1. INTRODUCTION
Satellite observation is a powerful tool for monitoring the earth remotely, without needing permission from the territory that is being observed. In addition to this traditional monitoring role, there is an emerging capability for using satellite remote sensing to measure atmospheric concentrations of greenhouse gas (GHG) emissions.Footnote 1 With the development of new commercial satellite systems that can measure GHG emissions from sources on the scale of industrial facilities,Footnote 2 and NASA's Geostationary Carbon Cycle Observatory (GeoCARB) mission – which will measure daily the total concentration of carbon dioxide (CO2), carbon monoxide (CO) and methane (CH4) in the atmosphere with a horizontal ground resolution of 3–6 miles (5–10 kilometres)Footnote 3 – more accurate remote attribution data is becoming available.Footnote 4 Such measurements made from space-borne platforms can augment the bottom-up calculation-based approaches typically used in state GHG inventories, and could allow improved integrated estimates of emissions utilizing top-down quantification data. The World Meteorological Organization (WMO) is developing a framework to harness these new developments in atmospheric concentration measurement capabilities and provide a fully integrated emissions information system,Footnote 5 and a group of 60 space agencies have signed the New Delhi Declaration, which aims to develop an ‘international, independent system for estimating and curbing anthropogenic GHG emissions based on accepted data’.Footnote 6 Such developments could facilitate the creation of independent data sets to enhance the comparability, replicability, and verifiability of state GHG emissions information.Footnote 7
Against this backdrop, this article evaluates the potential for satellite-enabled measurements of atmospheric GHG concentrations to contribute to transparency and answerability for state emissions, with a focus on international space law and policy,Footnote 8 and the Paris AgreementFootnote 9 to the United Nations Framework Convention on Climate Change (UNFCCC).Footnote 10 This is an exploratory analysis as these satellite technologies and techniques, as well as the relevant regulatory frameworks under the United Nations (UN) climate regime, are still evolving. Recognizing that greater transparency should not be seen as an end in itself,Footnote 11 we apply elements of the analytical framework of Gupta and van Asselt for evaluating the relationship between transparency and accountability.Footnote 12 As these authors note, in the context of the Paris Agreement, which has eschewed a sanctions-based enforcement model, the answerability elements of accountability, pertaining to relations, standards and judgments, are more pertinent than the enforceability dimensions, relating to sanctions and redress.Footnote 13 Similarly, as there are no binding emissions reduction commitments for states under international space law, enforceability considerations do not apply. Accordingly, we focus on the relationship between the aspects of transparency that relate to the answerability elements of accountability. We build upon the Gupta and van Asselt framework by emphasizing the technical dimensions of transparency in this context, which highlight the importance of data that is independent, replicable, accessible, and comparable. This focus on the technical and normative dimensions of transparency, and the relationship with answerability, yields new insights into the opportunities and challenges for utilizing emissions data facilitated by remote-sensing measurement capabilities under existing international legal frameworks.
Our analysis shows that there could be transparency gains arising from advancements in satellite-enabled measurement techniques and the public dissemination of the resulting integrated data sets. These gains are possible as the principles of international space law permit the remote sensing of territories and sharing of data in some circumstances without the permission of the state being observed.Footnote 14 Non-state actors can play an important role in naming and shaming states for failing to meet their international mitigation pledges, contributing to public answerability.Footnote 15 The standards against which transparent emissions data are assessed are likely to be derived from the UN climate regime because of the lack of emission mitigation targets under international space law.
There is also potential for improvements in the transparency of emissions data to translate into enhanced answerability for states under the Paris Agreement. Satellite-enabled measurement data could be used by states to verify their own emissions inventory reports, or as a reference point in the internationally coordinated expert review process under Article 13(11) of the Paris Agreement. However, it is unclear whether the latter option will be acceptable to states as remote-sensing measurements and the sharing of data without the permission of the sensed state conflict with the emphasis on non-intrusive transparency measures that are respectful of national sovereignty under the enhanced transparency framework of the Paris Agreement.Footnote 16 Furthermore, aggregated atmospheric measurement data could be used as an input into the global stocktake under Article 14. However, the absence of political judgments in this facilitative process limits the prospects for answerability arising from the global stocktake. Thus, there are a number of impediments to achieving greater answerability through the enhanced transparency afforded by satellite-enabled measurement techniques.
This article proceeds in four parts. Section 2 outlines the framework for evaluating the transparency-answerability relationship that will be applied in Section 4. Section 3 provides an overview of the issues with data quality and transparency in the current GHG inventory practices under the UN climate regime, and the potential for emerging atmospheric measurement techniques to address these concerns. A number of international initiatives seeking to harness space-based GHG measurement capabilities, both within and beyond the UN climate regime, are also canvassed. In Section 4, the analytical framework outlined in Section 2 is applied to evaluate the prospects of increased transparency, facilitated by advances in satellite technology and big data, leading to enhanced answerability for states’ GHG mitigation commitments. The options under both international space law and policy and the Paris Agreement are explored. Section 5 concludes and suggests that increased international cooperation is required to address concerns about new atmospheric measurement techniques, while encouraging access to the data collected.
