Before we go our separate ways

So before I say good bye, and we go our separate ways, I thought I would just take a few minutes to conclude some key findings and reflect upon my blog and blogging experiences.

 Long range pollution is a topic which is not that widely discussed, and something which i knew nothing about prior to this blog. Many long range pollutants have similar warming properties to greenhouse gases and therefore should be controlled to prevent further warming in the Arctic. Not all pollutants alter the climate, mercury for example, is extremely toxic (in large concentrations) for animals and humans in this region, and the negative impacts of these must not be ignored. Within this blog I have called for more attention to be drawn to these LRP and if I have enlightened just one person, then I see that as a success!

However the realistic truth is all too looming. As temperatures rise pollutants from more southern locations (warmer and wetter) can penetrate the Arctic dome and contribute further to the volume of pollutants concentrating in the Arctic, Also, long range pollution may well become localized pollution in the near future! As sea ice depletes, more shipping paths will open up, resulting in a greater number of vessels in the Arctic. Increased traffic will see greater sulphate and black carbon emissions, as pollutants no longer have to travel hundreds of miles to reach the Arctic. To prevent this, policy makers need to establish long range pollutants as a threat and begin to incorporate them in global mitigation plans. 

I'm sorry LRP but your passports are out of date....

In my first post I stated several aims so i thought i would just reflected upon how I believe I have completed these aims:

1)      To introduce other threats, beside climate change caused by green house gases, to my readers: throughout this blog I have a running argument that climate change as a result of GHGs overwhelms the public eye. I hope, after following my blog, you can understand and appreciate long range pollutants also pose a risk to the Arctic.

2)      I want to present topics which may be very scientific to my readers in a way which everyone, from whatever academic background, can understand and engage with: within my blog I explored topics including the influence of aerosols and bio-accumulation of mercury, both of which are challenging and very scientific topics. I put my hands up (and this particularly applies to the clouds blog post in which I had to read a lot of physics papers) these topics can be very heavily science based which is not everyone’s cup of tea. However, I hope I manged to express these topics in both an accessible and engaging way.

3)      Try and encourage people that these issues do matter and they should act to save the Polar Regions: this l aim is slightly harder but from the response I have had to my blog I do believe I have managed to change some people’s opinions and as to acting to save the Arctic check out my post on deodorant for an inspiration on what you can do to save the Arctic!

4)      To learn and teach other about something I have never personally learnt about throughout my geography studies: Finally I know I have completed this aim! I have learnt so much about the issues within the Arctic and to my surprise have begun to feel quite passionate about some of the topics! I have even changed the deodorant I use to one which does not emit aerosol! Also, based on the comments and other forms of feedback I have had about my blogs I was thrilled to hear people have learnt (and seemed to have enjoyed doing so) about the topics surrounding Long Range Pollution in the Arctic.

This blogging experience has been one of the most rewarding and yet challenging I have undergone throughout my university life. Throughout the last few months I have encountered a few challenges including addressing some very scientific topics. However with hard work and patience I have found I can address any subject no matter how technical it is. Secondly the engagement was something I initially found disconcerting. Positive comments are always a pleasant experience but ones which challenge you argument or your opinion I found harder to address! Yet, it was very interesting to see how others arguments varied from my own and encouraged me to become more critical of my own arguments.

Despite these challenges I have thoroughly enjoyed developing my blog and have learnt skills which will help me throughout my final year at UCL. So I hope you have learnt something and enjoyed reading this blog as much as I have enjoyed writing about it. If you have any questions either about long range pollution (something I now consider myself to be highly knowledgeable about!) or starting up the blog just drop me a message in the comment section and I will get back to you ASAP!

I know Harry Potter has nothing to do with the Arctic but this is a classic!

So all that is now left to say is GOOD BYE!

The results are in!

The results are in! The public have voted (and thanks to all of those who did!) and as expected global warming has come out on top! Exploration of oil comes in second and Long range and localized pollution coming joint third with no votes!

The Results of the poll. 

Upon reflection I should have said GHGs as opposed to global warming, as I have learnt now some long range pollution can also have warming properties. However after discussing with those who voted for global warming as the largest threat to the Arctic, stated that they associated greenhouse gases with global warming.

