Managing Climate Policy Information Facilitating Knowledge Transfer to Policy Makers

In the challenging context of intense negotiations and radical developments in the field of climate policy, informing stakeholders about opportunities and pathways and about scientific insights and warnings is important to help create positive dynamics. Policy makers need digestible information to design good policies, and understand their options and the possible impacts of these options. They need access to well-structured knowledge, as well as appropriate techniques to manage information and data. However, available information is often difficult to access, not in the right format and of limited use to stakeholders. The range of knowledge needs identified has to be effectively addressed by providing interested parties with suitable, to-the-point information, covering the identified gaps. This is the main aim of this article that proposes the design and development of a climate policy database, which contains all the resources that can cover the identified knowledge gaps. The resources are derived from a broad range of existing reports, research and climate policy decisions at different levels. The goal is to render climate policy associated stakeholders able to extract key policy conclusions. The added value of this database was verified by users and stakeholders that generally argued that the climate policy database facilitates solid understanding of climate policy implications and fosters collaborative knowledge exchange in the field.


Introduction
The international community has intensified its activity towards a collective response to climate change [1].The Paris Agreement of the United Nations Framework Convention on Climate Change (UNFCCC) meeting in December 2015 (COP21) ensures that all parties focus on the long-term goal to keep global mean temperature rise "well below 2 ˝C and to pursue efforts to limit the temperature increase to 1.5 ˝C" [2].The emission reduction pathways needed are ambitious but not impossible as many of the needed technological solutions are known.Mitigating climate change will not only prevent human suffering and protect our biological diversity, but will also be less costly than adapting to the effects of climate change [3].
It is, however, a great challenge in industrialised countries to restructure consumption and production patterns into a low-carbon system [4].On the other hand, developing countries are concerned that a low carbon pathway could hamper their overriding priorities of economic growth and poverty eradication [5].Furthermore, the international community has not yet agreed on how to distribute the cost of mitigation efforts and the level of ambition among themselves [6].It therefore does not come as a surprise that international negotiations are moving slowly and the level of ambition as shown by voluntary international pledges does not suffice to limit global warming below 2 ˝C.
In the difficult context of intense negotiations and radical developments in the field of climate policy, informing stakeholders about opportunities and pathways and about scientific insights and warnings is important to help creating positive dynamics.Policy makers need digestible information to design good policies, and understand their options and the possible impacts of these options [7].They need access to improved knowledge transfer and uptake, as well as appropriate techniques to manage information and data [8,9].However, available information is often difficult to access, not in the right format and of limited use to stakeholders [7,10].
For the European Union (EU), the changed climate negotiations perspective creates several new opportunities, as well as challenges.It is therefore important to coordinate and facilitate the information exchange and outcomes of existing research on climate policy and climate agreements in order to broaden the knowledge in the field and enable associated stakeholders to extract key policy conclusions.In this respect, the first step is to identify knowledge needs among stakeholders, concerning both, knowledge gaps, as well as knowledge presentation requirements.Knowledge gaps can either mean lack of awareness of existing knowledge, or actual absence of scientific analysis regarding an issue.
As a consequence, exchange of information about climate policy and knowledge transfer among stakeholders need to be facilitated in order to offer clear understanding of current regimes, their possible directions, implications and consequences and to render them capable of taking well-informed, consolidated decisions based on up-to-date reliable facts [11][12][13][14][15].
To this end, it is important to assimilate the in-stock knowledge on climate policy issues in a running database, which will be enhanced by relevant projects and discussion outcomes of climate negotiations.The aim of this paper is to present such a Climate Policy Database that serves as an electronic library and contains all the resources that can cover the identified knowledge gaps.The resources are derived from a broad range of existing reports, research and climate policy decisions at different levels.The goal is to render climate policy associated stakeholders better able to extract key policy conclusions.This particular study is oriented towards the presentation of the structuring of a climate policy database for the provision of accurate and easily accessible information.
In particular, this work aims to collect and cluster the existing knowledge on climate policy in an open input dataset, so as to provide the structured content for disseminating this knowledge to support informed decisions and beliefs of the policy makers, researchers, market actors and general public.A hierarchical structure of tags is created, where each tag provides semantic content to the relevant scientific studies and reports that form the resources collected.Since there are a vast number of research studies-with different assumptions and approaches-regarding the dynamics and direction of the new climate regime, a meta-analysis is carried out in order to decompose their results to the assumptions, factors and interactions considered.The outcomes of the decomposition is annotated with the aforementioned structure of tags so that semantic search is possible through a platform.
Apart from this introductory section, the paper is organized along five sections.The second section presents the requirements and functionalities to be met for the implementation of the Climate Policy Database.The third section provides an overview of the methodological approach, offering an analysis of the ontology and its applications.Following, the successive stages and technological choices followed to create the Climate Policy Database are presented.The last section summarizes the main conclusions arisen from the study.

