A rise of more than 0.7 °C in the average surface temperature has been seen in the past 100 years and there is increasing evidence that the earth’s climate is rapidly changing in response to increased inputs of carbon dioxide (Henson,2001 IPCC,2007). Global carbon dioxide emissions have increased from  an average  6.4 ± 0.4 GtC yr^–1  in the 1990’s  to 7.2 ± 0.3 GtC yr^–1 in the period 2000 to 2005(IPCC,2007).The extent that humans are polluting our atmosphere is at a staggering four metric tonnes per person per year (Henson,2001). Therefore mitigation of carbon dioxide into the atmosphere is essential. One method which has major potential in reducing carbon dioxide emissions is soil carbon sequestration (Peterson et. al, 2013).

What is soil carbon sequestration?

Soil carbon sequestration is the process of transferring carbon dioxide from the atmosphere into soil through organic solids and storing it (Sundermeier, Reeder,Lal,n.d). It is also commonly used to describe any increase in soil organic carbon content caused by a change in land management within the soil to mitigate climate change (Powlson, et al. 2011.) At present the attainable soil carbon capacity sink is only 50-60% of its potential capacity and with the added benefits of increasing food security as well improving soil quality, soil carbon sequestration seems a viable option (Halvorson,Wienhold,Black, 2002; Lal,2004a) .  It has been predicted that this technology could offset 2000-5000 Mt C/ ^yr-1 (Cannel, 2003).

What methods improve soil carbon sequestration?

Managing agricultural land

It has been well recognised that the conversion from natural to agricultural land has resulted in a significant loss of 50% of soil organic carbon globally (Kirkby, et al. 2013).  Most of the loss in soil organic carbon to the atmosphere can be explained due to reduced inputs of organic matter, increased decomposability of crop residues and tillage effects that decrease the amount of physical protection. Therefore increasing soil organic carbon through managing agricultural land is vital to increase sequestration (Post and Kwon, 2000).

Case study- Australia

Management of land use in Australia is being adopted throughout many regions and improved management of croplands through rotations, conservation tillage and stubble retention has caused a gain of 0.2-0.3  Mg C ha ^-1 yr^-1 in comparison to conventional management, even though small it can relate to large sequestration rates  of up 60 tg CO₂ per year (Sanderman, et al. 2010).

Managing peat lands

As well as managing agricultural lands, peat lands should equally be managed due to their wide global distribution and contribution to carbon dioxide emissions. They are unique soil carbon pools made from high densities of carbon which have accumulated over many years because decomposition is suppressed by the absence of oxygen under flooded conditions (Smith,2007b; Lal,2009). However increases in anthropogenic activities such as drainage and deforestation for agricultural land has released carbon to the atmosphere and reduced carbon sequestration function  (Page, et al, 2011).

References

-          Cannel, M., 2003. Carbon sequestration and biomass offset : theoretical potential and achievable capacities globally , in Europe and the UK. Biomass and bioenergy. Vol 24 (2).

-          Halverson,A., Weinhold, B., Black,A., 2002. Tillage, nitrogen and cropping effects on soil carbon sequestration.  Soil science society of America Journal. Vol 66 p906-912.

-          Henson, R., 2001. The rough guide to Climate Change. 3^rd ed. London: Penguin Group.

-          IPCC 2007. Climate Change 2007: The Physical Science Basis. Cambridge, UK: Cambridge University Press, 2007.

-          Kirkby,C., Richardson, A., Wade,L., Passioura, J., Batten,G., Blanchard, C., Kirkegaard. 2013.Nutrient availability limits carbon sequestration in arable soils. Soil biology and biochemistry. Vol 68 p402-409.

-          Lal, R., 2009. Agriculture and climate change: An agenda for negotiation in Copenhagen. The potential for soil carbon sequestration. [pdf]International food policy research institute. Available at : http://www.ifpri.org/sites/default/files/publications/focus16_05.pdf Accessed on 23rd November 2013.

-          Page, E., Morrison,R., Mallins,R., Hooijer,A., Rieley,O., Jauhianen, J., 2011. Review of peat surface greenhouse gas emissions from oil palm plantations in South East Asia . [pdf] The international council on clean transportation. Available at : http://www.theicct.org/sites/default/files/publications/ICCT_Peat-Emissions_Sept2011.pdf Accessed on 3rd December 2013

-          Peterson ,B., Knudsen, M., Hermansen,J.,Halberg, N., 2013. An approach to include soil carbon changes in life cycle assessments. Journal of cleaner production. Vol 52 p217-244.

-          Post,W., Kwon,K.,2000. Soil carbon sequestration and land use change: processes and potential. Global change biology . vol 6 p317-328.

-          Powlson, D.,Whitmore,A., Goulding,K., 2011. Soil carbon sequestration to mitigate climate change: a critical re-evaluation  to identify the true and false. European journal of soil science.  vol 62 issue 1.

-          Sanderman, J., Farquharson, ,R., Baldock,J., 2010. Soil carbon sequestration potential : A review for Australian agriculture. (pdf) National Research flagships sustainable agriculture. Available at: http://csiro.au/Portals/Publications/Research–Reports/Soil-Carbon-Sequestration-Potential-Report.aspx Accessed on 2nd December 2013.

-          Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O’Mara, C. Rice, B. Scholes, O. Sirotenko, 2007: Agriculture. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

-          Sundermeier,A., Reeder,R.,Lal,R., n.d.Soil carbon sequestation. (pdf) Available at: http://ohioline.osu.edu/aex-fact/pdf/0510.pdf accessed on 23rd October 2013. Accessed on 8^th December 2013.

