CDR methods comprise any technique that intentionally removes CO2 from the atmosphere [4, 5]. With this decrease in atmospheric CO2 concentration, we should see a reduction in the greenhouse effect. This then leads to a stabilization of global mean temperature or even a cooling effect [4], depending on the extent of removal and level of residual emissions. There are two subcategories of CDR methods: biological based solutions, which enhance the natural carbon sequestration of biological systems, and engineering based solutions, which use engineered systems to sequester carbon [4].

What can these methods look like?

An example of biological based CDR methods is ocean fertilization. In this method the biological pump of the ocean is enhanced by adding otherwise limiting nutrients (e.g. iron) to the water [4]. The idea behind this method is that the addition of nutrients leads to increased algae growth, which in turn leads to increased CO2 sequestration by photosynthesis [4]. Since algae are taken up by other organisms, which then release the CO2 by respiration in deeper layers of the ocean, carbon is removed from the surface and stored in deeper layers [4]. However, the effectiveness of ocean fertilization is debated, as not all of the sequestered carbon will be moved to deeper ocean layers and there might be a decrease in productivity and therefor carbon sequestration in neighboring areas of the ocean [4]. Thus, ocean fertilization might just lead to a shift in the location of carbon sequestration, but not an enhancement [4]. Also, this method impacts the whole marine ecosystem with unpredictable and possibly negative side effects [4]. Some authors argue that it is not a viable CDR method due to its sustainability issues and low efficiency [6].

Another biological based CDR method is enhanced weathering. The natural process of rock decomposition sequesters carbon [4]. The aim of enhanced weathering is to speed up this typically slow natural process and thus enhance carbon sequestration [6]. There are several ways this could be done, from enlarging the reactive surface by grinding rocks or spreading minerals in agricultural soil to catalyzing the reaction of rocks and CO2 in chemical engineering plants [4, 6]. Besides capturing carbon, the weathered rocks could also have a fertilizing effect in soils [6]. A downside to these methods lies in the fact that large quantities of minerals would be required in order to sequester a significant amount of CO2, the mining for which would be energy intensive and destructive to ecosystems [4]. Other side effects are hard to predict and would vary depending on the used rock and application site [6]. The sequestration potential of enhanced weathering is estimated to be between 2 and 4 Gt CO2/year by 2050 at a cost of 50 to 200 US$/t CO2 [6]. Up to now, discussions about enhanced weathering have been theoretical and are mainly based on models [6], but the previously mentioned trials in the UK will include a project involving the application of crushed silicate rocks on farmlands [2]. 

An example for an engineered CDR method is the direct air carbon capture and storage (DACCS). Here, CO2 is directly captured from ambient air and the resulting CO2 stream can either be further processed or stored (e.g., in geological formations) [4, 6]. There are no biophysical constraints to this method and minimal side effects are expected; the limitations come from costs and storage [6]. If these constraints were overcome, this technique would have a high potential [6]. A method very similar to DACCS is bioenergy with carbon capture and storage (BECCS). It basically works the same, but BECCS filters out the CO2 that gets emitted at bioenergy production sites [4]. At these locations, the CO2 concentration is higher than in ambient air, making the filtering process easier. However, this method comes with the limitations and side effects of bioenergy production by biomass, which requires large areas of land and induces land use change and associated emissions [6]. For both DACCS and BECCS, a potential of 0.5 to 5 Gt CO2/year by 2050 is estimated [6]. In terms of cost, BECCS is estimated to be slightly cheaper (100 – 200 US$/t CO2) than DACCS (100 – 300 US$/t CO2) [6]. Small-scale pilot projects already exist for both methods, but upscaling is still needed for wide-spread applications.

