GeoLog

Congratulations to Philipp Stadler, Yiming Wang and Eva van Gorsel, winners of this year’s Imaggeo photo competition!

Winning image: Frost by Philipp Stadler

Second place: Icebear Rising by Yiming Wang

Third place: Regrowth after fires by Eva van Gorsel.

Imageo photos are distributed by EGU under a Creative Commons licence and are available in Imaggeo, the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their images to this repository and since it is open access, these photos can be used by scientists for their presentations or publications as well as by the press. 

The selection committee received close to 200 photos for this year’s EGU Photo Competition, covering fields across the geosciences. The stunning finalist photos are below and they are being exhibited in Hall X (basement, Blue Level) of the Austria Center Vienna, where you will also find voting terminals.

Do you have a favourite? Vote for it! The results will be announced on Friday 12 April during the lunch break.

Gypsum Dunes by Robert Wills

Mendenhall Glacier by Daniele Penna

Mirror, mirror by Anna Nadolna

Greenland Ice Sheet by Andrew Sole

Smooth Ice by Kay Helfricht

Colourful hydrovolcanism by Stephanie Flude

Regrowth after fires by Eva van Gorsel

Icebear Rising by Yiming Wang

Frost by Philipp Stadler

Climate change is in our hands by Stephanie Flude

Black Sand Vortex by Yiming Wang

 These images are distributed by EGU under a Creative Commons licence and are available in Imaggeo, the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their images to this repository and since it is open access, these photos can be used by scientists for their presentations or publications as well as by the press. 

In this month’s Geoscience’s column, Alex Stubbings discusses the water scarcity problems in the Middle East and North Africa region and  the recent developments in modelling water resources here. 

The Middle East and North Africa (MENA) region is considered the most water-scarce region in the world. As such, the region faces a multitude of challenges in the 21^st century including population growth, economic development, food production and climate change. With these challenges in mind, a team of researchers led by hydrologist Dr. Peter Droogers explored how “Water resources trends in the Middle East and North Africa towards 2050” will change over the first half of the 21^st century. The study is published in EGU’s Open Access journal Hydrology and Earth System Sciences.

Presently, there exist huge spatial variations in water allocation, and the region as a whole is the driest and most water scarce region in the world. This is increasingly affecting the social and economic development of the region.  For example, the average water resource availability per capita is only marginally above the physical water availability of 1076 m³yr^-1, compared to the world average of 8500 m³yr^-1.

The prevailing arid conditions found within the area mean that over 85% of the MENA region can be considered desert. It follows that the region can be further subdivided into three distinct climate spaces: the Maghreb region, which constitutes North African countries with a Mediterranean climate, and is climatically heterogeneous; the Gulf Cooperation Countries located within the Middle East, and have a typical desert climate; and lastly, the Mashreq region, which includes countries that have a milder and wetter climate, such as Iraq and Syria.

The Middle East and North Africa (MENA) region (blue), (Source: Wikimedia Commons).

Therefore the lead question Droogers et al. focused on filling vital knowledge gaps. Indeed, they highlight that “a complete analysis on water demand and water shortage over the coming 50 year period based on a combined use of hydrological and water resource models, remote sensing and socio-economic changes has never been undertaken for the MENA region”. Moreover, they intend to achieve this by assessing water demand in the 22 MENA countries by taking into account the dynamics and uncertainties of climate change, demographic changes and economic development.

The team used two distinct models that covered a 50 year time period (2000–2050). Firstly, the PCR-GLOBWB (PC Raster Global Water Balance) hydrological model was run to determine the internal and external renewable water resources for present and future climate. And the second model employed was a water allocation model, referred to as the MENA Water Outlook Framework (MENA-WOF). This was chosen to analyse the linkage between renewable water resources and sectoral water demands, and utilises the Water Evaluation and Planning (WEAP) framework.

This approach allowed the research team to simulate the average hydrological conditions with great accuracy – best demonstrated by its ability to accurately model and replicate actual flows on the Blue Nile, White Nile and Atbora tributaries. The team singled this out as a key indicator of its robustness. They noted that other similar studies, to date, have yet to model these flow regimes accurately.

Long-term average annual observed and simulated flow (Source: Droogers et al., 2012).

Nevertheless, as with other empirical modelling studies the authors issue a caveat: that the results regarding water resources, derived through GCM output, should be interpreted with great care. The model predicts total water shortage will increase by 157 km³yr^-1, while water supply and demand are only projected to increase by 132 km³yr^-1.  In short, the overall trend is that all MENA region countries will see an increase in water shortages, as the increase in supply will not meet the growth in demand, except for Djibouti.

