourced from YouTube.

Ready?


S xx

Biochar

The final carbon reduction method that this blog will explore is upon us and how should we end this spell? With Biochar.

Biochar is created via a process known as pyrolysis, which is the combustion of organic material with little or no oxygen present. The outcome is a high density (black) carbon which can be used for carbon sequestration via underground terrestrial burial (Massachusetts Institute of Technology, 2009) (Seen below). Biochar has been championed due to its carbon storage capabilities, and its ability to enrich soils for crop production, hopefully enhancing a global food security (Levitan, 2010).

Source: DIY Natural

The idea to explore biochar as a carbon sequestration opportunity derived from the Amazon Rainforest. The terra preta soils were discovered to store 2.7 times as much carbon compared to regular soil (Glaser et al. 2001) but the idea had been speculated since 1996 by Kuhlbusch et al.

Biochar is actually produced by many farmers around the world as a fertiliser, and the pyrolysis is carried out in traditional kilns, which are easy to build and largely cheap to purchase (Massachusetts Institute of Technology, 2009). In order to translate biochar production onto a global scale, and as a geoengineering prospect, commercial pyrolysis machines are required. This is because the traditional method allows the escape of byproduct- synthetic gas (or syngas as it is known) which has a high carbon concentration and contributes to atmospheric carbon emissions. Commercial pyrolysis machines also reduce hydrocarbon levels, which also result from the pyrolysis process. It can be harvested as fuel if in liquid state, but residual (solid) hydrocarbons can actually limit crop productivity in plots with buried biochar. Ergo, commercial pyrolysis machines are therefore needed to prevent the result of residual hydrocarbon and have already solved the problem of potential carbon leakage to the atmosphere.

It has been suggested by Matovic (2011) that the combustion and burial of 10% of global biomass waste could sequester ~5 gigatons of Carbon per year. Putting this in perspective, humans emit 28 gigatons of carbon per year, of which a large proportion is taken up by the biosphere and oceans (Levitan, 2010) which means that global biochar production could have the potential to significantly reduce atmospheric carbon concentrations. Carbonscape have already been in talks of converting 930 hectares of land for biochar production (Monbiot, 2009) with hopes of being the first commercial company involved on a geoengineering scale!

Source: Re-Char

However, biochar has been a controversial proposal as to whether it really does classify as a geoengineering scheme. Surely it is just a method of carbon sequestration-  is its intent to be a large scale manipulation of the climate? This is why this post has become my ultimate carbon reduction post. Controversy revolves around its geoengineering status, but as long as it is still being considered as a potential geoengineering solution, it shall remain an interest within this blog feed!

Other concerns of biochar include that the global biochar initiative is subject to the same risks as any other carbon reduction method: The unknown. We cannot guarantee the outcome of global biochar- will it be successful? Can it respond to rapid climate changes? Will indirect consequences of land-use change or social or chemical problems arise? Similarly optimum biochar production would require a colossal number of commercial pyrolysis machines which is hugely expensive and largely impractical (Massachusetts Institute of Technology, 2009)! Can it possibly suit large scale implementation?

These questions are a constant to any geoengineering attempt, however, the difference between biochar and the carbon reduction attempts assessed so far, is that biochar is already happening at a local scale, and it is working. Even if this continued on a local scale alone, progress will be made to reduce atmospheric carbon concentrations, but as a geoengineering scheme- is it worth taking such a giant risk?

Apparently not yet anyway!

Source:Arctic Cartoons

Who knows, perhaps solar radiation methods will be more effective geoengineering techniques?

Until next time!


S xx

Trees, trees, trees!

From artificial trees to real trees... Let's move on to our penultimate form of CDR methods, let's talk about Afforestation.

It's exactly what it sounds like, just as artificial trees was the implementation of tree-imitating devices, afforestation is the planting of trees in previously non-forested places to create a net carbon sink and storage of carbon (Haszeldine & Scott, 2014), and is one of the biggest terrestrial geoengineering schemes proposed to date. The IPCC Fifth Assessment Report assumes that CDR afforestation will be used in the future as a geoengineering strategy (Bellamy et al. 2012). Large-scale afforestation has the capability to counterbalance carbon absorption with anthropogenic carbon emissions from industrialisation, through photosynthesis and increased biomass (Zhang et al. 2014). In fact, it has been suggested that afforestation in non-forested and urban areas could result in carbon storage of approximately 12% of current carbon emissions by 2015 (Andelin et al. 1991).

