Science in Parliament (Part I)

Science and technology are crucial pillars of any industrialised society. They serve the drive research and technological development in the public and private sectors, which increases the efficiency of the manufacturing, pharmaceutical, energy and infrastructural sectors and the economy in general. They also provide individual consumers with fascinating gadgets, computers and novel forms of transport, whilst also improving their quality of life via the medical and environmental sectors. Science seeks the know the unknown and unravel the tangled complexities of our world, hopefully providing answers and solutions to our tribulations and easing our anxiety of the undiscovered and unpredictable. A scientifically literate workforce is better equipped to deal with the demands of an increasingly digitised and globalised world, being more adaptable to new technology and more able to make informed, rational decisions firmly grounded in an intelligent and evidence-based approach. The UK can be proud of our strong reputation in the sciences and laud our many notable and erudite scientists, both past and present.

It holds therefore that the science and technology policy would be at the forefront of the political agenda in the UK and that many Members of Parliament (MPs) would be scientifically literate and actively or formally engaged in the practical application of science and technology in either the public or private sectors. It is to my despair that I have to conclude otherwise, and I intend to outline the disconnect between the architects of science policy in the UK’s most senior legislative bodies and their appropriateness for these roles in this and future posts.

Firstly, I turn my attention to the Science and Technology Select Committee (STSC) of the House of Commons. The STSC is comprised of 11 MPs drawn from three of the major parties (Conservatives, Labour and Liberal Democrats) and its role is to scrutinise the findings of the Government Office for Science, an otherwise commendable body that serves to support the Chief Scientific Advisor, Professor John Beddington. It is therefore not unreasonable to expect that the STSC is made up of MPs with a background in science or technology, who have since become politicians. Unfortunately, this does not appear to be the case.

The current members of the committee were selected on the 12th of July 2010 and the chair is Labour MP Andrew Miller. Mr Miller was a former laboratory technician in the Geology Department of Portsmouth Polytechnic, now the University of Portsmouth, after completing a diploma in Industrial Relations at the London School of Economics. Whilst not a published academic, at least Mr Miller has a background in science in the research sector. The same cannot be said for at least four of the members of the STSC, including Labour MPs Greg Claymont, who read History and Pamela Nash, who studied Politics, both at the University of Glasgow. Labour and Co-Op MP Jonathan Reynolds was a practising solicitor after obtaining a LLB from the BPP Law School Manchester campus. Perhaps the most extraordinary CV of all the members of the STSC belongs to Conservative MP David Morris, who trained as a hairdresser before owning his own salon, and then going on to become a successful songwriter alongside Pete Waterman. He also serves in the Royal Navy as part of the Armed Forces Parliamentary Scheme and is a friend of Baywatch star and cult personality David Hasselhoff.

Treading the line between science and industry are Tory MP Stephan Metcalfe who runs a small printing company and Conservative Stephan McPartland MP, who has a BA in History from the University of Liverpool but also holds a masters degree in Technology Management from Liverpool John Moores University.

Nevertheless, there are a few science degrees to be found amongst the members of the STSC. Conservative MP Gavin Barwell holds a degree in Natural Sciences from Cambridge, but has never worked in science, whilst Liberal Democrat Roger Williams MP holds the same qualification and formally worked as a livestock farmer. Stephan Mosley studied Chemistry at the University of Nottingham whilst Labour MP Graham Stringer completed the same degree at Sheffield before becoming an analytical chemist in the plastic industry. He has since however openly attacked the frankly substantial medical evidence behind the diagnosis of dyslexia, calling it a ‘false condition’ and a ‘cruel fiction’ devised, in his eyes, by education chiefs attempting to disguise poor teaching methods. Accordingly, Mr Stringer’s appointment to the STSC is worrying, despite his previous scientific qualifications, as his vehement attack on a credible and well justified area of medical science may reveal his apparent inability to critically analyse evidence and come to rational conclusion.

Surely, a Science and Technology Select Committee that contains very few scientifically trained representatives can not scrutinise science policy effectively, especially if the legislation contains technically complex theories as atmospheric science, climate science and pollution analysis often do. Despite the fact that not a single member of the STSC has a background in astronomy, physics, mathematics or biology some of the STSC current inquiries include those into Astronomy and Particle Physics, the soon-to-be defunct Forensic Science Service and an inquiry into the availability of rare earth metals. These are extremely complex issues, requiring expert analysis and opinion from experienced scientists. Whilst I am certain that an arts degree provides most MPs with a myriad of useful skills in political debating, qualitative analysis and linguistic prowess, I feel very strongly that matters of science policy should be analysed by accordingly educated representatives to provide the most efficient and democratic return. An industrialised country with a strong science and technology sector and an impressive research reputation deserves representative science policy makers that are in touch with the concerns and visions of the members of these areas.

In future posts I plan to outline the membership of the Lord’s STSC, the Energy and Climate Change Committee and the Environment, Food and Rural Affairs Committee, in the hope that the scientists-turned-politicians finally reveal themselves…

The Kepler 10 and 11 Planetary Systems

NASA’s Kepler Space Telescope has in recent months returned a veritable treasure trove of confirmed and as-of-yet unconfirmed exoplanets. The impressive haul is estimated at a preliminary 1235 planetary candidates (!), the most interesting of which to date has proven to be the Kepler 10 and 11 planetary systems, but more fascinating finds are likely to be announced in the coming weeks and months. These results will serve to double the repository of known extra-solar planets and possibly reveal, for the first time, an Earth-like planet orbiting within the habitable zone of its star.