Background
Ontologies are clear specifications of formalities [16][17][18].In brief, they are explicit depiction of theories, relations between theories (including, but not limited to, a hierarchy), instances, and axioms.The term explicit implies two facts: on the one hand, through the representation individuals could be able to understand the exact meaning of any component, so as to have a precise terminology available when commenting on data, communicating inquiries, or summarising outcomes.On the other hand, the depiction could assist machine reasoning, as it obtains a typical semantics.However, it is important to note that ontologies are not just formal representations of a domain, but much more community contracts about such formal representations.As a dialogue is a lively public procedure, it is often prior proposals to be amended, enhanced, or even rejected, and therefore new issues are essential to be added, such a community agreement should not be passive, but capable of following the community consensus at any point in time [16].
This semantic sharing of data becomes more and more important for web resources as more and more search engines are able to read this structured data and allow a more precise recall.Even more important, ontologies allow the structuring of knowledge and the creation and disambiguation of thesauri, definitions and the general alignment of knowledge.Ontologies or vocabularies have during the recent years developed from a tool for artificial intelligence researchers to a more and more widespread technology used by domain experts and in the World Wide Web.Ontologies are there used for creating a Web of Data, which allows computers to add semantics to data, so that machines can understand them.Many domain ontologies can be found and they are not only used by experts to better structure their data, but also to allow a meaningful sharing of that data [19].For these reasons we choose to model the gathered knowledge on climate policies under an ontology.

Methods
Certain knowledge gaps remain with reference to the implications of various options regarding EU and international climate policies.Achieving effective policy outcomes depends on identifying and filling these gaps.
In the above context, a methodology was applied within the framework of the Mobilizing and transferring knowledge on post-2012 climate policy implications (POLIMP) project (POLIMP is funded by the European Commission under the 7th Framework Programme-Grant Agreement No 603847) resulting in the identification of a series of knowledge needs and priorities per area of expertise.POLIMP identified and filled gaps in knowledge about climate, in order to support policy making.Its methodology focused on the identification of knowledge needs of different stakeholder groups within Europe regarding key topics of climate policy, resulting in composing knowledge packages as a response to the above needs, based on existing multidisciplinary knowledge, information and data.In addressing its goal, POLIMP developed a participatory process, including preparatory dialogue, thematic workshops and other events, questionnaire elaboration and targeted interviews with stakeholders needs (Figure 1).As noted above, the plethora of information on climate policy, needs to be registered and streamlined in an open input dataset, where policymakers, researchers, market actors and general public can insert their new knowledge and hence provide added value.
The implementation of the Climate Policy Database requires first a process for the identification of key areas that there is a lack of clear and targeted information in relation to the implications of future international and EU climate policy scenarios.The core objective is to cover these gaps with knowledge packages derived from a broad range of existing reports, research and climate policy decisions at, e.g., EU and UNFCCC levels.
In the above context, the knowledge gaps and needs on EU climate policy implications used for the development of this database were the finalized and validated outcomes derived from the application of POLIMP methodology, the extensive two-way stakeholder consultation process, as described in the previous paragraphs and are presented by main thematic area in Table 3 that follows.As noted above, the plethora of information on climate policy, needs to be registered and streamlined in an open input dataset, where policymakers, researchers, market actors and general public can insert their new knowledge and hence provide added value.
The implementation of the Climate Policy Database requires first a process for the identification of key areas that there is a lack of clear and targeted information in relation to the implications of future international and EU climate policy scenarios.The core objective is to cover these gaps with knowledge packages derived from a broad range of existing reports, research and climate policy decisions at, e.g., EU and UNFCCC levels.
In the above context, the knowledge gaps and needs on EU climate policy implications used for the development of this database were the finalized and validated outcomes derived from the application of POLIMP methodology, the extensive two-way stakeholder consultation process, as described in the previous paragraphs and are presented by main thematic area in Table 3 that follows.The identification of knowledge needs constitutes the first step towards enhancing understanding of possible directions of climate policies among policy makers and other stakeholders and enabling them to form well-informed, consolidated decisions.The range of knowledge needs identified has to be effectively addressed by providing interested parties with suitable, to-the-point information, covering the identified gaps.This is the main goal of the Climate Policy Database.
The following steps have been defined to accomplish the objectives of the Climate Policy Database: ‚ Classify the resources under a hierarchical schema to facilitate search.