From the outset it sounds like the idea is simple, deforestation has resulted in increased atmospheric carbon dioxide concentrations, so surely in an attempt to prevent this, we should plant more trees!

Source: Oecotextiles

Simple right?

Wrong.

If this were the case, the geoengineering scheme would be reforestation, yet afforestation requires previously non-forested land. Proposals first considered afforestation schemes to take place in temperate high latitudes, but research suggested that barren land has a higher albedo for an increasing cooling effect (Manfready, 2011). Ergo, afforestation proposals have been considered for desert environments.

Geoengineering projects have been initiated in China, the Sahara and Australia alike. In desert conditions, fast growing trees are preferred- particularly eucalyptus, as plantations of 1000 eucalyptus trees have the capability to sequester ~0.5-1 x 10⁴ kgC/hayr (Zhang et al. 2014).

Large-scale desert afforestation was launched in China in 1978 as the 'Great Green Wall Plan' to vegetate the north-western, north eastern and north provinces of China (Veste et al. 2006). The 'wall' would be made up of tree shelterbelts, which are a protective forest system designed to conserve soil and water supplies. The Three Norths Shelterbelt is part of the 'Great Green Wall' and is 4480km long, and between 400 and 1700km  wide, and covers 42% of China's territory (Veste et al. 2006). In China, afforestation is increasing carbon storage within the biosphere between rates of 30 to 74g/m2yr. Success!

Similarly, Orsntein et al. (2009) has gone so far to suggest that the combined afforestation of the Australian outback and Sahara desert could offset all carbon dioxide emissions resulting from fossil fuel burning. It has also been noted that afforestation succeeds on previously degraded land. For example, in India, Jatropha plantations on marginalised land can add 1450kgC/ha/yr to the soil as 4000kg of plant biomass (Zhang et al. 2014). This illustrates that afforestation schemes do not require greenfield sites and clean land to develop areas of forestry, and could greatly improve and flourish previously degraded land. Afforestation schemes, particularly in desert areas could also contribute socio-economically to local communities for agricultural and timber purposes.

Source: ClipArt

However, there are side effects to vegetating deserts, including an induced increase in ability to carry more avian diseases, which if prevalent in the Sahara, would impose risks to Sub-Sharan regions and mainland Europe (Manfready, 2011).

Research also suggests that large-scale afforestation activity can cause a decrease in local surface albedo, and an increase in air temperatures in neighbouring areas. The consequence of this action is that afforestation could be inducing more global warming than that that would ensue if geoengineered afforestation did not take place. Similarly, although afforestation can be praised for being almost 'risk-free' and highly feasible in comparison to other significant geoengineering proposals, the process is extremely slow, and therefore a less effective method (Keith, 2000). My previous post regarding artificial trees was proposed due to the slow rate of natural photosynthesis, therefore, simply planting trees to sequester atmospheric carbon is a slow process regardless of the amount of trees planted. This similarly means that should we be on the onset of reaching a climate tipping point, afforestation is not an emergency response to saving the climate and environment as we know it. The process is not rapid, and could not prevent significant climate changes, and ultimately the forested trees are likely to be subject to changes derived from the climate tipping point (Andelin et al. 1991).

Another caveat to this solution is the eventual re-release of carbon back into the atmosphere. Although trees have the ability to store carbon for years on end, carbon returns to the atmosphere in the tree's eventual death, through natural decomposition, or during tree harvesting (Andelin et al. 1991). Therefore, in order to capture carbon at a constant rate, trees would have to be disposed of and continuously replaced, and fertilisation would be required to re-enrich trees with the required nutrients, which is a highly intensive process which would require regular maintenance (Keith, 2000), and who would be willing to provide that? Would it be up to the host country to provide maintenance?

Afforestation does have potential, and despite a few associated risks, it is definitely a worthy geoengineering strategy but can it really produce effective and efficient reductions in carbon emissions? The process is almost too lengthy, and requires a large land area to produce any significant effects.