The role of CDR in tackling climate change

The methods discussed above are just a few examples for CDR methods, but they already show that more research and upscaling is necessary in order to remove significant amounts of CO2 from the atmosphere. Yet, given that our carbon budget is very limited, CDR methods are an important tool to achieve the Paris agreement goals – in fact, they are a substantial part of most 1.5 °C consistent pathways in the IPCC report [5, 6, 7]. CDR methods function to attain net negative emissions to come back to 1.5 °C after an overshoot and/or to offset residual emissions in these pathways [7]. The IPCC models mostly consider BECCS or afforestation/reforestation as CDR methods only, as the other methods are not understood well enough yet [7]. According to the IPCC, between 100 and 1.000 Gt CO2 need to be captured by CDR methods by the end of the century for 1.5 °C consistent pathways with no or low overshoot [7]. If only BECCS is considered, the implementation would have to reach a potential of up to 8 Gt CO2/year by 2050 and double that by 2100 [7], which might not be possible. Using several CDR methods on a smaller scale might be better than using one method on a large scale, because this way the limitations and side effects could be minimized [5]. It also should be mentioned that estimations of potentials of different CDR methods are debated and represent a current area of research. There has been a study that found that BECCS, DACCS, enhanced weathering and ocean liming could theoretically remove sufficient CO2 from the atmosphere separately from another to keep within the 1.5 °C target [8]. But the authors also argue that it is likely not possible to implement the methods in time to achieve this goal, as more research and a global infrastructure as well as coordinated governance is needed for their large-scale application [8].  

Due to their slow-acting nature, CDR methods cannot be seen as emergency solutions to climate change, but rather as complementary to conventional mitigation strategies [4, 5, 7]. We should also not solely rely on these methods, as they do have unpredictable and adverse side effects [6] and assume that we fully understand the carbon cycle and can influence it [5]. However, the less we reduce our emissions now, the more we will rely on CDR methods in the future [5].

References:

[1] Neate R. 2021. Elon Musk pledges $100m to carbon capture contest. The Guardian. Access here.

[2] UK Research and Innovation. 2021. UK invests over £30m in large-scale greenhouse gas removal. Access here.

[3] Carrington D. 2021. Trials to suck carbon dioxide from the air to start across the UK. The Guardian. Access here.

[4] The Royal Society. 2009. Geoengineering the climate: Science, governance and uncertainty. RS Policy document 10/09. The Royal Society, London, UK. 82pp. Access here.

[5] Minx JC, Lamb WF, Callaghan MW, Fuss S, Hilaire J, Creutzig F, Amann T, Beringer T, de Oliveira Garcia W, Hartemann J, Khanna T, Lenzi D, Luderer G, Nemet GF, Rogelj J, Smith P, Vincente JLV, Wilcox J, Dominguez MMZ. 2018. Negative emissions – Part 1: Research landscape and synthesis. Environmental Research Letters 13: 063001. Access here.

[6] Fuss S, Lamb WF, Callaghan MW, Hilaire J, Creutzig F, Amann T, Beringer T, de Oliveira Garcia W, Hartmann J, Khanna T, Luderer G, Nemet GF, Rogelj J, Smith P, Vicente JLV, Wilcox J, Dominguez MMZ, Minx JC. 2018. Negative emissions – Part 2: Costs, potentials and side effects. Environmental Research Letters 13: 063002. Access here.

[7] IPCC. 2018. Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte V, Zhai P, Pörtner HO, Roberts D, Skea J, Shukla PR, Pirani A, Moufouma-Okia W, Péan C, Pidcock R, Connors S, Matthews JBR, Chen Y, Zhou X, Gomis MI, Lonnoy E, Maycock T, Tignor M, Waterfield T (eds.)]. In Press. Access here.

[8] Lawrence MG, Schäfer S, Muri H, Scott V, Oschlies A, Vaughan NE, Boucher O, Schmidt H, Haywood J, Scheffran J. 2018. Evaluating climate geoengineering proposals in the context of the Paris Agreement temperature goals. Nature Communications 9: 3734. Access here.

Cover image: By Ralf Vetterle on Pixabay. Access here.

The post Carbon dioxide removal – Part of the solution to climate change? appeared first on Global Change Ecology.

As a master’s student of natural science, I know of what I am speaking: A vast number of scientific papers is extremely hard to read (and therefore understand). Additionally, the reach of the publishing journals is limited – often, you need to pay high amounts of money just to access a paper. People with a good understanding of the subject and with the ability to communicate these papers are truly needed. In order to get insights into this business, I went to the 11th World Conference of Science Journalists (WCSJ) in Lausanne, in the French-speaking part of Switzerland. It took place in the L’Ecole polytechnique fédérale de Lausanne (EPFL), a research institute and university in Lausanne.