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Create a user centric database where users can search, view and extend the resources collected.

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Provide generic and custom views of the resources to the users of the database depending on selection criteria and tags.
‚ Support collaborative authoring of the available resources and their information, as well as versioning control over the changes performed in the data of the database.
The hierarchical tags of the climate policy database should have the following characteristics: ‚ Support different schemas: There is no generally accepted schema or ontology for representing tags.Instead, there are several ones, which provide a structuration of the tagging processes on different levels.

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Tags are the first step in creating rich semantic knowledge bases.The database should support the future evolution of tags into rich semantic annotations.The tags should be extensible with additional metadata.This facility includes labels in different languages, relations between tags and other resources as well as relations between tags.

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Users should be able to annotate resources with tags, comments, notes and all possible other attributes.

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Additional filtering support: Filter performing an equality restriction to a certain value should be supported to facilitate search.Moreover, other filter types should be allowed, such as bound/unbound property of attributes, ranges of values on a facet as well as literal expressions.
The outcome is a living database, which could be easily enhanced by relevant projects and discussion outcomes of climate negotiations and will serve as input for climate policy knowledge procession.Data and knowledge collection refer to topics of interest, such as:

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Status quo of climate policy negotiations and the EU climate policy discussion (including the climate and energy package 2020 and longer term decarbonisation and energy roadmaps).

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Identification of key trends and drivers, such as key economic, energy and demographic trends in EU and Rest of World, and trends in global land use.

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Possible international climate policy developments and scenarios based, among others, on progress in negotiation processes, observers' opinions, papers, interviews, focusing especially on what the literature says about the social, economic and environmental impacts of climate policies and the resulting impact on their political acceptability by different stakeholders.

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Information about the way policies and measures proposed in international climate policy making might work in terms of direction, strength and expected effects in different EU stakeholder contexts.
The resources used come from a wide range of up-to-date sources.Publications of the Intergovernmental Panel on Climate Change (IPCC) and those of institutions like the United Framework Convention on Climate Change (UNFCCC) secretariat, the Organisation for Economic Co-operation and Development (OECD), International Energy Agency (IEA), International Renewable Energy Agency (IRENA), United Nations Environment Program (UNEP) or those of renowned researchers and institutes are considered throughout the knowledge collection process.They are of great importance and value when addressing issues like the effectiveness of a new international regime in terms of delivering the required mitigation objectives, projected socio-economic impacts, the role of low carbon technology development and transfer, relationship between climate change and land-use trends, trends in energy prices, etc.
More in detail, the Climate Policy Database brings together findings from: climate policy analysis projects, legal studies, studies on existing and new market mechanisms, projects on international cooperation and technology transfer and financial aspects of climate policy.Knowledge from research papers, scientific reports, decisions, articles and organizations' websites is collected, combined and utilized.
An ontology was developed for annotating and structuring the knowledge related to climate policies and provide a platform that allows exploration, editing and extension of the concentrated knowledge.The developed platform facilitates the search of information related to climate policies based on specific keywords, which in turn lowers the barrier for data re-use and integration.