If areal extent and tree maintenance were not potential social problems, and the rate of photosynthesis was not as slow as it appears to have been suggested, afforestation could be the answer to our climate change problems. However, afforestation cannot compete with the rapid climate changes which comprise our future!

All in all, it appears that carbon reduction methods are subject to success and failure, and have an incredible impact on global environmental change- but can they save our planet?

Find out next time!


S xx

Pure and simple?

The main problem surrounding climate change is our anthropogenic influence on atmospheric carbon concentrations. Human activity has enhanced carbon dioxide emissions from pre-industrial times (~1750) of 260-270 ppm (Wigley, 1983) to 395.93ppm today (Co2now, 2014. The geoengineering schemes that we have discussed so far have focused on carbon dioxide removal from the atmosphere via a plethora of methods and avenues, from enhancing weathering processes, foresting land and adding nutrients to the oceans, but why not find a direct method to remove carbon from the atmosphere? Why not undergo air purification?

Since 2009, the idea proposed by Lackner was to manufacture 'artificial trees' to capture carbon from the atmosphere. The design can be seen below.

Source: geoengineering2012

The trees are able to mimic the planet's natural uptake of carbon dioxide, as the prongs contain sodium hydroxide, which acts to chemically consume carbon dioxide and transform sodium hydroxide (lye) into sodium carbonate (Biello, 2009). The carbon dioxide is then heated at 900 degrees celsius, releasing the carbon dioxide to enable sodium hydroxide to re-react with atmospheric carbon dioxide once more. The artificial tree is able to remove carbon dioxide from the atmosphere at a  much faster rate than natural photosynthesis (Schiffman, 2013), and scientists have envisaged the existence of forests of these artificial trees to optimise carbon removal.

The idea has been supported by both the UK Royal Society and the Institution of Mechanical Engineers as the safest and most effective geoengineering technology suggested. However many statistics from 2009, when the advent of this proposed solution occurred, implied that these artificial trees would be demonstrated in society by at least 2014, which of course is today. Has anybody witnessed any demonstration of artificial trees yet?

The Institution of Mechanical Engineers actually believed that post-demonstration in 2014, a full scale 'forest' of artificial trees could be implemented by 2018, and global deployment by 2040 (Biello, 2009). The questions have to be asked: Why has this not happened? What has hindered the project's progress?

The hindrance could be a result of a multitude of reasons. Firstly, the concept sounds appealing: carbon dioxide is removed from the atmosphere using successful and efficient devices, yet where does this captured carbon go? The carbon inventory proposed was underground, and some geological formations have been tried and tested, for example Basalt, as it has the ability to absorb carbon dioxide over decadal timescales to produce minerals (Biello, 2009). However there have been many caveats concerned with underground sequestration. For example, how will it impact groundwater supplies? Is there potential for carbon leakage back into the atmosphere?

Other problems with air purification are dominantly economical. The project requires large land area, production of electricity and manufacture and installation, which will all come at a huge economical expense. It has been proposed that 10 million artificial trees would be required to reduce ~12% of anthropogenic carbon emissions per year (Schiffman, 2013), ergo making a colossal change in carbon reduction to pre-industrial levels would require a huge volume of air purification devices across the globe. Similarly each artificial tree is estimated to cost $24,000, therefore even 100,000 trees is already $2.4 trillion in expenses. Can we afford this?

In response to these caveats, and the Institution of Mechanical Engineers' proposals in 2009 for air purification to be ready for deployment and installation during 2014, I found it extremely difficult to find any recent academic papers evaluating artificial trees (mitigating those of course that were in reference to artificial Christmas trees, the latter end of November was probably not the best time to look!) or air purification. In fact, the academic scene is quite muted on the subject- does this mean that this proposed 'safest and most effective geoengineering scheme' is not as hopeful as first thought?

Source: Cartoon Movement

Similarly I think that the theory does have huge potential, however, finding suitable land areas to deploy the trees globally will undoubtedly be a struggle. People are already adverse to the sight of windfarms, despite their benefits of clean, renewable energy, due to aesthetics and impact on house prices, so it is highly unlikely that they would take to having artificial trees implanted in their back garden.

How do you think this project compares to the schemes proposed so far?

S xx

Enhanced Weathering... Weather away!