In the above image I have attempted to illustrate the orbital configuration of these two planetary systems, with Earth and Jupiter included for reference. Kepler 10 is a G-type star in the constellation Draco, with a mass of 0.895 solar masses, or M☉. Its single known planetary companion, Kepler 10b is the first confirmed rocky extra-solar planet, but at 8.8 g cm-3 it is significantly denser than the Earth, comparable to that of refined iron, and approximately 4.6 times more massive. It’s low semi-major axis means that it also completes an orbit of Kepler 10 in around 20 hours at an average distance of only 0.016 AU, or 2 519 230 kilometres. This proximity would result in an extremely harsh radiative environment and an average surface temperature of around 1833 °K (1560 °C), which is roughly the melting point of steel, and much to hot for any form of life as we know it. Nevertheless, the discovery of Kepler 10b has been triumphantly lauded by scientists responsible for the operation of the Kepler Space Telescope at NASA’s Ames Research Centre as the accurate detection of a planet of this size, orbiting in such close proximity to it’s parent star, is a testament to the effectiveness of the space telescope, and increases the likelihood that Kepler will return more significant findings of a similar planets.

Kepler 11 is a 8 billion year-old G-type star in the northern constellation Cygnus with a mass roughly similar to that of our Sun. Around Kepler 11 is a remarkable family of 6 closely packed planets, denoted Kepler 11b through g. This is significant as it is the first system discovered with more than 3 orbiting planets. The orbits of Kepler 11b to f would fit within that of Mercury in our Solar System, whilst Kepler 11g orbits at 0.462 AU, comparable to a distance roughly half-way between Mercury and Venus. The smaller planets (b to f) have orbital periods between 10 and 47 days, whilst Kepler 11g completes its orbit in 119 days. Despite this close orbital configuration, dynamical simulations suggest that the system would be stable, with only weak chaotic perturbations detected. Kepler 11d, e and f are thought to have atmospheres possibly consisting of hydrogen, although the volume of this envelope would be less than in the past due to atmospheric escape and stripping of H+ by high energy solar particles that make up the solar wind, especially if the planet has a weak or absent magnetic field. Planets b and c are thought to be either rich in volatile ices (primarily of water, methane or ammonia) or a hydrogen/helium mixture, or a combination of both. The surface temperatures on all of Kepler 11′s companion planets would be too great to support life, especially if any of the planets have a substantial atmosphere of any kind as the greenhouse conditions would only increase temperatures, possibly culminating in the runaway greenhouse effect experienced on Venus.

If you’re as interested in worlds beyond our Solar System as I am, then the findings of the Kepler Space Telescope are likely to provide you with much cause for excitement in the coming months as more data and discoveries are published.

                                                                                    

More information on Kepler 10 can be found at the Ames Research Centre page here and here.

The information above is derived from the paper by Lissauer et al. 2010 outlining the discovery of Kepler 11′s planetary system (draft copy). The nature paper (requires subscription) is here. More information can be found at the Ames Research Centre page here.

Our Pale Blue Dot

Pale Blue Dot, the image recorded by Voyager 1 in 1990 at a distance of c. 40 AU, or 6 billion (109) kilometres from Earth. You are on the tiny, blueish pixel, centre right.

Above is the image that has been come to be known as the Pale Blue Dot. It was taken by the Voyager 1 probe in 1990 as the spacecraft was leaving the Solar System on it’s indefinite journey into interstellar space . At over 40 Astronomical Units (AU), or 6 billion kilometres (that’s 6 109) from Earth, the image returned is incredible in its portrayal of our tiny world against the vastness of the cosmos.

This image was the inspiration for Pale Blue Dot, a book written in 1994 by the distinguished American astronomer Carl Sagan. I have only recently had the privilege of reading this book, mainly due to the its near criminal scarcity in bookshops and on the internet. Rarely has a work of non-fiction elicited such a powerful emotional response as Pale Blue Dot. Sagan was clearly a master wordsmith, as well as respected scientist and his prose and delivery is beautiful, fluent and elegant. In particular, the introduction and opening chapter, entitled Wanderers and You Are Here respectively, are perhaps some of the finest examples of science writing I have ever had the pleasure of absorbing. Sagan’s interpretation of the significance of the above image is so powerful and moving that nothing I can say here to paraphrase will do his eloquent delivery justice. I’ll reproduce one of my favourite passages from the book to illustrate my point, but I hasten to add that there were many contenders for this accolade.

