Why Germany and not Japan is the leader in renewable energy

By Jessica Jewell, IIASA Energy Program

Why have Germany and Japan, two large, and in many respects similar developed democracies pursued different energy options? A recently published study examines why Germany has become the world’s leader in renewable energy while phasing out its nuclear power and Japan has deployed only a trivial amount of renewables while constructing a record number of nuclear reactors.

The widespread story is that Germany rejected nuclear power in a politically bold move after Fukushima and instead pursued ‘Energiewende’ prioritizing wind and solar energy to combat climate change. Leading scholars such as Amory Lovins described Japanese policymakers as manipulated by the nuclear lobby, clinging to their old ways, and unwilling to properly support renewable energy. The lesson to other countries is that public anti-nuclear sentiments and a capable democratic government is what it takes to turn to decentralized renewable energy.

This research shows that these stories are myths. As I and my coauthor wrote in a letter to the editor in Nature last year, Japan had ambitious renewable targets already before Fukushima and there is no evidence that these have been affected by its nuclear plans. The same holds for Germany: its targets for renewable energy were not affected by the change in its nuclear strategy following Fukushima’s disaster in 2011.

© nixki | Shutterstock

In fact, the differences between Germany and Japan started not in 2011 after Fukushima, but some 20 years earlier in the early 1990s when Japan’s electricity consumption was rapidly growing and it desperately needed to expand electricity generation to feed demand that could not be matched with very scarce domestic fossil fuels. Furthermore, Japan was developing ‘energy angst’ related not only to its high dependence on Middle Eastern oil and gas but also to potential competition with China’s with its rising appetite for energy. At the same time, Germany’s electricity consumption stagnated in the 1990s and its energy security improved following the end of the Cold War. Germany was also one of the world’s largest coal producers and could in principle supply all its domestic electricity from coal. As a result, in the 1990s, Japan was forced to build nuclear power plants, but Germany could easily do without them.

There was another important development in the early 1990s: wind power technology diffused to Germany from neighboring Denmark. This was triggered by an electricity feed-in-law of 1990s, which obliged German electric utilities to buy electricity from small producers at close-to-retail prices. The law, which aimed to benefit a small number of micro-hydro plant owners, unexpectedly led to almost a 100-fold rise in wind installations in Germany. Although still insignificant in terms of electricity, this development created a large and vocal lobby of owners and manufacturers of wind turbines. In the early 2000s, the wind sector provided less than one-tenth of nuclear electricity but had more jobs than in the nuclear sector. In contrast, Japan’s similar policies of buying wind energy from decentralized producers did not result in any considerable growth of wind power, because the Danish technologies prevalent in the early 1990s could not be as easily diffused to Japan.

By the turn of the century, the electricity sectors in Germany and Japan still looked largely similar, but the political dynamics could not be more different. In Germany, a huge politically-powerful coal sector was represented by Socio-Democratic Party and the so-called ‘red-green’ coalition was formed with the Green party, who represented the rapidly growing wind power sector. The stagnating nuclear industry, however, had not seen new domestic orders or construction for 15 years and large industrial players like Siemens had begun to diversify away from it. All this was in the context of a positive energy security outlook and declining electricity prices. In contrast, in Japan, the nuclear sector had vigorously grown over the last decade and was becoming globally dominant by acquiring significant manufacturing capacities. Nuclear power was the only plausible response to the energy angst and it lacked any credible political opponents: the domestic coal sector in Japan virtually did not exist (Germany had around 70,000 coal mining jobs, Japan – about 1,000) and wind had never taken off.

© Pla2na | Shutterstock

The results of these very different political dynamics were predictably different: the red-green coalition in Germany legislated nuclear phase-out in 2002 and unprecedented financial support for renewables in 2000, while retaining coal subsidies and triggering construction of new coal power plants. Japan continued to support solar energy in which it had been the global leader since the 1970s but it also adopted a plan for constructing many more nuclear reactors designed to substitute imported fuels. Fukushima, rather than highlighting differences actually made the energy trajectories of two countries more similar as both countries began to struggle to replace their aging nuclear capacities with new renewables.

