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Geosciences Column: The World’s soils are under threat

Geosciences Column: The World’s soils are under threat

An increasing global population means that we are more dependant than ever on soils.

Soils are crucial to securing our future supplies of water, food, as well as aiding adaptation to climate change and sustaining the planet’s biosphere; yet with the decrease in human labour dedicated to working the land, never have we been more out of touch with the vital importance of this natural resource.

Now, the first-ever comprehensive State of the World’s Soil Resources Report (SWRS), compiled by the Intergovernmental Technical Panel on Soils (ITPS), aims to shine a light on this essential non-renewable resource. The report outlines the current state of soils, globally, and what the major threats facing it are. These and other key findings of the report are summarised in a recent paper of the EGU’s open access Soil Journal.

The current outlook

Overall, the report deemed that the world’s soils are in fair to very poor condition, with regional variations.  The future doesn’t look bright: current projections indicate that the present situation will worsen unless governments, organisations and individuals come together to take concerted action.

Many of the drivers which contribute to soil changes are associated with population growth and the need to provide resources for the industrialisation and food security of growing societies. Climate change presents a significant challenge too, with factors such as increasing temperatures resulting in higher evaporation rates from soils and therefore affecting groundwater recharge rates, coming into play.

The three main threats to soils

Soil condition is threatened by a number of factors including compaction (which reduces large pore spaces between soil grains and restricts the flow of air and water into and through the soil), acidification, contamination, sealing (which results from the covering of soil through building of houses, roads and other urban development), waterlogging, salinization and losses of soil organic carbon (SOC).

Global assessment of the four main threats to soil by FAO regions. Taken from Montanarella, L., et al. 2016.

Global assessment of the four main threats to soil by FAO regions. Taken from Montanarella, L., et al. 2016.

Chief among the threats to soils is erosion, where topsoil is removed from the land surface by wind, water and tillage. Increasing rates of soil erosion affect water quality, particularly in developed regions, while crop yields suffer the most in developing regions. Estimating the rates of soil erosion is difficult (especially when it comes to wind driven erosion), but scientists do know that topsoil is being lost much faster than it is being generate. This means soil should be considered a non-renewable resource. When it comes to agricultural practices in particular, soils should be managed in such a way that soil erosion rates are reduced to near zero-values, ensuring long-term sustainability.

Eutrophication in lake Slotsø, Kolding, Denmark. Credit: Alevtina Evgrafova (distributed via imaggeo.egu.eu)

Eutrophication in lake Slotsø, Kolding, Denmark. Credit: Alevtina Evgrafova (distributed via imaggeo.egu.eu)

Soils contain nutrients, such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S), crucial for growing crops and pastures for raising cattle. While nutrient balance in soils has a natural variability, farming practices accelerate changes in soil nutrient content. Over-use of soils rapidly depletes the land-cover of nutrients and result in lower food production yields. This imbalance is often remedied by the addition of nutrients; in particular N and P. Excessive use of these practices, however, can lead to negative environmental effects, such as eutrophication (which increases the frequency and severity of algal blooms) and contamination of water resources. The findings of the report advocate for the overall reduction of use of fertilisers, with the exception of tropical and semi-tropical soils in regions where food security is a problem.

Carbon (C) is a fundamental building block of life on Earth and the carbon cycle balances the amount of C which ultimately enters the atmosphere, helping to stabilise the planets temperature. Soils play a significant role in helping to preserve this balance. Soil organic carbon (SOC) acts as a sink for atmospheric C, but converting forest land to crop land saw a decrease of 25-30% in SOC stocks for temperate regions, with higher losses recorded for the tropics. Future climate change will further affect SOC stocks through increased temperatures and fluctuating rainfall, ultimately contributing to risks of soil erosion and desertification and reducing their ability to regulate carbon dioxide emissions. It is vitally important that governments work towards stabilising, or better still, improving existing SOC stocks as a means of combating global warming.

Preserving a valuable resource

The case is clear: soils are a vital part of life on Earth. It is estimated that worsening soil condition will affect those already most vulnerable, in areas affected by water scarcity, civil strife and food insecurity.