Information Setup and Resources
Knowledge gaps were identified for a range of priority issues related to climate policy making, in consultation with stakeholders as mentioned in the previous paragraph within the frame of POLIMP project.The gathered resources were structured by tagging them under the main issues addressed by the corresponding knowledge package.At a second level, resources are further tagged under a selection of relevant keywords in order to enhance searchability.Each resource can be tagged under one or more issues and one or more keywords.Issues and keywords are shown in the following Tables.
Main issues examined regarding climate change concern policy levels (European and International-within the UNFCCC), the issue of Adaptation to climate change, as well as three concepts that have inspired cornerstone policy instruments and targets of crucial importance, namely Emissions Trading, Renewable Energy and Energy Efficiency: The gathered resources were structured by tagging them under the selected keywords and issues (Figure 2).

Climate Policy Ontology
There are a lot of different ways to create an ontology that describes the resources of the Climate Policy Database and effectively categorize them using tags, such as the keywords and issues we described earlier.The focus of this work was to create an ontology with the use of existing standards and if and when required, to adopt new terminology to describe specific properties or concepts.
The climate policies ontology consists of two main classes the Knowledge Package class and the

Climate Policy Ontology
There are a lot of different ways to create an ontology that describes the resources of the Climate Policy Database and effectively categorize them using tags, such as the keywords and issues we described earlier.The focus of this work was to create an ontology with the use of existing standards and if and when required, to adopt new terminology to describe specific properties or concepts.
The climate policies ontology consists of two main classes the Knowledge Package class and the Climate Policies Taxonomy class.The Knowledge Package class has no further sub-classes and its instances are the knowledge packages defined in the POLIMP project.The Climate Policies Taxonomy class and its sub-classes provide us with the desired taxonomy for the information gathered.On the 1st level of sub-classes of the Climate Policies Taxonomy class we perform a first categorization on the selected issues and on the 2nd level of sub-classes we perform a further categorization on the selected keywords.The instances of the Climate Policies Taxonomy class are the collected resources.Table 4 presents the categorization we have just described.

Technological Choices
For the implementation of the Climate Policy Database several available tools had to be considered and also the features offered by existing software had to be reviewed in order to decide the right tools, both for the database and the user interface to the database of choice.
For the backend database that stores the resources collected, there was the need to decide between the available relational databases and Triple Stores.Considering the decision to use RDF (Resource Description Framework), in order to describe the concepts of the Climate Policy ontology, a Triple Store would be the right tool to fit the implementation of a Climate Policy Database."Triplestore" is the common name given to a database management system for RDF Data.These systems provide data management and data access via APIs (Application Programming Interface) and query languages to RDF Data.Much like a relational database, it stores information in a triplestore and retrieves it via a query language.A triplestore is enhanced for storing and recovering of triples, in contrast to a relational database.A triple is a unit of RDF Data (a graph) comprised of three pieces of information: Subject (S), Predicate (P), and Object (O), where S and O are nodes and P the node connector (also called edge or arc).Since RDF is based on a directed graph data model the edges always point from "Subject" to the "Object" (conceptual representation (Subject) -Predicate -> (Object)).In addition to queries, triples can usually be imported/exported using RDF and other formats.Among the available Triplestores, OpenLink Virtuoso [38] was the software of choice.
For the user interface to the stored information, one option is to use standard Wiki technology, as the platform for community-driven ontology building and maintenance.A wiki would provide the support for creating Uniform Resource Identifiers (URIs) plus human-readable definitions (using text and graphics) classes, instances, and relationships of the climate policy ontology in an easy and collaborative way.Moreover, this choice offers the opportunity for a large user community to establish unique identifiers for needed concepts, resulting in more current and more complete ontology.OntoWiki [39] was the wiki of choice as it provided all the functionalities needed and even more.In the following sections OpenLink Virtuoso and OntoWiki are briefly presented.

