
A taxonomy to map evidence on the co-benefits, challenges, and limits of carbon dioxide removal
- Select a language for the TTS:
- UK English Female
- UK English Male
- US English Female
- US English Male
- Australian Female
- Australian Male
- Language selected: (auto detect) - EN
Play all audios:
ABSTRACT Carbon dioxide removal is key to climate change mitigation, yet implications of its deployment remain unclear. Recent exponential growth in literature is rapidly filling this gap
but makes the synthesis of the evidence on carbon dioxide removal side effects increasingly challenging. Here we address this issue by mapping this literature and proposing a taxonomy to
synthesize and compare evidence on carbon dioxide removal side effects. The expansive evidence warrants the use of machine learning to systematically select relevant research and provide an
inventory of nearly 400 co-benefits, challenges, and limits. We find rich evidence in Europe but little information for Africa, South America, and Oceania, where large-scale carbon dioxide
removal is nevertheless projected. There is a predominance of articles discussing negative effects compared to positive ones. Starting from the limitations of our analysis and literature
gaps, we provide entry points for future studies that can build on our literature-based taxonomy. SIMILAR CONTENT BEING VIEWED BY OTHERS EVALUATING THE NEAR- AND LONG-TERM ROLE OF CARBON
DIOXIDE REMOVAL IN MEETING GLOBAL CLIMATE OBJECTIVES Article Open access 15 July 2024 COMPREHENSIVE EVIDENCE IMPLIES A HIGHER SOCIAL COST OF CO2 Article Open access 01 September 2022
SYSTEMATIC REVIEW AND META-ANALYSIS OF EX-POST EVALUATIONS ON THE EFFECTIVENESS OF CARBON PRICING Article Open access 16 May 2024 INTRODUCTION To comply with the Paris Agreement and to limit
global warming to 1.5 °C, rapid and deep reductions in gross CO2 emissions need to be complemented by active carbon dioxide removal (CDR) from the atmosphere1,2,3,4,5,6,7. CDR may
contribute to climate change mitigation by accelerating the realization of net-zero CO2 emissions, by offsetting residual emissions, which are often claimed to be hard to abate, and by
eventually achieving net-negative emissions to reverse a potential temporary overshoot of the carbon budget3,8,9 therewith gradually declining warming towards lower and safer levels10.
Mitigation pathways for 1.5 °C warming—be they with no, limited, or high overshoot—therefore typically imply substantial amounts of CDR, although actual deployment rates vary as a function
of policy choices11,12,13. CDR is continuously gaining attention and importance, partly due to ongoing delay in deep emission reductions but also as more and more net-zero pledges are being
put forward. Most of the currently discussed CDR options, however, are not yet available at the scale required to substantially contribute to climate change mitigation14,15. While this
implementation gap for CDR is already growing, there are also substantial environmental, socio-political, and economic implications arising from the deployment of CDR, which have not yet
been sufficiently understood. Previous literature reviews have identified both benefits and risks of CDR deployment16,17,18,19,20,21,22. However, the CDR literature has been growing
exponentially in recent years, which makes it increasingly challenging to comprehensively track and synthesize evidence on potential co-benefits, challenges, and limits15. In addition, the
absence of a taxonomy to categorize and analyze evidence severely hampers the synthesis and comparability of knowledge. We address this issue by systematically mapping the recent literature
evidence on co-benefits, challenges, and limits for six land-based CDR options: afforestation and reforestation (AR), bioenergy with carbon capture and storage (BECCS), biochar, direct air
capture with carbon capture and storage (DACCS), enhanced weathering (EW), and soil carbon sequestration (SCS). These options currently dominate the discussion on land-based CDR and are
increasingly incorporated in integrated assessment models (IAMs) that are used to inform long-term mitigation strategies11,12,15,23. In this study, we consider accompanying or consequential
effects of CDR deployment as well as phenomena hampering successful CDR deployment—details can be found in the Supplementary Note 2. These effects can be co-benefits, challenges, or limits
of CDR deployment. In the following, we collectively refer to these effects as positive or negative side effects of CDR deployment. We first show how the literature evidence on CDR side
effects has evolved over time. Based on the recent literature, we present an initial taxonomy of CDR side effects across multiple categories and aggregation levels to provide a comprehensive
overview of the literature evidence. We compare the literature-based effect profiles of the six considered CDR options and evaluate the available evidence regarding the desirability of the
effects identified, that is, whether effects are associated with societal, environmental, and economic benefits or disbenefits. Ultimately, we explore geographic differences in the
literature coverage and point towards potential literature gaps. More detailed information on the study’s approach is provided under Methods. RESULTS OVERVIEW OF LITERATURE GROWTH We
identified 982 peer-reviewed documents discussing side effects for the here-considered CDR options (Fig. 1a). The publication dates of these studies span across the last three decades, with
steep growth in the number of published documents in recent years. More than 50% of these documents have been published since 2018 (Fig. 1b). We find a large variety in study designs and
methodologies across studies, which can be categorized into five different study types. In recent years, the largest study type group was composed of quantitative analyses and modeling
studies, including IAM studies, life cycle assessments (LCAs), and other quantitative approaches to estimate effect sizes across CDR options. A smaller group of studies is focused on
qualitative analyses and conceptual deliberations, often focused on exploring policy implications and theoretical implementation challenges of CDR deployment. Empirical evidence mostly comes
from field experiments—often focused on soil-related implications of AR, biochar, and SCS—and partly from survey and interview studies, which often study the perception and acceptance of
potential future CDR deployment. In addition to these original research studies, there is a group of documents composed of reviews and meta-studies, often focused on an individual side
effect or CDR option. OVERVIEW OF SIDE EFFECTS Our literature inventory of CDR side effects in the full-texts selected for synthesis (_n_ = 233) resulted in nearly 400 individual effects,
covering a wide range of environmental, socio-political, technological, and economic aspects. These side effects were structured in a literature-based taxonomy for the six considered CDR
options, grouped in three overarching effect spheres and spanning three levels of effect aggregation (Fig. 2). Each effect category is assigned a unique identifier to make the taxonomy
easily operable and broadly applicable (Supplementary Fig. 2). The literature-based taxonomy is built on the peer-reviewed evidence for the six land-based CDR options considered in this
study, including information on unspecific CDR as a general mitigation concept. Beyond direct side effects, the taxonomy also contains phenomena that impact successful CDR deployment. Three
overarching effect spheres were identified. The largest sphere covers a wide range of effects related to environmental and human health implications of CDR deployment. A second sphere
includes the potential impacts of CDR deployment on economic prosperity and overall societal well-being. A third sphere entails a variety of potential implementation threats and challenges
that may undermine the successful contribution of CDR to climate change mitigation. Generally, the spheres on environmental and human health, as well as on economic prosperity and societal
well-being, primarily cover the direct side effects of actual or hypothesized future CDR deployment, while the sphere on implementation challenges mostly covers threats and barriers to