Droogers et al. naturally consider the contribution of climate change to water scarcity. Their results indicate that only 10% of the change in water demand will be attributed to climate change and the rest entirely due to socio-economic changes (under their average climate change scenario). Furthermore in the other two scenarios, wet and dry, socio-economic factors, again, are more important than the effects of climate change. However, they emphasise that despite the small contribution made by climate change its effects should still be taken into consideration when planning adaptation interventions.

The contribution of socio-economic changes and climate changes on total water demand in 2050 (Source: Droogers et al., 2012).

The findings presented here by Droogers et al. are unique. They have combined different data, models and tools in order to forecast changes in water demand and supply over a geographically diverse area. Despite this novel approach, a clear drawback of the study, recognised by the team, is that the spatial resolution is lower than the output for smaller geographical areas and utilising a single methodological approach would have allowed more in depth comparisons to be made between countries.

When looking at the wider landscape of climate change impacts and adaptation strategies the team refer to a World Bank study from 2010, which estimated the cost of adaptation for developing counties at 0.12% of GDP, with costs associated with adaptation increasing linearly with time. The authors offer a number of pragmatic solutions, which fall under the umbrella of ecological modernisation, highlighting the potential of desalination plants.

As a work in progress, Droogers and his team offer direction for future work. Firstly, they suggest that further research should be carried out at a higher spatial resolution, for instance, employing the same methodology but focusing on individual countries rather than on an entire region. And secondly, of the need to analyse potential adaptation strategies and the associated costs of implementing them within the region. Both directions have their merits, but with the uncertain nature of climate change makes it difficult to distinguish which step we should take next.

By Alex Stubbings

In this month’s Geoscience’s column, Sara Mynott discusses the geological hazards associated with climate warming and how recent research sheds new light on our understanding of rockfall frequency.

Rockfalls are the free-falling movement of bedrock material from a rock face, a phenomenon also encompassed by the terms ‘landslide’, ‘rockslide’ and ‘rock avalanche’. They range from small debris falls of only a few cubic-metres to large ‘bergsturz’ events of over 1 million metres-cubed. The number of rockfalls reported has increased in recent years and is often attributed to global warming, despite the lack of research in this area. The debate among scientists regarding the effect of climate change on geomorphic hazards has led to a lot of confusion among the media and hence, the public.

Climate change is expected to have numerous consequences for natural hazards and the IPCC has predicted that geomorphic hazards will increase in alpine regions as a result. However, recent research published in Natural Hazards and Earth Systems Science suggests that this may not be the case. In a recent assessment of Austrian rockfalls over the period 1990-2010, Oliver Sass and Manfred Oberlechner investigated how temperature influences their frequency. Their dataset was compiled from events that were large enough to be recorded in the media, restricting it to events that have the capacity to affect people and/or infrastructure. The Huben rockslide that occurred in 1999, which resulted in both the loss of alpine road access and the destruction of a local sawmill, presents one such example.

Rockfall in Huben, Austria, that occurred on 11 March 1999, far below the permafrost limit. This rockfall resulted in both the destruction of a sawmill and loss of road access (Source: Sass and Oberlechner, 2012).

Historical records of rockfalls are scarce, making predictions for the future a challenge and, until recently, little research on the temporal frequency of rockfall events had been carried out. This is partly due to the research focus on areas of permafrost, which cover less than 4 % of the Austrian Alps. Consequently, the relationship between surface temperature and rockslide frequency in permafrost regions is well-known. Permafrost, which exists at sub-zero temperatures, cements sediment together and gives it stability. Unsurprisingly, warming causes permafrost to degrade, leading to a loss of sediment stability and an increased risk of geomorphic hazards. The likelihood of these hazards occurring is a function of substrate type. However, areas of public interest (those with infrastructure) tend to be permafrost-free. In fact, 91% of the events studied were below the permafrost limit (less than 2100 m elevation).

Contrary to the IPCC’s predictions, the study found that there was no relationship between temperature and the number of rockfall events below the permafrost limit, nor was there any correlation between precipitation and rockfall frequency. The increasing settlements and infrastructure within the Alps means there is a greater risk of a geomorphic hazard occurring and the increase in availability of information means there appears to be more events than 20 years ago. Thus, the apparent increase in rockfall occurrence in recent years is likely to be due to a reporting bias.