OpenLink Virtuoso: A Framework for Storing and Querying Data
OpenLink Virtuoso Universal Server is a middleware and database engine hybrid that combines the functionality of a traditional Relational Database Management System (RDBMS), Object-Relational Database Management System (ORDBMS), virtual database, RDF, Extensible Markup Language (XML), free-text, web application server and file server functionality in a single system.Rather than having dedicated servers for each of the aforementioned functionality realms, Virtuoso is a "universal server"; it enables a single multithreaded server process that implements multiple protocols [40].

OntoWiki
OntoWiki is an open-source semantic wiki application, written in PHP and making use of either a MySQL database or a Virtuoso triple store, functioning as an ontology editor and a data acquisition system [40].OntoWiki focuses on not confusing the users with the complication of data representation formalisms, as it is more form-based than syntax-based.OntoWiki can be installed at any Web space and accessed by an ordinary Web browser.It facilitates the visual presentation of a knowledge base as an information map, with different views on instance data.It enables intuitive authoring of semantic content, with an inline-editing mode for editing semantic content, similar to WYSIWIG for text documents.

OntoWiki
OntoWiki is an open-source semantic wiki application, written in PHP and making use of either a MySQL database or a Virtuoso triple store, functioning as an ontology editor and a data acquisition system [40].OntoWiki focuses on not confusing the users with the complication of data representation formalisms, as it is more form-based than syntax-based.OntoWiki can be installed at any Web space and accessed by an ordinary Web browser.It facilitates the visual presentation of a knowledge base as an information map, with different views on instance data.It enables intuitive authoring of semantic content, with an inline-editing mode for editing semantic content, similar to WYSIWIG for text documents.To enhance, inform and erase data in OntoWiki pages, a specific element of OntoWiki named RDFauthor [39] is adopted.RDF-Author obtains RDFa [41] coded HTML data from the page's content to generate a procedure and a set of gadgets indicating this data.RDFa is the World Wide Web Consortium, W3C, proposal that permits incorporating human and machine-readable depiction inside a particular HTML file.The Climate Policy Database uses RDFa-annotations in web views, so as to make RDF model data accessible to the user.The extraction of RDF triples from RDFa-annoted Web pages and the transformation of the RDFa-annotated HTML view into an editable procedure, by using a set of authoring gadgets, are the main functions of the RDFauthor.The RDFauthor hides entirely syntax along with RDF and ontology data model obstacles from end users and permits editing data on arbitrary RDFa-annotated web pages.When the editing of all RDFa-annotated data on an OntoWiki page is finalised, the modifications are arbitrary disseminated to the Virtuoso triple To enhance, inform and erase data in OntoWiki pages, a specific element of OntoWiki named RDFauthor [39] is adopted.RDF-Author obtains RDFa [41] coded HTML data from the page's content to generate a procedure and a set of gadgets indicating this data.RDFa is the World Wide Web Consortium, W3C, proposal that permits incorporating human and machine-readable depiction inside a particular HTML file.The Climate Policy Database uses RDFa-annotations in web views, so as to make RDF model data accessible to the user.The extraction of RDF triples from RDFa-annoted Web pages and the transformation of the RDFa-annotated HTML view into an editable procedure, by using a set of authoring gadgets, are the main functions of the RDFauthor.The RDFauthor hides entirely syntax along with RDF and ontology data model obstacles from end users and permits editing data on arbitrary RDFa-annotated web pages.When the editing of all RDFa-annotated data on an OntoWiki page is finalised, the modifications are arbitrary disseminated to the Virtuoso triple store with use of the SPARQL/Update language [41].