successful CDR deployment. The literature-based taxonomy consists of 18 effect categories with several subcategory levels. An overview of these effect categories is given in Table 1. SIDE
EFFECTS PER CDR OPTION For each included CDR option, we evaluated the option-specific coverage of side effects in the considered literature (Fig. 3). For none of the considered CDR options,
the evaluated literature body provides information on all 18 effect categories. Between one and three effect categories are not available per CDR option, with many more subcategories either
missing or not applicable. In each case, a careful assessment is needed of whether the effect does not occur for a particular CDR option or whether the missing subcategory points to an
identified literature gap. The individual effect profiles and the level of detail of the available information vary considerably between the considered CDR options. Side effects of AR,
biochar, and BECCS are well-covered by the literature, while information on DACCS and EW is more limited in terms of the number of articles and the spectrum of covered effects. The coverage
of SCS ends up somewhere in the middle between the former and the latter group. The literature on option-unspecific CDR primarily deals with effects within the spheres of implementation
challenges and economic prosperity and well-being, with less information on effects within the sphere of environmental and human health. In addition to structuring the literature and
identifying the coverage of individual side effects per CDR option, the analysis of the number of articles and the spectrum of covered effects per category is important to understand and
synthesize the insights. Figure 4 shows, for each category, the number of evaluated articles focusing on positive and/or negative effects (desirability)—irrespective of effect sizes,
significance, or study contexts. AR: Changes to the water cycle, impacts on the flow of nutrients and minerals, biodiversity implications, soil changes, high land demand, and thermal impacts
are among the most widely discussed side effects of AR. Slightly more evidence on negative (_n_ = 9 articles) than positive (_n_ = 6) implications for the water cycle are found, with some
articles (_n_ = 6) describing the effects of unclear impact. The impact desirability on nutrients in soils such as nitrogen, phosphorus, and potassium is mostly unclear due to
context-dependency, with several articles indicating negative effects due to soil nutrient losses. The literature reports both positive and negative impacts on biodiversity with a small set
of effects for which desirability is unclear. For several articles (_n_ = 8), the desirability of effects on soils is unclear due to context-dependency, with a slight dominance of articles
on positive (_n_ = 6) compared to negative (_n_ = 4) effects. Both positive and negative thermal impacts, mostly in terms of albedo changes, are reported for AR and strongly depend on the
baseline conditions of the respective studies24,25. The land use impact of AR is described as negative in nine out of 11 articles. BECCS: Impacts on land use, water cycle, and energy clearly
dominate the considered literature body on BECCS side effects with still a comprehensive set of articles covering most other 15 effect categories—BECCS is the CDR option with the most
available literature on side effects (_n_ = 72). Effects on land use and the water cycle documented in the literature are predominately undesirable, while for energy, there are more studies
(_n_ = 17) indicating net energy production potential than studies (_n_ = 9) indicating net energy demand for BECCS26,27,28,29. Many of the predominately negative effects on biodiversity,
food, and yields, as well as nutrients and minerals, are related to the high land demand for bioenergy plantations for BECCS. Biochar: Implications for food and yield, nutrients and
minerals, and general soil conditions are the primarily discussed side effects of biochar soil amendment. Articles mentioning impacts on food and yield are predominantly positive (_n_ = 20)
compared to negative (_n_ = 5) due to observed biochar-related yield increases for various crops30,31. Described implications for nutrients and minerals appear to be both positive and
negative, with many effects for which desirability is unclear. The literature on soil effects of biochar is more positive (_n_ = 12) than negative (_n_ = 5), but many articles (_n_ = 10)
describe effects for which desirability is ambiguous or context-dependent and, therefore, unclear. The benefits of biochar described in the considered literature are the most manifold
compared to the other CDR options in this study. DACCS: Impacts on the water cycle, energy, acceptance, land use, and nutrients and minerals are the most discussed effect categories for
DACCS. Articles on DACCS predominantly discuss undesirable side effects (19 out of 24 articles). The literature body also holds some information on desirable effects of DACCS deployment
compared to respective baselines or counterfactual scenarios, e.g., reduced pressure on biodiversity or water and land demand32,33, however, the number of articles is comparatively low (_n_
= 4). EW: Nutrients and minerals, acceptance, pH change, food and yield, and energy are the most discussed side effect categories for EW, while the evaluated literature evidence base on side
effects of EW is the most limited (_n_ = 17) among the considered CDR options. Positive effects of EW include the provision of essential nutrients and minerals such as phosphorus,
potassium, calcium, and magnesium to soils and plants34,35. EW may also reduce soil acidification. The high energy demand for grinding rocks is described in several articles (_n_ = 4) as a
main drawback of this CDR option35,36. SCS: For SCS, impacts on nutrients and minerals, as well as on food and yield, are the most widely discussed side effects. Changes to general soil
conditions, the water cycle, and biodiversity are also studied in several articles. Both positive and negative effects on the abundance of nutrients and minerals such as nitrogen, potassium,
phosphorus, and related compounds in soils and their leaching are described, with a substantial set of effects for which the desirability is unclear37,38. More articles report benefits (_n_
= 10) than downsides (_n_ = 5) for food and yield due to observed yield increases for a variety of agricultural products, including maize, soybeans, and tomatoes39,40. Similar to biochar,
the positive effects of SCS predominate for the majority of the effect categories considered, based on the evaluated literature. Unspecific CDR: The reviewed articles on side effects of
option-unspecific or aggregated CDR strongly focus on implications for policy response followed by information on biodiversity impacts and acceptance. Overall, the side effect information
for unspecific CDR is dominated by undesirable effects. An array of different negative policy developments to the availability of CDR, including reduced and delayed climate action or issues
of burden sharing36,41, is described, as already laid out in detail in the previous section. The evaluation of effect desirability shows comparatively comprehensive literature evidence for
positive effects for biochar and SCS across most effect categories. For BECCS, DACCS, and option-unspecific CDR, available information for the 18 evaluated effect categories appears to be
more negative than positive in most cases. The number of articles covering positive versus negative side effects of AR appears to be balanced—for EW, the evidence on side effects is
relatively scarce. The general and CDR option-specific information on side effects can be complemented by looking at the geographical coverage of the evaluated literature (Fig. 5). There is
substantial research on CDR side effects in Europe (_n_ = 58) despite the continent’s comparatively small size, while few studies on CDR side effects in Africa (_n_ = 13), Oceania (_n_ =
13), and South America (_n_ = 11) have been identified. The few available studies for these three regions predominately discuss negative aspects—for at least 50% of the considered effect