After spending the last few weeks exploring the dangers (and some positives) or long range pollution I find it boggling that NO-ONE voted for long range pollution, people don't seem to be aware of how damaging they can be! This is feel is reflected in the policies (as a mentioned in an earlier post!) as despite being present, long range pollution policies are often swamped by their cousins Green House Gases. I feel the media also has an influence (as it always does!) by focusing reports on the effects of Carbon Dioxide. “It is thought a natural warming and cooling cycle could be responsible for up to 30% of the melting - but the rest is the result of human activity releasing greenhouse gases” NOT TRUE!

Well I believe it is time Carbon Dioxide moved over! One of the main aims of my blog was to open your eyes to some other pollutants who threaten the future of the Arctic. In my next post, in which I will be concluding this blog and expressing my final opinion on the subject. In the meantime let me know your opinion by commenting! Has it changed throughout the course of the blog?

Mercury and Ecosystems 2: Bioaccumulation

Moving on from bio-magnification as this post is going to focus on bioaccumulation in predators at the top of the food chain and the consequences of having a build-up within an animal or human system. So I’m just going to jump straight in!

Top of the food chain

For those at the top of the food chain this large accumulation of mercury, within their system, can be detrimental to their health. There are two ways which the toxicity of mercury can be assessed in predators. Firstly the comparison of the total amount of mercury in an animals system to calculated thresholds. These thresholds are based on a database of known concentrations, calculated from lab observations. The second approach includes examining animals for mercury biomarkers. Biomarkers are certain behavioural responses by animals. As Arctic animals are exposed to many different types of pollutants these markers allow effects of mercury to be specifically identified. Mercury is often stored within the liver of marine mammals and the kidney of terrestrial mammals. One of the reasons mercury is so toxic results from it’s potential to cross the blood brain barrier. This causes a disruption of the nervous system and symptoms such as numbness and decreased co-ordination in large terrestrial mammals (ie. polar bears). Furthermore this toxin can be passed from mother to baby though the placenta or milk, both considerable causes of mercury exposure in new born animals.

Mercury concentrations in Human and polar bears.

Concentration of mercury in pregnant women in the Arctic

What I found shocking, from this graph (above), was the high levels of mercury found in humans! However upon further consideration this isn’t so shocking. Humans are at the top of many food chains within the Arctic, with seals and fish provide an efficient protein source in this region. Arctic indigenous communities are particularly prone to mercury exposure due to their traditional cultural practices of hunting and fishing. Negative impacts of the bioaccumulation, of large concentrations of mercury within the human system, can affect the reproductive and cardiovascular systems, and cause neurotoxicity. These impacts are leading to Arctic residence having to make a choice between the readily available food source and potential health risks associated. Like in many animals, mercury can pass through the placenta to an unborn human child, because of this many studies focus on monitoring mercury levels in the blood of pregnant women. Recent awareness of the impacts of mercury have seen a decrease in mercury concentrations in blood since the 1990s but the graph still shows high concentrations in pregnant Inuit women in Greenland (above).

Within academia there seems to be a lot of ambiguity of results of studies, some establishing bioaccumulation in food chains were others stating they do not exist. Inconsistency of findings may be due to the difficulty of measuring trophic structures and the movement of the element. Publishing bias must be considered, as journals are unlikely to accept studies which do not show any notable relationship between mercury. Simply from my own reading I have found a great consistency between results of studies with most food chains displaying some form of bio magnification and bioaccumulation. I found this a very interesting but alarming topic! So if you have any thoughts on this topic please let me know by commenting.

Mercury and Ecosystems 1: Bio-magnification

My previous post introduced a new pollutant to the blog. Just to recap, mercury is a toxic element accumulating in the Arctic at a rate of 80 to 140 tonnes, per year. I wish to move on today by looking at some of the major impacts of mercury on Arctic Ecosystems. Unlike the other LRP I have explored mercury does not influence the climate in the Arctic. Mercury has the potential to bio-magnify in food chains, entering at the bottom and passing though the trophic stages to larger predators. Traces of the substance has even been found in human blood! Due to the amount of literature on this topic I have decided to split it into two post; the first discussing bio-magnification and the second bioaccumulation.