Paper

Several measures to reduce our paper consumption can be achieved by using thinner paper, efficient printing technologies, duplexing and printing on demand (Hekkert, et al.,2002)

Lighting

Lighting control integrated with daylighting control is recognised as an important useful strategy in energy efficient buildings. Installation of proper day-lighting schemes may help to reduce the electrical demand. A study in Hong Kong reported that as much as 20-30% of the electric load derived from lighting in office buildings (Li and Lam,2001). Within the UK office lights which have been left on overnight use enough energy in a year to heat a home for 5 months highlighting how significant monitoring lighting could be (Carbon Trust, 2014).

Air conditioning

Around 40% of floor space is expected to be air conditioned by 2020 which is likely to increase our contribution to carbon emissions and our energy consumption is expected to double by 2020 because of this as well. In order to try and reduce these emissions careful consideration of its use should be adopted (Carbon Trust, 2012).

-          Consideration of layout, design and operation are important as this impacts the room temperature,

-          The design and efficiency of the air conditioning plant is very important.

-          The amount of fresh air provided per person should also be considered.

Turning computers off

Profiles from 94 computers in Canada indicated that there were long periods during the night and day when computers were turned on but not being used, and it was predicted that significant energy savings could be achieved if the electricity was used efficiently. The company used stickers to remind colleagues to turn off their computers when not in use and as a result over 14% reduction in consumption over a 2 month period was achieved (Newsham and Tiller,1994).

Simple changes within the office can therefore help you to reduce greenhouse gases and reduce your carbon footprint for a cleaner and more efficient environment!

References

Carbon Trust, 2014. Climate change at work. (online). Available at: http://www.carbontrust.com/media/195259/pfl306_lighting.pdf. Accessed on 24^th August 2014.

Carbon Trust, 2012. Air conditioning. (online). Available at: http://www.carbontrust.com/media/17824/j7906_ctg005_air_conditioning_aw_interactive.pdf. Accessed on 24^th August 2014.

Counsell,T and Allwood,J.,2007. Reducing climate change gas emissions by cutting out stages in the life cycle of office paper. Resources, Conservation and  Recycling. Vol 49. P340-352.

Hekkert,M.,Reek,J.,Worrel,E.,Turkenburg,W.,2002. The impact of material efficient and end-use technologies on paper use and carbon emissions. Resources, Conservation and  Recycling. Vol 36, p241-266.

Li,D and Lam,J.,2001. Evaluation of  lighting performance in office buildings with daylight controls. Energy and Buildings. Vol 33. P793-803.

Newsham,G.R. and Tiller,D.K.,1994. The energy consumption of desktop computers: measurement and savings potential. IEEE transactions on industry applications. Vol 30 (4)

Carbon footprints exist to show us the true impact of our actions on global warming. It can be hard to know how to be more energy smart when you do not know how much emissions you produce, or which part of your day to day life contributes the most. One of the most important results of understanding your impact on the environment, is taking that knowledge and using it to reduce your impact by focussing on the parts of your life that produce the highest emissions.

What is a carbon footprint?

A carbon footprint is the sum total of the amount of carbon dioxide that is released due to a specific person, organisation or larger group’s activities. Our everyday actions, from driving to work to turning on the heating on a cold day, have an effect on the environment, and the term ‘carbon footprint’ is an easy way to express the sum of these emissions over a period of time. Carbon footprints can be used to measure emissions not only for individuals, but for manufactured items, countries and even animals.

A carbon footprint mainly comprises of energy used for heating your home, electronics and appliance use, day to day transport, and frequency of flying [1]. However, a variety of other variables should also be taken into account, such as pets, recycling habits and diet.

What about other greenhouse gases?

Carbon dioxide is not the only gas that contributes to global warming, but for most individuals it is the most important gas. However, other greenhouse gases such as nitrous oxide and ozone can be taken into account and measured in the equivalent amount of carbon dioxide that would have the same impact in terms of global warming. Expressing other gases in terms of CO₂e makes calculations far less confusing, and allows more potent gases such as methane to be included in emissions totals.

Direct or indirect emissions?

Most of our individual emissions are indirect. When we turn on our heating, or leave the television on, electricity or gas comes from a power station, and this is where the fuel is burnt and released into the atmosphere. At present, the majority of electricity is generated by burning fossil fuels, which release a variety of greenhouse gases into the atmosphere.

How do I calculate my carbon footprint?

For most of us, the thought of sitting down and calculating our yearly emissions is impossible. While working out direct emissions such as petrol consumption is more straight forward, indirect emissions are more tricky. However, there are now online tools which allow you to input a range of information, and work out your approximate carbon footprint.

• Act on CO₂ is a DirectGov calculator, which asks questions about your home, appliance use and travel habits, before providing you with your result and allowing you to compare with other people [2].
• Cool the World provide a fun and informative online calculator for kids, and provides tips to reduce emissions in an easy to understand way [3].
• WWF provide a calculator which also takes food into account, and other factors such as pets and recycling. Your result is displayed as both carbon emissions per annum, and the total number of planets that would be needed to support your lifestyle [4].

What do I do now?

Working out your carbon footprint is one thing, but knowing what to do with your results is another. Most online calculators will break down your emissions into sections, such as home, travel and diet. By looking at where you are most emissions-heavy, you can then start to plan ways to reduce your emissions. If travel is your worst area, consider your mode of transportation: could you be walking or taking public transport instead of driving? If your home produces the most emissions, a move to more energy efficient appliances could be a simple way to cut your carbon footprint.