How does this story relate to wider questions such as: why are some countries more successful in deploying renewables than others? The answer is not in ‘stronger political will’ and in the strength of climate change concerns, but in economy, geography, and the structure of energy systems. Political wins for renewables and the climate can also be the result of dubious political compromises such as the alliance with the coal lobby in Germany, which led to the rapid growth of renewables and demise of nuclear power. It may be particularly difficult for countries with fossil fuel resources to implement renewable energy policies if they lead to the contraction of domestic coal, gas or oil industries.

Reference: Cherp A, Vinichenko V, Jewell J, Suzuki M, & Antal M (2016). Comparing electricity transitions: A historical analysis of nuclear, wind and solar power in Germany and Japan. Energy Policy 101: 612-628.

Acknowledgements

The study was supported by the CD-LINKS project and the Central European University’s Intellectual Theme’s Initiative.

This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

 

Are the Paris climate commitments fair?

Shinichiro Fujimori, guest researcher in the IIASA Energy Program, discusses the implications of a recent paper with IIASA Science writer and Editor Daisy Brickhill.

The climate mitigation costs of the Paris Agreement are fairly distributed between countries, but they are not fair for future generations, a new IIASA study has found. This suggests that the relative differences between countries’ climate commitments can be kept the same, but to ensure equity for our descendants they must all be raised .

The Paris Agreement allows each country to set its own climate commitments (known as the Intended Nationally Determined Contributions, or INDCs), and while this autonomy encourages more states to enter into the agreement, it may result in some countries freeloading by not making their fair share of cuts. There is also a trade-off between the mitigation investments we make now, and how much we leave for our descendants to deal with. The study by Fujimori and colleagues examines the issue of equity from different angles.

How did you measure the equity of the climate commitments?

We designed four scenarios: there was the baseline, which has no climate policy, and therefore no emission constraints at all. Then there was a scenario with a carbon price that is the same all over the world, set high enough to put us on course to meet targets to keep warming well below 2°C by 2100. The third scenario allowed different countries to have different carbon prices, meaning that they followed their current INDCs until 2030, but at that point a global carbon price was again put in place to ensure that we reach 2°C targets by the end of the century. Finally, we created a scenario where all emissions reduction targets were 20% higher than the INDCs until 2030. Again, after that a global carbon price was set. For all of the scenarios we also varied what is known in economics as the “discount rate.”

What is a discount rate?

People tend to devalue the future. So, for example, given the choice of €100 now or €150 in five years, many people would choose the €100 now. This is known as a time preference. You can add to this an “inequality aversion.” This is the amount that a wealthy person is willing to reduce their consumption by in order to increase the amount a poor person can consume. Together they make the discount rate.

We used different values of discount rate to see what might happen if people cared a lot about future generations, or poorer countries, or if they did not.

And, are the INDCs fair?

We found that delaying emissions reductions will push the costs onto future generations. In all our scenarios, regardless of the discount rate, there was inequality between the generations. The best scenario for equity between current and future generations was the second scenario with high, globally uniform carbon taxes that start immediately.

© Robwilson39 | Dreamstime

© Robwilson39 | Dreamstime

The inequity between generations was not unexpected, but what was surprising was that under the Paris Agreement the equity between countries was good. The third scenario, which followed the INDCs until 2030, has much better equality between the regions until the global carbon price began in 2030. This is because low-income countries tended to set lower carbon prices, and more developed countries had higher carbon prices.

That means that the last scenario is the ideal. We can keep the relative differences between the INDCs the same but raise them all so that we can meet the targets. That would give us both inter-regional equity and inter-generation equity.

What about the costs of the impacts of climate change? The Paris Agreement mentioned the need for a mechanism to support the victims of climate-related loss and damage.  Might that not create a completely different picture of equity?

That is not something we covered in the study, but it is very important. We need many more studies in that area. We need flood teams, agricultural teams, and others, all collaborating across disciplines. Very much how IIASA works, in fact. Fortunately, the model we constructed for this study can incorporate all of these aspects, as they become available, and translate them into a comprehensive economic assessment.