2. THE RELATIONSHIP BETWEEN TRANSPARENCY AND ACCOUNTABILITY
Transparency is an emerging norm in global environmental governance,Footnote 17 but it should not be pursued for its own sake.Footnote 18 The definition of transparency is contested.Footnote 19 For present purposes, we adopt a broad conceptualization of transparency as ‘a governance of information, including demands for active transparency and access to information, but also demands for confidentiality and privacy, and for legal or political controls on the gathering and use of policy-shaping information’.Footnote 20 This definition acknowledges the tension between secrecy and disclosure, as well as the substantive choice associated with providing access to the information that underpins the exercise of power.Footnote 21
From a normative perspective, there is frequent contestation over ‘what transparency is good for’ in a particular context.Footnote 22 Potential rationales associated with the pursuit of transparency include enhancing accountability,Footnote 23 good governance,Footnote 24 and democratization by promoting informed participation of states or citizens.Footnote 25 However, in the process of implementing global regulation, alternative rationales for disclosure – such as rationalizing expert decision making, facilitating markets for environmental goods, or augmenting private authority and gain – tend to come to the fore.Footnote 26 In this article, we focus on evaluating if and how the increase in transparent information on GHG emissions generated by emerging satellite capabilities can contribute to the answerability of states for their mitigation commitments, adding to the literature on the transparency-accountability nexus.Footnote 27
Accountability is a salient concern of global environmental governance and related fields, the prominence of which has been enhanced by the growing body of work on global administrative law.Footnote 28 Like definitions of transparency, there are diverse understandings of accountability in the literature. These include broadFootnote 29 and narrowFootnote 30 definitions, and can feature both mechanistic and normative dimensions.Footnote 31 For the purpose of evaluating the desirability and utility of satellite-enabled emissions measurement capabilities, a functional approach to accountability is preferable. From this perspective, accountability can be analyzed in terms of its components: ‘accountability of whom; to whom; for what; and by what means’.Footnote 32
It is also helpful to differentiate between two dimensions of accountability relations: answerability and enforceability.Footnote 33 Gupta and van Asselt disaggregate answerability and enforceability into five elements:
• relations: agreeing on who is to be held to account (and to whom);
• standards: agreeing on standards of performance against which to be held to account (i.e., agreeing on accountability for what);
• judgments: agreeing on a process by which to assess whether standards are being met (i.e., the how of accountability);
• sanctions: agreeing on (legal, reputational, financial) penalties if standards are not met; and
• redress: agreeing on the scope and modalities of liability and compensation for harm inflicted as a result of standards not being met.Footnote 34
Relations, standards and judgments relate to answerability, whereas sanctions and redress constitute the enforceability component of accountability.Footnote 35 In the context of the Paris Agreement, the answerability dimensions are the most pertinent as states have explicitly eschewed an enforcement-oriented approach to compliance focused on sanctions and legal redress.Footnote 36 That is, unlike the Kyoto Protocol Enforcement Branch, which provides for the imposition of economic sanctions in the event of non-compliance by industrialized states,Footnote 37 the parties to the Paris Agreement have not agreed to sanctions or other enforceability measures for deficient performance.Footnote 38 Moreover, there are no binding emissions reduction commitments for states under international space law, and thus no formal consequences for failing to meet the required standards. Accordingly, the primary focus of this analysis will be on the answerability components of accountability.
Corresponding transparency arrangements can be linked to the disaggregated elements of answerability, providing benchmarks for evaluating the transparency-answerability relationship. Specifically, Gupta and van Asselt propose that the following transparency elements are relevant to the relations, standards and judgments aspects of answerability outlined above:
• Transparency from whom: Who has to be transparent (and to whom)?
• Transparency about what: What aspects of performance are to be made transparent?
• Transparency how: Reporting and review processes to make visible whether standards are being met.Footnote 39
These three elements are required for transparency to promote answerability, and provide valuable criteria for evaluating the potential benefits of transparent emissions data generated by satellite measurement techniques. The focus on transparency of whom, to whom, for what, and by what means – and on the nexus with relations, standards and judgments – facilitates evaluation of the extent to which transparency arrangements promote or hinder answerability: in this instance, the answerability of states for their emissions reduction pledges under the Paris Agreement.
We build upon the framework proposed by Gupta and van Asselt by expanding on the technical dimensions of transparency in the context of GHG emissions inventories. Inventories typically contain the total emissions of specific GHGs, originating from all source categories and sinks in a certain geographical area and within a specified time span. Under the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories, there is an expectation that ‘there is sufficient and clear documentation such that individuals or groups other than the inventory compilers can understand how the inventory was compiled and can assure themselves it meets the good practice requirements for national greenhouse gas emissions inventories’.Footnote 40 From this standpoint, transparency requires the provision of methodologies, data and data sources, assumptions, and quantifiable information, which should be explained clearly to facilitate replication, comparability and assessment of reported information by diverse stakeholders.Footnote 41 This dimension of transparency in emissions inventories is critical because, as the experience in the context of other multilateral environmental agreements (MEAs) has shown, poor data quality stemming from inaccurate and incomplete data can undermine both the transparency and accountability of compliance decisions predicated on this information.Footnote 42 These technical insights into the importance of independent, comparable, replicable and verifiable emissions data complement the Gupta and van Asselt framework for analyzing the relationship between transparency and answerability.