Entering the food chain

To enter a food chain mercury has to be in a state which can be readily consumed by Arctic organisms. Most organisms (not including those at the bottom of the food chain eg. Algae) cannot take up inorganic mercury. Upon conversion to methylmercury (by bacteria in oxygen depleted environments) the toxin is easily taken up by animals. Production is dominant around ocean waters which contain layers of concentrated nutrients, but little is known about the rate of conversion by this bacteria.

Moving up the food chain

Un-bear-able Cute!
But these guys often have less mercury in their system
 that predators further down the food chain!

Once entering the food web methylmercury progresses from prey to predator up the web. A “bottom up” process is most common within the Arctic, as focuses on “factors that influence the extent to which methylmercury concentrates at successive tropic levels of the food chain”. This “bottom up” process is also prone to bio-magnification at each tropic step of the food chain. For example, the bio-magnification of an ecosystem in the Gulf of the Farallones was measure to have a trophic magnification factor of 0.32 (this is slightly lower than an average food chain as the Farallones food web is dominated by sea birds, who accumulate mercury differently to other organisms. Furthermore the study was based on the sampling of many tissues including their eggs, so comparison to studies based on muscle tissues may not be representative). As mercury moves through the chain the level of mercury can amplify by approximately 2-7 times, so in the case of a very long food chain, predators at the top can contain methylmercury levels up to a million times greater than those which initially digested the toxic. An expectation of this was found by Atwell et al (2011), who state polar bears demonstrated a lower mean mercury concentration than their prey (ringed seals in this case).

How mercury can enter and leave the system of a polar bear and seal

As mercury is bio-magnifies through a food web it lead to bioaccumulation within predators at the top of the food chain, which can result a series of unwelcome consequences. Stay tuned! My post of bioaccumulation will be coming very soon!

Mercury: Headlining the Arctic

Ladies and gentlemen please welcome to the stage a new form of long range pollution… Mercury! *APPLAUSE*. This post aims to explain what mercury is, where it is from and its presence in the Arctic region. Despite being a remote region, the Arctic has accumulated high levels of Mercury. The element is having many negative implications for the biota in this region thus creating a topic of both interest and concern.

Mercury is headlining the Arctic.

What is mg?

Mercury (Hg) is a naturally occurring element. With a very low melting point of -38.87 degrees Celsius, mercury is most often found as a silver liquid. Before the industrial revolution the total amount of mercury in the environment was in equilibrium. The anthropogenic creation of mercury has upset this balance causing excess mercury to be found in the soils, surface water and oceans (all of which are large global stores of the element).

Map showing Mercury released into the atmosphere
tonnes per year

Sources of Mercury.

The natural abundance of mercury, in the environment is doubled, by that produced from human innovation (about 4000 tonnes). Burning coal is by far the largest production of man-made mercury, followed by the smelting and metal production industries (as Hg is used in the creation ferrous and non-ferrous metals). A larger proportion is generated through the mining industry, which uses mercury to extract from gold natural ores. “Hot Spots” for release of atmospheric mercury include China, Sudan and the North West Coast of South America, demonstrated by the map (right).

Chart showing the sources of anthropogenic
Mercury.

Mercury’s presence in the Arctic.

It has been estimated that the net amount of mercury added to the Arctic environment each year is between 80 to 140 tonnes (NB: mercury is also leaving the Arctic system). Most of the Mercury present in the Arctic is transported by prevailing winds, ocean currents and rivers. Atmospheric pollution, from mid latitude power stations, can take as little as a few days to be transported from source to the Arctic. Transportation through the atmosphere can have detrimental impacts as gaseous Hg can have a lifespan of up to a few months (within this time a mercury atom has the potential to circulate the majority of the northern hemisphere).

The oceans are also a great transporter of Hg, yet a much slower method of distribution. However, it is important to remember the amount of mercury reported in the atmosphere is smaller in comparison to the volume stored in the oceans.

Mercury budget in the Arctic Ocean.

The Mercury budget, for the Arctic Ocean, suggests the Atlantic and Pacific oceans, coastal erosion and the atmospheric (through mercury depletion events during spring) are all large inputs of mercury to the Arctic system. The proportion of mercury sourced from atmospheric deposition demonstrates the large surface area of the Arctic Ocean. The outflows of mercury are less apparent including sedimentation, the removal through ocean systems and to a very small extent the remission of gases. The disproportionate ratio of inflows to outflows demonstrate why the Arctic is a site of mercury accumulation.