Now this post will no doubt sound familiar.. Enhanced weathering? Wasn't that essentially the process behind ocean liming?

Yes, yes it was. However, this process is not confined to the oceans, but also to the biosphere.

Over millions of years rocks are worn away by rain, forming carbonates due to the slightly acidic nature of rain, as a result of its uptake of carbon dioxide. The alkaline carbonate formation, (usually calcium carbonate) is therefore induced by this chemical weathering process, and eventually washes down into the sea (Hamilton, 2013).

Source: Rgbstock

This background theory of the process of chemical weathering has been applied as a potential geoengineering scheme to reduce atmospheric carbon dioxide concentrations. Chemical weathering locks up carbon dioxide through chemical reactions between the rock minerals and air. The optimum material for enhanced weathering is Forsterite (magnesium olivine), due to it's high abundance and reactivity (Hartmann et al. 2013). An example of olivine (magnesium iron silicate) weathering with water and carbon dioxide is represented by the equation below, which results in magnesium carbonate and silicic acid, storing carbon in the process:

Schuiling et al. (2011) reviewed the above equation investigated by Kohler et al. (2010) which suggests that dissolution of 1 mole of Olivine can sequester 4 moles of carbon dioxide. This is through the consumption of carbon dioxide and the release of cations, in this case, Mg2+ into the solution. Enhanced weathering would use the natural process occurring above, but increase the surface area of rock for weathering, or increase temperature and pressure to influence ocean pH.

The process is rather advantageous. Ultimately it would help remove atmospheric carbon dioxide by accelerating natural geological processes transferring carbon and trace elements between the atmosphere, biosphere, and eventually the oceans, which is the aim of any geoengineering scheme. However, it also reduces ocean acidification- a variable caused by climate change, and induces the transferral of trace elements including phosphorous, silicon and potassium (Hartmann et al. 2013), which in turn, enhances biological productivity within the oceans, increasing photosynthesis and carbon dioxide uptake.

However, to uptake maximum carbon, theoretically the rock would have to be crushed, yet in practice, natural rock weathering is an extremely lengthy process, and ideas of quantity and volume of rock are unknown to be able to mitigate the high anthropogenic and atmospheric carbon concentrations. Similarly, should Olivine be prevalently used, it contains toxic metals including nickel that could accumulate within the biosphere, and in attempting to also reduce ocean acidification via this method, could result in higher alkalinity levels to which some marine organisms are not acclimatised (Cressey, 2014).

Enhanced weathering is therefore subject to the same flaws or uncertainties as the proposals discussed previously within this blog. Nothing has ever been induced in the large-scale, so some effects will always be unknown. Similarly, attempts at accelerating natural processes cannot guarantee emergency response to increasing carbon dioxide emissions, and combined with lack of human understanding, projects are no where near ready for installation.

Will we find an appropriate geoengineering method to solve our climate problems? Luckily proposed schemes are not limited to those discussed in this blog so far, stay tuned for more geoengineering projects! Next time- air purification!

S xx

Liming in South Australia

A corresponding case study to ocean liming is with a company called Cquestrate, who proposed an ocean liming scheme in the Nullarbor Plain of South Australia. Tim Kruger is the founder of this company, and aims to reutilise liming in a means to protect the environment from increasing global warming effects.

Nullarbor Plain is feasible for potential liming activity due to the abundance of limestone (over 200,000 km2), approximately 20MJ per m2 of daily solar radiation and only 200-300mm of rainfall per year (Cquestrate, 2008).

According to calculations, the Plain contains 10,000km3 of limestone, of which, only 5% consumption would return the 305GtC of carbon dioxide emitted between 1750-2003 back to pre-industrial levels (Cquestrate, 2008)!

Ideal!

Source: Bbm Live

This project however has been questioned with regards to using 'dirty energy' such as coal power to undergo calcination, but Cquestrate aim to use 'stranded renewable energy'. For example, according to Kurokawa (2003) deserts are untapped resources which could utilise solar radiation through photovoltaic power generation schemes. As this is never used on a large scale, it is a cheap energy source and great in the right location. This reasoning is why Australia's Nullarbor plain has been chosen by Cquestrate, as it receives ample sunlight, and is abundant in limestone material (Sandstone, 2007).