3. THE TRANSPARENCY POTENTIAL OF ATMOSPHERIC EMISSIONS MEASUREMENT TECHNIQUES
Before proceeding to apply the analytical framework articulated in Section 2 to atmospheric measurement of GHG emissions under international space and climate governance frameworks, this section first outlines the ways in which such measurements have the potential to improve the technical transparency of GHG emissions reporting. We start by providing a brief overview of the current processes for preparing state emissions inventories under the UNFCCC, and the data quality issues that have arisen in this context. We then explore the potential advantages of satellite-enabled measurement techniques to redress these data quality concerns, and enhance the transparency of national emissions data.
3.1. Limitations of Current Emissions Data under the UNFCCC
The current practice under the UNFCCC is for states to report their GHG emissions data, compiled in accordance with IPCC Guidelines,Footnote 43 in national inventory reports that are submitted to the UNFCCC Secretariat. These guidelines allow for three categories of approach to determine emissions, which are increasingly demanding in terms of complexity and data requirements:
• calculations using statistical information, especially for fossil fuel use;
• satellite measurements of land use using imagery;Footnote 44 and
• tracer-transport inversion, a technique based on atmospheric and/or oceanic measurements of the gases and mathematical models of air and water flow.Footnote 45
The first listed statistical method for calculating emissions is the most widely adopted as fossil fuel use is the dominant source of CO2 emissions in most countries.Footnote 46 Emissions data is derived from figures calculated using activity data and emission factors for each GHG. These calculation-based methodologies have significant scope for error because of the inherent uncertainty in quantifying emission factors, coupled with uncertainty in the activity data to which they are applied.Footnote 47
While the accuracy of the underlying data and emission factors has generally been improving over time,Footnote 48 concerns about data quality persist. As calculation-based approaches depend on the availability of activity data and the accuracy of emission factors, the quality of inventories varies significantly between countries and contributes to uncertainty in global estimates.Footnote 49 Using atmospheric measurements, Levin and her co-authors show that some emissions reported to the UNFCCC have been underestimated by 70% to 80%, reinforcing the need for an additional layer of top-down review of emissions estimates to verify bottom-up calculations.Footnote 50 Inventories also frequently require revision, especially for more heterogeneous and dispersed sources such as methane from waste management and pipeline transmission, which are difficult to estimate.Footnote 51 For example, the German methane (CH4) emissions for 2001 reported to the UNFCCC Secretariat were revised upwards in 2004, resulting in an increase of reported CH4 emissions of approximately 70% for the whole-time series 1990–2001.Footnote 52 As Weiss and Prinn observe, ‘the discrepancies are large enough to call into serious question the reliability of the emission factors that are used in bottom-up emissions accounting’.Footnote 53 Such discrepancies raise significant concerns about the accuracy and completeness of national inventory reports based primarily on calculation-based methodologies, and draw into question governance decisions predicated on this information.
A related issue is poor quality baseline data, which is subsequently revised. Based on 2010 data, Zahar analyzed how states respond to scrutiny of emissions inventories under the Kyoto Protocol by expert review teams (ERTs).Footnote 54 He found that dialogue between states and the ERT during the review frequently led to voluntary revision of initial estimates. Specifically, 34 out of 37 Annex B parties’ base-year estimates reviewed were voluntarily revised, or ‘adjusted’ by the ERT in rare instances.Footnote 55 Of these parties 23 (62% of the total of 37 reviewed parties) had initially advantageously over-reported their emissions in the base year, with 11 parties under-reporting their base-year emissions estimates to their own disadvantage.Footnote 56 The expectation that baseline data is revisable and ‘negotiable’, which has also been evident in the compliance systems of other MEAs,Footnote 57 underscores the need for independent and reliable data on GHG emissions.
Recent developments in satellite-enabled measurement techniques have the potential to address some of the deficiencies in bottom-up emissions data, with concomitant transparency benefits. Satellite technologies can be used to isolate the anthropogenic component from highly accurate atmospheric GHG concentration measurements, which facilitates verification of bottom-up estimates of emissions.Footnote 58 Moreover, as foreshadowed above, there is an emerging capability for satellite remote sensing to quantify CO2 emissions and other GHG concentrations from large-scale point sources, such as industries, power plants and megacities.Footnote 59 Gurney recommends a hybrid approach that takes advantage of the ‘best’ estimate of a flux, irrespective of the method used, taking into account considerations of ‘accuracy, cost, availability and political viability, in addition to the usual scientific metrics’.Footnote 60 These existing and emerging satellite measurement techniques can contribute to technical transparency by quantifying GHG emissions in a way that is accurate, independent, and replicable. As is shown below, such techniques can enhance the flexibility of the transparency options available, and broaden the range of actors to whom states are potentially answerable for their emissions progress.