categories, there is no literature evidence on desirable effects. A large part of the available literature covers a global or multi-regional scope. For all regions considered, there is a
predominance of articles describing negative effects compared to positive ones. Available information on CDR benefits is especially rich for Asia and Europe. For Africa, there is no evidence
for DACCS, EW, and option-unspecific CDR in the evaluated evidence base. No articles studying SCS implications in South America were found. For all other regions, there is information on
potential side effects for all considered CDR options. Interestingly, the evidence on benefits appears to be more constrained to individual regions than the evidence on disbenefits for
DACCS, EW, and option-unspecific CDR. DISCUSSION AND OUTLOOK The presented taxonomy of CDR side effects, the comparison of effect profiles for the considered options, and the evaluation of
available evidence on benefits versus disbenefits, including geographic differences, provide a comprehensive overview and map of the diverse and rapidly growing literature evidence on CDR
implications. Our inventory of nearly 400 partly interrelated side effects underlines the multi-layered and complex nature of CDR as a climate change mitigation option. The diversity in CDR
effect profiles and the perceived parallel existence of benefits and disbenefits across several CDR options indicate the potential to optimize climate change mitigation strategies and
portfolios to foster advantages and minimize risks42. Our literature-based taxonomy of CDR side effects can be an initial but seminal tool for future studies to efficiently and
comprehensively enhance knowledge on individual aspects of CDR implications and thus help close remaining research gaps. For policymaking, our map provides an overview of the various aspects
that need to be carefully considered in the context of national and international CDR legislation and regulation. Below, we discuss current limitations as well as entry points for future
extensions and opportunities for impactful analyses. LIMITATIONS While taking a comprehensive and systematic approach to scan for evidence, the findings presented here are, by design,
constrained by the currently available peer-reviewed literature. This study synthesizes the evidence on CDR side effects that were found and discussed by recent studies across different
geographic contexts, suggesting a structured taxonomy for further analysis and highlighting where evidence is comparatively comprehensive or scarce. However, this reviewed literature might
not yet be a complete representation of all potential effects and their desirability—categories might evolve as new evidence arises. The search for recent CDR studies was as broad as
possible, yet the selected body exclusively consists of articles where side effects of CDR were explicitly framed as such. While for the refined literature selection and full-text analysis,
both explicit and implicit side effects of CDR were considered, the initial literature identification was restricted to articles written in English and explicitly articulating side effects
or phenomena hampering successful CDR deployment in their title, abstract, or keywords (see Methods and Supplementary Table 1 for details on the applied side effect identification). Evidence
that uses a different vocabulary or language to discuss CDR side effects might thus have been missed. Furthermore, only articles that consider side effects in an explicit CDR context have
been considered. Articles that deal with CDR components or options in non-CDR contexts, such as afforestation as a nature-based solution or bioenergy without CCS as an energy source, were
not considered. This more focused approach is meaningful, as many side effects of the considered CDR options are setup-specific. However, there may be several side effects that have not been
discussed in an explicit CDR context but would also occur when a specific CDR option is deployed. The focus on original research articles published since 2018 allowed for a more in-depth
evaluation of the individual full-texts on up-to-date effects; however, it excluded side effect literature that was published before. To evaluate potential blind spots, the inventory of side
effects of this study was compared to the CDR side effects described in other review articles and the IPCC AR6 report16,17,18,19,20,21,22,43. Potential implications for non-CO2 emissions
are mentioned for AR19 and BECCS17,18 in previous reviews, which were not covered in our literature-based inventory. For biochar, ref. 17. mention policy implications concerning potential
competition over biomass resources, which is also not part of our literature body. Apart from this, we conclude that despite the restriction to articles published after 2018, the vast
majority of effect categories per CDR mentioned in other reviews is comprehensively covered and, in many cases, further detailed by our study. However, modifying the set of considered
research articles would likely have an impact on the evaluation of effect desirability in terms of the distribution between articles discussing positive versus negative effects—especially
for CDR options where the available evidence is comparatively scarce. There are also limitations induced by the assessment of the identified literature. The evaluated articles are very
heterogeneous. They differ in terms of methodological approaches, considered CDR deployment volumes, effect sizes, effect baselines, and CDR intervention contexts with various temporal and
geographical scopes. Furthermore, effect desirability is determined in comparison to an associated baseline or counterfactual scenarios defined within the context and scope of a respective
study, which might make wider comparability challenging. Our approach allowed for an integration of a wide range of different study designs, including IAM modeling, LCAs, small to
medium-scale field experiments, surveys, as well as conceptual works (Fig. 1b). This resulted in a rich evidence base and provided an overall picture of the diverse CDR side effects and
their current academic discussion. However, the current approach does not yet allow for a comparison of the sizes or significance of identified benefits and disbenefits. THE WAY FORWARD The
proposed taxonomy and effect profiles of studies per CDR option allow to identify key gaps in the literature. For example, several theoretically relevant side effect categories are not
extensively covered in the evaluated literature for BECCS. These gaps are apparent in direct comparison to AR, for which there is comprehensive information on albedo changes or impacts on
soil composition and quality, while for the bioenergy plantations that are integral to BECCS, this is not the case despite expected effect similarities. Importantly, for bioenergy production
without CCS, the literature body for the two mentioned effect categories is much larger44,45,46, which partly links to limitations discussed in the previous section but also to challenges
that need to be overcome when synthesizing evidence on complex CDR options. Similarly, impacts on non-CO2 greenhouse gas emissions from soils are discussed in several articles on biochar and
SCS, while there is little information in the evidence base of recent literature for AR, BECCS, and EW even though these three options also actively influence soils, as previous reviews
highlighted17,18,19. These differences in literature coverage, despite similarities in the expected effects, indicate potential research gaps. Generally, the here presented effect profiles
per CDR option may support future investigations to evaluate whether missing information on certain effect categories points to their non-existence in the real world or only in the
literature. Our map identifies clear gaps in geographical coverage. Comparatively few studies focus explicitly on CDR side effects in Africa, South America, and Oceania, while there is
substantial evidence of side effects in Europe, Asia, and on a global or multi-regional basis. This insight is also supported by recent findings on literature coverage on CDR in general15.