Modelling the Arctic mercury budget must be completed on a global scale to incorporate the influence of long range transport. A large scale results in a greater level of uncertainty associated with the models as resolution of results are low. This can be overcome by using a multi-scale approach (using models which integrate global and regional scales) which is adopted within a study published in the Atmospheric Environment Journal. Within the paper Dastoor and Larocque use a global/regional atmospheric heavy metals model to simulate the movement of mercury within the atmosphere, allowing a higher resolution to be obtained.

Stay tuned for my next post which will delve deeper into the impacts of mercury on ecosystems in the Arctic. Until then please comment any questions or thoughts you have in response to this post.

P.S. For those of you who found the topic of mercury particularly thrilling this website http://www.mercurywatch.org/ is well worth a read. The site monitors the use of mercury across the world in small scale gold mines. Sponsors aid projects which aim to reduce mercury production by training workers to use mercury free extraction methods in Ghana, Senegal and Burkina Faso. Benefiting both the environment and the health of works. 

Why don't Black Carbon and climate models get along?

Modelling the impacts of Black Carbon (BC) is in abundance in academic geography. However, only recently has Black Carbon begun to be incorporated into studies modelling climate change (ie. ice sea ice retreat) within the Arctic. Either models have advanced (and details such as BC can be accounted for) or black carbon has just been established as contributor to climate change in the Arctic, I do not know. This post sums up my series on black carbon as a form of long range pollution and aims to discuss the presence of black carbon in modelling studies by comparing two studies.

Published in 1995, Cattle and Crossley, discuss the basic predictions of climate change in the Arctic region. The model adopted is that used by the Hadley centre for climate prediction and research at the meteorological office, to model the impacts of future climate change resulting from increased concentrations of greenhouse gases. It is important to remember climate change did not become a global phenomenon till the late 20^th so this knowledge was quite new at this time. The results suggested a temperature change by approximately 2 degree centigrade by 2030 (this is based on Greenland predictions but generally results varied very little), thus causing a thinning of ice and a maximum ice thicknesses of 3m in March and 2m in September (within the central Arctic).

This seems to be a very large underestimate of what has occurred over the past 10 or so years. Currently, 4 years before the predicted temperature rise, parts of the Arctic are witnessing temperature rises of 2-3 degrees PER DECADE! So by 2030 this temperature change will be well above what the model simulations in Castle and Crossley's study. This gap between predicted and observed results could have resulted from a lack of consideration of the albedo feedback systems created by black carbon. Having said this it is unlikely black carbon could be able to single handedly cause an accelerated rate of sea ice retreat. Graversen et al (2008) suggest black carbon and the resulting change to albedo could contribute to the warming when associated with warming of the middle troposphere (as a result of an advection of energy bringing warmer air into the Arctic region).

Map showing sea ice retreat.

In order to accurately predict abrupt sea ice retreat, anthropogenic forcing, such as the influence of particulates, must be incorporated within Arctic Models. Holland et al (2006) incorporate changes to albedo (as a result of anthropogenic particulates) as a forcing of sea ice reduction. The study concludes major summer ice reduction could be expected as early as 2015. A focus is placed on the influence of surface albedo feedbacks accelerating retreat. So we are currently in 2015 and have experienced the predicted sea ice retreat. The map (Right) shows the sea ice retreat between the extents in December 2015. The magenta line represents the median ice edge for 1980-2010 and just illustrates the overall sea ice loss occurring within the past 5 years.

To sum up, in order to create accurate simulations, models must include anthropogenic forcing from pollutants such as black carbon, to realistically represent albedo feedback systems. The extent of the influence of black carbon on warming is questionable and some studies such the UNEP/WMO Assessment, conducted by the World Bank, does not consider the forcing properties of the particulates. The influence of sources of black carbon in this study is deemed so insignificant (in comparison to other forcing factors), so it is not included. Furthermore the level of uncertainty associated with the calculation of the forcing effect of black carbon is so high it contradicts it inclusion in some cases. However, the literature still generally suggests to achieve realistic results black carbon should be included in Arctic models.