Liu JY, Fujimori S, & Masui T (2016). Temporal and spatial distribution of global mitigation cost: INDCs and equity Environmental Research Letters, 11 (11): 114004.

This article gives the views of the interviewee, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Pipe dream or savior?

By Daisy Brickhill, IIASA science writer and editor.

Many of the options proposed for achieving a stable climate rely on ‘bioenergy with carbon capture and storage’ — burning plant matter for energy, capturing the carbon, and storing it underground. However, this technology has hardly been deployed on anything approaching the large scale. Is it a realistic tool for climate mitigation?

Limiting global warming to 2°C above pre-industrial times has long been a reference point for policymakers and researchers trying to reduce the chances of dangerous climate change. The 2015 Paris climate summit went even further, with countries agreeing to try and limit temperature rise to 1.5°C.

However, while there is a strong scientific consensus that we need to aggressively cut greenhouse gas emissions immediately, there is also growing evidence that we may not be able to achieve the necessary reductions in the time available. This means that we may need a way of removing CO2 already in the atmosphere — a process known as negative emissions.

Negative emissions can come in many forms: from simply planting more trees, to crushing rocks that naturally absorb CO2. One widely considered option is using plant matter as a fuel to produce energy, then capturing the CO2 that is emitted and storing it underground. This is known as bioenergy with carbon capture and storage (BECCS).

This latter technology is cited by research as being an important part of restricting warming to safe — or at least safer — levels since it contributes to both carbon sequestration and decarbonization of the energy system. In fact, more than half of the future scenarios that give at least a 66% chance of limiting warming to 2°C, which were developed for the Intergovernmental Panel on Climate Change (IPCC), feature BECCS.

However, the technology remains mostly untested on a large scale and there are doubts about its sustainability in terms of land and water use, and other potentially negative impacts on the environment. With so many IPCC scenarios including BECCS, information on whether it is at all a practical solution is desperately needed.

A recent IIASA study addresses deployment of BECCS in Indonesia, examining whether adapting existing coal-fired power stations so that they can burn a mix of coal and plant waste from agriculture (such as seed kernels or stems that are usually discarded), is more effective than building specific biomass-burning power stations.

Rice paddies in Indonesia. Plant waste from agriculture can be used in bioenergy with carbon capture and storage systems.

The team found that although both options saved the same amount of CO2, the combined stations were more efficient, producing more electricity for the amount of biomass burnt. “More efficiency means that burning biomass in adapted coal-fired power stations would be more economically viable,” says IIASA researcher Ping Yowargana, coauthor of the study. “It is also likely to be easier and cheaper to convert existing coal power stations than build new specific biomass-burning stations. With lower investments and existing infrastructure, policymakers and other stakeholders are more likely to embrace the idea.”

There are limitations: the study results indicate that under the current conditions it is not possible to burn any more than 30% biomass in a combined power station, for instance. There are also uncertainties surrounding whether it is possible to collect enough biomass on the scale needed. “We need to do further work on the logistic and financial feasibility of BECCS,” says Yowargana. “But these results are broadly general, and can be applied to other countries and situations, making them a valuable starting point.”

And while a complete conversion to a decarbonized energy system is needed in the long term, this work points the way to how BECCS might be deployed now to help prevent the damaging climate change we have sown for ourselves.

Reference: Hetland J, Yowargana P, Leduc S & Kraxner F (2016). Carbon-negative emissions: Systemic impacts of biomass conversion: A case study on CO2 capture and storage options. International Journal of Greenhouse Gas Control, 49. pp. 330-342.

Further reading:

https://www.carbonbrief.org/beccs-the-story-of-climate-changes-saviour-technology

Moreira, J. R., Romeiro, V., Fuss, S., Kraxner, F. and Pacca, S. A. (2016) BECCS potential in Brazil: Achieving negative emissions in ethanol and electricity production based on sugar cane bagasse and other residues. Applied Energy, 179. pp. 55-63. Item availability may be restricted.