3.2. International Initiatives to Improve Access to Transparent Emissions Data
A number of international initiatives, both within and beyond the UNFCCC, seek to harness the potential of satellite-enabled capabilities to improve the monitoring, measurement, and verification practices for GHG emissions. Under the UN climate regime, atmospheric monitoring and measurement techniques currently are addressed under provisions for research and systematic observation. Article 4(1)(g) UNFCCC requires states, inter alia, to promote and cooperate on ‘systematic observation and development of data archives related to the climate system’. In 2004, the first implementation plan for global climate observations to be coordinated by the Global Climate Observing System was finalized,Footnote 61 and later extensively updated at the tenth conference of the parties to the UNFCCC (COP-10) in 2010.Footnote 62 However, as discussed in the following section, the potential uses of atmospheric emission measurements under the UN climate regime are far broader than the focus on research and systematic observation of the climate system as a whole suggested in Article 4(1)(g).
Beyond the UN climate regime, the WMO, a UN specialized agency, is seeking to develop enhanced technical capabilities for a fully integrated emissions information system. In June 2015, the 17th World Meteorological Congress passed a resolution initiating the development of an Integrated Global Greenhouse Gas Information System (IG3IS) to be ‘an information source and framework that will join atmospheric GHG composition and flux measurements and other observations … with temporally explicit socioeconomic emission inventory data’.Footnote 63 The objectives of the IG3IS project are:
• to reduce the uncertainty in national emissions inventory reporting to the UNFCCC Secretariat;
• to locate and quantify previously unknown emissions reduction opportunities, such as fugitive methane emissions from industrial sources;
• to provide subnational entities, such as large urban source regions (megacities), with timely and quantified information on the amounts, trends and attribution by sector of their GHG emissions to evaluate and guide progress towards emissions reduction goals; and
• to provide support for the Paris Agreement's global stocktake.Footnote 64
The long-term WMO vision is for a GHG analysis and forecast system that will incorporate multiple coordinated satellites, aircraft, balloons and ground observation, together with inventory data, in a system of systems.Footnote 65 There is thus growing international interest in combining satellite-enabled measurement techniques and big data to provide access to transparent emissions data to inform monitoring, reporting, and verification activities.
National space agencies have also underlined their commitment to using space-based emissions data to develop an inclusive global data set, with a view to ‘establishing an international approach to estimating greenhouse gas emission changes for global use based on internationally accepted data’.Footnote 66 Recognizing the significant contribution of satellite data to climate change studies and disaster management support, the heads of space agencies from around the world expressed their determination to strengthen their role in informing decisions under the UN climate regime as part of the Mexico Declaration in September 2015.Footnote 67 Thereafter, following the signing of the Paris Agreement on 12 December 2015, more than 60 space agencies endorsed the New Delhi Declaration in April 2016 and committed to the development of an international, independent system for measuring GHG emissions to support the objectives of the Paris Agreement.Footnote 68 While the Declaration does not create legally binding obligations under international law, it does represent the consensus of two multilateral institutions and 58 states, including the world's leading space powers. One practical step towards implementation was agreed during the Paris Climate ‘One Planet’ Summit in December 2017, leading to the establishment of a Climate Space Observatory under the Paris Declaration.Footnote 69 Details of this Declaration – which, according to media reports, was adopted by Austria, China, the European Union (EU), Germany, India, Israel, Italy, Japan, Norway, Romania, Sweden, Switzerland, Ukraine, the United Arab Emirates and the United Kingdom (UK)Footnote 70 – are yet to be finalized. The initiators are seeking to coordinate this observatory under the framework of the Outer Space regime.Footnote 71 This means that the proposed space climate observatory is likely to be coordinated under an international space governance framework rather than under international climate law.Footnote 72
4. SATELLITE-ENABLED EMISSIONS MEASUREMENT: PROSPECTS FOR ENHANCING TRANSPARENCY AND ANSWERABILITY
Concerns about data quality and transparency in national emissions inventories under the UN climate regime, combined with recent advances in satellite-enabled emissions measurement capabilities, raise the following question: in what ways, if any, can an increase in transparent data facilitated by satellites and big data contribute to the answerability of states for their emissions reduction pledges? As explained in Section 2, focusing on transparency of actions, actors and process, and the relationship with relations, standards and judgments, facilitates evaluation of the extent to which transparency arrangements promote answerability. This section applies this analytical frame to the international space governance framework and the UN climate regime, with a focus on the Paris Agreement. In the former context, it shows that the public dissemination of integrated emissions data sets in accessible formats has the potential to enhance answerability for states’ mitigation performance through non-state actor scrutiny and review. There is scope under the Paris Agreement for space-based measurement data to contribute to verification activities for national emissions inventories. However, the emphasis on non-intrusive transparency measures that are respectful of national sovereignty under the enhanced transparency framework is likely to present a barrier to technical ERTs referring to such data in verification processes under Article 13(11) of the Paris Agreement. Aggregated measurements could also provide a reference point for the global stocktake under Article 14, yet the absence of political judgments in the stocktake process detracts from the prospects of increasing answerability through improvements in transparency in this context.
