Can we fix it?

We have finally trawled through all of the climate-rescuing geoengineering schemes proposed to date, and the endgame of all of this lateral geoengineering thinking is to find the answer to the one very big question:

Can we fix it?

Source: Ebay

Maybe it's a job for Super Engineer!

Source: Engineering Institute of Thailand

We cannot deny that there is massive potential in geoengineering - the past 16 blogs are evidence of the scope and wide variability of creative thinking to re-stabilise our climate before everything tips over and the situation changes irrevocably! These weeks of researching and sifting through the ideas for the major geoengineering processes has enabled me to personally and critically assess which proposals have in my view, the greatest potential for deployment and success.

My ranking is as follows (from deployable to avoidable):

1. Artificial Trees
2. Afforestation
3. Biochar
4. Enhanced Weathering
5. Marine Cloud Brightening
6. Ocean Liming
7. Iron Fertilisation
8. Land Albedo Enhancement
9. Sulfur Aerosol Injection
10. Sun Shades

As you can see from my rankings above, artificial trees have been regarded with the greatest potential as they are able to imitate natural processes within trees and plants but optimise photosynthesis rates, mitigating greater volumes of atmospheric carbon emissions. I believe that there is longevity and potential in carbon reduction methods.  The problems I foresee with solar radiation management is they neglect to mitigate carbon dioxide emissions as although installations within space reduce incoming solar radiation and global temperatures, they can lull us into a false sense of security that current anthropogenic activity is okay, allowing the continuation of an accelerating rate of atmospheric carbon dioxide emissions. This situation provokes great concern: what if the 'fix' goes wrong?

The downside of a technological fix is that despite how sophisticated it is, you cannot guarantee that it will work, continue to work, and not have unforeseen and undesirable, unintended consequences - to quote Donald Rumsfield (2002):

"There are known knowns. These are things that we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we know we don't know."

The solar radiation schemes would remove all impacts of climate change suddenly, and require constant maintenance to prevent any glitch in the system, which is enough to bring the entire project to a halt with catastrophic effects. It is the rapidity of the return of intensified climatic effects that people are concerned about and Schneider (1996) uses the following metaphor:

"It is better to cure heroin addiction by paced medical care that weans the victim slowly and surely from drug addiction than by massive substitution of methadone or some other 'more benign' or lower cost narcotic." (Page 299).

Geoengineering failure would result in rapid climate change effects at such speed that the Earth and its eco-systems would not be able to adapt. This is because geoengineering is a technological fix - but that's all it is isn't it? The size and global impact of climate change needs more than that. A combination of measures that will mitigate carbon dioxide emission growth need to be researched and developed further before we resort to technology to delay the impending impacts of climate change at such high risk of global devastation. 

So should we fix the climate?

Source: Code Green

Currently, there is adverse criticism to geoengineering due to the great uncertainty and implications it entails. As of yet, no proposal has made it past laboratory stages (Bellamy, 2014) (bar SPICE) so further development is needed before there is any attempt at deployment. However great progress and potential has been noticed in recent years towards geoengineering. The IPCC included it for the first time in their fifth assessment report in 2013, and according to Ken Caldeira :

"Back in 2000 we just thought of it as a 'what if experiment'... In the last few years, the thing that's surprising is the degree to which it's being taken more seriously in the policy world" 

Geoengineering is becoming an increasingly viable option to resolve climate change problems, however there is far too much uncertainty particularly as the world is at stake. I believe that geoengineering should be a last resort and  research should be focused on mitigation strategies as they have greater potential to respond to climate change. 

But what do you think? 

I hope you have enjoyed reading this blog as much as I have writing it! Geoengineering is at the forefront of climate debates today, and who knows, could be the answer to our climate change problems in years to come...

Source: Grist

Let us not end here, but further research why the geoengineering methods have not worked, due to its relationships between science, policy and the general public!

Watch this space!

S xx

Painting the floor white...