Source: Mike on bike

It would appear from the statistics that liming of the ocean could be the technological approach needed to stall the effects of current global warming, especially if the dirty energy solution can be solved, and could be applied in the large scale, as that is what the definition of geoengineering requires to take place. Also, despite the attributes listed by Cquestrate, there has been no mention of timescale, and how long it would take to reap the benefits of their project.

Who knows, Cquestrate could become future geoengineering giants (subject to project success)- watch this space!

S xx

Liming the oceans

It's time to move onto Carbon Dioxide Removal (CDR) geoengineering: Part Two.

This time the focus again revolves around the oceans, this time: Liming the oceans.

This method mirrors that of my previous post on ocean iron fertilisation, as both methods focus on utilising the ocean's ability to store copious amounts of carbon; a storage greater than any other carbon sink on the planet.

Source: wattsupwiththat

Yet, ocean liming differs from ocean iron fertilisation as it is a chemical geoengineering process using chemical reactions to increase ocean carbon storage capacity whereas iron fertilisation used biological means of enhancing carbon dioxide removal from the atmosphere. Liming was first suggested by Haroon Kheshgi, and it is the sprinkling of lime (otherwise known as Calcium Oxide (CaO)) into the ocean as a means (according to Renforth et al. 2013) of manipulating the carbonate system through the addition of CaO to improve net sequestration of atmospheric carbon into the deep ocean.

Here follows a key background of why and how liming works...

So as established in my previous post, colder waters are more optimal than warmer waters at absorbing greater volumes of carbon dioxide concentrations. Yes? Right, however anthropogenic activity in recent years has both increased carbon dioxide emissions to the atmosphere and induced a decrease in ocean pH by 0.1 units. Continuation of this pattern of behaviour could result in a 0.4 unit pH decrease over the next 100 years (Renforth et al. 2013) resulting in....

Acidification of ocean surface waters.

The climatic impacts of ocean acidification results in biodiversity loss as microorganisms such as phytoplankton within the surface waters cannot form strong shells, which is crucial as these microorganisms are greatly responsible for carbon dioxide uptake via photosynthesis.

Source: Just only

How does liming stop this?

Liming is the addition of calcium oxide, an alkaline compound. By sprinkling this compound into the oceans, it increases the oceans pH to mitigate acidification, and optimise carbon dioxide uptake. When proposed by Keshgi, hydroxide particles were added to the ocean incurring the following dissolution reactions to take place:

CaCO_3 --> CaO + CO2
CaO + 2CO₂ + H₂O --> Ca²⁺ + 2HCO₃^-

On addition to seawater, calcium oxide reacts with carbon dioxide to produce calcium bicarbonate solution. The net effect of this series of reactions is beneficial in terms of carbon sequestration as 1 mole of calcium oxide absorbs 2 moles of dilute carbon dioxide, and the production of calcium oxide only required 1 mole of pure carbon dioxide for formation (Cquestrate, 2008).

The prevalence of limestone (CaCO3) making up 10% of the Earth's land surface, makes it an ideal and abundant material to use, especially as projected input into the ocean on a global scale should only subject a minor change in ocean chemistry which suggests minimal impact on the environment.

This all sounds good, but what if too much alkalinity is added to the ocean? What happens then?

Upon initial addition of lime into the ocean, a localised elevation in pH around the point of addition is induced, which in small increments has little environmental impact, however over an increased period of time, higher pH levels are detrimental to some living organisms, and could result in carbonate precipitation, which hinders the effect of ocean liming (Renforth et al. 2013).

Also, research has discovered that the benefit of liming derived from limestone could take decades before it takes effect due to the slow process of deep ocean upwelling, and is therefore unlikely to be an emergency response to global warming. If 4 billion tonnes of powdered limestone was added to the water yearly from 2020 onwards, 1 billion tonnes of carbon dioxide could be taken up by the oceans, reducing atmospheric concentrations by 30 parts per million by 2200 (Hamilton, 2013). But can we wait this long?

The extraction of lime from limestone is both costly and emits carbon dioxide through the process, (which requires coal power)- so why not forget liming and just concentrate on reducing use of coal power plants to prevent pollution of carbon dioxide in the first place? Unless lime can be extracted using renewable energy, the scheme surely is not worth the pollution and costs of producing lime in the first place.