The WCSJ is an event by the World Federation of Science journalists and is held every two years. In 2017, it was in San Francisco, USA. The next conference will take place in Medellín, Colombia, as was announced at the end of the event in Lausanne. This notice made for loud cheering from the side of the Colombian people at the conference.

In total, 1200 people took part in this conference: journalists, scientists, members of the EU, chairpersons of international scientific associations such as the IPCC or IPBES, members of communication boards of universities all around the globe – and some (very few) students like me. The aim of this biannual conference is to bring together professionals and students in science journalism to exchange skills, ideas and thoughts. But also, to build networks and form collaboration on a global scale. During the conference, many science journalists reported about their way into science writing and the possibilities and challenges of this job. 

The spectrum of talks, panel discussions, workshops and presentations was broad. There were three big auditoriums, hosting one major event after the other with a variety of topics. “The new goldrush: Prospects and controversies in deep seabed mining”, “Fake-news in science: How to recognize and fight it” or “Biodiversity: Reporting a silent crisis” – there was something for everyone. Researchers and science journalist from all over the world came together, discussed possible solutions for different challenges. Not all speakers could attend the conference physically, which is why some of them were called in via Skype. During a talk about marine protection, a number of researchers took part in a panel discussion, some of them sitting in chairs at the beach on a small island in the Indian Ocean, their feet in the white sand, the sound of the waves in the background echoing in the big hall in Lausanne. One of the highlights of the conference was the talk of the Intergovernmental Panel on Climate Change (IPCC) chairman Hoesung Lee. The auditorium was jam-packed, everyone wanted to hear what he had to say. He spoke about the findings of the current report on 1.5°C warming. He especially pointed out the necessity of combining different fields of research: “We have a good understanding of the technological and economic feasibility, but the social dimensions leave room for more knowledge”, Hoesung says. “We need a change in behaviour. We need a different economy.” He also talks about the choices in private and daily life. Particularly, he emphasizes the need for better infrastructure in remote areas: “Public transportation in cities is often very good. But in the countryside, you often have no choice.” Yet, one aspect he is not talking about – even when asked from the audience – is a change in diet. Even though it is well known that the meat consumption is one of the main reasons for greenhouse gas emissions. “What food choices people make, is not our area.”

Another special feature of the conference were the field trips offered on various days. Every participant could sign up in advance for the field trip they were interested in. Those trips included, for example, a trip to the research station at Jungfraujoch at 3700 meters of altitude, where climatic research has been done for the last 100 years. As temperature measurements at the station suggest, that the annual mean temperature has risen by 1.8°C since 1933. “I remember, when I started my research here around 40 years ago, the glacier was so much bigger”, Bertrand Calpini says and lets his glance wander over the Eiger glacier, which spans under the research station. He is head of the Deputy Director of the Federal Office of Meteorology and Climatology (MeteoSwiss) and Head of the Measurements and Data Department in MeteoSwiss.

The final speech of the conference was held by Bob Watson, chairmen of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) since 2017. With wild gestures and his loud voice, the 71-year-old scientist with the greying white beard calls the audience for action. In his speech – which was originally set for 40 minutes and shortly before Watson’s presentation was cut to 20 minutes – he urges everyone to do write about biodiversity loss and climate change, pointing out the absolute necessity to change humankind’s current lifestyle. “In 2060, we will be probably beyond 2°C of global warming, more likely are 3-3.5°C”, he says while walking on the stage. “That means that countries have to double and triple their efforts to maintain the climate below 2°C warming! This is necessary to secure biodiversity and the global climate!”

What I have taken home from this conference is that it is absolutely necessary to look at as many facets of science as possible. Only focussing on one topic, one direction, may give ideas for this very subject. Yet, in order to understand the bigger picture, and to be able to write about it in a comprehensible way, it is essential to illuminate it from every perspective possible. It’s not only political injustice – but it can also go in hand with environmental disasters caused by political decisions. It’s not only climate change – it’s as well the social impacts that go along with it.

The post A review on the World Conference for Science Journalists appeared first on Global Change Ecology.