Bed planting in northern Ethiopia. Credit: Elise Monsieurs (distributed via imaggeo.egu.eu)

Bed planting in northern Ethiopia. Credit: Elise Monsieurs (distributed via imaggeo.egu.eu)

Initiatives such as the 2015 International Year of Soil and the production of the SWRS report are fundamental to raise awareness of the challenges facing soil resources, but more needs to be done:

      1. Sustainable soil management practices, which minimise soil degradation and replenish soil productivity in regions where it has been lost, must be adopted to ensure a healthy, global, supply of food.
      2. Individual nations should make a dedicated effort to establish appropriate SOC-improving strategies, thus aiding adaptation to climate change.
      3. Manging the use of fertilisers, in particular N and P, should be improved.
      4. There is a dearth of current data, with many of the studies referenced in the SWRS report dating from the 1980s and 1990s. For accurate future projections and the development and evaluation of tools to tackle the major threats facing soils, more up-to-date knowledge about the state of soil condition is required.

Soils, globally, are under threat and their future is uncertain. The authors of report argue that “the global community is presently ill-prepared and ill-equipped to mount an appropriate response” to the problem. However, adoption and implementation of the report findings might (by policy-makers and individuals alike) just turn the tide and ensure soils remain “humanity’s silent ally”.

By Laura Roberts Artal, EGU Communications Officer

References

Montanarella, L., Pennock, D. J., McKenzie, N., Badraoui, M., Chude, V., Baptista, I., Mamo, T., Yemefack, M., Singh Aulakh, M., Yagi, K., Young Hong, S., Vijarnsorn, P., Zhang, G.-L., Arrouays, D., Black, H., Krasilnikov, P., Sobocká, J., Alegre, J., Henriquez, C. R., de Lourdes Mendonça-Santos, M., Taboada, M., Espinosa-Victoria, D., AlShankiti, A., AlaviPanah, S. K., Elsheikh, E. A. E. M., Hempel, J., Camps Arbestain, M., Nachtergaele, F., and Vargas, R.: World’s soils are under threat, SOIL, 2, 79-82, doi:10.5194/soil-2-79-2016, 2016.

Status of the World’s Soil Resources, 2015, Food and Agricultire Organization (FAO) of the United Nations.

Soils are endangered, but degradation can be rolled back, 2015, FAO News Article.

Geoscience hot topics – Part II: the Earth as it is now and what its future looks like

Geoscience hot topics – Part II: the Earth as it is now and what its future looks like

What are the most interesting, cutting-edge and compelling research topics within the scientific areas represented in the EGU divisions? Ground-breaking and innovative research features yearly at our annual General Assembly, but what are the overarching ideas and big research questions that still remain unanswered? We spoke to some of our division presidents and canvased their thoughts on what the current Earth, ocean and planetary hot topics will be.

Because there are too many to fit in a single post we’ve brought some of them together in a series of posts which will tackle three main areas. The first post focused on the Earth’s past and its origin, while today’s post will focus on the present Earth and its future. The final post of the series will explore where our understanding of the Earth and its structure is still lacking. We’d love to know what the opinions of the readers of GeoLog are on this topic too, so we welcome and encourage lively discussion in the comments!

Sustainable development

As populations across the globe continue to grow, geoscientists have a key role to play in sustainable development. The demands placed on planet Earth to supply our societies with anything from drinking water to food and energy are ever rising. Managing these resources in a way that ensures we can meet the needs of current and future generations is one of the biggest challenges faced by scientists and policy makers worldwide.

Humanity’s pursuit of a sustainable future, where our activities do not contribute to increased greenhouse gas emissions to the atmosphere (something which has be high on policymakers agenda’s recently) will open new, important, avenues of research. Goals need to be achieved so that food, energy and water resources are available for future generations and methods must be found to exploit resources in a way that minimises the impact on the environment.

Producing fuel for a growing population
The boundaries of technology and our knowledge of where and how resources can be exploited will be pushed as the demands for energy increase. Traditional oil and gas resources will continue to be exploited, but new emerging technologies and fuel sources will mean a shift to lesser known research areas.

Angelo De Santis, President of the Earth Magnetism and Rock Physics (EMRP) Division adds that: “Such fields as rock physics, geomagnetism and rock magnetism will have a role to play in future resource exploration.”