Smith, P., Davis, S.J., Creutzig, F., Fuss, S., Rogelj, J., McCollum, D., Krey, V., Grubler, A., Jonas, M., Kraxner, F., Nakicenovic, N., Obersteiner, M. and Rogner, M. (2016) Biophysical and economic limits to negative CO2 emissions. Nature Climate Change, 6 (1). pp. 42-50.

Fuss, S., Canadell, J.G., Peters, G.P., Tavoni, M., Andrew, R.M., Ciais, P., Jackson, R.B., Jones, C.D., Kraxner, F., Nakicenovic, N., Le Quere, C., Raupach, M.R., Sharifi, A., Smith, P. and Yamagata, Y. (2014) Betting on negative emissions. Nature Climate Change, 4 (10). pp. 850-853.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Pessimism is not an option: The road to sustainable development

Interview with Naoko Ishii, CEO and Chairperson of the Global Environment Facility (GEF), an independent organization that provides grants for projects working towards sustainability. IIASA, the GEF, and the United Nations Industrial Development Organization (UNIDO) have recently partnered on a new project to explore integrated solutions for water, energy, and land.

Naoko Ishii ©Global Environment Facility

Naoko Ishii ©Global Environment Facility

Q What is sustainable development and why is it important?
As Brundtland put it, sustainable development meets the needs of the present without compromising the ability of future generations to meet their own needs.

If we do not achieve sustainable development, we will fail to provide even the barest essentials of life—food, water, and shelter—for the growing population. The extra two billion people that will inhabit the world in 2050 can only be accommodated if we are serious about sustainable development.

On a personal level I care about sustainable development because I care about the future, I care about young people, and I care about humanity. Achieving sustainable development is, in my opinion, the single most important issue we face today. Without it, all life on Earth is in jeopardy.

The Global Environment Facility (GEF) was created on the eve of the 1992 Earth Summit in Rio to assist in the protection of the global environment and promote sustainable development. The benefits of such an endeavor have only become clearer over time. It is no coincidence that in 2015 all nations of the world will adopt a set of sustainable development goals which place a strong emphasis on the “global commons,” and that in parallel we have a new global agreement on climate change within reach.

How do you see the world in 2050? What are your most optimistic and pessimistic visions?
I am an optimistic person so I will say that, by 2050, every government, every business, and every individual will take the environment into consideration in all their actions. By 2050, we will all be caring for the Earth, taking responsibility for the use of our planet’s resources, and building economies which will leave no one without dignity or necessary subsistence. We will live within safe planetary boundaries. Pessimism is not an option for me.

How can science help the world achieve sustainable development?
Science plays a critical role.  We need it to monitor the state of our resources, the impacts of our activities, and the progress being made.  Science can also help identify solutions. It can help encourage businesses to make smart decisions, for example, about saving money though energy efficiency, risk mitigation, and new revenue opportunities driven by innovation and new business models.

Sustainable development is a truly cross-cutting endeavor: it spans many sectors, from agriculture to economics, and transcends national boundaries. Science can play an important role by producing research that is integrated, cross-sectoral and international. In this way, synergies, co-benefits, and trade-offs can be explored in order to identify the smartest paths to achieving multiple sustainable development goals at the same time

©The GEF

“Sustainable development is a truly cross-cutting endeavor: it spans many sectors, from agriculture to economics, and transcends national boundaries.” ©The GEF

How do you see the role of Global Environment Facility in implementing the Sustainable Development Goals?
The GEF is uniquely placed to support the global commons—the planet’s finite environmental resources that provide the stable conditions required for a sustainable, prosperous future for all.  Our new strategy—GEF2020—lays out an ambitious vision for the GEF, aimed at addressing the underlying drivers of environmental degradation and delivering integrated, holistic, solutions. We are building on more than 20 years of experience providing support to over 165 countries. By working with national governments, local communities, the private sector, civil society organizations and indigenous peoples, we help find and implement integrated solutions to global challenges.