The airplane is making its landing approach around 10 am at the airport of Namibia’s capital city, Windhoek. Quite exhausted after the 10 hours flight through the night, I look up. Outside I can see dry grass, some bushes and a seemingly endless savannah. I am finally in Africa! A bright sun is gleaming in a cloudless blue sky and I am preparing myself for the heat. But when I step out of the plane, a strong gust of cold wind blows in my face. Shivering I draw my jacket closer around my shoulders. What a start for spending the next two weeks in Namibia!

We are spending the first two days of our excursion in Windhoek, a clean, and quite European looking city, trying to acclimatize to the windy and colder than expected conditions. On our very first day, we have the opportunity to meet John Kasaona, who is the head of the the IRDNC (Integrated Rural Development and Nature Conservation), one of two major nature conservation agencies in Namibia (the other one is NASCO (Namibian Association of Community-Based Natural Resource Management Support Organizations)). John Kasaona is a huge man with lively eyes, who greets us friendly and guides us into his office.

John tells us that Namibia experienced a severe drought in 1980 that endangered many wildlife species and threatened the life of the communities depending on the animals. Thus, the government decided to act and engage rangers to protect wildlife. But who knew the bush and the animals best? The answer was simple: Local poachers. So, John’s father, a former poacher, became a conservationist und John became one after him. In 1986, the number wildlife began to increase again and communities got the right to manage the nature surrounding them. To make nature conservation work, it is crucial that the locals can also benefit from nature. “Conserve and make sure that you benefit from the resources that you protect,” says John. Ten years later, the “Nature Conservation Amendment Act” finally passed, allowing communities to become so-called “conservancies”. This would prove to be a very successful concept throughout Namibia in terms of nature conservation.

Communities wanting to become a conservancy have to define their boundaries, give themselves a constitution, elect representatives of the community and submit management and financial plans. Thus, a conservancy resembles a national park, with the exception that people are still allowed to live on and use the land in defined areas. Nevertheless, the local communities have to respect certain restrictions e.g. in hunting and land use, to conserve nature. In turn, the conservancy gets the right to manage its own land. To generate income, conservancies can set up contracts with investors, who want to build lodges for tourists and trophy hunters. Part of the profit of the lodge goes then to the conservancy. The money is can be distributed evenly amongst the conservancy members or be used to build schools, health points or other projects that benefit the community. To make the foundation process even easier, the IRDNC provides assistance when communities choose to become a conservancy. John told us, he once camped under a large tree for many weeks, until the conservancy was finally running. Now, the conservancy office building is built under that tree. (Check out John’s TedTalk as well.) Today, in 2018, the number of conservancies has summed up to 82 conservancies in Namibia. And it is working: Wildlife numbers are increasing, poaching is becoming harder and harder and ecosystems find their balance again. Thus, Namibia, which is one of the few countries who specifically address habitat conservation and the protection of natural resources in their constitution, can set an example for us all.

The post Blog Journal: How nature conservation works in Namibia appeared first on Global Change Ecology.

As mentioned above, we will go to the Wuparo conservancy. For eight days, we will span out tents there and during the day a lot of fieldwork has to be done. The aim of our study trip to the Caprivi region is to collect information and data about the impact of the conservancy on the life of the locals and on biodiversity. We teamed up in three working groups – as we are only six students and one professor – and we will look at different aspects of the conservancy. One team is going to interpret satellite data and compare it with the data collected in the field: The aim is to see how biodiversity is developing in the conservancy and if there are disturbances and threats to biodiversity (which can also be caused by animals for example by browsing of cattle on trees). The second team will investigate how humans and wildlife live together: Are there conflicts between the two groups? If yes, which ones? Is this causing an increase or a decrease of biodiversity? The third group will have a closer look at the impacts of the conservancy on the people living and working there: We want to check if the people benefit from the conservancy, if the management plan is successful. In total, we have around 8-10 days for research.

As we have two members of the blog travelling to Namibia for doing research, we want to try something new: We want to write a little scientific and also personal journal here. Probably, the articles will just be uploaded after the trip as we are not sure how the situation is concerning internet (or phone) access in the remote area we stay at. Before we leave in the beginning of September, we both would like to share our expectations for this trip with you.