The first step in reducing your carbon footprint is knowing where your emissions come from, and once you have that information, there are a wealth of websites, books, films and other media which provide tips and tricks to be more energy and resource smart. Whatever your budget or situation, being more environmentally friendly has never been easier.

With Energy Saving Warehouse we have all the tools you need to become more environmentally friendly and hopefully take a small step in reducing your carbon footprint.

References

[1] Energy Saving Trust. Reduce your carbon footprint. 2013. http://www.energysavingtrust.org.uk/scotland/Take-action/Reduce-your-carbon-footprint

[2] DirectGov. Carbon Calculator. 2013. http://carboncalculator.direct.gov.uk/index.html

[3] Cool the World. Kids Carbon Footprint Calculator. 2013. http://www.cooltheworld.com/kidscarboncalculator.php

[4] WWF. WWF Footprint Calculator. 2013. http://footprint.wwf.org.uk

The World’s Oceans are a sink for CO₂, with various factors affecting carbon uptake including wind, sea surface temperature, and biota. Since the industrial revolution anthropogenic emissions of CO₂ have increased, this has led to an increase in CO₂ in the oceans. So far around 500 billion tons, approximately one third of CO₂ emitted, has been absorbed by the oceans (NRDC, 2009). Have you ever considered how much CO2 your lifestyle creates or thought about trying to reduce it? The rise in CO₂ in seawater has already increased the acidity of the by 0.1 pH units since the industrial revolution, and pH could by the end of this century decrease by a further 0.3-0.4 pH units. Increased CO₂ in seawater leads to the formation of carbonic acid which causes ocean acidification. The oceans act as a buffering system taking up excess amounts of CO₂ which control the pH of seawater by a series of reactions (IPCC, 2007):

                        CO₂ + H₂O —>  H₂CO₃ —> H⁺ + HCO₃^- —> 2H⁺ + CO₃^2-                               

Carbon dioxide + Water —> Carbonic acid —> Bicarbonate —> carbonate

Over the time the amount of CO₂ in the oceans with increase the chemical reactions taking place with the ocean. Just looking at the reaction above would imply that the amount of carbonate within the ocean would increase however this will not be the case. In fact the carbonate reacts with the seawater to produce more bicarbonate, as is shown in the equation below:

               CO₂ + H₂O + CO₃^{2- —>} HCO₃^- + H⁺ +CO₃^{2- —>} 2HCO₃^-

Carbon dioxide + Water + Carbonate —> Bicarbonate + Carbonate —> Bicarbonate

The amount of carbonate is in oceans will decrease but the amount of bicarbonate found will increase. The reduction in carbonate affects key calcifying organisms, such as coral and plankton which use calcium carbonate to form their hard shells and skeletons (Iglesias-Rodriguez et al. 2008).  These key organisms form the base of marine food webs, any change in the species has the potential to impact entire ecosystems (NOAA, 2008). This study examines the socio-economic effects that ocean acidification could bring.

The impact of reduced carbonate and pH will travel through the marine environment. Some types of plankton may be unable to maintain their hard exterior, meaning a decrease in the numbers within their species group. The expected loss of plankton will impact the commercial and local fisheries that rely on plankton as a food source for the majority of marine life. Commercial fisheries are a multi-billion dollar business; in excess of $60 billion per year is spent of fish and shellfish (NOAA, 2008). Fishing provides the livelihoods for over 500 million people, with 90% of these living in developing countries and supporting entire communities (UN, 2009). Global fisheries are generally located in zones of upwelling water. Here nutrients are brought to the surface, bringing large concentrations of plankton, and therefore attracting schools of fish feeding. These areas are particularly vulnerable to ocean acidification, as lower pH water will be brought to the surface from upwelling deep water (Turley and Williamson, 2011). Fish is an important source of protein for around 1 billion people. As the population of the world increases, if the fisheries fail it could greatly affect global food security (UN, 2009).

The reduction of calcium carbonate and increase in oceanic acidity will lead to a decrease in coral reef formation and diminished resiliency to coral bleaching, a term which describes the death of a the symbiotic bacteria that live within the coral themselves. Many ecosystem services are provided to us through coral reefs. Corals are an important ground for fisheries, they provide shellfish, reef fish, and act as a nursery for commercial fish (European Science Foundation, 2009). Furthermore coral reefs protect coastal communities from events such as storm surges and hurricanes, if natural shoreline protection was compensated more expensive man made sea defences would be needed to replace the natural protection (NERC, 2009).

In some countries corals bring an important source of income, through tourism and cultural heritage, corals in the Great Barrier Reef are showing a recent decline in calcification (UN, 2009).  The Great Barrier Reef Marine Park Authority (2009) estimated that the reef contributed to 8.6% of Australia’s Gross Domestic Product (GDP) for 2006-07, this is a highly significant portion for one tourism attraction.

Acidification could also lead to more rapid climate change, as it slows down the oceanic carbon pump, reducing the oceans ability to absorb additional CO₂. This will lead to an increase in costs to cap the CO₂ in the atmosphere (European Science Foundation, 2009).  Hood et al. (2009) have attempted to quantify the ecosystems service of carbon uptake by the oceans using the current price of carbon credits. They claimed that the oceanic uptake of CO₂ was equal to an annual subsidy of 0.1-1% of the Gross World Product or $40-400 US billion.