          “From this distant vantage point, the Earth might not seem of particular interest. But for us, it’s different. Look again at that dot. That’s here, that’s home, that’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”


Wow.
 I think the reason that these words are so emotionally striking is that, for me, they represent the the ability of science to amaze and humble us, to provide sensible solutions to difficult questions and to reconcile our differences in opinion, nationality and ideology. It is often said that a life in science can make you cold, removed and unattached. Absorbed in grey objectivity and burdened by the realisation of the insignificance and futility of our fleeting existence. This book, and in particular these words, prove otherwise. These words are true, not metaphors or conjecture, but statements of fact based on a distant image of our little globe. Our Earth, our tiny watery home, is a very small planet in an otherwise uninteresting star system, in a remote corner of a common barrel-spiral galaxy. It is the only home we’ve ever known and we have a responsibility to care for it and each other, because on the scale of the universe, our differences are minuscule and unidentifiable, our existence brief and uneventful and our impact on the rest of the vastness of space, practically nil. No religion was required to reach this conclusion, no scripture needed, no proverbs recited or prayers offered. These words were penned by the careful and balanced hand of science, yet they dispel our fundamentally flawed sense of self-importance, reveal our basic evolutionary solidarity with each other, and with all other organisms that we have the privilege to share our planet with. They serve to focus our priorities when attempting to preserve the balance of our delicate world.
I would urge every single person on our planet to read this book. It has inspired and humbled me, but also made me proud to be a member of a species that has ventured out into the cosmos, landed on other planets and sent speculative messages to the stars. We have great potential, but there is a chance we will waste what opportunities we have if we remain focussed on our differences in race, religion and culture. These differences are human constructions, inconsequential on the grand scale of the stars, that will stunt our growth as a species and keep us perpetually rooted in the superstitions and anachronistic philosophies of the past. I try to keep these words fresh in my mind, floating gently through my subconscious, quietly reminding me to maintain perspective and to dispel ignorance and presumption, and I would urge you to do the same.
                                                                                    

Some amazing videos featuring excerpts from Carl’s book can be found online, my favourites are here and here. I challenge you not to be moved.

How Would London Deal With Drought?

This essay is based on the Greater London Authority’s Climate Change Adaptation Strategy, which can be found here

The London Climate Change Adoption Strategy was published in 2008 by the Greater London Authority (GLA) and outlines the likely effects of global climate change on London, with particular reference to risk assessment and understanding, long-term management, emergency planning and public policy issues. Drought prediction and water management in the Thames Valley is given emphasis as a very serious concern for the future sustainability of London. Several authors, (notably: Hennessy et al. 1997; Blenkinsop and Fowler, 2007 and 2007a; Hirabayashi et al. 2008; Hulme et al. 2002 and May, 2008) have attempted to quantify the effect of greenhouse gas induced climate change on precipitation frequency and intensity in the near and distant future under various scenarios. The general consensus is that both the frequencies and the length of dry spells are likely to increase in the future. However, drought variability over the past century has changed very little (Hughes and Saunders, 2002; Hisdal et al. 2001 and Easterling et al. 2000) indicating that perhaps more understanding of both drought and climate change processes, as well as the intrinsic relationship between the two, is required.

Hisdal et al. (2001); Hughes and Saunders (2002) and Easterling et al. (2000) all conclude that whilst there is no indication that drought frequency and severity have increased across Europe over the last 100 years it is important to understand that the quality, drought parameters and spatial and temporal resolutions of the data strongly influences these results. Recently, several authors have used statistical and remote sensing models to illustrate and predict the frequency and severity of extreme events, such as drought, under various climate change scenarios. Notably, Hulme et al. (2002) predicts that whilst winter precipitation under all IPCC Special Report on Emissions Scenarios (SRES) scenarios (low, medium-low, medium-high and high) is likely to increase by a maximum of 30% by 2080, summer, autumn, spring and the overall annual average rainfall is likely to decrease considerably. Their findings are summarised in the table below.

SRES Emission Scenario
Summer Precipitation (% change)
Winter Precipitation (% change)
Annual Average Precipitation (% change)
Low
-20 to -30
+15 to +20
0 to -10
Medium – Low
-30 to -40
+15 to +20
0 to -10
Medium – High
-40 to -50
+25 to +30
0 to -10
High
> -50
+25 to +30
0 to -10

Whilst precipitation frequency during winter is predicted to increase, its intensity (amount of rainfall, per unit of time, per unit of area) is also set to increase, as shown by the figure below, from May (2007). This is significant as more intense rainfall events are likely to be more localised, shorter, have larger raindrop sizes and facilitate more rapid run-off processes which may not necessarily contribute to groundwater recharge.

Similar findings were reported by Frei et al. (1998). A warming of 2°C was predicted to increase the frequency of heavy (> 30mm day-1) precipitation events by 20%. Correspondingly, Easterling et al. (2000) concluded an increase in both one day and ‘multiday’ intense precipitation events would be ‘very likely’ across Europe by the end of the 21st Century.

Under all SRES scenarios, Hulme et al. (2002) also predict a significant increase in annual, summer and winter temperatures, with the greatest increase occurring during the summer months. This increase, coupled with the warming effect of the urban heat island (UHI) would serve to further exacerbate evapotranspiration and increase public water demand, putting further pressure on London’s water resources.