Similar ethical questions can be raised such as, who owns rights to the ocean? Should anyone be allowed to experiment with the ocean's chemistry? Can we account for unexpected changes?

With all of this in consideration, should it go ahead? I think as proposed geoengineering schemes go, this one makes sense, as it utilises the abundance and renewal of limestone and has little known impact on biological life. However, until this process can be derived from alternative, carbon-free means, and there is a way to increase the rate of progress, the proposal still requires considerable development.

Any thoughts?
See you next time!


S xx

On a global scale...

Just an impromptu post!

I found this map on the Guardian website indicating where Geoengineering projects were taking place in 2012, and what type of activity!

The map clearly illustrates that a large proportion of the world is involved in the development of geoengineering projects, but it is most prevalent in the 'hotspots' of westernised countries including the US, Canada and those of Europe.

This map helps to illuminate the proliferation of geoengineering across the globe, and just how strong a candidate geoengineering is in the world's attempt to mitigate climate change.

Source: ETCGROUP.ORG

Enjoy!

S xx

Iron's the answer!

So we have now set the processes of Geoengineering in motion....

But what actually is Geoengineering?

I reiterate my previously brief introduction on what composes the term 'Geoengineering' by first defining the process as 'as an intentional large scale manipulation of the environment...' (Keith, 2000).  The action of geoengineering must be primarily for inducing environmental change, and on a large scale (continental or global). The currently credible methods of Geoengineering can be divided into Carbon Dioxide Removal (CDR) and Solar Radiation Methods (SRM).

This post will focus on all processes CDR related. So what are they?

They have one aim. 

Carbon dioxide removal methods resolve to reduce the amount of carbon dioxide within the atmosphere through extraction for long term storage in a sink such as land, vegetation or sequestration in the deep ocean (Hamilton, 2013). This process manipulates the mighty global carbon cycle, shifting the current equilibrium balance away from its present state of an increasingly enlarging atmospheric carbon sink. The removal of atmospheric carbon dioxide should slow then begin to diminish the increasing warming effects that excess carbon dioxide has already caused. 

Ocean Iron Fertilisation is one of the CDR approaches and will be the focus of today's post.

The world's oceans are crucial within the global carbon cycle, as the largest sink of carbon. More than 38,000 billion tonnes of carbon are stored in the ocean,compared to 800 billion tonnes in the atmosphere (Hamilton, 2013). Carbon dioxide initially dissolves into the ocean surface layer where great mixing occurs. This surface layer becomes saturated quickly, and carbon is then drawn down into the deep ocean. Little mixing occurs in the deep ocean so carbon storage is greater. Ocean temperature is an important variable in the uptake of carbon, as colder waters are able to absorb greater quantities of carbon, therefore deep oceans at high latitudes are optimum for carbon storage.

Ocean iron fertilisation has been proposed to increase biological productivity through increased iron content within the waters. The increased productivity would induce an increase in carbon uptake within the deep oceans through photosynthesis. Iron is an important trace element for all living organisms, but increasingly so for cellular functions including chlorophyll synthesis in phytoplankton to undertake photosynthesis processes.

Phytoplankton growth is more prolific in areas of high nutrients and low chlorophyll, such as the Southern Ocean and sub-Arctic Pacific (Allsop et al. 2007) due to the lack of availability of iron. Phytoplankton blooms are stimulated by increased iron content, and iron fertilisation is idealised as a geoengineering preposition to enhance the biological pump through phytoplankton population growth, to draw more carbon dioxide into the oceans. When these micro-organisms perish, the carbon is stored for a very prolonged period within the deep ocean. (The video below describes the iron fertilisation process with the bonus of visual aids). One tonne (metric ton) of iron could promote the removal of 30,000 to 110,000 tonnes of carbon from the atmosphere, and the process of iron fertilisation is estimated to cost only approximately $30-300 per tonne of carbon sequestered (White & Mitchell, 2012). 

Sounds great, right?

Surely this process could mitigate climate change? 

(Source: www.youtube.com/watch?v=sPRKLpDdM0s) 

As easy as this all sounds there are limitations.