Areas most affected by ocean acidification will be small island developing states, developing countries and coastal regions as they rely on services provided by marine ecosystems the most for their livelihoods (UN, 2009). The reduction in CO₃^2- brought about by increased anthropogenic CO₂ in the atmosphere will affect marine life, but to what extent is largely unknown as there is a scarcity of relevant data which inhibits the assessment of the possible impacts. Future research should focus on the possible reductions of ocean acidification and areas where the impacts are likely to be the greatest both for the human population and environment. Moreover the cumulative impacts of various environmental problems need to be predicted and mitigation options explored, such as rising sea levels, temperature combined with the possible effects of ocean acidification.

If this issue has got you thinking about what you could change about your lifestyle to become a little more environmentally friendly, why not take a look at Energy Saving Warehouse’s range of products to help you do just that?

References

European Science Foundation (2009) Impacts of Ocean Acidification. Science Briefing Policy. No: 37. France.

GBRMPA (2009). Research Publication No. 98: Economic Contribution of the Great Barrier Reef Marine Park, 2006-07. G.B.R.M.P. Authority. Queensland, Great Barrier Reef Marine Park Authority: 19-21

Hood M. et al. (2009) Ocean Acidification: A summery for policy makers from the second symposium on the ocean in a high- CO₂ world. The Second Symposium.

Iglesias-Rodriguez, D. M. (2008) Phytoplankton calcification in a high-CO₂ world. Science. Vol: 320, 336-340.

IPCC (2007) Climate Change 2007: Working group I: The Physical Science Basis. Chapter 10.4 Changes Associated with Biogeochemical Feedbacks and Ocean Acidification.

NOAA (2008) Ocean Acidification. State of the Science Fact Sheet. National Oceanic and Atmospheric Administration. US Department of Commerce.

NRDC (2009) Ocean Acidification: The other CO₂ problem. Natural Resources Defense Council.

Turley and Williamson (2011) Socio-Economic Aspects of Ocean Acidification. Report for UNFCCC Subsidiary Body for Scientific and Technological Advice. Bonn, Germany.

UN (2009) Ocean Acidification: A hidden risk for Sustainable Development. UN-DESA Division for Sustainable Development. Copenhagen Policy Brief No 1.

Instead of driving, consider walking, cycling or taking public transport, which not only save you money but can help improve your fitness. If, however, you do use a vehicle, there are a number of simple ways to reduce the amount of fuel you purchase and use. Every day large amounts of fuel is wasted by inefficient driving, especially during peak hour. The following driving tips can help to save you up to 15% off fuel costs [1], and also significantly reduce your carbon footprint.

Your Vehicle

There are some simple ways to make sure that your vehicle itself is more fuel efficient:

• Make sure you have the right type of tyres for your vehicle, and look for tyres that have low rolling resistance and maximum efficiency.

• Make sure that your tyres are the correct pressure as under inflated tyres can cause drag and resistance, while both under and over filled tyres can be dangerous to road holding [2].

• Make sure you have your vehicle serviced regularly, and that you use the right engine oil.

• Remove excess weight such as roof racks and boxes, and items stored in back seats and the boot. This not only reduces drag and wind resistance but can also help to significantly reduce fuel consumption. Studies have shown that on average for every extra 50 kilograms a car carries, fuel consumption is increased by around 2% [3].

Driving Tips

• Avoid using air conditioning if possible, as this increases the amount of work the engine has to do while driving. If driving at lower speeds open the window instead, however if driving at high speeds the air conditioning should be used as an open window can cause drag.

• Vehicle engines in general do not need to be ‘warmed up’, so only turn on your engine before you are ready to begin driving, and when your vehicle is stationary do not leave the motor running.

• Keeping your vehicle at a steady speed reduces work done by the engine. Keeping your vehicle at a lower speed also helps, with 45-50 mph the most efficient speed for the average car [4].

• Try to avoid making short trips, and instead try to plan ahead to combine multiple trips.

• Avoid ‘aggressive driving’ by driving more smoothly. Hard braking and accelerating can increase fuel consumption so stay a safe distance behind the vehicle in front and try to avoid areas and times of heavy traffic congestion to cut down on ‘stop-start’ driving.

Eco-driving Courses

If you have a large fleet and a large fuel bill, you can now send employees on eco-driving courses, which are designed to teach effective driving techniques to help reduce petrol consumption in everyday driving situations. The Institute of Advanced Motorists (IAM) has developed Ecolution, a course which can improve fuel consumption by up to 25% [5], while other companies such as AA [6] and RoSPA [7] also provide eco-driving courses around the country.

For more energy saving tips and gadgets have a look at Energy Saving Warehouse’s range of products.

References
[1] Energy Saving Trust. Fuel-efficient driving tips. 2013. http://www.energysavingtrust.org.uk/scotland/Travel/Driving
[2] Ibid.
[3] WWF Australia. Eco-driving tips. 2013. http://www.wwf.org.au/what_you_can_do/change_the_way_you_live/sustainable_living/travel_transport_and_sustainable_living/eco_driving_tips/?desktop=1
[4] [a] Energy Saving Trust. Fuel-efficient driving tips. 2013. http://www.energysavingtrust.org.uk/scotland/Travel/Driving
[5] IAM. Ecolution. 2011. http://www.iamdriveandsurvive.co.uk/our-products/on-road-learning/ecolution
[6] AA. Eco-driver Training. 2011. http://www.theaa.com/businessservices/risk_management/eco_driver_training.html
[7] The Royal Society for the Prevention of Accidents. Driver Development- Eco-Driving Course. 2013. http://www.theaa.com/businessservices/risk_management/eco_driver_training.html

The implications and impacts from ever increasing greenhouse gases emitted into our atmosphere are profound.  It is the responsibility of scientists and policy makers to find methods of reducing these emissions and increasing the worlds carbon sinks. The oceans are one of the largest natural carbon sinks in the world, absorbing around 30-50% of anthropogenic emissions per year. With this in mind, scientists have come up with a way of potentially enhancing the amount of carbon that can be sequestered by the ocean by using iron to increase the amount of photosynthesis that occurs in surface waters. This method is known as iron fertilisation.