It is time to move on to the ultimate solar radiation management technique! How time flies... (particularly in the race against climate change!)

This next geoengineering scheme which we are going to consider is increasing land albedo, which like all solar radiation management techniques, is aimed to boost the reflectivity of Earth's surface to incoming solar rays but through increasing the albedo intensity on Earth's land surfaces. A 1.5% change in albedo would be needed in order to counteract climate change (Keith, 1998) - can this be achieved?

Irvine et al. (2011) present a thorough analysis of albedo enhancement schemes by categorising attempts into:

1. Urban Albedo Geoengineering-  This has been a strategy of response to impacts created by the urban heat island effect, and entails implementing new roofing and paving materials with more reflective materials, as these materials make up 60% of urban surfaces (Akbari et al. 2009). These usually include materials of lighter colours as they absorb a greater reduction of sunlight than dark coloured materials.This is being widely researched as it is highly feasible and despite initial high costs for materials and equipment, these are displaced by the amount of energy that the scheme saves. Bracmort et al. (2011) stated that the US Department of Energy (USDOE) National Nuclear Security Administration (NNSA) buildings saved 70% on their energy bills due to the installation of cooling roofs.

Source: Bits of Science

2. Crop Albedo Geoengineering- This requires a calibre of crops with higher albedos than currently planted. Crop land area covers 3.1% of  the Earth's surface (Irvine et al. 2011) and they have increased albedos in comparison to natural vegetation (Irvine et al. 2011). Human proliferation of agricultural activities historically has already modified albedo strengths within crops which has cooled the globe by 0.17°C (Matthews et al. 2003).  In a modelled global scenario of doubled carbon dioxide emissions, crop albedo geoengineering enhances cooling in the northern hemisphere- particularly in Eurasia and North America (Irvine et al. 2011).

3. Desert Albedo Geoengineering- This has the highest albedo enhancement potential, due to the large expanses of 'useless' space (Gaskill, 2004), and the high levels of incoming solar radiation experienced in these regions. Approximately 4.5 million kilometres of desert are available for surface albedo enhancement (Gaskill, 2004)  with reflective, high albedo enhancing materials.

Source: Weird Twist

However, could these three sub-schemes ultimately work to enhance land surface albedo?

Yes, however there do appear to be many caveats associated with increasing land albedo. Firstly urban land albedo requires constant maintenance, and the bright reflectivity of the material surface could cause glare and be aesthetically displeasing (Bracmort et al. 2011). Crop albedo enhancement is limited by time as increasing the reflectivity will take at least a decade on a commercial scale (Bracmort et al. 2011 ), this means it cannot respond quickly enough to the implications of climate change! Desert albedo enhancement was popularised due to its high potential, however, it has been criticized for its impacts on local eco-systems due to the installation of sheets of reflective materials, and rows of mirrors (Cascio, 2009). The costs of installing such devices would be colossal!

Enhancement of land albedo also has great influence on precipitation patterns which imposes large environmental changes that can have socio-economic impacts on livelihoods due to agricultural patterns change and surface adaptation. Studies have similarly shown that enhanced land albedo proposals could result in a cooler northern hemisphere (Irvine et al. 2011) but a warmer southern hemisphere. This is because the majority of Earth's land mass is situated in the northern hemisphere, so increased albedo and reflectivity in the northern hemisphere will reduce incoming solar radiation absorption in that area alone. This will have dominating regional effects on climate and could have significant impacts on the ocean due to increased temperatures. In fact, a strong association of increased temperatures of surface waters enhances the formation of hurricanes and storm events. This could increase the magnitude and frequency of freak storm events, which can have significant detrimental impacts on demography and livelihoods worldwide.

Enhancing land albedo is often compared to increasing ocean albedo, which is achieved through cloud brightening (see previous post!). But which one works better? Can they achieve similar results?

