climate change

Geosciences Column: Using tall trees to tot up tropical carbon

Forests in the tropics account for about half the above-ground carbon on Earth and as the trees grow older they are capable of storing more and more. In fact, their carbon-storing potential is so large that they are increasingly being viewed as a means of mitigating climate change. Take, for example, the United Nations effort to reduce degradation and deforestation by assigning value to forest carbon.  But programmes like this can only operate if we can calculate forest carbon stocks effectively.

The first step is to suss out a tree’s dimensions. Biomass directly relates to tree height and trunk diameter, so if you know these two details you can work out the amount of carbon stored in a particular tree. This calculation owes its ease to a lot of hard-collected data on tree dimensions and biomass, which, when combined, produces a neat relationship between the two.

Tropical forest in Martinique. (Credit: Wikimedia Commons user Fameme)

Tropical forest in Martinique. Credit: Wikimedia Commons user Fameme)

You can calculate tree height using a tape measure or using LIDAR. LIDAR, short for Light Detection and Ranging, uses a laser to measure the distance to an object by analysing the amount of light reflected back to a detector. Whether you’re using the high tech method or the tape, you’ll always need a little trigonometry. With a quick calculation you can use the distance to the tree base, the distance to the tree top, and the angle from where you’re standing to the top of the tree to work out its height. There are other ways to work this out if you fancy conducting a garden experiment with your smartphone .

But what if you wanted to work out the biomass of not one tree, ten or a hundred, but an entire forest of them? Trekking your way through the trees to measure each in turn would take an unimaginably long time, not to mention that, by the time you finish, the trees you started with will have grown, changed and increased their biomass to boot.

Is there a more practical method? Yes! Satellites are also capable of using LIDAR to estimate tree height remotely – data can be used to calculate the amount of carbon contained in a tropical forest.

Forest canopy in Peru. (Credit: Geoff Gallice)

Forest canopy in Peru. (Credit: Geoff Gallice)

The method is a treat for the budding biogeoscientist. Here’s how it works:

  1. Head out to your favoured forest and use your field skills to measure the height and diameter of 100 or so trees. This means you can ground-truth your measurements and apply them to the rest of the forest.
  2. Scoop up some satellite data on tree height.
  3. Use the relationship between height and biomass that you gathered from trees in the field to find the biomass of the rest of the forest.

A group of scientists, led by Maria Hunter, set out to understand the uncertainty in these measures of biomass. Provided you have your 100 or so local trees as a reference, the biggest uncertainty lies in determining their height. A whole host of uncertainties enter here: from the method used to grab the data to the obstacles that cause you to both over- (in the case of tape measures) or under- (in the case of LIDAR) estimate the height of a tree. Some of these uncertainties can cause major problems for tree height estimation, particularly when the tree is unusually tall.

Despite these difficulties, Hunter found that values for forest biomass were still rather good. This is because many measurement errors cancel each other out when applying the results to a large area.  What’s more, since the majority of trees are not unusually tall, their contribution to biomass determining difficulties are relatively small, leading to an overall error in biomass estimates of approximately 6%. Not too bad at all.

By Sara Mynott, EGU Communications Officer


Hunter, M. O., Keller, M., Victoria, D., and Morton, D. C.: Tree height and tropical forest biomass estimation, Biogeosciences, 10, 2013.

Imaggeo on Mondays: How sea urchins can help mitigate climate change

This week’s Imaggeo on Mondays stars the humble sea urchin – a creature suffering from the effects of climate change, but one that could also provide a way to sequester some of the CO2 responsible…

Carbon dioxide and water react to form carbonic acid – a mixture of bicarbonate and hydrogen ions. Sea urchins bag the bicarbonate to grow bigger, stronger shells, or ‘tests’, but without a catalyst, this reaction happens fairly slowly. In fact, because the reaction is reversible, the hydrogen ions and bicarbonate can recombine, rendering the bicarbonate unavailable for the urchin. Not ideal.

To help themselves on their way to adulthood, larval urchins use trace nutrients from the water as catalysts for carbonate uptake. Catalysts to molecules are like bars are to people – interaction is much more likely to occur.

This image shows a sea urchin long past the end of its life cycle, but back when it was a little nipper, it was quite an amazing creature! (Credit: Natalia Rudaya, distributed via

This image shows a sea urchin long past the end of its life cycle, but back when it was a little nipper, it was quite an amazing creature! (Credit: Natalia Rudaya, distributed via

By building nickel into their tests, urchins can speed up the conversion of carbon in the water to carbon for growth because the nickel, like any catalyst, provides a site for the reaction to occur.