What is the Iron Fertilisation hypothesis?

Some areas of the world oceans are known to be rich in nutrients but have very little growth. In the late 1980’s Scientist John Martin claimed that iron was a limiting factor in growth in these areas and by adding iron he could stimulate phytoplankton growth in surface oceanic layers (Buesseler et al. 2003). Phytoplankton use carbon dioxide during the process of photosynthesis, therefore, by adding iron to oceanic waters and increasing the phytoplankton growth, this would also increase the amount of CO₂ absorbed through the oceans.

What evidence supports the hypothesis?

John Martin needed to prove that iron was a limiting factor in phytoplankton growth. He studied the depth profile of iron throughout the oceans and found that iron acted in the same way as nitrogen and phosphorus, both micronutrients. It has a high surface depletion, indicating that something is taking it out of the surface waters; furthermore iron is regenerated at depth due to bacterial decomposition. This signifies that iron is a micronutrient and can be a limiting factor from growth.

Twelve oceanic iron experiments were carried out to test whether iron enrichment would increase primary productivity in areas of high nutrients but low productivity (Boyd et al. 2007). Buesseler and Boyd (2003) studied three experiments all with locations in the southern ocean. They stated that all of the experiments produced noticeable increases in biomass and associated decreases in dissolved inorganic carbon and macronutrients. Powell (2008) also reported that all 12 experiments reported up to a 15 fold increase in chlorophyll content in the surface of the oceans.

The 12 experiments verify that iron enrichment does enhance primary productivity in high nutrient but low chlorophyll areas of the oceans and therefore iron has a fundamental role in photosynthesis.

However, very little work has been carried out to test whether the amount of carbon taken up in the surface waters during these experiments has been transported down throughout the water column, and sequestered into the seafloor or deep layers of the ocean. If this process is not completed then the carbon will re-emerge later in a different location.

What are the impacts of iron fertilisation?

Iron fertilisation is a popular notion in carbon sequestration as it has been portrayed as a cheap, fast and easy way to mitigate climate change. However uncertainties and doubts regarding this method of geo-engineering have increased dramatically since John Martin first came up with concept.

So far only 12 small scale experiments and computer models have been used to predict the impacts and benefits of large scale long term iron fertilisation. While this is a fairly risk free process of assessing the costs and benefits of this method of carbon sequestration, it by no means can replicate the effects of a large scale experiment.

Creating large scale phytoplankton blooms could change the balance of the oceans food chains and could increase the number of large predators including fish, jellyfish and algae concentrations. The increase in fish and commercially available food could lead to an increase in the world’s fisheries. However some phytoplankton blooms are toxic and could therefore be harmful to the whole food chain, including human consumption.

The fertilisation of the oceans could cause deficits in oxygen or nutrient in far removed areas of the ocean, due to the oceanic circuits. Areas that have been enriched with iron months or even years previously will be lacking in nutrients as they will have already been consumed.

The UN Convention on Biodiversity states that precautionary action must always apply in the face of uncertain consequences. This applies to iron fertilisation experiments in the oceans, and it is now forbidden for any iron enrichment to take place within a countries coastal waters. Furthermore the London Protocol against marine pollution could also apply to the input of dissolved iron as the consequences of this are still mostly unknown.

According to Boyd (2008) the costs of iron fertilisation have been severally underestimated. The amount of carbon that can be absorbed by iron fertilisation in the long run has greatly decreased over the past 20 years by 5-20%. Especially when compared to the amount of fossil fuel emissions that are emitted into our atmosphere, iron fertilisation alone, can be considered to make little difference to the greenhouse gas effect.

Conclusion

Iron fertilisation is an interesting concept of geo-engineering and is successful at drawing carbon out of the atmosphere in short periods of time. However the impacts of large scale experiments, or even the commercialisation of iron enrichment to reduce the effects of climate change, are largely unknown and high in risks. It is unlikely that iron fertilisation will ever occur to the scale that will achieve significant impacts in aiding the efforts to reduce the amount of greenhouse gases in the atmosphere. However, every little does help in terms of reducing these gases, especially carbon dioxide so why not have a look at our tool to help you consider your footprint?

References

Buesseler, K. et al. (2008) Ocean Iron Fertilisation –Moving Forward in a Sea of Uncertainty. Science Vol: 319. P: 162

Powell, H. (2008) Will Ocean Fertilisation Work? Oceanus Magazine. Vol: 46. P: 10-13

Boyd, P. (2008) Implications of large scale Iron fertilisation of the Oceans. Marine Ecology Progress series. Vol: 364. P: 213-218.