What are the advantages of a cross-sectoral and cross-border approach to identifying paths to sustainable development?
Many environmental challenges and threats to sustainable development do not respect borders.  Moreover, they are often interdependent, or share common drivers. For example, biodiversity loss and climate change is partly driven by unsustainable forest management, which is in turn connected to production of globally traded commodities like palm oil or soy. Problems like this require an integrated, cross-cutting approach.

Given the importance of cross-sectoral interventions, at the GEF we will be implementing a program of integrated approach pilot projects. We believe that these will help countries and the global community in tackling underlying drivers of environmental degradation. I am also very excited about a research program we have recently launched in partnership with IIASA and the United Nations Industrial Development Organization, focusing on development and implementation of integrated solutions to tackle the water-food-energy nexus.

Note: This article gives the views of the interviewee, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

10 steps to removing carbon from the global economy

By Nebojsa Nakicenovic, Deputy Director General, International Institute for Applied Systems Analysis (IIASA), Austria (Originally published on the World Economic Forum Agenda Blog.)

Nebojsa Nakicenovic

Nebojsa Nakicenovic

Goal 7 of the Sustainable Development Goals is ambitious: Ensure access to affordable, reliable, sustainable and modern energy for all. This must be accomplished without compromising Goal 13: climate. This is achievable.

In spite of ups-and-downs and outright shocks in the global economy, some quite recent, the economic success stories of the industrialized countries are role models for the countries that are still developing. This puts the entire global community in the dichotomous position of needing to fire up the engine of growth, without producing the greenhouse gases it has been emitting since the beginning of the Industrial Revolution. What is the answer?

Very few questions in the complex area of energy and climate change can have a simplistic answer, but I am going to attempt one here: decarbonization, namely, drastic reduction of carbon dioxide and other greenhouse gas emissions per unit of economic activity.

Back in 1993, I wrote this:

“The possibility of less carbon-intensive and even carbon-free energy as major sources of energy during the next century is consistent with the long-term dynamic transformation and structural change of the energy system.”

My view in 2015 is the same; however, the scientific community 22 years later has a much better understanding of “the decarbonization challenge” and how it can be addressed. I will sketch out a 10-step approach to the removal of carbon from the global economy, but first I’d like to paint in a bit of the background.

Carbon dioxide is the main greenhouse gas and contributor to climate change. The largest source is our use of fossil fuels to drive development. Carbon dioxide emissions have increased exponentially since 1850 at about 2% per year, while decarbonization of the global economy is only around 0.3% per year.

The 2012 Global Energy Assessment, in which IIASA played a leading role, puts the current decarbonization rate at approximately six times too low to offset the increase in global energy use of about 2% per year. To meet the goal of the 2009 climate agreement (the Copenhagen Accord), namely, “the scientific view that the increase in global temperature should be below 2 degrees Celsius” to prevent dangerous anthropogenic interference with the climate system, global net emissions of carbon dioxide and other greenhouse gases will need to approach zero by the second half of this century, implying deep, deep decarbonization rates.

working oil pumps © Kokhanchikov | Dollar Photo Club

“Carbon dioxide is the main greenhouse gas and contributor to climate change. The largest source is our use of fossil fuels to drive development.” © Kokhanchikov | Dollar Photo Club

But we need deep decarbonization while energy needs are increasing to meet the demand of the developing world, including the three billion without access today to sustainable energy. All scenarios in the academic literature that lead to further economic development in the world, universal access to sustainable energy, and the stabilization of climate change to less than 2 degrees Celsius, anticipate deep and urgent decarbonization. Here’s my 10-point plan for doing that.

