Negative Emissions”: a Challenge for Climate Policy WP S Oliver Geden and Stefan Schäfer

Introduction

Stiftung Wissenschaft und Politik German Institute for International and Security Affairs Comments

“Negative Emissions”: A Challenge for Climate Policy WP S Oliver Geden and Stefan Schäfer

The objective of the Paris Agreement is to limit global warming to well below 2 degrees Celsius, and to pursue efforts to limit the temperature increase to 1.5 degrees. The Inter- governmental Panel on Climate Change (IPCC) believes that these targets cannot be reached through conventional mitigation measures alone. The IPCC assumes that in addition to reducing emissions, technologies for removing greenhouse gases from the atmosphere will become indispensable. The preferred technology option combines increased use of bio-energy with the capture and storage of carbon dioxide. To date, climate policy has largely ignored the necessity for “negative emissions” to achieve the temperature targets set out in the Paris Agreement. Discussions on the underlying model assumptions, potentials and risks of imaginable technological options, as well as their political implications, are only just beginning. It would be wise for the EU and Germany to proactively shape this debate and increase funding for research and development. If the Paris climate objectives are upheld, climate policy pioneers will soon be facing calls to set emission-reduction targets of much more than 100 percent – a notion that today seems paradoxical, but may soon become reality.

Global climate stabilisation targets, such be consumed by the mid-2030s, the budget as restricting global warming to 1.5 or 2 for 1.5 °C as soon as the early 2020s. Since degrees Celsius (°C) above pre-industrial, completely decarbonising the world econo- are usually translated into carbon budgets my within a time frame of only 5 to 20 years that show the total amount of emissions is unrealistic, climate models build on the that would still be allowed for meeting the concept of negative emissions. By using target. According to current calculations, technologies to remove CO2 from the atmos- the remaining emissions budget for the phere, the original emissions budget could 2 °C target is about 800 gigatonnes (Gt) of initially be overshot, with the resulting carbon dioxide (CO2). However, for 1.5 °C, deficit then being recouped over the course it is only about 200 Gt. Given that annual of the 21st century. However, the looming

CO2 emissions currently stand at about budget deficit has now reached an alarm- 40 Gt, the world’s budget for 2 °C would ing size. The IPCC’s climate models show

Dr Oliver Geden is Head of SWP’s EU/Europe Division SWP Comments 53 Dr Stefan Schäfer is Programme Leader at the Institute for Advanced Sustainability Studies (IASS), Potsdam December 2016

1 that a total of 500 to 800 Gt in negative climate-economic models would require an emissions would have to be generated by additional area for growing biomass that 2100 to limit global warming to 2 °C or is equivalent to one-and-a-half to two times 1.5 °C – in other words, up to twenty times the surface area of India. Transporting the

the current annual CO2 emissions. CO2 and storing it underground would also In principle, all governments accept the require enormous capacities. And yet the use scientific consensus set out by the IPCC in of this technology is always already included its 5th Assessment Report (2013-2014). The in the calculations of climate researchers, report points out that negative emissions environmental NGOs or policymakers when cannot be avoided if ambitious climate tar- they insist that, based on the IPCC’s calcu- gets are to be met. Currently, however, there lations, targets such as 2 °C or even 1.5 °C is hardly any discussion on how to bring can still be met. about negative emissions. This is particularly Over half a dozen other technological worrying because building the necessary options are also under discussion. They capacities would have to start by 2030 at range from apparently unproblematic the latest. Since there is no political debate measures, such as afforestation, to fertilis- on negative emissions yet, potential con- ing or liming the oceans. On closer inspec- flicts of interests or public acceptance prob- tion, however, even a universally supported lems can only be guessed at. The possible measure such as afforestation raises the ques- social and ecological consequences of such tion of whether it can really help to limit