Leonie:

This is my second time visiting an African country. Last time, I was in Tanzania – East Africa. Now, it is the other side of this large continent. Namibia has always been in my dreams: Wide deserts, endless skies, wildlife and in general a colourful spectacle – and indigenous people, a very dear and special interest of mine in general. The research part of this trip is going to be hard, I expect. As it is only short time we have for our investigations, we have to get the most out of it. And that’s a challenge I am really looking forward to. I hope to get insight into the culture of the people we are visiting, talk to them, get to know them. This way, our two cultures can connect and understand each other better – for me an absolutely necessary aspect if our generation wants to enter the frey against challenges like climate change, biodiversity loss or global inequality. We have to understand and respect each other. Therefore, I am really looking forward to meeting the people living in the Caprivi region. If there is the chance to meet people belonging to indigenous tribes in Namibia, like Himba, San, Nama, Semba or Twa people, I would be delighted. Indigenous communities have an understanding of the world and the environment which has always interested and fascinated me – in many ways they know much more than we do in our industrialized, western cultures. I will keep you updated about the experiences we make in Namibia.

Katharina:

As I’m writing these lines, it will be less than 32 hours till we will be leaving Germany. After a 10 hours flight we will arrive in Windhoek, the capital city of Namibia. My last visit in Africa, more precisely Madagascar, last year got me thinking a lot. And I am sure, this excursion will teach me a lot as well – about the attitude towards life, about a very different nature and about how other cultures perceive and use their land. I am looking forward to return to this fascinating continent and to see a completely different facet this time. Visiting the wide steppes of Namibia, encountering wildlife, meeting people from different cultures, sleeping under the African night sky – I cannot even imagine how this journey will change myself. I have a great interest in the relationship between man and nature and how both can coexist. Thus, I will investigate the attitudes of the local people towards wildlife and try to identify indicators that enhance or reduce human-wildlife conflicts. I’m looking forward to get to know another country, other cultures, other ecosystems. And I hope, one day, I can use this knowledge to help fighting climate change, the global inequality or help protecting nature.

The post Blog-Journal: Excursion to Namibia appeared first on Global Change Ecology.

First of all, meeting all these people, specialists, freelancers, professors at universities was quite a nice experience. They come from all over the EU, some of them are currently working and living at such distant places as New York State in the US or the French island La Réunion in the Indian Ocean. In total, there were around 25 people coming by train, car or plane to Burg Rabenstein. They have totally different backgrounds in their studies and also work for different institutions like universities, research institutes or the United Nations.

It was fascinating to see how EU projects work. There were different topics researchers are working on: Some groups dealt with mountainous ecosystem services and how they could be assessed, others wanted to create a new type of databank, in another room, the members aimed to assess the services of Lake Ohrid in Macedonia. Also, the functioning of the group as a whole was interesting because so many different nationalities and cultures clashed during these intense workshops – it was noticeable in subtle ways like the different forms of approaches or varying opinions on the meaning of certain words. Some discussions took much more time than they were meant to, for reasons like a very long debate about how to use the term “ecosystem services” correctly. Despite all differences and discussions, it is remarkable that there was never a lack of respect and even though hands were thrown into the air and, during heavier discussions, loud sighs were made and sometimes eyes were rolled, there was an overall kindness and understanding for the others.

As the topics were widely ranged as mentioned above, the groups worked also with different approaches. Some groups would directly start off with brainstorming and writing their ideas down in a word document. Others made mind maps and drew graphs on paper, trying to get their topic from another angle. While a few groups only consisted of two or three people, in others there were more people involved. Not all members of Ecopotential could manage to come to Franconia to join their colleagues. So, there were quite a lot of Skype calls during the working sessions.

During these days of intense workshops, I had the chance to not only see the researchers as such, but also to look behind the facade. This is a very important fact that we often tend to forget: Researchers are also only human beings. This means they have a passion they live and work for but on the other side, this means that they also have “normal” interests besides their research like good food, music, books. They have families and other beloved ones they care for. And some of them are extremely funny – something that doesn’t really correlate with the stereotype of the serious researcher who appears to be from another planet.

It was an eye-opening time in Burg Rabenstein because in another context I would have gotten to know these professors and international specialists in another way. Maybe this is something, we should do more often: Read between the lines, look at things from other perspectives and to think outside our own very narrow box.

The post Ecopotential – Insights to an EU-funded project appeared first on Global Change Ecology.