Perusing the programme of the 2016 General Assembly gives a flavour of some of the emerging avenues of research in this field. Take for instance deep geothermal reservoirs: this little know source of renewable energy provides an alternative to conventional fuel sources, with the potential to reduce fossil-fuel consumption as well as curbing greenhouse-gas emissions. Yet, the understanding of how to engineer the reservoirs so that they remain productive and safe over long time-scales is still being developed, and having better handle on the rock physics and mechanics of the reservoirs would help in this regard.

"Geothermal energy methods". Licensed under Public Domain via Commons.

Geothermal energy methods“. Licensed under Public Domain via Commons.

Ensuring the integrity of any reservoir be it conventional or unconventional, requires collaboration. Seismology has a large part to play here too. Away from the well-known and exciting work being carried out on understanding earthquakes, the field of ‘ambient noise’ seismic data has the potential to revolutionise our understanding of Earth dynamics and can be applied to monitoring changes in zones of natural and induced (minor tremors caused by human activity) seismicity in oil & gas reservoirs and also geothermal fields, highlights P. Martin Mai, President of the Seismology (SM) Division.

In seismology, ambient noise, or “background noise” recorded on seismic instruments refers to the seismic energy that is continuously generated by various natural (e.g. ocean waves, wind, etc) and man-made (traffic, industrial activities) processes. Classically, seismology wants to avoid any noise contamination of seismic recordings, as the noise masks or even destroys the desired “deterministic” signals from earthquakes or exploration-driven seismic excitations. However, experimental and theoretical work over the last ~10 yrs has shown that the mathematically predicted relation between “noise” and the Earth elastic properties can be applied to use “noise” for making inference about Earth structure. “Ambient noise” studies in seismology have been used, for instance, to infer properties of the Earth crust and how it may change on small scales (like in earthquake fault zones) over time, but ‘ambient noise tomography’ also helps to unravel Earth properties in the upper mantle (down to ~150 km depth). Research in ambient-noise seismology requires dense seismic recording networks that continuously record the subtle movements of the ground. Advanced processing and interpretation techniques then allow to also, for instance, monitor the processes within, and thus the state, or geothermal or oil & gas reservoirs.

Raw materials

 A new rural landscape in Irpinia. Credit: Sabina Porfido (distributed via imaggeo.egu.eu)

A new rural landscape in Irpinia. Credit: Sabina Porfido (distributed via imaggeo.egu.eu)

According to Chris Juhlin, President of Energy, Resources and Environment (ERE) Division, it will be crucial for scientists in this field not only to focus on establishing how energy can be produced in a way that will continue to allow societies to live comfortably, but also establish where the resources to produce and supply energy will come from.

The advantages of exploiting resources, such as solar, wind, geothermal energy and nuclear energy over fossil fuels are clear: their emissions of greenhouse gases to the atmosphere are limited. That being said, an often overlooked fact is that they still require natural resources in order to operate.

Juhlin uses wind turbines as an example to illustrate the point: “Wind turbines require significant amounts of rare earth metals, as well as steel, to be built. These metals need to be mined and the mining operation produces CO2.”

Both mining of metals and storage of nuclear waste require that sophisticated geological, geochemical and geophysical surveying methods are available. Not only that, when finding and choosing new locations to mine for resources and store waste, looking at the bigger picture is also important. How these human activities will affect the ecosystems in which they take place will take on greater significance as the loss of habitats and biomes increases.

Juhlin emphasises that: “It is important to understand how a decision at local level may affect the energy balance on a global level.”

Defining a new geological epoch – The Anthropocene

That humans will leave their mark on Earth is undeniable. Human kind has already caused extinctions, polluted oceans and the atmosphere, as well as influenced land use and biodiversity. But pin-pointing the exact time at which our actions became a major geological agent is a source of heated debate.

Traditionally, new epochs are defined by an abrupt change in the chemistry of rock strata which signifies the occurrence of a major geological or palaeontological event. However, in the case of defining the age of humans, the Anthropocene, the lack of a rock record makes applying this traditional approach difficult.

Nevertheless, since it was introduced in 1980s and popularised in the past decade or so, the notion of the Anthropocene epoch has been gaining momentum and opened up further research questions.