  1. Change attitudes
    Attitudes to energy use are based on many factors, from cultural norms to overall infrastructure design. We need much greater political will to affect a change in attitudes: it is critical that policy interventions should communicate to citizens the ethical notion of improved well-being and health now and for future generations of a zero-carbon economy. .
  1. Transform governance
    The transformation needed this century is more fundamental than previous transformations, like the replacement of coal by oil, because of the significantly shorter time needed to achieve it. Thus, government policies are essential, and are needed particularly in changing buildings codes, fuel efficiency standards for transportation, mandates for the introduction of renewables, and carbon pricing.
  1. Improve energy efficiency
    More efficient provision of energy services, or doing more with less, and radical improvements in energy efficiency, especially in end use, will reduce the amount of primary energy required and represents a cost-effective, near-term option for reducing carbon dioxide emissions, as well as having multiple benefits in different areas of life.
  1. Ramp up renewable use
    We can show that the share of renewable non-fossil energy from solar, wind, rain, tides, waves, and geothermal sources in global primary energy could increase from the current 17% to between 30% and 75%. In some regions it could exceed 90% by 2050, provided that public attitudes change and efficiency increases.
  1. Reduce global energy intensity
    The energy intensity in the industrial sector in different countries is steadily declining due to improvements in energy efficiency and a change in the structure of the industrial output. Far greater reductions are feasible by combining these improvements with adoption of the best-achievable technology.
  1. Use known technologies
    Carbon dioxide capture and storage (CCS), now being piloted, is a pathway that leads to decarbonization with continued use of fossil energy. It requires: reducing costs, supporting scale-up, assuring carbon storage integrity and environmental capability, and securing approval of storage sites. Nuclear energy could make a significant contribution in some parts of the world, or it could be phased out as, for instance, in Germany.
  1. Improve buildings
    Retrofitting buildings can reduce heating and cooling energy requirements by 50–90%; new buildings can be designed and built using close to zero energy for heating and cooling. Passive energy houses and those that produce energy onsite are another great opportunity to achieve vigorous decarbonization. In conjunction with compatible lifestyles oriented toward rational energy use, efficient buildings are an important decarbonization option.
  1. Cut transport carbon
    A major transformation of transportation is possible over the next 30–40 years and will require improving vehicle designs, infrastructure, fuels and behavior. Electrically powered transportation reduces final energy use by more than a factor of three over gasoline-powered vehicles. A shift toward collective mobility is an essential option. This also implies behavioral changes and new business models like car-sharing, and self-driving cars to replace individual mobility.
  1. Clean industrial processes
    Overall, global industry efficiency is only 30%. Improved energy efficiency in industry results in significant energy productivity gains and, in turn, improved productivity boosts employment and corporate competitiveness. A shift toward low to zero emission energy sources in industry is another important and much-needed change. For example, with an aggressive renewables strategy, near-zero growth in GHG emissions in the industrial sector would be possible. Finally, decarbonization would also involve changes of industrial processes, for example, from high to low temperatures.
  1. Stranded assets and ‘derisking’ renewables.
    The flow of investment needs to be changed away from fossil fuels and toward efficiency, renewables, decarbonization of fossil energy sources, and especially efficient end-use in buildings, transport, and industry. Sustainable energy futures require relatively high up-front investments with the benefit of low long-term costs. They are attractive in the long run, but the up-front investments need derisking and other forms of support, such as feed-in tariffs.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Making ends meet: Negative emissions for climate stabilization

By Sabine Fuss, Mercator Research Institute on Global Commons and Climate Change (MCC) and IIASA Ecosystems Services and Management Program

The Sleipner CCS plant in Norway was the world's first commercial CO2 storage facility. Photo: Kjetil Alsvik/Statoil

The Sleipner CCS plant in Norway was the world’s first commercial CO2 storage facility. Photo: Kjetil Alsvik/Statoil

Current strategies for limiting climate change to no more than 2°C above pre-industrial levels are centered around a shift towards less carbon-intensive technology, increases in energy efficiency, and changes in management and behavior.

This won’t be enough.

Global carbon dioxide concentrations have exceeded the benchmark of 400ppm, and it is clear that we’re headed for an overshoot. This means that to have a chance of stabilizing climate change below 2°C, we will actually need to extract greenhouse gases from the atmosphere, thus achieving what we call “negative emissions.” This is even more evident when we look at continued population growth, our dependence on existing infrastructure in the near future, and rising living standards in many emerging regions.