Water Resources, Demand and Drought Management in London
An annual average of 690 mm of rain falls over the Thames catchment. Of this, 455 mm (66%) is lost by evapotranspiration. Of the remaining 235mm, 129 mm (55%) is abstracted (the highest proportion of any catchment in England) and 105mm (45%) is allowed to flow back into rivers. 80% of London’s water is stored in reservoirs around the city after being extracted from the Thames and the River Lee. The remaining 20% is abstracted from groundwater stored in the chalk aquifer below the city. Groundwater recharge, which replenishes both the aquifer and the river network, occurs during the winter, when rainfall is at its highest and evaporation is at a minimum. Londoners, due mainly to increased prosperity and lower occupancy densities, consume 18 litres more water per day on average (168 litres person-1) than people in the rest of the country, yet the Thames region has a considerably lower water availability (265 m3 person-1 year-1) than the rest of England and Wales (1,334.1 m3 person-1 year-1). Although this clearly illustrates the value of the limited water resources in London, a further 600 million litres per day is lost through leakage caused by the aging water network, subsidence of the clay strata on which the network is laid, vibrations from transport and pipe corrosion.

The GLA report highlights some of the key areas of drought vulnerability in London and attempts to address these issues by identifying the risks and possible mitigation and adaption strategies available. Whilst addressing these issues is a commendable step towards sensible drought management, it is important to realize that these are merely theoretical concerns hypothesised on the basis of contemporary drought frequencies and intensities. Future drought events in London should be considered relative to the wider context of climate change across both the UK and the world. The GLA report, whilst going some way to documenting policy and planning initiatives, lacks the quantitative drought prediction capabilities in the vein of Hulme et al. (2002) and others.

If the predicted decrease of between 20% and 50% in summer rainfall in the UK due to climate change holds, this would put unprecedented pressure on London’s water network. Also, an increase in the intensity of winter precipitation would not facilitate the efficient replenishment of the groundwater store, further exacerbating drought conditions during the summer months. Whilst the UHI effect would undoubtedly intensify temperature extremes between the city and its surrounds, its effect on drought events seems uncertain. Increased hygroscopic pollution and convective uplift associated with urban canopy layer would serve to seed cloud formation and augment convective rainfall consecutively. The small increase (c.10%) in precipitation would be negligible when considered relative to the negative effect predicted to be caused by national and global climate change and would mainly affect downwind areas. Certain London-specific factors, such as the extremely high abstraction rate coupled with the below average individual water availability, the use of CSOs and river-fed cooling systems in power plants as well as leakage from aging pipes may also serve to intensify the social, economic and environmental implications of a drought event. The GLA report provides a concise policy framework for drought management but operates within the theoretical structure of past and/or present physical drought impacts. It also lacks any substantial quantitative drought prediction models and fails to identify a timescale for change which could be used to realistically assess and address the risks of drought in the City.

References:
Blenkinsop, S. and Fowler, H.J. (2007) Changes in drought frequency, severity and duration for the British Isles projected by the PRUDENCE regional climate models. Journal of Hydrology. 342 (50 – 71)
Blenkinsop, S. and Fowler, H.J. (2007a) Changes in European drought characteristics projected by the PRUDENCE regional climate models. International Journal of Climatology. 27 (1595 – 1610)
Easterling, D.R., Meehl, G.A., Parmesan, C., Changnon, S.A., Karl, T. R. and Mearns, L. O. (2000). Climate Extremes: Observations, Modelling and Impacts. Science. 289 (2068 – 2074)
Frei, C., Schär, C., Lüthi, D and Davies, H.C. (1998). Heavy precipitation processes in a warmer climate. Geophysical Research Letters. 25 (9) (1431 – 1434)
Greater London Authority (2008) The London climate change adaptation strategy: Draft report. London: Greater London Authority.
Hisdal, H., Stahl, K., Tallaksen, L. and Demuth, S. (2001). Have streamflow droughts in Europe become more severe or frequent? International Journal of Climatology. 21 (317 – 333)
Hughes, B. L. and Saunders, M. A. (2002). A drought climatology for Europe. International Journal of Climatology. 22 (1571 – 1592)
Hulme, M., Jenkins, G. J., Lu, X., Turnpenny, J. R., Mitchell, T. D., Jones, R. G., Lowe, J., Murphy, J. M., Hassell, D., Boorman, P., McDonald, R. and Hill, S. (2002) Climate Change Scenarios for the United Kingdom: The UKCIP02 Scientific Report. Norwich:  Tyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia.
May, W. (2008). Potential future changes in the characteristics of daily precipitation in Europe simulated by the HIRHAM regional climate model. Climate Dynamics. 30 (581 – 603)
Met Office (2008). Microclimates. [Online] Available at: http://www.metoffice.gov.uk/education/secondary/students/microclimates.html. (Accessed on the 12 Feb 2011)