4.1. International Space Law and Policy
A number of key principles of international space law pertain to both earth observations and satellite-enabled atmospheric measurement techniques. The Outer Space Treaty states that the exploration and use of outer space are to be carried out for the benefit and interests of all countries, and shall be ‘the province of all mankind’.Footnote 73 The principles of sovereignty that extend to airspace do not extend to outer space.Footnote 74 Space is subject to the principles of free exploration and use of outer space, which have enabled states to perform earth observations without the permission of the state being observed.Footnote 75 While this creates contention in some areas, it is tempered by the Outer Space Treaty's calls for international cooperation and for due regard to the interests of all other states in carrying out state activities in space.Footnote 76
In terms of whose information is transparent to whom, the data policy regulations that apply to space-based data allow data about a state to be transparent to the observing state, to a monitored or sensed state, and to other states on a non-discriminatory basis. The global standard for satellite earth observation data policy regulation is articulated in the UN General Assembly's 1986 Remote Sensing Principles.Footnote 77 As the principles themselves are articulated in a General Assembly resolution, they are not legally binding but, to the extent that they represent state practice,Footnote 78 they have considerable weight. The sensed state has no veto to prevent the remote sensing activity. Moreover, the sensed state does not have an exclusive, free, or preferential right of access to the data as a result of Article 1 of the Outer Space Treaty, which allows states to observe other states from the non-sovereign vantage point of space. However, by virtue of Principle XII of the Remote Sensing Principles, once the primary data and the processed data concerning its territory are produced, the sensed state has the right of access to such data on a non-discriminatory basis and on reasonable cost terms. This means that, for a particular set of remote-sensing data concerning its territory, the sensed state does not differ from any other state with regard to the terms under which it can access the data.Footnote 79 In practice, access to earth observation data can be hampered by restrictive access and pricing policies, and is ultimately subject to the political, strategic, and military considerations of the most powerful states.Footnote 80
The extent to which space data is shared impacts on which state activities are transparent to whom. While some nations make data from their unclassified, government-owned earth observation satellites publicly available without charge, facilitating open access to important climate data, such practices are by no means universal.Footnote 81 A number of international initiatives seek to promote unrestricted international exchange of free environmental data. For example, the Global Earth Observation System of Systems (GEOSS)Footnote 82 has developed open data-sharing principles which accord with transparency aims. These data-sharing principles stipulate that:
• there will be full and open exchange of data, metadata and products shared within GEOSS, recognizing relevant international instruments, and national policies and legislation;
• all shared data, metadata and products will be provided with minimum time delay and at minimum cost; and
• all shared data, metadata and products, being free of charge or no more than cost of reproduction, will be encouraged for research and education.Footnote 83
In a similar vein, the purpose of the WMO World Data Centres is to collect data from contributorsFootnote 84 to the Global Atmosphere Watch programme, to archive the processed data and make it publicly available, and provide support in the ‘quality assurance, analysis and interpretation’ of such data.Footnote 85
Despite these initiatives, a number of impediments to the sharing of space data remain, including the culture that data sharing is not part of the producers’ mission, the cost implications, restrictions to promote commercial sales, and national security concerns.Footnote 86 Each of these factors contributes to gaps in the availability of environmental data from satellites, undermining the potential for answerability through transparency.
The range of stakeholders who have access to states’ environmental data is expanding as private actors increasingly collect, use, store, and disseminate space data. Alongside national space agencies, private sector actors and non-governmental organizations (NGOs), such as GHGSat Inc. and the Environmental Defense Fund, are developing capabilities to measure GHG emissions from industrial sources using remote-sensing microsatellites.Footnote 87 California has recently announced a partnership with earth observation satellite operators Planet Labs Inc. to launch a satellite to track GHG emissions by 2021.Footnote 88 Some of these operators are storing large satellite datasets on the cloud. For example, Planet Labs has announced that it is using the Google cloud and DigitalGlobe through Amazon's cloud services.Footnote 89 Thus, state data is potentially transparent to state and non-state actors, and the broader public via the cloud.
States are likely to have significant concerns about sensitive integrated emissions data being available on the cloud, especially as national governments are unable to track or restrict the individuals who access the cloud.Footnote 90 In an integrated data environment, even if information has been provided voluntarily by users, aggregated data from both government and non-government sources might provide additional information about users that they did not necessarily wish to disclose.Footnote 91 Recognizing these transparency opportunities and challenges, new technologies are needed that can receive, archive, process, analyze, and distribute the actionable information, and develop the security protocols necessary for the level of information sharing required for sensitive state data.Footnote 92 Such systems should seek to strike a balance between the transparency benefits of publicly available environmental data, including emissions information, and the need for privacy, confidentiality, and data sovereignty.