In a session on negative emissions at this year’s CFCC conference in Paris jointly organized by members of the Global Carbon Project at IIASA, MCC and CSIRO, and CO2-GEONET, a group of leading international researchers discussed the need for negative emissions and the implications of large-scale removal of CO2 from the atmosphere, and took a closer look at the outstanding questions and uncertainties on the topic.

Bioenergy with Carbon Capture and Storage (BECCS), and afforestation are two possibilities that could contribute to negative emissions, removing greenhouse gases from the atmosphere. © zlikovec |Dollar Photo Club

Bioenergy with Carbon Capture and Storage (BECCS), and afforestation are two possibilities that could contribute to negative emissions, removing greenhouse gases from the atmosphere. © zlikovec |Dollar Photo Club

A wide range of possibilities – but many open questions
The IPCC’s AR5 scenarios show that negative emissions could be achieved by combining carbon-neutral Bioenergy with Carbon dioxide Capture and Storage (BECCS), but also through afforestation. Most of the ambitious climate stabilization pathways show that we would need BECCS by the middle of the century, even though the removed emissions would not outweigh the remaining positive emissions at that point, that is, we would not yet see net negative emissions.

More precisely, the most recent scenarios of Integrated Assessment Models (IAMs) show that to achieve the 2°C limit, negative emissions of up to 13.2 GtCO2-eq./yr in 2100 are needed. This could be reached by BECCS, which might run into problems as competing for land with other demands, or a technology known as Direct Air Capture, which is more energy-intensive. Enhanced Weathering and afforestation might also deliver negative emissions, though of a smaller magnitude. However, all the presented negative emission technologies have their limits and none is a silver bullet. Clearly, there are more cards in the deck than just BECCS and we will have to aim for a portfolio respecting limits and trade-offs with other policy goals, but also opportunities and synergies.

One glaring clear point: negative emissions cannot be used to continue “business as usual” and then remove the bulk of the emissions mid-century. The required carbon flows would simply be too large. At the same time, such a high-emissions world would bring with it major environmental feedbacks, such as ocean acidification.  Thus, negative emissions have to be understood as just one element of a mitigation portfolio complementing drastic GHG emission reductions in the near term.

Many scenarios for limiting climate change require negative emissions by mid-century. Image: Global Carbon Project, 2014. http://www.globalcarbonproject.org/carbonbudget/

Many scenarios for limiting climate change require negative emissions by mid-century.
Image: Global Carbon Project, 2014.

While the large-scale use of biomass and its impacts have been at the center of bioenergy discussions for a while, CCS will also need to be scaled up to massive amounts of up to 25 GtCO2 per year by 2100. However, geology experts at the meeting were optimistic with respect to the storage potentials for these large amounts. The only challenge would be to find enough viable storage sites with assured capacity.

Other challenges include the need to investigate negative emission options that are not yet included in the AR5 scenarios, such as Enhanced Weathering, Direct Air Capture, and a method to improve CCS and BECCS with geothermal energy. How much the combined potential of these negative emissions options will indeed reduce temperatures also depends on the response of the climate system. However, two modelling teams presented new insights on reaction to overshoot, and negative emissions physically needed to keep global warming below 2°C.

While negative emissions are needed at large scale, many questions remain, which will need to be addressed very soon in order for scenarios meet reality. Communication must improve between scientists, politicians, practitioners, but also media and the public. Existing misunderstandings, for example, that negative emissions are just an excuse to continue on a business as usual pathway, or that negative emissions carry the same risks as geo-engineering, need to be resolved.

Read the full session report (PDF)

Sabine Fuss is leading the working group “Sustainable resource management and global change” at the Mercator Research Institute on Global Commons and Climate Change (MCC) in Berlin and holds a guest affiliation with IIASA’s ESM program. She is co-leading (with D. v. Vuuren) the research initiative “MAnaging Global Negative Emission Technologies (MaGNET)” hosted at the GCP Tsukuba Office

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.