Helmut Weissert, President of the Stratigraphy, Sedimentology, and Palaeontology (SSP) Division, says that comparing the role humans have played versus past natural variations is becoming increasingly important. Take an example: what role have humans played in accelerated soil erosion vs. natural variations? Equally, what role has humankind played in affecting the global biogeochemical cycles? By comparing current changes with natural changes recorded in marine and lake sediments we may better understand the role humans have played in shaping the modern Earth.

An exotic solution?

The scientific consensus is that in order to minimise our impact on the planet, while at the same time moving towards zero net emissions of greenhouse gases by the second half of this century, a combination of approaches are needed. While renewable resources and nuclear energy will provide energy which has minor contributions to greenhouse-gas emissions, it is just as important to reduce and find ways to deal with emissions from burning fossil fuels (think carbon capture and storage).

Hot_Topics2_cloudseeding.png

Sketch illustrating the process of cloud seeding. Cloud seeding by DooFi. Distributed via Wikimedia

Geoengineering might provide a more exotic solution to the problem. The premise behind it is to use technology to counter the effects of a warming climate. Proposed solutions include reflecting sunlight into space to cool the planet, cloud seeding, scrubbing CO2 out of the atmosphere, … But at this stage, the majority are deemed unrealistic; not to mention that there is an ongoing ethical debate as to whether they should be used at all and that the consequences of their implementation are also largely unclear

So it seems, the presence of human kind on Earth has paved the way for an astonishing period of research, not only in the geosciences but also in other fields, fuelling an exciting opportunity for cross-disciplinary investigation. And the time is most certainly now, if we are to minimise the mark we leave on the planet while at the same time ensuring a sustainable future for generations to come.

By Laura Roberts Artal, EGU Communications Officer in collaboration with EGU Division Presidents

Next time, in the Geosciences hot topics short series, we’ll be looking at our understanding of the Earth as we know it now and how we might be able to adapt to the future.

Enhancing Earth science education in Africa

In 2008 UNESCO launched the Earth Science Education Initiative in Africa in response to a call from African governments to aid them in closing the ever widening gap between their need to further exploit the continent’s natural resources and their skills and research facilities. Reacting to this call, UNESCO first set up a series of scoping workshops across the continent to understand African capacities and needs. The workshops focussed on educational structure in the geosciences, research facilities and relationships with industry in order to identify an appropriate role for UNESCO. The result was a clear need for stronger action at the root of the problem: education.

A proper understanding of the Earth sciences is essential for sustainable development across the world, with research applications ranging from atmospheric to agricultural sciences and knowledge of the deep Earth. And yet, the scoping study found that Earth sciences are underappreciated as an essential part of development by governments, policymakers and development organisations across the world. In response, UNESCO identified the need to expand their reach through both formally and informally educating about the geosciences across Africa, and the need to go beyond the traditional topics covered in geoscience disciplines and focus on the multidisciplinary ‘real life’ applications.

Ensuring sustainable development involves understanding tectonic geological processes, the climate, surface of the Earth and the multiple interactions between them. (Credit: Joyce Schmatz)

Ensuring sustainable development involves understanding tectonic geological processes, the climate, surface of the Earth and the multiple interactions between them. (Credit: Joyce Schmatz)

UNESCO’s scoping workshops found that the geosciences are only introduced into African education schemes at university level, which automatically lowers the numbers of students who enrol in these subjects due to lack of exposure. It also may be a result of this that African geoscientists are so isolated in their fields, with little contact or collaboration between research facilities, which themselves are commonly under equipped and few and far between. In a complementary study undertaken by UNESCO in 2011 it was found that many articles published in African journals were written by geoscientists in only 10 countries, with fewer authors per article than those published across the world. The study confirmed that there needed to be a strengthening of geoscience education at university level, and more done to ensure there is more collaboration between geoscientists across the continent.

The final, major issue identified by UNESCO in their scoping study, causing a lack of geoscientific expertise in sustainable development efforts was the shortage of strong connections between universities and industry. Without these crucial relationships, the students who do graduate from universities with outstanding degrees in geoscience do not necessarily make it into the roles that can make an impact on sustainable development. This issue is serious enough that industries have begun to build their own schools to train employees, or employ people from outside of Africa, meaning they lose the important local knowledge needed for development.