Firstly there is a huge lack of understanding within this area of research, and the concepts are highly simplified (Allsop et al. 2007).  There have been only 12 small scale experiments between 1993 and 2008 to see the impact that increased iron concentration has on phytoplankton growth, with successful results (Lampitt et al. 2008), but none of these experiments were designed to measure sequestration. Since then, there have been 2 more, including a  release of 100 tonnes of iron sulfate into the North Pacific Ocean, just off Canada in 2012 (Tollefson, 2012), but this sparked conflict and experimentation ceased (Bellamy, 2014). No project has yet been applied on a large scale, which could have great hindering effects or hitherto unforeseen consequences. Therefore whilst the potential is there to enhance ocean carbon sequestration by this technique, modelling and observation attempts have not yet provided a foundation stable enough for this method to develop further (Lampitt et al. 2008) due to lack of verification. All methods have to be verified in front of policy-makers and the scientific community for success, (this can be illustrated by the advent of carbon credits within policy) yet such certainty of outcomes is not yet demonstrable for iron fertilisation. 

Source: Translating Science

Similarly a large envelope of uncertainty surrounds the methodology due to unknown global carbon cycle processes and interactions with the upper ocean. Side effects of iron fertilisation could be ocean acidification, due to increased carbon dioxide absorption into ocean surface layers. Such a decrease in ocean pH is likely to have implications and alternative effects on the ability for calcification and a shift in phytoplankton populations (Lampitt et al. 2008). 

The process could similarly cause a redistribution of minerals within the ocean, causing nutrient deficits elsewhere. Similarly increased phytoplankton populations could absorb more heat from the sun, and produce warmer ocean surface layers (Powell, 2008). 

There are big ethical problems - such as who owns the oceans? Whose piece of ocean shall we try this out on first? What about impacts on fish stocks and harvest from the sea? There are many interdependent and delicate ecological systems in the oceans? How do we assess the environmental impact of such complexity? Are adverse impacts on some species OK but not others? Who will decide?

The examples above are uncertainties to name a few. But the list goes on. There are too many uncertainties associated with ocean iron fertilisation, which are preventing it from becoming, in the near future, any more than a geoengineering application or proposal. 


However, which other carbon dioxide removal methods have been proposed - and with what likelihoods of future success?

Let's check these out next time!   


S xx

After you, no after you...

So how did Climate Engineering become shortlisted as a climate change solution?

We established in my first post that it had not been acknowledged within policy until the IPCC Summary for Policy Makers Report in 2013, so what were the solutions that preceded it?

The first and foremost approach was initiated as an attempt by the governments of the major industrialised countries to attempt to incorporate climate within policy making, setting targets and initiatives to reduce the amount of carbon dioxide emissions polluting our increasingly warmer atmosphere. This globalised mitigation strategy, an attempt to limit the enhanced effects of carbon dioxide by diminishing current consumption behaviours, has been developed by global summits to create a universal sustainable power against climate change and targets and goals have been proposed.

Maybe international targets of a worldwide reduction in carbon dioxide emissions per capita by 50% could be applied?

Seems rather unlikely.

Could the most highly developed countries really (and hypocritically) inform the newly industrialised countries (NICS) and underdeveloped countries of the world, that they can no longer develop as rapidly, and potentially as successfully, as they did so long ago?



Source: Rweb

Developing countries have refuted any full participation in climate mitigation methods, claiming that, compared to industrialised countries, developing countries have much more to lose from climate change due to agricultural dependence, and that a growing economy was the only way to mitigate any climate change effects (Schelling, 2002).

In fact it was agreed at the Kyoto Protocol in 1997 that a heavier burden of responsibility would be applied to the developed countries worldwide, as they had a greater impact on increasing anthropogenic carbon dioxide emissions and that the global north and south should have 'differentiated responsibilities' (UNFCCC, 1992). In 2010 alone, the US emitted 17.6 metric tons of Carbon Dioxide per capita, compared to 0.1 metric tons per capita in Guinea (www.data.worldbank.org/indicator/).

The G8+5 Climate Change Dialogue in 2006 convened the world's 16 highest polluting countries, recognising that 20 countries are responsible for more than 80% of global carbon dioxide emissions (Prins & Rayner, 2007).

How effective then have carbon trading methods been at reducing our climate change problems?