If integrated emissions data sets are made available publicly, answerability may be promoted through a greater role for non-state actors in reviewing the accuracy, completeness, and comparability of states’ reported emissions. According to Guzman, reputational impact and sanctions are two key factors that contribute to state compliance with international law.Footnote 93 With regard to the former factor, public ‘naming and shaming’ is an indirect enforcement strategy used by international organizations, NGOs, and the media to promote public accountability for international law violations.Footnote 94 This relates to the argument by Brown Weiss and Jacobson that transparency can promote compliance with MEAs by bringing the behaviour of states and targeted actors ‘into the open for appropriate scrutiny’.Footnote 95 Research and civil society organizations have already played a role in scrutinizing the underlying assumptions and data in states’ individual nationally determined contributions (NDCs)Footnote 96 under the Paris Agreement.Footnote 97 In a similar vein, non-state actors can monitor transparent information on state emissions enabled by satellite and big data technologies,Footnote 98 and exert public pressure on states to be answerable to the international community for their progress on mitigation.
Questions remain, however, as to the standards against which the transparent information is to be measured, and what is the process for reaching judgments about this information. The standards of performance for GHG emissions against which states are held to account in international law are found in the Kyoto Protocol and the Paris Agreement. Under the Kyoto Protocol, each Annex I party has committed to achieve differentiated and legally binding emissions targets of at least 5% below 1990 levels during the first commitment period (2008–12).Footnote 99 The Paris Agreement, in contrast, imposes a collective obligation on all parties to hold ‘the increase in the global average temperature to well below 2°C [degrees Celsius] above pre-industrial levels’, and each state is required to specify its own NDC to the global climate change response, which will be strengthened progressively.Footnote 100 These emissions mitigation commitments under the UN climate regime can provide standards against which publicly available space-based emissions data can be assessed, contributing to enhanced answerability through public scrutiny and review. However, how judgments about the achievement of these standards will be reached is unclear as there is no formal mechanism for review by non-state actors, and due process guarantees do not apply.
4.2. The Paris Agreement
The Paris Agreement provides a suite of processes for promoting accountability for state emissions reduction pledges, and there is scope for satellite-enabled measurements to provide a data source to inform a number of these processes. The Paris Agreement allows states to set their own mitigation targets in their NDCs and provides for four key oversight arrangements for state reports submitted through the formal reporting system: (i) the transparency framework for action and support,Footnote 101 (ii) multilateral consideration of progress,Footnote 102 (iii) global stocktakes,Footnote 103 and (iv) the formal non-compliance process.Footnote 104 In this subsection, we examine the prospects for satellite-enabled emissions measurement data to be used as a reference point in national inventory reports, technical expert review, and the global stocktake.
Improving state emissions inventories
As satellite technology continues to develop, there is an opportunity for states to use remote-sensing measurement techniques to verify the emissions levels and trends reported in their national inventory reports. Under Article 4(13) of the Paris Agreement, parties are required to ‘account for’ their NDCs in a way that promotes ‘environmental integrity, transparency, accuracy, completeness, comparability and consistency’. Each party is required, inter alia, to submit to the UNFCCC Secretariat a national emissions inventory report, and information ‘necessary to track progress’ towards implementing and achieving its NDC,Footnote 105 which will be subject to technical expert review and multilateral consideration of process.Footnote 106 The national inventory report of ‘anthropogenic emissions by sources and removals by sinks of greenhouse gases’ is to be prepared ‘using good practice methodologies accepted by the Intergovernmental Panel on Climate Change (IPCC)’.Footnote 107 The current IPCC Guidelines were published in 2006,Footnote 108 and the 2019 Refinements to the 2006 Guidelines are expected to be published in May 2019.Footnote 109 As part of these revisions, the IPCC is updating and elaborating upon the guidance on quality assurance and verification as it acknowledges that the existing guidance is outdated, ‘especially the guidance on comparisons with atmospheric measurements and new datasets’, given recent developments in, among other things, atmospheric concentration data and independent monitoring of carbon stocks and fluxes.Footnote 110 Thus, there is increasing recognition that atmospheric measurement data can be used to check and corroborate data in emissions inventories, thereby enhancing technical transparency. This guidance is likely to be advisory rather than mandatory in recognition of some states’ capacity constraints.
A number of initiatives are already being undertaken to improve the verification of national inventory reports using satellite-enabled measurement techniques. For example, the UK's second biennial report highlights the use of an inversion modelling technique – informed by high-frequency, high-precision measurements of atmospheric trace gases – to verify the emissions levels and trends reported in its GHG inventory.Footnote 111 Switzerland and, to a lesser extent, Australia also utilize top-down quantification and analysis to inform improvements to their bottom-up emissions inventory reporting.Footnote 112 In the EU, a European integrated observation systemFootnote 113 is proposed to monitor fossil CO2 emissions using independent atmospheric observations, which will, in time, provide an ‘operational independent verification system’.Footnote 114 By the mid-2030s, this system aims to ‘enable the accurate, transparent and consistent quantification of fossil CO2 emissions and their trends at the scale of megacities, important industrial sites, small regions, countries, and the Earth as a whole’.Footnote 115 Provided that there is clarity around the methodologies, data and data sources, and assumptions underpinning this data, satellite-enabled techniques hold considerable promise for enhancing the technical transparency of states’ national inventories. These transparency gains can, in turn, contribute to greater answerability for states’ progress towards achieving their NDCs by reducing uncertainty in reported information.