This fantastic feature of sea urchins is now being mimicked in a pilot process that uses nickel to help capture carbon from the atmosphere and store it as stony sediment.

The application was a chance discovery. Physicist Lidija Šiller, while working on a carbon capture project at Newcastle University, was also investigating how sea urchins convert CO2 to calcium carbonate. “When we analysed the surface of the urchin larvae we found a high concentration of Nickel on their exoskeleton. Taking Nickel nanoparticles which have a large surface area, we added them to our carbonic acid test and the result was the complete removal of CO2,” Šiller explains in a press release for the study.

The carbon capture process used to use an enzyme to speed up the conversion carbon dioxide into calcium carbonate, but the enzyme is only active for a short time and it rapidly fails under acidic conditions. To speed up the process, and prevent enzyme wastage, the scientists took a leaf from the urchin’s book. Nickel nanoparticles can used to catalyse the conversion of atmospheric CO2 into carbonate. What’s more, the nanoparticles are magnetic, so can be removed from the mixture and reused in another round of carbon capture.

While urchins themselves aren’t the key to climate mitigation, the urchin-inspired process has great potential. Watch this space!

By Sara Mynott, EGU Communications Officer


Gaurav A. Bhaduri, Lidija Šiller. Nickel nanoparticles catalyse reversible hydration of carbon dioxide for mineralization carbon capture and storage. Catalysis Science & Technology, 3, 1234-1239, 2013.

The EGU’s open access geoscience image repository has a new and improved home at! We’ve redesigned the website to give the database a more modern, image-based layout and have implemented a fully responsive page design. This means the new website adapts to the visitor’s screen size and looks good whether you’re using a smartphone, tablet or laptop.

Photos uploaded to Imaggeo are licensed under Creative Commons, meaning they can be used by scientists, the public, and even the press, provided the original author is credited. Further, you can now choose how you would like to licence your work. Users can also connect to Imaggeo through their social media accounts too! Find out more about the relaunch on the EGU website. 

Sending GIFT to Africa: A new collaboration between the EGU, UNESCO and ESA

For the past ten years, the EGU’s Geosciences Information for Teachers (GIFT) workshops – spreading first hand scientific research to teachers of primary and secondary schools – have been hugely successful in shortening the time that research takes to disseminate from scientist to textbook to teacher and offering usable practical activities for the classroom. GIFT workshops are usually held at the EGU General Assembly in Vienna, adding to the experience of the teachers by immersing them in a world of geoscientific research and discussion. In recent years, workshops have also been held in association with Alexander von Humboldt conferences in Mexico, Malaysia and Peru and are now on the way to Africa.

UNESCO’s Earth Science Education Initiative in Africa was set up to support the development of the next generation of African Earth scientists. The initiative aims to provide the necessary tools, networks and perspectives to apply sound science to solving the challenges of sustainable development and in turn gathering opportunities from them. Challenges and opportunities range from evolution in mineral extraction techniques to environmental management including mitigation of climate change, prevention of natural hazards, and ensuring access to clean drinking water.

Education is key to forging the next generation of ‘Earth stewards’ and give Earth sciences a status that reflects the importance that this discipline plays in the everyday life of African people. One of the three initial activities of the initiative was a focus on Earth science education at primary and secondary level in schools. To achieve this, it was recognised that first providing teachers with the necessary information, conveyed in an engaging way by scientists was essential for inspiring and educating future generations.

Bringing together the expertise of the EGU with UNESCO’s Earth Science Education Initiative in Africa, the EGU are proud to announce a new series of annual GIFT workshops to be held around the African continent over the next four years. As international events, the workshops will be held in four different regions of Africa, starting with Southern Africa. They will cover various topics of societal relevance such as climate change, groundwater, geohazards, mineral resources and environmental sustainability. The UNESCO-EGU-ESA African GIFT workshops will take place over the course of 3 days with 40 teachers from across the region and 8-10 speakers, half of whom will be non-African experts. 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 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.


At the EGU, the Committee on Education will be responsible for developing the programme with the help of the new EGU Educational Fellow. Programme specialists from the Division of Ecological and Earth Sciences at UNESCO headquarters, Paris and UNESCO African field offices will be jointly organising the workshops. For the first UNESCO-EGU-ESA GIFT workshop, to be held from the 26th-28th February 2014 in Port Elizabeth, South Africa, the European Space Agency and African Earth Observatory Network will be offering support and expertise and the Nelson Mandela Metropolitan University will be hosting the workshop. To reflect on one of the most pressing societal issues and the release of the 5th Assessment Report of the IPCC, the first workshop will be on ‘Climate Change and Human Adaptation’.