By Jane Robb, EGU Educational Fellow

In collaboration with UNESCO and ESA, the EGU are running the first Geosciences Information For Teachers (GIFT) workshop in Africa in February. You can find out more about the workshop on the EGU website. Secondary-school science teachers can apply to participate in the South African GIFT workshop by filling in an online form or sending their application materials to sa-loc@egu.eu by January 24. The application information is available for download in PDF format, a document which also includes further details about the UNESCO-EGU-ESA GIFT workshops.

The new EGU blog series on Education: GeoEd

Welcome to GeoEd, the new column on GeoLog dedicated to education in the geosciences! This is a series of posts written by the EGU Educational Fellow, Jane Robb that will cover the new and ongoing education initiatives across the EGU, as well as individual posts under the broad global pedagogical theme of education for sustainable development. GeoEd posts are aimed at formal and informal educators in the geosciences, primarily those teaching ages 11-18 but hopefully the content will be interesting for all educators, science communicators and scientists interested in public engagement. Jane’s posts can be used as thoughtful pieces for developing your own understanding of a topic or as teaching ideas as she incorporates questions, promts and links to useful external resources and some may be an adaptation of a complete lesson plan.

To start this series of educational posts, I will explore education for sustainable development through the lens of someone in the future – a sort of thought experiment if you will. I came across this approach on UNESCO’s teacher education programme: Teaching and Learning for a Sustainable Future.

Let’s start off with how much you know about climate change, not the only topic important in sustainable development, but one that stands out given the recent release of the first staggered part of the 5th IPCC Assessment (which I wrote about here). To start with, take this quiz developed by Know Climate Change – I’m expecting near full marks for most readers!

Climate Change: the words on everyone’s lips. (Credit: Jorge Mataix-Solera)

Climate Change: the words on everyone’s lips. (Credit: Jorge Mataix-Solera)

Now, with the current global anthropogenically induced crisis firmly in our minds, lets take a critical look at ourselves, our communities, society and governments and answer the question: how do you think people in the future (lets say 200-300 years) will feel about the way we are responding to and managing climate change now?

Anthropogenic forcing has caused unprecedented changes in the Earth’s climate. (Credit: Dimitri Defrance)

My response was: disappointed. On a lighter note, I also used the key word: conflicted. There are many people, communities and even key decision makers (and of course scientists) who care about the Earth’s future and those people are making important changes to their lives and the lives of others which are resulting in progress. However, is this progress enough and and how effective is it on a global scale?

UNESCO produced an adapted ‘letter from the future’, based on Allen Tough’s ‘What future generations might say to us’. I would be interested to know whether those reading the letter believe this message is accurate, based on our own best judgements.

The letter mentions that we are at a pivotal moment in humanity’s development and that each of us have the power to influence the course of humanity’s story. How accurate do readers think these statements are? In comparison to other times in recorded human history, are we at the most important point? This could be a good place to begin discussing other key subjects in the context of science, society and culture that may have influenced our lives now.

Do we also believe that every individual has the power to influence the course of humanity through their daily lives: what is the state of power distribution in society? How do governments work? How are policies developed and changed? We know that individuals can make small changes to their lives – switching off the lights, saving on water in the home – or band together to make changes on a local or regional scale to lifestyles of themselves and others. It is also possible to influence local council policy through campaigning to representatives or even to relevant members of their government but when it comes to the issue of climate change, a global problem, the power of individuals is greatly reduced. Governments need to act on an international scale, where the important issues involve, importantly, economic power and maintaining or developing this power.

Anthropogenic forcing has caused unprecedented changes in the Earth’s climate. (Credit: Dimitri Defrance)

Geoscientists, planners, construction managers and policymakers need to understand each other and work together for a more sustainable future. (Credit: Lurii Kaliukh)

It may seem far from the geosciences and yet aspects of socio-economic education including sustainable development, poverty alleviation and public engagement are increasingly important in science, a topic I have written about in a feature in Geology Today.

 In order to enhance the impact of geoscience on the wider public, educational institutions such as schools and universities in particular need to look inwards at what they can do to help inspire and educate students of the geosciences to have broader career horizons and bigger public impacts through their research.

By Jane Robb, EGU Educational Fellow