This underrepresentation of Africa and South America is critical as these regions are considered essential for CDR deployment in mitigation pathways in IAMs15,23,47 and, therefore, require
urgent further investigation. This is especially the case since the few available studies for these regions mostly highlight negative aspects. Our analysis does not allow to identify a clear
reason for these regions’ underrepresentation. Interlinkages and overlaps between side effect categories, observed throughout conducting this study, were highlighted in part in Table 1,
e.g., for land use and biodiversity or soil conditions and the water cycle. While beyond the scope of this study, a more systematic analysis of such effect chains and feedbacks could further
enhance the understanding of CDR implications and potentially feed into further extensions of the here presented taxonomy. The comparison and evaluation of implications of different CDR
options would further benefit from systematic reviews of the evidence on effect sizes and has already been started to some degree16. Our map and taxonomy can provide guidance for determining
effect categories and related evidence as entry points for more comprehensive effect quantifications. Several side effects, such as pH change or nutrient cycling, may have optimal ranges,
where benefits may be turned into disbenefits and vice versa, depending on whether effect sizes are within the optimal range or not. This is highly context and option-setup-dependent and has
implications for sustainable CDR potentials, which warrants further analysis. Ultimately, we hope this evidence map and taxonomy will facilitate more comprehensive and consistent analyses
of CDR side effects to ensure an evidence-based integration in mitigation strategies and CDR portfolios that minimize disbenefits and maximize benefits. METHODS This systematic map of CDR
side effects consists of four main methodological steps, namely, literature identification, literature selection, literature coding, and literature synthesis. The individual steps are
detailed below. LITERATURE IDENTIFICATION Potentially relevant peer-reviewed literature on CDR for this study was systematically identified via the abstract and citation database Scopus,
using one keyword-based search query per considered CDR option and an additional query for unspecific CDR as a general mitigation concept. The developed search queries were partly informed
by the queries used in the review and map by ref. 17, and ref. 48. The CDR queries were combined with additional subqueries to restrict the selection to articles explicitly discussing
positive or negative side effects of CDR, as well as potential threats to CDR deployment. The queries are presented in Supplementary Table 1. By the time the queries were applied (May 20,
2022), 14,704 individual articles were identified. LITERATURE SELECTION Not all literature resulting from the search queries was indeed relevant to this study. For the literature selection,
we used a machine-learning-assisted selection process to separate relevant from irrelevant studies. To ensure consistency and transparency, first, a set of inclusion and exclusion criteria
for selecting relevant studies was developed (Supplementary Table 2). Based on the inclusion and exclusion criteria, a random sample (_n_ = 1010) of the potentially relevant literature (_n_
= 14,704) was manually labeled as relevant or irrelevant based on titles, abstracts, and keywords, making use of the NACSOS platform49. The labeled subset was used to train a machine
learning relevance classifier, which is made available. The classifier was used to predict the relevance of the unseen literature. The prediction scores allowed us to sort the remaining
literature in descending order of predicted relevance for the further screening process. The sorted unseen literature was screened by hand and iteratively tested if a recall target of 95%
with _p_ < 0.05 was met, using the stopping criterion developed by ref. 50. The statistical stopping criterion was met after screening 7714 documents, which allowed for around 50%
work-saving—982 truly relevant articles were identified. The selection was further restricted to original research articles (no review articles) and limited to publications since 2018 to
focus on the most recent developments and literature evidence on CDR side effects since the comprehensive review on CDR side effects by ref. 17.—importantly, more than 50% of all relevant
articles were published in or after 2018. The full list of articles labeled relevant, including their study type (see Data availability statement), as well as a PRISMA-aligned51 flow chart
(Supplementary Fig. 1) of the literature identification and selection process, are made available52. LITERATURE CODING Before selected full-texts were systematically reviewed and coded, each
selected document was critically re-evaluated to ensure that all requirements of the defined inclusion criteria were also met based on the full-text and that no labeling errors had
occurred. Eventually, 233 articles were considered in the evidence synthesis. For each considered full-text, all quantitative and qualitative information on side effects was extracted and
systematically documented, following coding guidelines developed for this purpose. The coding guidelines are made available in the Supplementary Note 2. LITERATURE SYNTHESIS To develop a
literature-based taxonomy of CDR side effects, all identified effects and implications were manually grouped into categories and subcategories based on thematic similarities and differences.