Climate

I fail to see it as a coincidence that many on the right of the political spectrum in the UK and USA, and elsewhere I’m sure, fail to acknowledge the mountain of evidence in support of the argument that climate change is happening, and it’s happening right now, and that humans are to blame. They call themselves ‘climate sceptics’ but this couldn’t be further from the truth. Scientists are the real sceptics here, as the scientific method essentially requires scepticism and objectivity of all theories and hypotheses. It requires rigorous testing of these assumptions, examination of the methodology, data analysis and conclusions and it requires these tests to be repeated again and again, until the either the hypothesis can be effectively rejected or the theory is accepted by the wider scientific community, not as fact, but as theory. A framework in which further work can be carried out, details examined and improved and further testing implemented. Climate change is now at this stage. It is a theory, yes, only a theory, but one that has been tested over and over, analysed and scrutinised from all angles by erudite scientists, with no vested interests except for the hope that we can avert the dangers that we are about to unleash on our only home. These are men and women who have dedicated their lives, careers and reputations to objective, scientific truth, or at least to get as close to the truth as it’s possible to be, not conspiracy theorists who have researched the topic on some obscure website for 20 minutes. They are people who are not prone to being alarmist, and in fact make every attempt to the contrary.  The details may require work, but to continue to deny the basic fact that carbon dioxide is a greenhouse gas, and that the combustion of hydrocarbons by our industrialised society is releasing CO2 into the atmosphere at unprecedented levels is not sceptical, it’s frankly stupid.

There is no scepticism shown by the climate deniers, as I shall now refer to them. The evidence is there for them to analyse to their heart’s content. If they conduct the science properly they will come to the same conclusion as many before them have done. Instead, they tend to resort to argumentum ad hominem, as keenly demonstrated by the fiasco that resulted in the malicious publication of irrelevant, stolen personal emails from the Climatic Research Unit (CRU) at my old haunt, the University of East Anglia. If you can’t win the argument because the facts are just not on your side, why not resort to some good old-fashioned character assassination? In my mind, the whole debacle was not handled particularly well however. The CRU went on the defensive, refusing to release their climate data to just any old crazy person. At worst, this made them look like they had something to hide, or that they were aloof and indignant of those outside of the scientific community.

There are many and varied reasons that I can think of for why an individual or organisation would choose to ignore the veritable enormity of the evidence for anthropogenic climate change, the main one being, and in this respect I agree, that it’s bloody frightening. Humans base response to news of this gravitas, i.e. that the world may end and that it’s almost certainly our fault, is to go into a state of indignant denial, followed by anger directed at the messenger of said news, in this case the scientists. The unthinkable consequences of our uncontrolled climate tinkering will most likely result in the deaths of many, many people, mainly in the poorest countries on Earth, either from flooding, or droughts or displacement due to wars being fought over meagre resources such as water, fuel and food. Another reason that a sensible, if unwilling, person may want to continue to deny hard evidence to the contrary, is that is requires a rather drastic response from us, the members of the developed world, that would almost certainly alter the basic dynamics of our lovely, quaint way of life. We would have to make tough financial and societal compromises via an increased cost of living or taxation. We would have to abandon, or at least drastically alter our predisposition to all things hydrocarbon, be it our motor-friendly cities, or our polluting coal power plants. These are all things that would drastically and permanently alter the ‘status-quo’, that old conservative rhetorical mainstay, and this is enough to significantly upset a good proportion of the population.

The main point I’m trying to make is that this whole argument is essentially a one-sided political disagreement, if you can entertain such an idea. Those on the right have never been considered to respond rationally to most decisions, a fact that is often by their own admission considered as a strength. Science and academia in general are often considered to be broadly ‘liberal’ in their outlook, mainly due to the fact that science is often carried out in progressive, rational and forward-thinking way using novel technologies in an attempt to push the boundaries of human understanding. Needless to say, this is incompatible with conservatism and tradition. The climate change ‘debate’ is not an attempt by liberal scientists to turn our lovely planet into a green dystopia of carbon taxing and expensive airfares, despite being perceived as such. All that climate scientists are doing is reporting the facts, as they have always done and will always do in the future. Perhaps the facts should be provided to all that request them, regardless of their agenda, and I agree that this is the main failure of this entire scientific paradigm to date. It is obvious that there is nothing to hide, save the uncomfortable truth that we are inexorably altering the basic atmospheric chemistry of our planet, and this is a fact that should be available for all to witness first hand, given they have the training to carry out the analysis of data on this scale.

Let’s take a step back. Is it really such a bad idea to wean ourselves off our oil and coal habit? To breathe cleaner air and drink less-polluted water? No one can really say that coal and oil combustion is a pleasant activity that they would be happy to carry out in their own back yard. I admit that the transition will be difficult and expensive, but surely it will be worth it in the end? Besides, we’ll run out of those resources soon, perhaps even in this century. Even if there was only a tiny scrap of evidence, forgetting the huge repository of journal articles and papers available, I would still want to take the opportunity to avoid the catastrophic possibility that that evidence may be correct, especially if, in the process we provided a safer, cleaner world for generations to come.

Methane Extraction in Lake Kivu

Lake Kivu, on the border of the Democratic Republic of the Congo (DRC) and Rwanda, is unique in the fact that it is one of only three known ‘exploding lakes’ in the world, along with Lake Nyos and Lake Monoun, both in Cameroon. These lakes are so named due to the violent limnic eruptions they occasionally experience, which are caused by the sudden expulsion of significant quantities of carbon dioxide (CO2) and methane (CH4) from the lake depths into the surrounding atmosphere. By displacing the surrounding lighter, oxygenated air the heavier released gasses form a mazuku (Swahili for ‘evil wind’); an anoxic air pocket that proves lethal to wildlife and humans. The deadliness of the mazuku was brought abruptly to the attention of the world’s media on the 21st of August 1986 after a limnic eruption of 0.3 – 1 km3 of CO2 from Lake Nyos resulted in the asphyxiation of 1700 people and thousands of cattle. A similar, smaller eruption occurred late in the evening of the 15th of August 1984 and resulted in the deaths of 37 people in the low-lying regions around Lake Monoun.