Urban heat islands develop in cities when due to human activities the temperature is much higher than that of the surrounding environment. This is mainly caused by the type of materials used for buildings, roads, pavements – especially concrete and asphalt. Water cannot filter into the ground easily, and dark materials absorb light and then later in the day emit it as heat. Cars, air conditioners, and other equipment also release heat while operating, further increasing the temperature – and pollution. [2]

This temperature difference can be quite high – up to 12C degrees in the night – and it has various effects.

According to the USA’s Environmental Protection Agency [1] heat island effect not only increases energy costs, but also air pollution grows, and in the summer heat-related illnesses and deaths are more frequent and also water quality can suffer.

Some of the solutions for easing the problem include adding more parks and green surfaces, as well as green roofs [rooftop gardens]. Buildings could be painted with lighter colours and pavements can also be built in a more efficient way, for example by using alternative materials [1].

Hence, there are ways to reduce the urban heat island effect but it cannot be totally eliminated. While many believe that it’s also driving climate change, it significantly affects the lives of the residents – both financially and personally.

[1] http://www.epa.gov/hiri/

[2] http://science.howstuffworks.com/environmental/green-science/urban-heat-island1.htm

However, the Centre for Alternative Technology (CAT) has developed a “fully integrated solution to climate change” [3] that outlines how Britain could cut net greenhouse gas emissions to zero by 2030, surpassing the government target, with the added benefit of creating thousands of new jobs and regaining energy security [4]. This was published as a 384 page report, written by authors including policy makers, scientists, academics, NGOs and industry experts, on 16^th June 2010.

The main idea of the Zero Carbon Britain 2030 strategy is that energy demand can be significantly reduced without decreasing services provided. This would be achieved by “Powering Down” by reducing energy demand through use of new technology, efficient design and behavioural change, and then “Powering Up” using renewable technology [3]. The report also asserts that as the global cut in emissions required to limit global warming to 2^oC higher than pre-industrial levels is severe, industrialised nations such as the UK, which are historically responsible for human-induced climate change and also have the resources and technologies available to rectify it, should take a greater share of the burden and cut emissions faster than less industrialised countries [3]. The report itself is long and detailed, but some main points can be summarised:

Examples of “powering down” (with supporting evidence and suggestions on how to achieve them) given in the report include:

• Designing buildings to be more energy efficient, so that demand for domestic heating and lighting would see a reduction of 80% by 2030. Strategies which will go some way to achieving this are already in place, for example new homes and schools have to have zero net carbon emissions by 2016, with public and other non-domestic buildings complying by 2018 and 2019 respectively, and existing buildings would be refurbished
• Constructing new buildings from natural materials with low “embodied energy” (the total energy used in resource extraction, transportation, manufacture and fabrication of an item) that can also sequester carbon (carbon sequestration is the removal of carbon from the air to be locked up elsewhere, for example in the land or in plants)
• Increased use of improved public transport systems, with private car owners paying for travel per mile to make comparison with public transport costs easier, and pay-per-hour car clubs
• Increased use of electricity as a domestic transport fuel
• Transport of cargo by ships powered by solar panels, sails and sustainable fuels
• No domestic air travel, and a cut in long-haul flights, resulting in an overall aviation reduction of about two-thirds on current levels
• Only allowing about 15% of food consumed in Britain to come from the EU and 7.5% from the tropics, with remaining food needs being met domestically – this is important due to the embodied energy in imported foods
• No new arable land, and protection of peat-lands, to preserve the carbon reservoirs that are stored in soil and released if the land is disturbed
• Meeting the nation’s food needs using only 29% of the land that is currently used for this purpose
• A greater proportion of plant-based products compared to livestock products, which will be reduced by 70-80% with a particular focus on sheep and cows as they require high land use and produce a lot of greenhouse gases
• Land freed up by reducing livestock would be used to grow biomass (plants grown for providing fuel) and for sequestration of carbon to balance out necessary carbon emissions, therefore creating zero net carbon emissions
• Energy demands would be decreased by 55% on 2008 levels, allowing for a doubling in electricity demand due to increased use of electric cars

Methods suggested (again with supporting figures, suggestions for overcoming potential problems and topics highlighted for further research) for “powering up” include:

• Sources of energy would be renewable, such as biofuels (liquid fuel derived from plants, which carbon neutral as the plants absorb CO₂ whilst growing), wind turbines and solar, marine and hydro power where appropriate
• Offshore wind would be particularly important – Britain already has the highest offshore wind deployment in Europe and there are plans for more
• Large hydro power, which can be switched on in seconds, and biomass fuels would be used to balance out the dependency of power sources such as wind, wave and solar on weather conditions and ensure demand is met at all times
• Biogas could be made from materials currently considered as waste, such as animal dung, sewage, food waste or grass
• Using renewable energy, Britain’s reduced energy needs, including the doubling in electricity demand, could be met without the use of fossil fuels or nuclear power, which is excluded for safety, security and financial reasons
• Offering rewards and incentives for producing renewable energy, such as are already in place
• Using microgrids and distributed renewable energy generation (so that energy is generated close to the consumer) to minimise energy losses during transmission and deal with energy shortages at peak times
• A small amount of energy from renewable sources would be imported to manage variability
• A larger amount of energy would be exported than imported, helping to cover costs associated with decarbonising the electricity supply and managing variability
• Use of High Voltage Direct Current (HVDC) cables, rather than alternating current (AC) cables when transporting power over long distances, to minimise transmission losses
• Nationwide smart meters or smart appliances which control times at which appliances such as electric storage radiators, electric vehicles, air conditioners, washing machines and dishwashers are charged or in use, to manage energy demand and reduce cost to the consumer if these times coincide with surplus energy in the grid (likely to be at night as wind power generation would continue overnight)
• Buildings could be fitted with larger hot water storage cylinders containing smart meters so that they could be charged at night for space heating during the day