a far-reaching use of technologies for CO2 global warming. Especially for the boreal removal have barely been examined. The forests of the northern hemisphere, the biggest problem, however, is that almost darkening of the Earth’s surface that would all the technological options currently result from an afforestation of large regions, being favoured are still in the early stages and the attending warming effect, might of development, making their potential for more than cancel out the cooling effect

successful deployment extremely uncer- that would result from binding CO2 in trees tain. – thus achieving the very opposite of the intended outcome. By contrast, suggestions for afforestation of the Sahara or Australian Technological options outback simply seem unrealistic. In its current climate-economic models, the Fertilising the oceans is based on the idea IPCC almost exclusively refers to a techno- that algae growth in some maritime regions logical option that combines planting fast- is limited by a lack of nutrients, especially growing biomass, burning it in power sta- iron. A targeted addition of iron could pro-

tions to generate electricity, and capturing voke algae growth, removing CO2 from the

and storing the CO2 that is released in the atmosphere: when the algae die and sink to

process (bio-energy with carbon capture the seabed, the CO2 stored in them would and storage – BECCS). During its growth be permanently sequestered there. In 2009, phase, the biomass absorbs carbon dioxide the German-Indian iron-fertilisation experi- from the atmosphere that is then captured ment LOHAFEX attracted international at- during combustion and subsequently tention to the idea of ocean iron fertilisa- stored, for instance in geological forma- tion. From a climate-policy perspective, tions. This process would be constantly however, the results were disappointing. repeated with new biomass, thus reducing The algae growth primarily caused a local

the CO2 concentration in the atmosphere. population of crustaceans to multiply. The

So far, however, BECCS has barely been amount of CO2 that was removed from the tested: there is only one single pilot facility atmosphere was very small. in the US. Moreover, generating the amount Another possibility is liming the oceans. of negative emissions that is assumed in This involves adding calcium oxide powder

SWP Comments 53 December 2016

2 (lime) to sea water to increase its pH value. “negative territory” below the zero line – Since water that is more alkaline absorbs assuming, in other words, that emission more CO2 from the air, this method could reductions of more than 100 percent are extract carbon dioxide from the atmos- possible and worthwhile – could perpetuate phere. At the same time, it could ease the the principle of “common but differentiated acidification of the oceans. However, the responsibilities”. Should the limit of what effectiveness of this option is once again is currently conceivable in emissions miti- questionable: producing calcium oxide gation be removed, new conflicts about powder is a CO2-intensive process, and burden sharing would be inevitable. Pos- transporting it would also generate emis- sibilities for differentiating national cli- sions. mate targets would greatly increase, and the pioneers would have to play their part for much longer. For the year 2100, the New distributional conflicts IPCC considers net negative emissions of In climate research, at least, the potentials around 10 Gt to be feasible. This would and risks of the individual technological correspond to a global emissions-reduction options are now beginning to be explored. target of around 125 percent against the By contrast, the political implications of a base year 1990. If this became a point of negative emissions climate policy have not reference in the UN climate negotiations, yet been elucidated. The United Nations’ key emitters like China or India, and most (UN) policy to protect the climate has so far of the developing countries would likely relied on allotting differentiated levels of argue that the industrialised nations organ- responsibility to individual groups of states ised in the Organisation for Economic Co- that will converge in the long term – at the operation and Development (OECD) should very latest when all states have reduced continue to take on more far-reaching their emissions to zero. First, because of responsibilities. For instance, emerging their historical responsibility and greater economies and developing countries could economic capability, the ‘old’ industrialised demand that OECD countries invest more nations have to substantially reduce their in carbon-dioxide removal whilst they emissions. Some of them, such as the north- themselves might not even reduce their western member states of the EU, have own emissions to zero. If the EU agrees to claimed a pioneering status for themselves. a reduction target of, say, 150 percent, we Here, the so-called “zero line” – reducing should also expect to see conflicts within emissions by 100 percent – has been the the Union: the latecomers from Central conceptual reference point. Some EU coun- and Eastern Europe will be keen to main- tries will reach the zero line earlier than tain the EU’s internal distribution of others, but member states from Central and responsibilities. Eastern Europe will be obliged to follow Similar conflicts should also be expected suit. This is also true for large emerging between different economic sectors. If BECCS economies like China and India. Convergence becomes the world’s preferred carbon- towards zero thus means a pioneering role removal technology, the electricity sector for a limited period of time. The assump- would be the very first to be called upon to tion that such a role will bring positive generate negative emissions. The sector is economic effects rests not least on the idea already the focal point of emissions- mitiga- that the countries initially lagging behind tion efforts and is likely to reach the zero will have to follow suit eventually, and will line long before the transport or buildings do so using technologies developed by the sector. pioneers. However, conceptually expanding the scope of mitigation policy by entering