Figure 1: Map of the Republic of Rwanda showing Lake Kivu on the western border with the Democratic Republic of the Congo (CIA World Fact book, 2011)

The exact cause of the cataclysmic release of CO2 from either of these lakes remains unknown, despite significant scientific interest in the aftermath of the disaster. The most widely accepted theory is that of the limnic eruption hypothesis; an as yet unknown trigger results in the local supersaturation and subsequent release of CO2 that has been accumulating the in water column. Under normal conditions, a vertical difference in the density of the water column confines much of the trapped gas to the deeper reaches of the permanently stratified lake. Beyond this, CO2 and CH4 concentrations increase with depth. A baroclinic disturbance in the local pycnocline, caused for example by a landslide, earthquake or volcanic eruption, could result in the creation of an area of intense local supersaturation and the eruption of these gases into the atmosphere. Although the limnic eruption theory is supported by observations of slow CO2 recharge after the Lake Nyos disaster, the possibility that the outgassing was caused directly by volcanic activity in the very tectonically active Great Rift Valley cannot be ruled out.

A report in Nature outlined the theory that magmatic CO2 diffusing into the benthic deposits at the bottom of Lake Kivu is fuelling the further production of CH4 by methanogenic bacteria in the sediment. It is now thought that Lake Kivu holds 300 km3 of CO2 and 60 km3 of CH4 at depths below 50 – 80 m, a respective increase of 10 and 15% since the 1970s. This gas reservoir is up to 350 times greater than that of Lake Nyos, the eruption of which would be devastating to the 2 million people that live along the shore of Lake Kivu. However, unlike Lake Nyos, concentrations of dissolved gases in Lake Kivu are thought to be below supersaturation at present and there are no plans to artificially degas the lake to reduce the probability of an eruption event.

Due to economic importance of the CH4 dissolved in Lake Kivu, and the uncertainties involved in its abstraction, recharge and volatility, the governments of the DRC and Rwanda recently jointly commissioned a technical appraisal of the viability of methane abstraction for power generation. Based on a 50 year economic yield, and using current estimates of gas recharge, the working group estimates that depending on the rate and efficiency of the extraction the methane reservoir in the lake could provide between 160 and 960 MWe (megawatts of electrical power), worth between US$7 and $42 billion at $100/MWh. This is a substantial estimate that neither government is likely to ignore, especially given the deteriorating economic and political climate in the DRC, and the relative scarcity of natural resources in Rwanda. It is therefore important that the science behind the extraction process is sound and the technology well monitored and maintained.

References:
Evans, W.C., Kling, G.W., Tuttle, M.L., Tanyileke, G., and White, L.D. (1993). Gas build-up in Lake Nyos, Cameroon: The recharge process and its consequences. Applied Geochemistry. 8 pp 207 – 221

Nayar, A. (2009). A Lakeful of Trouble. Nature. 460 pp. 321 – 323

CVO (Cascades Volcano Observatory) (2001). Volcanic Lakes and Gas Releases [Online] Available at: http://vulcan.wr.usgs.gov/Glossary/Lakes/description_volcanic_lakes_gas_release.html (Last accessed: 6th February 2011).

Scmid, M., Lorke, A., Wüest, A., Halbwachs, M. and Tanyileke, G. (2003). Development and sensitivity analysis of a model for assessing stratification and safety of Lake Nyos during artificial degassing. Ocean Dynamics. 53 pp. 288 – 301

Tietze, K., Hirslund, F., Morkel, P., Boyle, J., Wüest, A., Schmid, M. (2007). Management Prescriptions for the Development of Lake Kivu Gas Resources. Report to the Ministry of Infrastructure (Republic of Rwanda) and Ministry of Hydrocarbons (Democratic Republic of Congo).

Extremophiles

The physical and chemical environments that are created and maintained by the proximity of a given planet to a star of a given class, as well as the magnetic, radiative and atmospheric dynamics that result from this association, represent the most fundamental controls on the ability of life to evolve and flourish. Once life has emerged the biosphere also plays a role in maintaining the planetary system through a number of complex feedback loops and geochemical cycling. However, our understanding of the prerequisites, subsequent requirements and limits of both ‘simple’ and advanced life has been shaped by the study of organisms on Earth. Therefore, our knowledge of the limitations on the ability of organisms to evolve is a product of the terrestrial environment in which, at present, all life has been found. In recent times our understanding of the physical and chemical boundaries for life, here on Earth and in the Solar System and beyond, have been radically revolutionised by the discovery of several species of ‘extremophile’; defined as organisms that can tolerate “…conditions that disrupt the integrity or function of aqueous solutions of organic compounds…” (pg. 114, Rothschild, 2007). This definition illustrates the importance of water as a solvent, and organic carbon as the basis of life on Earth. Extremophilic species can be found in the Archaea, Eubacteria and Eukarya taxa (Rothschild, 2007).