This was done in an iterative process to continuously refine the categories. Based on the identified categories and subcategories, the literature-based effect profiles of the six CDR
options were compared. The quantitative and qualitative literature evidence per side effect of the considered CDR options was also evaluated concerning effect desirability, meaning whether
side effects are associated with societal, environmental, and economic benefits or disbenefits. Where no explicit information on effect desirability was provided in the evaluated articles,
desirability was assigned in comparison to the articles’ respective effect baselines, given that desirability was unambiguous and not strongly context-dependent. For example, described
increases in energy generation through BECCS were considered unambiguously desirable, while the desirability of described soil pH changes was more unclear and thus not manually determined,
as different regions, land uses, or soil types have various optimal pH ranges. A complete list of coded side effects with related effect groups and effect desirability is made available in
the ZENODO repository corresponding to this study. Extracted information on the geographical scopes of the articles in the evidence base was used to evaluate regional differences in the
literature coverage. Code for processing and visualizing the data is made available. DATA AVAILABILITY The literature-based data set underlying this study is made available at:
[https://doi.org/10.5281/zenodo.10822108]. CODE AVAILABILITY The code for the machine learning classifier, as well as for processing and visualizing the data, is made available at:
[https://doi.org/10.5281/zenodo.10822108]. REFERENCES * Rogelj, J., McCollum, D. L., Reisinger, A., Meinshausen, M. & Riahi, K. Probabilistic cost estimates for climate change
mitigation. _Nature_ 493, 79–83 (2013). Article Google Scholar * Rogelj, J. et al. Energy system transformations for limiting end-of-century warming to below 1.5 °C. _Nat. Clim. Chang._ 5,
519–527 (2015). Article Google Scholar * Rogelj, J. et al. Mitigation pathways compatible with 1.5 °C in the context of sustainable development. in _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_. (eds. Masson-Delmotte, V. et al.) (Cambridge University Press, 2018). * Rogelj, J. et al. Scenarios towards limiting
global mean temperature increase below 1.5 °C. _Nat. Clim. Chang._ 8, 325–332 (2018). Article CAS Google Scholar * Luderer, G. et al. Residual fossil CO2 emissions in 1.5–2 °C pathways.
_Nat_. _Clim. Chang._ 8, 626–633 (2018). CAS Google Scholar * Clarke, L. et al. Energy systems. in _IPCC: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group
III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change_ (eds. Shukla, P. R. et al.) (Cambridge University Press, 2022). * Strefler, J. et al. Between Scylla and
Charybdis: delayed mitigation narrows the passage between large-scale CDR and high costs. _Environ. Res. Lett._ 13, 044015 (2018). Article Google Scholar * Hilaire, J. et al. Negative
emissions and international climate goals—learning from and about mitigation scenarios. _Clim. Chang._ 157, 189–219 (2019). Article Google Scholar * Babiker, M. et al. Cross-sectoral
perspectives. in _IPCC: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change_
(eds. Shukla, P. R. et al.) (Cambridge University Press, 2022). https://doi.org/10.1017/9781009157926.005. * Rogelj, J. et al. A new scenario logic for the Paris Agreement long-term
temperature goal. _Nature_ 573, 357–363 (2019). Article CAS Google Scholar * Byers, E. et al. AR6 Scenarios Database. https://doi.org/10.5281/zenodo.5886912 (2022). * Riahi, K. et al.
Mitigation pathways compatible with long-term goals. in _IPCC: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the
Intergovernmental Panel on Climate Change_ (eds. Shukla, P. R. et al.) (Cambridge University Press, 2022). * Prütz, R., Strefler, J., Rogelj, J. & Fuss, S. Understanding the carbon
dioxide removal range in 1.5 °C compatible and high overshoot pathways. _Environ. Res. Commun._ 5, 041005 (2023). Article Google Scholar * Minx, J. C. et al. Negative emissions - Part 1:
Research landscape and synthesis. _Environ. Res. Lett_. 13, 063001 (2018). * Smith, S. M. et al. _The State of Carbon Dioxide Removal_ 1st Edn https://doi.org/10.17605/OSF.IO/W3B4Z (2023). *
Smith, P. et al. Biophysical and economic limits to negative CO2 emissions. _Nat. Clim. Chang._ 6, 42–50 (2016). Article CAS Google Scholar * Fuss, S. et al. Negative emissions - Part 2:
Costs, potentials, and side effects. _Environ. Res. Lett_. 13, 063002 (2018). * Vaughan, N. E. & Lenton, T. M. A review of climate geoengineering proposals. _Clim. Chang._ 109, 745–790
(2011). Article Google Scholar * Russell, L. M. et al. Ecosystem impacts of geoengineering: a review for developing a science plan. _Ambio_ 41, 350–369 (2012). Article CAS Google Scholar
* Shepherd, J. G. Geoengineering the climate: an overview and update. _Philos. Trans. R. Soc. A Math. Phys. Eng. Sci._ 370, 4166–4175 (2012). Article CAS Google Scholar * Preston, C. J.
Ethics and geoengineering: reviewing the moral issues raised by solar radiation management and carbon dioxide removal. _WIREs Clim. Chang._ 4, 23–37 (2013). Article Google Scholar *
Lawrence, M. G. et al. Evaluating climate geoengineering proposals in the context of the Paris Agreement temperature goals. _Nat. Commun._ 9, 3734 (2018). Article Google Scholar *
Strefler, J. et al. Carbon dioxide removal technologies are not born equal. _Environ. Res. Lett._ 16, 074021 (2021). Article CAS Google Scholar * Huang, L., Zhai, J., Liu, J. & Sun,
C. The moderating or amplifying biophysical effects of afforestation on CO2-induced cooling depend on the local background climate regimes in China. _Agric. For. Meteorol._ 260–261, 193–203
(2018). Article Google Scholar * Cerasoli, S., Yin, J. & Porporato, A. Cloud cooling effects of afforestation and reforestation at mid-latitudes. _Proc. Natl. Acad. Sci._ 118,
e2026241118 (2021). Article CAS Google Scholar * Fuhrman, J. et al. Food–energy–water implications of negative emissions technologies in a +1.5 °C future. _Nat. Clim. Chang._ 10, 920–927
(2020). Article CAS Google Scholar * Donnison, C. et al. Bioenergy with Carbon Capture and Storage (BECCS): Finding the win-wins for energy, negative emissions and ecosystem services—size
matters. _GCB Bioenergy_ 12, 586–604 (2020). Article CAS Google Scholar * Hanssen, S. V. et al. Global implications of crop-based bioenergy with carbon capture and storage for
terrestrial vertebrate biodiversity. _Glob. Change Biol. Bioenergy_ 14, 307–321 (2022). Article CAS Google Scholar * Cheng, Y. et al. Future bioenergy expansion could alter carbon
sequestration potential and exacerbate water stress in the United States. _Sci. Adv_ 8, eabm8237 (2023). Article Google Scholar * Bi, Y. et al. Assessing the viability of soil successive
straw biochar amendment based on a five-year column trial with six different soils: Views from crop production, carbon sequestration and net ecosystem economic benefits. _J. Environ.