In fact, enhancement of ocean and land albedos have been found in research to have opposite effects. Increased land albedo has global repercussions of reduced precipitation on a large scale (Bala & Nag, 2011) as in a world of doubled carbon dioxide concentrations, precipitation is reduced by 13.38% (plus or minus 0.28%) (Bala & Nag, 2011). A study by the same leading author: Bala et al. (2010) on cloud albedo enhancement illustrated a dominance of increased precipitation and overland runoff, this contrast between the two studies is because land albedo enhancement is only applicable over land surface areas (Bala & Nag, 2011). But do either of these climatic impacts really benefit the globe? Application of increasing land albedo could cause strife, as deployment of the scheme in the US (for arguments sake) could have detrimental effects in Australia, a southern hemisphere country which is hot enough already without the scheme! Compensation would be owed, conflicting priorities could arise, and all because of the consequences of a humanly induced geoengineering project which is perhaps beyond the scope of human control.

Is it worth it?


S xx

Spice up your life!

CASE STUDY ALERT!

We have previously discussed the proposal of sulfate aerosol injection into Earth's atmosphere to mitigate incoming solar radiation, so a real time attempt to engineer this begs a mention.

Which case study is this?

The SPICE Project.

This must be the one of the most famously known geoengineering projects yet. The Stratospheric Particle Injection for Climate Engineering project (SPICE project) was proposed in 2010, and is a technological means of pumping sulfate particles into the atmosphere to reflect incoming solar radiation away from the Earth's surface. The project is a collaboration between the University of Bristol, Edinburgh and Oxford co-funded by EPSRC, NERC, and STFC (SPICE, 2014). It consists of a large tethered weather balloon (the size of Wembley stadium!) attached to a 1 kilometre long pipe from a ship (Hale, 2012).

Source: The Guardian

It looks pretty simple- almost a replica of a WW1 Zeppelin.

Source: The Conversation

However, what is exceptional about the SPICE project is that it managed to surpass laboratory based modelling stages and became a field experiment in the real world, unique progress within solar radiation management. In fact it was even backed financially by the government with £1.6 million invested (Vidal, 2011). The project was tested on a small scale, and 150 litres of water were pumped into the atmosphere. The water was a proxy for the real project which would pump sulfate aerosol particles into the atmosphere, to estimate the feasibility of engineering the project on a larger magnitude (Vidal, 2011).

So why was it cancelled?

Cancellation of the project occurred in June 2012, and it was a result of social and commercial concern as opposed to a major failures of the SPICE project. The initial prolonged hesitation of two scientists working on the SPICE project to hand over patents of similar previously used technology to the SPICE project cause alarming concern within the scientific community, and progress resorted to laboratory research once more (Pidgeon et al. 2013).

Despite this, the project was already subject to great public concern about the unprecedented large scale uncertainty that the project could ensue, and the fear that geoengineering attempts were replacing carbon emission mitigation strategies, which are more optimal to recover our climate situation. Solar geoengineering methods do not tackle the increasing atmospheric carbon emissions which are the source of global warming issues and concerns. Similarly the high risks associated with sulfur aerosol emissions as discussed in the previous blog have prevented any such scheme from taking off! There were concerns of technological issues too such as the hose breaking away, or constant maintenance requirements.


S xx

P.S. There was a great UCL lunchtime lecture regarding geoengineering and it has a mention of the SPICE project. Here is a link below:

'Should we experiment with Climate?'

Sulfur Injection

We've almost listed them all, but one of our final geoengineering schemes to discuss is... Sulfur Particle Injection into the stratosphere.

Let's start with:

What?

Sulfur Particle Injection is the injection of sulfur particles into the stratosphere as a means of inducing global cooling, and increasing global albedo, and potentially diminishing the impacts of increasing carbon dioxide emissions (Rasch et al. 2008). It was first suggested by Budko (1977) (cited in Rasch et al. 2008) by burning sulfur from aeroplanes to create solar reflecting aerosols and the idea has generated large audiences of researchers and has since been developed further in detail. Sulfur aerosols can reside in both the troposphere and stratosphere, however within the application of geoengineering, the stratosphere has been selected as the residing site of Sulfur because it has a longer residence time. Aerosols will remain within the stratosphere for 1 to 2 years, as opposed to the troposphere where they will only remain for a week long period (Crutzen, 2006). This means that a smaller proportion of Sulfur would be required for the project, significantly reducing the risk of the application.