Besides limiting climate change, other noted benefits [3, 5] of achieving the target of zero net carbon emissions include:

• Dealing with the peak oil/gas problem (the point at which the global peak production rate of oil and gas is reached, currently forecast to occur sometime between now and 2031, after which production will decline and prices will rise accordingly)
• High employment due to the development of new energy technologies
• An ease in the decline of the UK steel industry as this will be needed to develop offshore wind power
• Better food and energy security as most food and energy would be produced domestically
• Improved diet and health
• A potential increase in biodiversity
• A better urban/rural balance

There are also suggestions for international and national policy frameworks and schemes to be established to facilitate these actions, and an exploration of the potential of a zero carbon Britain to increase employment and social equality. For example, policies would need to be in place to ensure fair pricing and avoid fuel poverty. Obviously a lack of or reduction in things we have become accustomed to, such as domestic and long-haul flights, car ownership and imported and other types of food, will mean radical lifestyle changes for some. But unfortunately these things will eventually become less and less sustainable and available with diminishing fossil fuel reserves anyway, making behavioural changes unavoidable. As the report points out, with the imminence of peak oil production and the decline of UK fossil fuel reserves, it is advisable to reduce the dependency of our society and transport system on oil.

Zero Carbon Britain 2030 is a scenario suggested by CAT and has triggered some debate, as might be expected with any proposal to limit climate change by altering every day practices, however public support for the idea it outlines is growing. For example, a similar plan has been drawn up in Australia, and 16^th July 2011 saw events take place as part of Zero Carbon Britain day. Achieving these targets or those set out by the UK government for 2050 will require a large shift in behaviour and policies and these changes may be difficult to implement, but this report shows that they are not impossible.

[1] http://www.direct.gov.uk/en/Environmentandgreenerliving/Thewiderenvironment/Climatechange/DG_072901

[2] http://www.decc.gov.uk/en/content/cms/tackling/2050/calculator_exc/calculator_exc.aspx

[3] http://www.neweconomics.org/publications/zero-carbon-britain-2030

[4] http://www.cat.org.uk/news/news_release.tmpl?command=search&db=news.db&eqSKUdatarq=37990&home=0

[5] http://www.ecoinnovationlab.com/uploads/attachments/article/432/Peter%20Harper%20ZCB%20Public%20Lecture%20Slideshow_Australia2011.pdf

There are several ways of treating fruit that isn’t going to be eaten straight away, including freezing, preserving or drying. Freezing is a quick and easy way of preserving food, but might not be ideal if freezer space is limited. Methods of preserving such as jam-making can take time, effort and equipment. Drying is a simple process and special equipment is not essential.

It is worth considering that drying, as with any preservation method, will remove some of the nutrients from fruit [3]. Fruits that brown easily, such as apples, can be pre-treated by dipping in a mixture of water and lemon juice to prevent this [3, 4] and fruits with tough skins should be “cracked” (by dipping in boiling water for 30-60 seconds, then dipping in cold water) [3] or pricked so that they don’t burst during the drying process. Dried fruit is ready when it is chewy, rather than brittle [3, 4]. There are various methods that can be used to dry fruit, depending on the time and equipment available.

Air or sun drying

Air and sun drying use no extra energy, but might not be a viable option in the UK, even in summer as high temperatures and low humidity are needed. If conditions are suitable, fruit can be air dried by spreading it out on trays or placing it in a pot (stirring regularly) and covering it with netting to keep birds off, then placing it in the sun for several days [5], or by hanging cored or sliced fruit on string [4]. Alternatively, a sun dryer can be built with wood and mesh [6].

Using an oven or microwave

Perhaps the most straightforward way of drying fruit, particularly if it is being done infrequently and in small batches, is in a very cool oven or microwave. For an oven, about 40 ^oC (100 ^oF) is the ideal temperature; although most oven controls don’t go that low, they can still be used on the lowest temperature possible to save energy and avoid cooking or burning the fruit.

Alternatively fruit can be dried when the oven is cooling down after cooking, which also saves energy as the oven isn’t being used specifically for drying the fruit. Some fruit will need 6-8 hours to dry completely, so will need to be dried in several stages and stored in between if using a cooling oven; don’t leave it until it’s almost off to start this process.

The time needed will depend on the fruit, and whether the oven has a fan or not, so progress will need to be checked regularly. Small fruits can be dried whole, while larger ones should be thinly sliced, or pitted and placed with the pitted side up. Individual pieces of fruit should not touch each other, as they need as much air to circulate around them as possible. Instructions and approximate drying times for common fruits have been supplied online by Colorado State University [3]. The door can be left slightly open (or opened periodically) to release moisture and allow adequate ventilation [7].

Drying fruit in a microwave is quicker, but not suitable for more delicate fruits due to the higher heat levels compared to a very cool oven [8]. This method is also only suitable for small batches of fruit (but is probably more energy efficient than leaving a fan oven running for 8 hours to dry only a small amount, depending on the energy ratings of the appliances). The microwave should be used on the defrost setting, and the fruit spread out and turned regularly – the drying process should take 30-45 minutes [8].