Manage._ 245, 173–186 (2019). Article CAS Google Scholar * Roobroeck, D. et al. Biophysical potential of crop residues for biochar carbon sequestration, and co-benefits, in Uganda. _Bull.
Ecol. Soc. Am._ 100, 1–3 (2019). Article Google Scholar * Cobo, S., Galán-Martín, Á., Tulus, V., Huijbregts, M. A. J. & Guillén-Gosálbez, G. Human and planetary health implications of
negative emissions technologies. _Nat. Commun._ 13, 2535 (2022). Article CAS Google Scholar * Fuhrman, J. et al. The role of direct air capture and negative emissions technologies in the
shared socioeconomic pathways towards +1.5 °C and +2 °C futures. _Environ. Res. Lett._ 16, 114012 (2021). Article CAS Google Scholar * Kelland, M. E. et al. Increased yield and CO2
sequestration potential with the C4 cereal Sorghum bicolor cultivated in basaltic rock dust-amended agricultural soil. _Glob. Chang_. _Biol._ 26, 3658–3676 (2020). Google Scholar * Kantzas,
E. P. et al. Substantial carbon drawdown potential from enhanced rock weathering in the United Kingdom. _Nat. Geosci._ 15, 382–389 (2022). Article CAS Google Scholar * Sovacool, B. K.,
Baum, C. M. & Low, S. Risk–risk governance in a low-carbon future: exploring institutional, technological, and behavioral tradeoffs in climate geoengineering pathways. _Risk Anal_ 43,
838–859 (2023). Article Google Scholar * Gao, S. & DeLuca, T. H. Biochar alters nitrogen and phosphorus dynamics in a western rangeland ecosystem. _Soil Biol. Biochem._ 148, 107868
(2020). Article CAS Google Scholar * Parihar, C. M. et al. Long-term impact of conservation agriculture and diversified maize rotations on carbon pools and stocks, mineral nitrogen
fractions and nitrous oxide fluxes in inceptisol of India. _Sci. Total Environ._ 640–641, 1382–1392 (2018). Article Google Scholar * Bossio, D. A. et al. The role of soil carbon in natural
climate solutions. _Nat. Sustain_ 3, 391–398 (2020). Article Google Scholar * Chahal, I., Vyn, R. J., Mayers, D. & Van Eerd, L. L. Cumulative impact of cover crops on soil carbon
sequestration and profitability in a temperate humid climate. _Sci. Rep._ 10, 13381 (2020). Article CAS Google Scholar * Buck, H. J. The politics of negative emissions technologies and
decarbonization in rural communities. _Glob. Sustain._ 1, e2 (2018). Article Google Scholar * Fuss, S. et al. Moving toward Net-Zero Emissions Requires New Alliances for Carbon Dioxide
Removal. _One Earth_ 3, 145–149 (2020). Article Google Scholar * Pathak, M. et al. Technical Summary. In _Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group
III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change_ (eds. Shukla, P. R. et al.) (Cambridge University Press, 2022). * Ruf, T., Makselon, J., Udelhoven, T.
& Emmerling, C. Soil quality indicator response to land-use change from annual to perennial bioenergy cropping systems in Germany. _GCB Bioenergy_ 10, 444–459 (2018). Article CAS
Google Scholar * Sieber, P., Ericsson, N., Hammar, T. & Hansson, P.-A. Including albedo in time-dependent LCA of bioenergy. _GCB Bioenergy_ 12, 410–425 (2020). Article CAS Google
Scholar * Abraha, M. et al. Albedo-induced global warming impact of Conservation Reserve Program grasslands converted to annual and perennial bioenergy crops. _Environ. Res. Lett._ 16,
084059 (2021). Article CAS Google Scholar * Popp, A. et al. Land-use futures in the shared socio-economic pathways. _Glob. Environ. Chang_ 42, 331–345 (2017). Article Google Scholar *
Lück, S. et al. Scientific literature on carbon dioxide removal much larger than previously suggested: insights from an AI-enhanced systematic map (Preprint).
https://doi.org/10.21203/rs.3.rs-4109712/v1 (2024). * Callaghan, M., Müller-Hansen, F., Hilaire, J. & Ting, Y. NACSOS: NLP assisted classification, synthesis and online. _Screening._
https://doi.org/10.5281/zenodo.4121526 (2020). Article Google Scholar * Callaghan, M. W. & Müller-Hansen, F. Statistical stopping criteria for automated screening in systematic
reviews. _Syst. Rev._ 9, 1–14 (2020). Article Google Scholar * Page, M. J. et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. _BMJ_ 372, n71 (2021).
Article Google Scholar * Prütz, R., Fuss, S., Lück, S., Stephan, L. & Rogelj, J. A taxonomy to map evidence on the co-benefits, challenges, and limits of carbon dioxide removal.
https://doi.org/10.5281/zenodo.10822109 (2024). * Deutz, S. & Bardow, A. Life-cycle assessment of an industrial direct air capture process based on temperature–vacuum swing adsorption.