Whilst there is no evidence for warming increasing the annual number of rockfalls, changes in seasonal weather patterns have resulted in a shift in their occurrence throughout the year. Rockfalls are generally more common in spring than at any other time of year as both the increase in water supply (through snowmelt and high precipitation rates) and high degree of freeze-thaw activity (also known as cryoturbation) destabilises the sediment. However, in recent decades, a greater proportion of rockfalls have occurred during the summer months, leading to a more even distribution of these hazards throughout the year.

Below the permafrost limit there is insufficient evidence to support the notion that increasing rockfall events are associated with climate warming. In fact, the study reveals that milder winters may even reduce the number of rockfalls outside areas of permafrost. Whilst Sass emphasises that these results are preliminary, they highlight the complexity of predicting the impacts of climate change and expose an alternative way in which it can affect hazardous earth processes.

By Sara Mynott, EGU Communications Officer

It’s time for the fifth edition of the EGU’s Twitter Journal Club, our interactive online discussion about a timely scientific article. If you have not yet taken part in one of these discussions, read more about it in our introductory post and make sure to participate when we meet online next week! 

This time, we will be discussing the recent peer-reviewed policy briefing Water Resource Resilience, produced by the UK Parliamentary Office of Science & Technology (POST).

The discussion will take place on Twitter next Thursday 15 November at 14:00 CET, and you can take part by following the EGU’s Twitter account (@EuroGeosciences) and using the hashtag #egutjc5 on your tweets. Please email the EGU’s Science Communications Fellow Edvard Glücksman if you have any further questions.

Happy reading!

The availability of water resources is fundamental for society and economic activities. (Photo: Edvard Glücksman)

Water Resource Resilience

Published 17 September 2012 | POST notes POST PN 419

Summary. The availability of water resources is fundamental for society and economic activities. This POSTnote describes the reasons for uncertainties in water resource availability for future supply and demand and possible responses to managing these risks in the medium term.

Questions to think about:

1. How would you summarise this briefing in a tweet?

2. How does the framework presented here apply internationally, particularly in other European countries?

3. Why are Environmental Flow Indicators (EFIs) important?

4. What would you add to this paper, if given an extra two pages of space?

The EGU’s Twitter Journal Club had its fourth virtual meeting yesterday, this time focusing on a paper from the journal Atmospheric Environment. The work examines methods of assessing contributions of individual emissions to ozone and hence to climate change. Read a full transcript of the discussion on our Storify page!

Emissions of nitrogen oxides (NOx) lead to formation of ozone, which is an important greenhouse gas. (Photo: Edvard Glücksman)

Teachers and educators interested in taking part in the 2013 Geosciences Information for Teachers (GIFT) workshop should submit their symposium applications and requests for travel and accommodation support by 30 October 2012.

As previously announced on the EGU website, the GIFT workshop will be taking place on April 8-10 2013 at the EGU General Assembly in Vienna, Austria. The topic of the 2013 edition of GIFT is Natural Hazards, and the workshop will explore the complex relations between natural hazards – such as earthquakes, tsunamis, wildfires, or floods – and society. Application information is available for download in PDF format, and the document also includes the preliminary programme.

More information about the GIFT workshops can be found in the GIFT section of the EGU website.

GIFT 2013 – Natural Hazards

It’s time for the fourth edition of the EGU’s Twitter Journal Club, our interactive online discussion about a timely scientific article. If you have not yet taken part in one of these discussions, read more about it in our introductory post and make sure to participate when we meet online next week! 

This time, we will be discussing a recent Open Access article from the journal Atmospheric Environment, covering the various approaches used to calculate contributions of individual nitrogen oxide emissions to creating ozone – and hence towards climate change.

The discussion will take place on Twitter next Thursday 25 October at 14:00 CEST, and you can take part by following the EGU’s Twitter account (@EuroGeosciences) and using the hashtag #egutjc4 on your tweets. Please email the EGU’s Science Communications Fellow Edvard Glücksman if you have any further questions.

Happy reading!