The idea behind carbon trading is that any country who underuses their assigned limit of carbon dioxide emissions can sell its remaining quota to other countries and the buyer gains an increase in allowance of carbon dioxide emissions.

Simple.

Or is it?

In theory, it is potentially possible that by capping maximum carbon dioxide emissions this would, over time, gradually reduce our carbon consumption, and contribute to a decline in pollution emissions. However, in practice, the terms of trade are continually under renegotiation, and countries with an 'excess' of allowable quota, can ask for greater sums of money upon each occasion, due to increased demand for the allowance (Schelling, 2002).

Similarly, no nation has the power to monitor these trading process on a worldwide scale, nor be able to impose sanctions against those who do not comply. Despite this being a global problem, carbon trading would have greater success on a local scale (Hilsenrath, 2009). Prins & Rayner (2007; p975) stated that 'rather than the top-down universalism embodied in Kyoto, countries would choose policies that suit their particular circumstances'. Yet post-Kyoto, this approach has largely been ignored.

Maybe we should wait? But for how long? The Climate Clock ticks on...



Source: Homosapiensaveyourearth

The main outcome of recent international governance attempts has been the acknowledgement of the existence of climate change and its impacts. There has been no achievement at all so far in reducing carbon dioxide emissions, nor has there been any real implementation of potentially effective measures to achieve this aim, and this same problem has recurred every four years at each international climate congress. Economic growth and development has always been highly desirable and a political necessity, and no country is willing to sacrifice rapid economic development for a compromise in environmentally friendly but low capital boosting alternatives, or are likely at least to volunteer to be first to take this economic cold plunge... 

That's where the Geoengineers need to step in and take centre stage to 'Save the World'! Possible climatic devastation could be imminent, policy agreements are not yet in place to tackle rapid climate change effects and should any carbon emission reduction method be enforced it would take years to notice a significant decline to emission levels.

Geoengineering, on the other hand, can make prompt changes, it can be unilaterally forced - no international agreement necessary, and it could ultimately become our most effective shield against climate change... Right?

Time to get started??


 S xx

Make way, Climate Engineering is here to stay!

The advent of Climate Engineering

Today marks my first contribution to the renowned blogosphere and world of science. My blog aims to explore Global Environmental Change through the controversial topic of Climate Engineering.

Climate change is an indisputable problem. Our awareness has soared globally yet the issue remains, persistent, looming, unsolved.

Political efforts have reached international status, with global climate congress attempting to draw any solution to the problems climate change has caused and threatens to present. Global powers have met to discuss our options, climate agreements have been successfully made, yet occasion upon occasion, very little outcome has resulted from these significant events.

Trouble similarly arises from a lack of economical compromise. Alternative methods of renewable energy appeal for their environmental benefits, but are never prioritised due to their lack of ability to produce energy as efficiently as fossil fuel methods. These mitigation and adaption hindrances have caused considerable concern towards our responses to imminent, extreme climate disruptions.

So what is a possible solution?

Climate Engineering (also known as Geoengineering) is defined as ''...the intentional large scale manipulation of the environment...' to counteract anthropogenic climate change' (Keith, 2000). It is a scientific, technological approach to contest climate change, and is a combination of two dominant methods:



Source: Washington University Political Review

The first is Carbon Reduction Methods (CRM). This is the removal of carbon dioxide through extraction from the atmosphere for storage in a sink such as land or the deep ocean, and the second approach is Solar Radiation Methods (SRM) which seek to reduce the amount of solar radiation reaching the Earth, thus reducing the amount of greenhouse gases trapped in the Earth's atmosphere (Hamilton, 2013).

The advent of Climate Engineering was finally brought to serious global attention in its first mention in the most recent IPCC Summary for Policy Makers Report in 2013:

"Methods that aim to deliberately alter the climate system to counter climate change, termed geoengineering, have been proposed..."

Ergo, Climate Engineering is becoming an increasingly stronger candidate as the solution towards climate change, but could it really solve the world's thermostat problem?

This blog will progress to determine what climate engineering really is and whether it is necessary, its successes and failures, and ultimately if it can be combined with government and market initiatives as a collaborative force to combat the effects of climate change!


Stay tuned!

S xx