_Nat. Energy_ 6, 203–213 (2021). Article CAS Google Scholar * Madhu, K., Pauliuk, S., Dhathri, S. & Creutzig, F. Understanding environmental trade-offs and resource demand of direct
air capture technologies through comparative life-cycle assessment. _Nat. Energy_ 6, 1035–1044 (2021). Article CAS Google Scholar * Pour, N., Webley, P. A. & Cook, P. J. Opportunities
for application of BECCS in the Australian power sector. _Appl. Energy_ 224, 615–635 (2018). Article Google Scholar * Stoy, P. C. et al. Opportunities and trade-offs among BECCS and the
food, water, energy, biodiversity, and social systems nexus at regional scales. _Bioscience_ 68, 100–111 (2018). Article Google Scholar * Fujimori, S. et al. Land-based climate change
mitigation measures can affect agricultural markets and food security. _Nat. Food_ 3, 110–121 (2022). Article CAS Google Scholar * Heck, V., Hoff, H., Wirsenius, S., Meyer, C. &
Kreft, H. Land use options for staying within the Planetary Boundaries—Synergies and trade-offs between global and local sustainability goals. _Glob. Environ. Chang_ 49, 73–84 (2018).
Article Google Scholar * Doelman, J. C. et al. Afforestation for climate change mitigation: potentials, risks and trade-offs. _Glob. Chang. Biol._ 26, 1576–1591 (2020). Article Google
Scholar * Schreyer, F. et al. Common but differentiated leadership: strategies and challenges for carbon neutrality by 2050 across industrialized economies. _Environ. Res. Lett._ 15, 114016
(2020). Article Google Scholar * Weng, Y., Cai, W. & Wang, C. Evaluating the use of BECCS and afforestation under China’s carbon-neutral target for 2060. _Appl. Energy_ 299, 117263
(2021). Article Google Scholar * Demenois, J. et al. Barriers and strategies to boost soil carbon sequestration in agriculture. _Front. Sustain. Food Syst_. 4, 1–14 (2020). * Cook-Patton,
S. C. et al. Lower cost and more feasible options to restore forest cover in the contiguous United States for climate mitigation. _One Earth_ 3, 739–752 (2020). Article Google Scholar *
Zhang, S. et al. Incorporating health co-benefits into technology pathways to achieve China’s 2060 carbon neutrality goal: a modelling study. _Lancet Planet. Heal._ 5, e808–e817 (2021).
Article Google Scholar * Papageorgiou, A., Azzi, E. S., Enell, A. & Sundberg, C. Biochar produced from wood waste for soil remediation in Sweden: carbon sequestration and other
environmental impacts. _Sci. Total Environ._ 776, 145953 (2021). Article CAS Google Scholar * Sundberg, C. et al. Biochar from cookstoves reduces greenhouse gas emissions from smallholder
farms in Africa. _Mitig. Adapt. Strateg. Glob. Chang._ 25, 953–967 (2020). Article Google Scholar * Branch, O. & Wulfmeyer, V. Deliberate enhancement of rainfall using desert
plantations. _Proc. Natl. Acad. Sci. USA_ 116, 18841–18847 (2019). Article CAS Google Scholar * Scheiter, S. et al. Climate change promotes transitions to tall evergreen vegetation in
tropical Asia. _Glob. Chang. Biol._ 26, 5106–5124 (2020). Article Google Scholar * Osuri, A. M. et al. Greater stability of carbon capture in species-rich natural forests compared to
species-poor plantations. _Environ. Res. Lett._ 15, 034011 (2020). Article CAS Google Scholar * Terlouw, T., Treyer, K., Bauer, C. & Mazzotti, M. Life cycle assessment of direct air
carbon capture and storage with low-carbon energy sources. _Environ. Sci. Technol._ 55, 11397–11411 (2021). Article CAS Google Scholar * Luo, Y. et al. Development of phosphorus composite
biochar for simultaneous enhanced carbon sink and heavy metal immobilization in soil. _Sci. Total Environ._ 831, 154845 (2022). Article CAS Google Scholar * ALVES, B. S. Q. et al. Effect
of sewage sludge and sugarcane bagasse biochar on soil properties and sugar beet production. _Pedosphere_ 31, 572–582 (2021). Article CAS Google Scholar * Azzi, E. S., Karltun, E. &
Sundberg, C. Life cycle assessment of urban uses of biochar and case study in Uppsala, Sweden. _Biochar_ 4, 18 (2022). Article Google Scholar * Beerling, D. J. et al. Potential for
large-scale CO2 removal via enhanced rock weathering with croplands. _Nature_ 583, 242–248 (2020). Article CAS Google Scholar * Güner, Ş. T., Erkan, N. & Karataş, R. Effects of
afforestation with different species on carbon pools and soil and forest floor properties. _CATENA_ 196, 104871 (2021). Article Google Scholar * Zhou, J., Chen, H., Tao, Y., Thring, R. W.
& Mao, J. Biochar amendment of chromium-polluted paddy soil suppresses greenhouse gas emissions and decreases chromium uptake by rice grain. _J. Soils Sediments_ 19, 1756–1766 (2019).
Article CAS Google Scholar * Kumar, N. et al. Impact of zero-till residue management and crop diversification with legumes on soil aggregation and carbon sequestration. _Soil Tillage Res_
189, 158–167 (2019). Article Google Scholar * Leonzio, G., Mwabonje, O., Fennell, P. S. & Shah, N. Environmental performance of different sorbents used for direct air capture.