SWP Comments 53 December 2016

3 A necessary strategic decision need to be avoided, and specific incentive

Following the IPCC’s calculations, carbon schemes for using CO2 removal technolo- removal technologies will have to be gies have to be created. It would seem logi- deployed extensively if ambitious global cal to clarify these points as part of the climate targets are to be met. This does existing regulatory framework, such as the not mean that climate policy is obliged to EU emissions trading directive or the EU’s go down this path, let alone to the extent sustainability criteria for biomass. discussed above. One could still decide Politically, the most sensitive issues in against it. However, under the strictly cal- any potential German strategy for negative culative logic of carbon budgets, this would emissions are linked to the fundamental have consequences for the attainability of decisions that have already been taken on global climate targets. Without negative Germany’s energy transition. Would Ger- emissions, the 1.5 °C target would be out many be prepared to rethink its energy of reach, and the 2 °C target could only be transition planning for the electricity sec-

© Stiftung Wissenschaft und met at far greater cost, if at all. tor if BECCS emerged as the technology Politik, 2016 If climate policy pioneers like the EU with the greatest potential at the global All rights reserved and Germany do not want to prematurely level? Would the federal government be These Comments reflect abandon the temperature targets decided willing to change course drastically on bio- the author’s views. in Paris, they will have to start developing mass and on carbon capture and storage,

SWP strategies for CO2 removal soon. Global even at the expense of the decentralised ex- Stiftung Wissenschaft und emissions budgets for 1.5 °C and 2 °C will pansion of wind and solar power? Or would Politik German Institute for be consumed within five to 20 years. This it primarily encourage measures whose de- International and means that the reduction corridor of 80 ployment would barely impact on the struc- Security Affairs to 95 percent by 2050, which is valid for ture of the national energy system, such as Ludwigkirchplatz 34 Germany and the EU, can only be an ad- liming the oceans? 10719 Berlin equate contribution to meeting global tem- There is still time for a broad discussion Telephone +49 30 880 07-0 Fax +49 30 880 07-200 perature targets if emissions in the second on the unconventional forms that an ambi- www.swp-berlin.org half of the century are pushed substantially tious climate protection policy might take, [email protected] below the zero line. To date, neither the EU and for pursuing the corresponding techno- ISSN 1861-1761 nor Germany has declared itself ready to logical options. The longer it takes to open Translation by Tom Genrich aim for long-term reduction targets of more such a debate, the greater is the risk that the than 100 percent. And even if they did, it Paris climate targets will slip out of reach. (English version of SWP-Aktuell 70/2016) remains unclear whether such a policy would be technologically and economically feasible, and if it would find sufficient socio-political support. In principle, a negative-emissions strategy can only be realised if climate, energy and research policy rapidly set the process in motion. Not only would it be necessary to invest substantially in research and development, but also to start a broad political and societal debate, and initiate regulatory considerations. In many respects, these considerations concern challenges that also had to be solved (or still remain to be solved) in deploying conventional emissions-mitigation technologies. For example, precise accounting rules for negative emissions need to be set out, undesired side effects

SWP Comments 53 December 2016