Extremophiles

The study of extremophiles promises to provide a wealth of useful information and discoveries, both in the field of astrobiology and in other disciplines, and it is hoped that some of the fundamental questions in this area of science can be answered by continued research into species of organisms can exist on the edge of what is thought possible for life (Rothschild, 2007). For example, understanding of the chemical and physical mechanisms of extremophile survival could result in a number of useful applications on Earth and in space and the continual discovery of extremophilic species continues to extend the limits for life in the universe, as well as our understanding of the biodiversity of Earth (Rothschild, 2007). Meanwhile, other uses of extremophiles include food preservation, biological warfare, biotechnology, environmental biosensors, waste treatment, methane production, oil discovery, medical plastics and cancer detection, dietary supplements and other innumerable applications in industry, food production and preservation and healthcare and medicine (Rothschild, 2007; Satyanarayana, 2005)

Table 1 outlines some of the extreme environments in which species of hardy organisms have been found which include: in and around geysers, hotsprings and ‘black smokers’ on the ocean floor, within acidic mine drainage, salt lakes and nuclear reactors and waste (Rothschild, 2007; Southam et al., 2007).

Table 1: Classification of extremophiles and examples of ecosystems and organisms (Rothschild, 2007; Southam et al., 2007)



Parameter
Classification
Definition
Ecosystem
Organism
Temperature
           Hyperthermophile
           Thermophile
           Mesophile
          Psychrophile
>  80 °C
60 – 80 °C
15 – 60 °C
< 15 °C
Geyser
Hotsprings

Ice or snow
Pyrolobus fumarii


Psychrobacter
pH
          Alkaliphile
          Acidophile
pH > 9
Low pH
Soda lakes
Mine drainage
Natronobacterium
Cyanidium caldarium
Salinity
          Halophile
Salt-loving
Salt lakes
Halobacteriacea
Desiccation
          Xerophile
anhydrobiotic
Desert
Artemia salina
Pressure
          Barophile
          Piezophile
weight-loving
pressure-loving
Deep ocean
Unknown
Radiation


Nuclear reactors and waste
Deinococcus radiodurans
Oxygen
           Aerobe
           Microaerophile
           Anaerobe
oxygen-loving
tolerates some O2
Cannot tolerate O2
Most of Earth

Deep ocean
Homo sapiens
Clostridium
Methanocaldococcus jannaschii
Gravity
           Hypergravity
           Hypogravity
> 1 g
< 1 g

Unknown
Vacuum

Tolerates vacuum

insects, seeds, tardigrades
Chemical

Tolerates high levels of metals and concentrations of chemicals
Mine drainage
Cyanidium caldarium
Ferroplasma acidarmanus
Ralstonia spp.


Thermophiles and hyperthermophiles tolerate temperatures above which normal biomolecules such as chlorophyll (near 75°C) degrade; even nucleic acids break down well below 100 °C with some variation depending on base composition, polymer length and solvent concentration (Rothschild, 2007). Proteins that form structural compounds degrade with increasing temperature and enzymes begin to lose their catalytic ability both above and below an optimal temperature whilst soluble gases such as oxygen and carbon dioxide are less well absorbed into solvents (like water) at higher temperatures (Rothschild, 2007). On the other end of the temperature spectrum are psychrophiles that are able to withstand temperatures that are lower than would normally be conducive to biological functioning. Ice crystals can penetrate and destroy cell membranes and frozen water acts to spatially concentrate solutes to potentially toxic levels (Rothschild, 2007). The discovery of organisms able to withstand prolonged vacuum, extreme acceleration and deceleration (‘jerk’) and radiation exposure is contributing considerably to the concept of lithopanspermia and the possibility that life may have arrived on Earth from further afield via an asteroid or meteorite impact.

Life on Exoplanets

Extremophiles have extended the once rigid physical and chemical boundaries of life and I feel that this has important implications for both the habitable zone theory and for the existence of possible life on exoplanets in low mass star systems. If life were to exist on an exoplanet or its moon in an M-class star system the organisms are likely to be significantly dissimilar to life on Earth, potentially employing as-of-yet undiscovered metabolic pathways and utilising non-aqueous solvents and other hypothetical forms of biochemistry.  
However, scientists suggest that the universality of our biochemistry may confirm that the biological and physical limits of life of Earth may also apply elsewhere. For example, Pace (2001) states that:
“…it seems likely that the basic building blocks of life anywhere will be similar to our own, in the generality if not in the detail. Thus, the 20 common amino acids are the simplest carbon structures imaginable that can deliver the functional groups used in life… Similarly, the five-carbon sugars used in nucleic acids are likely to be repeated themes…”
(Page 806)
Therefore, whilst extremophilic organisms may extend the parameters of our understanding, the general limits and basic requirements of life may be a universal trend and the habitable zone theory may be the instrument through which our search for life should be focussed. 