_Sustain. Prod. Consum._ 32, 101–111 (2022). Article Google Scholar * Tribouillois, H., Constantin, J. & Justes, E. Cover crops mitigate direct greenhouse gases balance but reduce
drainage under climate change scenarios in temperate climate with dry summers. _Glob. Chang. Biol._ 24, 2513–2529 (2018). Article Google Scholar * Hu, B., Zhang, Y., Li, Y., Teng, Y. &
Yue, W. Can bioenergy carbon capture and storage aggravate global water crisis? _Sci. Total Environ._ 714, 136856 (2020). Article CAS Google Scholar * Dolan, K. A., Stoy, P. C. &
Poulter, B. Land management and climate change determine second-generation bioenergy potential of the US Northern Great Plains. _GCB Bioenergy_ 12, 491–509 (2020). Article CAS Google
Scholar * Cox, E., Spence, E. & Pidgeon, N. Public perceptions of carbon dioxide removal in the United States and the United Kingdom. _Nat. Clim. Chang_ 10, 744–749 (2020). Article CAS
Google Scholar * Bellamy, R., Lezaun, J. & Palmer, J. Perceptions of bioenergy with carbon capture and storage in different policy scenarios. _Nat. Commun._ 10, 743 (2019). Article
CAS Google Scholar * Peacock, K. A. As much as possible, as soon as possible: getting negative about emissions. _Ethics, Policy Environ._ 25, 281–296 (2022). Article Google Scholar *
Crusius, J. “Natural” climate solutions could speed up mitigation, with risks. additional options are needed. _Earth’s Futur_ 8, e2019EF001310 (2020). Article Google Scholar * Realmonte,
G. et al. An inter-model assessment of the role of direct air capture in deep mitigation pathways. _Nat. Commun._ 10, 3277 (2019). Article CAS Google Scholar * Krause, A. et al. Large
uncertainty in carbon uptake potential of land-based climate-change mitigation efforts. _Glob. Chang. Biol._ 24, 3025–3038 (2018). Article Google Scholar * Lan, Z., Chen, C., Rezaei
Rashti, M., Yang, H. & Zhang, D. High pyrolysis temperature biochars reduce nitrogen availability and nitrous oxide emissions from an acid soil. _GCB Bioenergy_ 10, 930–945 (2018).
Article CAS Google Scholar * McLaren, D. P., Tyfield, D. P., Willis, R., Szerszynski, B. & Markusson, N. O. Beyond “net-zero”: a case for separate targets for emissions reduction and
negative emissions. _Front. Clim_. 1, 1–5 (2019). * Geden, O., Scott, V. & Palmer, J. Integrating carbon dioxide removal into EU climate policy: prospects for a paradigm shift. _WIREs
Clim. Chang._ 9, e521 (2018). Article Google Scholar * Vetter, S. With power comes responsibility—a rangelands perspective on forest landscape restoration. _Front. Sustain. Food Syst_. 4,
1–10 (2020). * Schneider, L. Fixing the climate? How geoengineering threatens to undermine the SDGs and climate justice. _Development_ 62, 29–36 (2019). Article Google Scholar * Carrer,
D., Pique, G., Ferlicoq, M., Ceamanos, X. & Ceschia, E. What is the potential of cropland albedo management in the fight against global warming? A case study based on the use of cover
crops. _Environ. Res. Lett._ 13, 044030 (2018). Article Google Scholar * Schwinger, J., Asaadi, A., Goris, N. & Lee, H. Possibility for strong northern hemisphere high-latitude cooling
under negative emissions. _Nat. Commun._ 13, 1095 (2022). Article CAS Google Scholar Download references ACKNOWLEDGEMENTS R.P., S.F., and J.R. acknowledge funding from the European
Union’s Horizon 2020 research and innovation programme under grant agreement No 101003687 (PROVIDE). S.F. acknowledges funding from the German Ministry for Education and Research under grant
agreement No 01LS2101F (CDRSynTra). S.L. was supported by the ERC-2020-SyG under grant agreement No 951542 (GENIE). R.P. and S.F. acknowledge funding from the European Union’s Horizon 2020
research and innovation programme under grant agreement No 101081521 (UPTAKE). FUNDING Open Access funding enabled and organized by Projekt DEAL. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS
* Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany Ruben Prütz & Sabine Fuss * Mercator Research Institute on Global Commons and Climate Change (MCC), Berlin,
Germany Ruben Prütz, Sabine Fuss, Sarah Lück & Leon Stephan * Grantham Institute for Climate Change and the Environment, Imperial College London, London, UK Ruben Prütz & Joeri
Rogelj * Centre for Environmental Policy, Imperial College London, London, UK Joeri Rogelj * Energy, Climate and Environment Program, International Institute for Applied Systems Analysis
(IIASA), Laxenburg, Austria Joeri Rogelj Authors * Ruben Prütz View author publications You can also search for this author inPubMed Google Scholar * Sabine Fuss View author publications You
can also search for this author inPubMed Google Scholar * Sarah Lück View author publications You can also search for this author inPubMed Google Scholar * Leon Stephan View author
publications You can also search for this author inPubMed Google Scholar * Joeri Rogelj View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS
R.P., S.F., and J.R. conceptualized the study; R.P., S.F., S.L., and J.R. devised the methodology; R.P., S.L., L.S., and S.F. worked on the literature identification, selection, and coding;
R.P. and J.R. prepared the visualizations; R.P. wrote the original draft; and all authors reviewed and edited the paper. CORRESPONDING AUTHOR Correspondence to Ruben Prütz. ETHICS
DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. PEER REVIEW PEER REVIEW INFORMATION _Communications Earth & Environment_ thanks the anonymous reviewers for
their contribution to the peer review of this work. Primary Handling Editors: Clare Davis. A peer review file is available. ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer Nature remains
neutral with regard to jurisdictional claims in published maps and institutional affiliations. SUPPLEMENTARY INFORMATION PEER REVIEW FILE SUPPLEMENTARY INFORMATION RIGHTS AND PERMISSIONS
OPEN ACCESS This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or
other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in
the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the
copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Prütz, R., Fuss, S., Lück,
S. _et al._ A taxonomy to map evidence on the co-benefits, challenges, and limits of carbon dioxide removal. _Commun Earth Environ_ 5, 197 (2024). https://doi.org/10.1038/s43247-024-01365-z
Download citation * Received: 15 September 2023 * Accepted: 02 April 2024 * Published: 11 April 2024 * DOI: https://doi.org/10.1038/s43247-024-01365-z SHARE THIS ARTICLE Anyone you share the
following link with will be able to read this content: Get shareable link Sorry, a shareable link is not currently available for this article. Copy to clipboard Provided by the Springer
Nature SharedIt content-sharing initiative