Nitrogen oxide emissions from burning fossil fuels are important contributors to the formation of ozone, and hence to climate change. (Source: Wikimedia)

Attributing ozone to NOx emissions: Implications for climate mitigation measures

Atmospheric Environment 59 (2012) 102-107

Abstract. Emissions of nitrogen oxides (NOx) lead to formation of ozone, which is an important greenhouse gas. Despite its relevance, little emphasis was previously given on verifying approaches to calculate contributions of individual emissions to ozone and hence to climate change. Basically two methods (perturbation method and tagging method) were used in the past. We demonstrate that both methods are valid and have their area of application, but only tagging calculates contributions of emissions to concentrations, whereas the perturbation method identifies changes in the ozone concentrations due to emission changes. Our results show that the contribution of road traffic emissions to climate change is underestimated by a factor of 5 in the perturbation method. This is caused by non-linear compensating effects from other emission sectors, which are concealed in the perturbation method but disclosed with tagging. Consequently, the effectiveness of mitigation measures for individual sectors (i.e. concentrating on road traffic induced ozone) is only correctly expressed by the tagging method. The perturbation method provides accurately the total impact (i.e. total ozone) of a mitigation measure. However, current approaches, which evaluate the effectiveness of a mitigation measure based on the perturbation approach, do not reflect changes in the chemical state of the atmosphere (i.e. ozone production rates). These largely affect the effectiveness of subsequent measures and hence make the evaluation of the effectiveness of two measures dependent on their chronology of application. We show that also in this regard, the tagging method is better suited to evaluate the effectiveness of a mitigation measure than the perturbation method.

Questions to think about:

1. How would you summarise this article in a tweet?

2. What are the broader implications of this study?

3. Which approach seems to be the most effective in calculating contributions of individual emissions to ozone?

4. What would be an interesting follow-up study to this work?

It’s time for the third edition of the EGU’s Twitter Journal Club, our interactive online discussion about a timely scientific article. If you have not yet taken part in one of these discussions, read more about it in our introductory post and make sure to participate on this third edition! 

This time, we will be discussing an article recently published in the EGU’s Open Access journal Biogeosciences that features an innovative way of calculating the amount of carbon stored in tropical forests which incorporates tree-height data. The discussion will take place on Twitter next Thursday 27 September at 17:00 CEST, and you can take part by following the EGU’s Twitter account (@EuroGeosciences) and using the hashtag #egutjc3 on your tweets. Please email the EGU’s Science Communications Fellow Edvard Glücksman if you have any further questions.

Happy reading – and don’t be scared of the equations, they won’t bite!

Incorporating tree-height data into calculations of the amount of carbon stored in tropical forests reduces the estimates by roughly 13%. (Source: Imaggeo.net, credit: Alina Mihaela Luchian)

Tree height integrated into pantropical forest biomass estimates
Biogeosciences, 9, 3381–3403, 2012

Abstract. Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions:

1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass?

2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots?

3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates?

The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (< or = to 40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg/ha (range 6.6 to 112.4) to 8.0 Mg/ha (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg/ha (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 PgC (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation.

Questions to think about:

1. How would you summarise this article in a tweet?

2. What are the broader implications of this study? (hint: see recent Nature blurb linked to below)

3. What methods could be used to improve data within biomass maps?

4. What are the practical implications of this and similar studies on how we interpret carbon storage within biomass?

5. Could this article be improved – specifically, are there too many equations?

Related media coverage:
Nature

The European Geosciences Union, through publishing house Copernicus Publications, publishes 14 peer-reviewed Open Access journals. Biogeosciences (BG, IF 3.859) is an international scientific journal dedicated to the publication and discussion of research articles, short communications and review papers on all aspects of the interactions between the biological, chemical and physical processes in terrestrial or extraterrestrial life with the geosphere, hydrosphere and atmosphere. The objective of the journal is to cut across the boundaries of established sciences and achieve an interdisciplinary view of these interactions.

The EGU’s Twitter Journal Club had its second virtual meeting yesterday, this time focusing on a paper from the EGU’s journal Biogeosciences, investigating the means by which microscopic life is sustained in the hostile aridity of the Atacama Desert. Read a full transcript of our discussion on our Storify page!

Vast expanse of Chile’s Atacama Desert, one of the most arid regions in the world. (source: Wikimedia)

The European Geosciences Union, through publishing house Copernicus Publications, publishes 14 peer-reviewed Open Access journals. Biogeosciences (BG, IF 3.587)  is an international scientific journal dedicated to the publication and discussion of research articles, short communications and review papers on all aspects of the interactions between the biological, chemical and physical processes in terrestrial or extraterrestrial life with the geosphere, hydrosphere and atmosphere. The objective of the journal is to cut across the boundaries of established sciences and achieve an interdisciplinary view of these interactions.