Why?

Climate Change of course! The ever-increasing carbon emission concentrations within the atmosphere are still a cause for frightful concern. Mitigation strategies thus far are being too slow at resolving a solution to reducing or putting a plug in carbon dioxide emission. Sulfur aerosol emissions into the stratosphere are an "emergency brake" (Crutzen, 2006), a rapid solution to the climate change problem.

How?

The idea of sulfate aerosol injection was to replicate that of a volcanic eruption. The 1991 eruption of Mount Pinatubo exerted 10TgS of sulfur dioxide into the stratosphere over a period of three days (Rasch et al. 2008) inducing a 0.5°C drop in global temperature over the following year (Lacis & Mishchenko, 1995; Crutzen, 2006). This colossal eruption successfully cooled the Earth system without any noticeable disruptions to the climate systems, and therefore was opportunist for geoengineering development of the mechanism. Research has sparked disagreement between scientists; Crutzen (2006) and Wigley (2006) both suggest that 5TgS per year is required to balance global warming associated with a doubling of atmospheric carbon dioxide. However Rasch et al. (2008) and Robock et al. (2008) suggest a smaller value of 1.5TgS per year. The consensus suggests at least 15 times the amount of stratospheric sulfur of today!

In order to replicate a volcanic eruption, research was undertaken to find a way to inject the sulfur into the stratosphere. Ideas including artillery shells, airplane jets and balloons (e.g. the SPICE project) all of which would release concentrated sulfur into small, local regions of air (Rasch et al. 2008). There has been success with this approach, namely the SPICE project. Sulfur can also be injected via an antecedent gas of the troposphere, which according to Rasch et al. (2008) will oxidise within the stratosphere to naturally transport Sulfur into the stratosphere. Anthropogenic carbonyl sulfide has been suggested as the antecedent gas however, carbonyl sulfide is only prevalent as 1-2TGs per year of which only 15% is anthropogenic (Montzka et al. 2007). A least a factor of 10 increase is needed for the global requirement of sulfur aerosols (Rasch et al. 2008).

Source: Gifbay

(Currently Who? and When? are not applicable... Perhaps answerable in due course!)

And why not?

As always, there are a multitude of reasons against a geoengineering project of this enormity. The highlighted risk of uncertainty of large scale planetary applications is still a major concern. In this case the sulfur particle emissions from volcanoes are single eruption events of which the effects last for a few years, whereas the geoengineering scheme proposes continual emissions of sulfur. Can the Earth's system cope with this? Similarly, no information exists on volcanic eruptions in a warmer climate than experienced today (Crutzen, 2006), would it have a significant impact on sulfur aerosol concentrations?

Concern also arises from its effect on regional climate. Research combining the Mount Pinatubo eruption and hydrology illustrates that the eruption caused a decrease in precipitation of 0.07 mm a day over land surfaces- even drought in South East Asia (Trenbirth & Dai, 2007), and further modelling simulations have supported this consequence. This could have major implications to ecological systems.

A final overruling concern is how long will it have to go on for? By resorting to technological approaches such as sulfur aerosol injection on a continual basis, can we ever stop? A huge risk of geoengineering is the consequence of having to terminate a process. All of the associated effects of increasing atmospheric carbon dioxide emissions would rapidly return at a rate that the Earth system is unable to adapt to. The consequences would be catastrophic. This means that sulfur aerosol injection may have to continue for centuries, even millennia into the future (Bengtsson, 2006)! Is it worth the risk or the cost of maintenance?

Result?

This proposal remains too high risk for the immediate future. However, this isn't to say experiments haven't continued to go ahead...


S xx

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