References:
Pace, N.R. (2001). The universal nature of biochemistry. Proceedings of the National Academy of Science. 98 (3) pp. 805 – 808
Rothschild, L.J. (2007). Extremophiles: defining the envelope for the search for life in the universe. In: Pudritz, R., Higgs, P. and Stone, J. (2007). Planetary Systems and the Origins of Life. Cambridge: Cambridge University Press
Satyanarayana, T., Raghukumar, C. and Shivaji, S. (2005) Extremophilic microbes: Diversity and perspectives. Current Science 89(1) pp. 78 – 90
Southam, G., Rothschild, L.J. and Westall, F. (2007) The Geology and Habitability of Terrestrial Planets: Fundamental Requirements for Life. In: Fishbaugh, K.E., Logonné, P., Raulin, F., Des Marais, D.J. and Korablev, O. (2007) Geology and Habitability of Terrestrial Planets. London: Springer
  

The Water Reservoir of Mars

Much of the research currently focussed on the hydrological resources of Mars is being conducted using the modelling approaches established by the pioneering research studies based on the first successful imaging missions to the planet in the latter half of the last century. Martian groundwater research was advanced greatly in the 1980s and early 1990s when the currently accepted ideas regarding the subterranean dynamics and subsurface structure of the planet were initially hypothesised. Contemporary investigations are examining and testing these assumptions using the wealth of imagery and data now collected by the extensive array of Martian orbiters, landers and rovers previously and currently in operation on or around the planet, particularly NASA’s Mars Odyssey satellite, launched in 2001 and the ESA Mars Express, in orbit since 2003.

As Mars has a very thin atmosphere and no planetary magnetic field cosmic rays from the Solar wind reach the surface unimpeded where they interact with the nuclei in subsurface layer up to 2 m in depth, producing gamma rays and neutrons of differing kinetic energies that leak from the surface. These can then be passively detected by instruments on board the Mars Odyssey orbiter and used to calculate the spatial and vertical distribution of soil water and ice in the upper permafrost layer. The fluxes of high energy neutrons (‘fast’ neutrons) and thermal and epithermal neutrons vary relative to subsurface water content. The results showed water ice content ranging from 53% to 11.2% of soil by weight, depending on latitude, with the highest concentrations in and around the North Polar Region. Knowledge of water content in the upper layers of the subsurface is useful for determining potential outgassing and atmospheric transport.

While the Mars Odyssey orbiter searched for water in the upper few meters of the subsurface, the Mars Express satellite searched for groundwater at depths of up to 5 km using the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument. The sensor analyses the reflection of active, low frequency radio waves to identify aquifers containing liquid water as these will have a significantly different radar signature to the surrounding rock (figure 1).

Figure 1: The principal of operation of the MARSIS instrument onboard the Mars Express orbiter (ESA, 2011)

The initial findings were promising as the MARSIS sensor effectively identified the basal interface, ice density, quantity and thickness of the South Polar Region layered deposits to a depth of 3.7 km, allowing improved volume estimations of the polar reservoir to be calculated.

The most recent studies however presented a lack of direct evidence for the existence of sub-surface and groundwater resources on Mars using the MARSIS instrument. It is thought that the absence of any direct detection of subterranean water could be a result of the high conductivity of the overlain crustal material (a mix of water ice and rock), resulting in the radar echo being under the MARSIS instruments detectable limits. It was emphasised that groundwater reservoirs could still exist and that the lack of evidence supporting this hypothesis was due to the technical shortcomings of the sensor. This article in particular received widespread attention in the technical and popular science media as the null result could mean that important assumptions regarding the storage and role of water on Mars may have to be re-evaluated.

Other current studies concentrating on groundwater modelling approaches to explain various topographical features on Mars have come to the conclusion that a global, confined aquifer system is unlikely to exist and regionally or locally compartmentalised groundwater flow is more probable. This finding is likely to have important implications for the future development of groundwater flow models and the interpretation of remotely sensed data.

References:
ESA (2011). Mars Express. [Online]. Available at: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=9 (Accessed on 6th February 2011)

Mitrofanov, I.G. (2005) Global Distribution of Subsurface Water Measured by Mars Odyssey in Tokano, T. (ed.) (2005) Water on Mars and Life. Berlin: Springer Advances in Biogeophysics and Astrobiology (pp. 99 – 128)

Plaut, J.J., Picardi, G., Safaeinili, A., Ivanov, A. B., Milkovich, S.M., Cicchetti, A., Kofman, W., Mouginot, J., Farrell, W.M., Phillips, R.J., Clifford, S.M., Figeri, A., Oroseq, R., Federico, C., Williams, I.P., Gurnett, D.A., Nielsen, E., Hagfors, T., Heggy, E., Stofan, E.R., Plettemeier, D., Watters, T.R., Leuschen. C.J. and Edenhofer, P. (2007). Subsurface Radar Sounding of the South Polar Layered Deposits of Mars. Nature. 316 (5821) pp. 92 – 95.

Farrell, W.M., Plaut, J.J., Cummer, S.A., Gurnett, D.A., Picardi, G., Watters, T.R., and Safaeinili, A. (2009). Is the Martian water table hidden from radar view? Geophysical Research Letters. 36 L15206

Harrison, K.P. and Grimm, R.E. (2009). Regionally compartmented groundwater flow on Mars. Journal of Geophysical Research. 114E04004