Using a dehydrator

Fruit can also be dried in dehydrators, which are available in a range of sizes. They should be placed somewhere with good air circulation, so that the moist extracted air is not reused in drying the fruit [9]. Again fruit should be spread out on the trays, without touching, and trays could be rotated to ensure even drying – times will vary according to fruit, and might be indicated by the manufacturer instructions [10]. Dehydrators tend to be low wattage [11], but they do need electricity to power them, and unlike a cooling oven which would have been used for cooking anyway, they are only usable for the purpose of drying food.

Dried fruit should be stored in dry (glass jars, for example, can be dried in a cooling oven to make sure all the moisture has been removed), airtight containers. It can be used and eaten dried, or rehydrated if necessary by placing in boiling water [3, 9]. An online calculator is available to estimate the weight of food after drying from its pre-drying weight [12]. Dried fruit can be added to cereals, yoghurt, cakes, biscuits and other meals and recipes, combined with herbs and spices to make tea infusions, or eaten alone.

[1] http://www.wrap.org.uk/retail_supply_chain/research_tools/research/report_household.html

[2] www.wrap.org.uk/downloads/Household_Food_and_Drink_Waste_in_the_UK_Nov_2011.39e8bf7a.8048.pdf

[3] http://www.ext.colostate.edu/pubs/foodnut/09309.html

[4] http://www.wikihow.com/Make-Dried-Fruit

[5] http://www.ehow.com/how_2083871_dry-fruit.html

[6] http://www.ehow.co.uk/how_7921776_build-nonelectric-food-dehydrator.html

[7] http://www.allotment.org.uk/allotment_foods/drying-food/index.php

[8] http://www.ehow.com/how_5103996_dry-fruit-microwave.html

[9] http://www.fruitexpert.co.uk/DryingFruitFromYourGarden.html

[10] http://www.ehow.com/how_6393689_dry-fruits-vegetables-dehydrator.html

[11] http://www.discountjuicers.com/dehydratorcompare.html

[12] http://www.food-dehydrator.com/calculator/food-dehydrator-weight-calculator.aspx

The amount of space, time and equipment needed will vary depending on the fruit or vegetable to be grown, but there are some general practices that are applicable to all types:

• Whether growing outside in the ground or in pots or containers indoors or outdoors, the same general rules apply, but on a smaller scale for pots [2]
• Choose a warm sunny spot, avoiding shade and adding shelter from the wind (for example with a windbreaker) where necessary [2]
• Plants grown in plastic pots or containers will require less watering than those grown in terracotta pots [6] because terracotta is porous and will absorb some of the water
• Use fruit/vegetable planners (e.g. [7, 8]) to determine when to plant and harvest different types of crop. The Royal Horticultural Society also has a list of general tasks that should be done at the current time of year [9]
• In pots, use compost rather than soil from the garden, as soil will pack down too hard and can also contain weeds [10]
• When planting in the ground, dig the soil over and remove weeds before planting [9]
• Different seeds will need to be sown at various depths within the soil – always check instructions or growing guides
• Plants need a constant supply of water at their roots in order to produce the best crop – soil should be kept constantly and evenly moist [11]
• Check for weeds regularly and remove
• Check if the plant being grown needs a particular food, and if so supply this as instructed for the best results

Plants can be grown from seed, or bought as already germinated seedlings. Both seeds and seedlings are available at garden centres, or even in some supermarkets. The Royal Horticultural Society has a Grow Your Own Fruit and Veg A-Z guide [12] that has a lot of useful information and instructions specific to different types of plants. This is specific to the plant being grown and is far more than can be given in a general article – detailed instructions for each type of plant should always be followed in order to get the best results. In particular, check how much care and watering are needed. With a garden, there are numerous types of fruit and vegetables that can be grown depending on preference. However, if space is more limited, plants that can easily be grown in pots include tomatoes, courgettes, strawberries, chillies, carrots, cucumbers, peppers and rhubarb, among others, and even potatoes can be grown in large patio pots [12, 13].

If the right amount can be grown to meet individual needs, wastage of excess food, and all the associated energy, can be reduced [4]. Even if you can’t produce enough for all your needs, food you’ve grown yourself can be an enjoyable and useful addition to your meals, and if you grow too much it can always be given away or preserved for later use by freezing (whole or in soups), pickling, making into jams or drying. Why not couple your growing with a composting bin for even more environmental benefits?

[1] http://www.transitiontownwestkirby.org.uk/files/ttwk_nsalg_survey_2011.pdf

[2] http://www.lovethegarden.com/how-to-grow/vegetable-garden

[3] http://www.makeitandmendit.com/2011/06/07/grow-your-own-gardening/

[4] http://www2.btcv.org.uk/display/freefoodguide

[5] http://www.direct.gov.uk/en/Environmentandgreenerliving/Greenerhomeandgarden/Greenergarden/DG_177399

[6] http://www.lovethegarden.com/how-to-grow/growing-fruit-and-vegetables

[7] http://www.deliciousmagazine.co.uk/articles/planting-guide

[8] http://www.lovethegarden.com/projects/vegetable-planner

[9] www.rhs.org.uk/Gardening/Grow-Your-Own/jobs-to-do/

[10] http://www.deliciousmagazine.co.uk/userfiles/file/GrowYourOwn_delicious_Apr09.pdf

[11] http://www.rhs.org.uk/Gardening/Grow-Your-Own/Advice/Veg-advice/Watering

[12] http://www.rhs.org.uk/Gardening/Grow-Your-Own/Veg-A-to-Z/

[13] http://www.which.co.uk/home-and-garden/garden/guides/growing-your-own-veg/six-of-the-best/