Such initiatives are being led by industrialized states at this stage because of the resource-intensive nature of these sophisticated data infrastructures. Capacity-building support may be required for other states – particularly developing states – to create similar initiatives.Footnote 116 In this regard, it is notable that Article 13(14) and (15) of the Paris Agreement mandates that support will be provided to developing countries for implementing the transparency requirements and for building transparency-related capacity. Paragraphs 84 and 85 of the Decision adopting the Paris Agreement establishes a Capacity-Building Initiative for Transparency to build institutional and technical capacity and support developing country parties, upon request, in meeting the enhanced transparency requirements under Article 13.Footnote 117 In the absence of support to develop and maintain the satellites and other infrastructure required to utilize atmospheric measurement techniques, the potential transparency benefits of these techniques to verify states’ emissions inventories will remain patchy and largely untapped.
The enhanced transparency framework
Accurate information about state GHG emissions reveals trends and sets the baseline against which mitigation action can be measured. It is thus pivotal to the success of the Paris Agreement. Conversely, failure to correctly measure and report emissions might not only erode trust between parties, but also could lead to a misreading of the progress made in achieving targets. Therefore, the process of quantifying emissions, as well as information on the implementation and achievement of NDCs, must be transparent. To this end, an enhanced transparency framework for action and support is established under Article 13(1) in order to build ‘mutual trust and confidence’ and promote ‘effective implementation’. As articulated in Article 13(5), the purpose of this framework is to provide a clear understanding of climate change action, including clarity and tracking of progress towards achieving parties’ individual NDCs, and informing the global stocktake. The modalities, procedures, and guidelines (MPGs) for the enhanced transparency framework were agreed as part of the Katowice Climate Package in December 2018.Footnote 118 This transparency framework will play a critical role in promoting the answerability of states for the realization of their NDCs and ultimate achievement of the Paris Agreement's overall objective.Footnote 119
Prima facie, satellite-enabled emissions measurement data could serve as a valuable independent reference point for internationally coordinated review processes under Article 13(11), enhancing states’ answerability to the technical ERTs. One shortcoming of the current ERT process under the UNFCCC and Kyoto Protocol is that while the ERT may use relevant technical information in the review process, it is unable to refer to data from independent, non-state sources to verify reports, unless the data was formally supplied to that source by the authorities of the state under review.Footnote 120 The main checks that ERTs have been able to make are:
• comparisons with a state's historically reported data;
• conformity with standard IPCC methodologies;
• country-level statistics on the production, import, and export of fuel from the International Energy Agency; and
• comparisons with the types of issue reported in other states’ reports.Footnote 121
The review powers granted to ERTs prioritize deference to state sovereignty,Footnote 122 and the limitations on the ability of ERTs to independently verify emissions data means that while reviewed emissions inventories are deemed to be legally compliant, they may not be compliant scientifically.Footnote 123 Measurement of emissions using satellite remote-sensing techniques would provide an independent counterpoint to state-provided information, and has the potential to considerably enhance the robustness of the technical expert review processes under the Paris Agreement. This is significant as such processes will inform the multilateral consideration of progress and the non-compliance mechanism under the Paris Agreement,Footnote 124 both of which play a role in holding states to account for their emissions reduction pledges.
Although satellite-enabled approaches to measuring GHG emissions may be consistent with the expected revisions to the IPCC Guidelines, a broader question remains as to whether such approaches are congruent with Article 13(3) of the Paris Agreement. This provision emphasizes that the enhanced transparency framework should be implemented in a ‘facilitative, non-intrusive, non-punitive manner, respectful of national sovereignty’. Ellis and co-authors highlight measures that can ensure a non-intrusive process that is respectful of national sovereignty:
• formalized procedures for continued communication;
• providing opportunities for the country concerned to comment on results of reviews;
• limiting the distribution of results;
• establishing a clear mandate, and potentially also a mutually agreed set of criteria, upon which to measure progress; and
• taking account of the implications of each country's legal and political systems, and the needs and views of the country concerned.Footnote 125
In the light of these elements of a non-intrusive process under the UN climate regime, it is likely that remote sensing of territories and possible sharing and use of these data as an independent source, without the permission of the state being observed, could be seen as intrusive and lacking the required deference to national sovereignty.Footnote 126 Thus, the use of atmospheric measurement data without state consent is likely to be in tension with the requirements of Article 13(3).