With preparations already underway for this first African workshop, all those involved are looking forward to a successful event that will become a sustainable part of teacher education in Africa.

By Carlo Laj (Chair of the EGU Committee on Education), Sarah Gaines (Assistant Program Specialist, UNESCO) and Jane Robb (EGU Educational Fellow)

Update (11/12/13): The closing date for applications has been extended to 24 January 2014. 

Assessing transatlantic cooperation on energy security and climate change

At the first flagship Emerging Leaders in Environmental and Energy Policy (ELEEP) Network conference, participants dug deep to identify key areas in energy and environment where transatlantic cooperation could be most effective. ELEEP member and former EGU Science Communication Fellow Edvard Glücksman reports back from Washington DC.

Finding solutions through cooperation is not necessarily the paradigm of choice in Washington DC these days. Yet it was with precisely this aim that energy experts converged on the non-partisan Atlantic Council’s headquarters earlier this month to participate in the first ever public event hosted by the ELEEP network of young energy and environment specialists.

The one-day conference featured a set of panel discussions on energy and environmental policy which, taken together, aimed to outline the compelling case for transatlantic cooperation.

Acknowledging the problem

The broader challenge, laid out by Christian Burgsmüller of the Delegation of the European Union to the United States, is cooperating to identify and deploy the ideal energy mix for the 21st century. This idea was echoed by Rear Admiral Neil Morisetti, who, based on his decorated Royal Navy career, proposed a transatlantic roadmap by which humanity can square its need for energy with the potentially catastrophic risks of climate change.

Full house at the first Emerging Leaders in Environmental and Energy Policy (ELEEP) Network conference at Atlantic Council headquarters in Washington DC. (Credit: Edvard Glücksman)

Full house at the first Emerging Leaders in Environmental and Energy Policy (ELEEP) Network conference at Atlantic Council headquarters in Washington DC. (Credit: Edvard Glücksman)

Morisetti, currently Special Representative for Climate Change with the UK Foreign & Commonwealth Office, argued for a long-term energy strategy driven by improvements to efficiency, the proliferation of renewables, effective distribution infrastructure, and guaranteed security. Alluding perhaps to the current political situation in the US, he suggested that simply realising that there is a problem is an important and often overlooked first step in finding a solution. Only then can new technologies be developed and these, in turn, can only be effectively implemented through close intercontinental collaboration between nations and companies.

Morisetti also predicted that military installations will become increasingly important as experimental microcosms for testing potentially important future energy technologies, as the cooperative mechanisms are already in place within a power-hungry sector continuously trying to make efficiency savings.

“I have likely been responsible for more energy consumption in my lifetime than everybody in the room put together,” joked the former aircraft carrier commander.

Last chance for transatlantic cooperation

Adding a sobering layer of realism to the discussion, Czech Ambassador-at-Large for Energy Security Václav Bartuška spoke of the consequences of waning transatlantic cooperation. According to Bartuška, a former envoy in the Russia-Ukraine gas dispute, Europe and North America retain plenty of common interests despite recent political rifts and historically diverging approaches to energy policy. As China’s global economic influence grows, transatlantic nations currently face what Bartuška believes is a final decade to devise and implement a long-term energy and environmental strategy for the planet. Transatlantic leadership in these sectors is beneficial, Bartuška argues, because the West has already made its mistakes and learned from them.

Former US Ambassador to the EU C. Boyden Gray speaks with cautious optimism about future transatlantic relations. (Credit: Edvard Glücksman)

Former US Ambassador to the EU C. Boyden Gray speaks with cautious optimism about future transatlantic relations. (Credit: Edvard Glücksman)

“Whereas we have overcome the age of not being able to breathe on account of air pollution in cities, Shanghai is currently reaching that point,” he warned.

Bartuška cited nuclear power as an example of an area where the US and Europe imminently have to choose whether to cooperate with one another to set global standards, or to take a step back and cede their influence to countries with historically lower environmental priorities, including China, India, Russia, and South Korea.

In this context, the forthcoming Transatlantic Trade and Investment Partnership (T-TIP) meeting, which holds the potential to open up trade between the United States and Europe, represents the most important round of transatlantic negotiations in many years, according to Former US Ambassador to the EU C. Boyden Gray. Apart from the obvious economic benefits of cooperation, Gray points out that the T-TIP would offer Europe and North America a final chance to reaffirm their historically shared values, including in the energy and environment sector.

In a last-minute twist, as a result of the US government shutdown, the latest round of T-TIP talks were postponed last week.

For more details and video highlights from the conference, visit the official website.

By Edvard Glücksman, Postdoctoral Research Fellow, University of Duisburg-Essen