A related issue is that if only a small number of states or actors have the capacity to produce satellite measurement data, and the data of one state or actor is chosen as an authoritative source for emissions measurements, other states may be concerned about the independence of such data. Moreover, in the absence of systematic and universal monitoring, decisions need to be made about where satellite gaze is directed. For example, new satellite operators such as Planet Labs Inc., which has the largest constellation of earth observation satellites, have the capacity to monitor the entire planet on a daily basis, and use machine learning to detect trends and priority areas of focus.Footnote 127 The previously mentioned European integrated observation system will have a data assimilation and forecasting system and aims to quantify fossil CO2 emissions and their trends at the scale of megacities, important industrial sites, small regions, and countriesFootnote 128 – again raising questions about how observational focal points will be identified. Decisions about where to direct satellite gaze may raise potential equity concerns, and are likely to be politically contested.Footnote 129 Therefore, the requirements of Article 13(3) and these relational concerns are anticipated to pose an obstacle to remotely sensed emissions data contributing to enhanced answerability in the technical expert review process.
The global stocktake
Given its emphasis on collective progress rather than individual state accountability, there may be greater scope for referring to aggregated atmospheric measurement data as part of the global stocktake, and providing information on emissions mitigation as envisaged by the WMO IG3IS project.Footnote 130 The stocktake will be held every five years, beginning in 2023, and its aim is to assess ‘collective progress towards achieving the purpose of this Agreement and its long term goals’.Footnote 131 Aggregated emissions measurement data could contribute to assessing collective mitigation progress, and thus states’ mutual answerability for their shared goal of limiting increases in the global average temperature to well below 2°C above pre-industrial levels.Footnote 132 The MPGs include an option for input from non-party stakeholders in the global stocktake process,Footnote 133 potentially providing an opportunity for consideration and discussion of independent data and measurements. Article 14(1) of the Paris Agreement specifies that the stocktake will be conducted in a facilitative manner ‘in the light of equity and the best available science’, and its focus will be on mitigation, adaptation, and the means of implementation and support.Footnote 134 Given this emphasis on a facilitative process, political judgments are likely to be avoided,Footnote 135 detracting from answerability through transparency in this context.
5. CONCLUSION
Atmospheric measurement technology is improving rapidly, and holds significant promise for increasing the accessibility and assessability of state GHG emissions data. Applying and expanding upon elements of the Gupta and van Asselt framework for analyzing the transparency-accountability relationship, this article has shown that there are a number of impediments to translating these transparency gains into enhanced answerability for states’ emissions reduction pledges. In the context of international space law and policy, there have been rapid advancements in satellite remote-sensing measurement techniques and public access to the resultant data, with concomitant benefits for transparency and, to a lesser extent, answerability. In terms of relations, non-state actors, such as research and civil society organizations, may scrutinize integrated emissions data sets, as has already occurred for the assumptions and data in states’ NDCs. In the absence of mitigation commitments under international space law, the standards for any such scrutiny are likely to be sourced from international climate law. As public ‘naming and shaming’ by non-state actors is an indirect and unofficial enforcement strategy, the processes for reaching judgments about the achievement of these standards are opaque and unclear.
Satellite-enabled emissions data also has the potential to enhance transparency under the Paris Agreement, although the flow-on benefits for answerability again are less clear. As is already occurring, states can use satellite remote-sensing measurement techniques to verify their own emissions inventory reports, which contributes to technical transparency by providing quantified, accurate and replicable GHG emissions data. The capacity constraints of some states is likely to limit the widespread uptake of such techniques unless capacity-building support is provided. In addition, atmospheric measurement approaches could be used as an independent data source as part of the internationally coordinated technical expert review process under the Paris Agreement, using the standards in the enhanced transparency framework, the accompanying MPGs finalized in late 2018, and the revised IPCC Guidelines expected to be published in May 2019. In terms of relations, information sourced through remote sensing of territories and data sharing, without the permission of the observed state, is likely to be resisted by some states, given the emphasis on non-intrusive measures that are respectful of national sovereignty under the enhanced transparency framework. Despite this, there may be scope for aggregated atmospheric measurement data to feed into the global stocktake under Article 14, thus contributing to states’ mutual answerability for their collective mitigation goals. However, given the emphasis on a facilitative process, the absence of political judgments will mean that the global stocktake falls short of achieving answerability.
We suggest that increased international cooperation is required to address concerns about satellite-enabled measurement techniques, while encouraging access to the information collected. Because the New Delhi Declaration signals the intent of a group of 60 space agencies to develop an international system for estimating and reducing anthropogenic GHG emissions, initiators of the Declaration should consider establishing an open forum where a wide variety of stakeholders can discuss issues around measuring emissions and the linkages with other climate initiatives, supporting capacity building, and addressing data policy issues.Footnote 136 This work, in combination with other similar initiatives under the WMO and EU, could feed into the UNFCCC process and support the transparency goals of the Paris Agreement.Footnote 137 There is also an important role to be played by international environmental lawyers in contributing to technical and policy discussions to promote the integration of existing legal frameworks and satellite measurement techniques as the scientific integrity of the latter increases.Footnote 138 Through such cooperation and dialogue, the potential transparency and answerability benefits afforded by emerging satellite-enabled measurement capabilities can be harnessed and shared across multiple climate governance forums.