Climate Policy Database Setup
The Climate Policy Database is an open database, easily accessible through the POLIMP project "Home" page (polimp.eu).The typical workflow of the use of the Climate Policy Database can be directly experienced through a navigation in the Climate Policy Database and is also depicted in Figure 4.
In the following paragraphs the main building blocks of the database, as well as its functionalities are presented.

Main Building Blocks
The Climate Policy Database user interface is separated in building blocks to facilitate their description.There are five main building blocks:

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The knowledge bases-the knowledge bases provides a list of the available knowledge bases.

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The navigation component-the navigation component is a powerful OntoWiki extension that is able to extract the structure of knowledge bases and facilitate the navigability of datasets.

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The main window-in this area the resource list of chosen class is presented.Moreover, the main window serves as a form editing area when the user selects to edit a particular resource.

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The resource search field-the resource search field enables the user to perform searches on the resources based on keywords.

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Additional modules area-in this area additional helpful modules are displayed.

Main Building Blocks
The Climate Policy Database user interface is separated in building blocks to facilitate their description.There are five main building blocks:

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The knowledge bases-the knowledge bases provides a list of the available knowledge bases.

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The navigation component-the navigation component is a powerful OntoWiki extension that is able to extract the structure of knowledge bases and facilitate the navigability of datasets.

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The main window-in this area the resource list of chosen class is presented.Moreover, the main window serves as a form editing area when the user selects to edit a particular resource.

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The resource search field-the resource search field enables the user to perform searches on the resources based on keywords.

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Additional modules area-in this area additional helpful modules are displayed.By choosing the Edit Properties button in the single instance view, an editable form with the instance's properties appears in the main window.The user can edit the properties of the instance and also add new properties by selecting the Add Property button.In a similar way as modifying instances of the Climate Policy Database, the user is able to modify the existing classes of the Climate Policy ontology or in other words make changes to the pre-defined set of hierarchical tags.

Querying the Climate Policy Database-Applying Filters on the Resources
Viewing the instance list of a class by selecting the class in the navigation component provides a way on querying the Climate Policy Database based on the set of the pre-defined tags.In addition, the resource search field described earlier gives a second option for querying the database.OntoWiki also provides a third option for querying the database based on applying filters on an existing resource's list view through the Filter module.The form enables the user to apply filters on the resource list of the main window.Filters perform an equality restriction to a certain value of a resource's property.OntoWiki also supports other filter types including bound/unbound property of attributes, ranges of values on a facet as well as literal expressions.

Community Features
The users of the database may comment the resources available.This enables community driven discussions, for example about the validity of certain statements or the proposal of certain changes.The discussions can be performed within the Community tab of the main window area.

Change Tracking and Versioning
All the modifications made to a knowledge base are traced.OntoWiki allows revision of changes, such as adding new instances and classes, deleting instances and classes, modification of a specific instance, changes on instances of a class, or changes made by a distinct user.Each change committed to the database is associated with an ID.The user that performed the change, the timestamp of the change and the action type are also tracked.The user has the ability to rollback to a previous state of the resource.

Results and Discussion
The integration of all the data concerning climate policy making, information and negotiations, within a database system has many advantages.First, it allows for data sharing among policy makers, researchers and other stakeholders, helping to conduct research for science-based decision making.
Second, it provides users the ability to generate more information from a given amount of data than would not be possible without the integration.
Existing knowledge on climate policy was collected and clustered in an open input dataset, so as to enable a policy assessment, as well as to provide the structured content for supporting informed decisions of the policy makers, researchers, market actors and general public.A hierarchical structure of tags was created, where each tag provided semantic content to the relevant scientific studies and reports that form the resources collected.A meta-analysis was also conducted, in order to decompose the results, assumptions, factors and interactions of the numerous studies available in the literature and annotate them with the aforementioned structure of tags so that semantic search is possible through the database.
The Climate Policy Database was introduced to several stakeholders so as to receive inputs, comments and recommendations for its improvement.In addressing this, POLIMP team developed a participatory process, including preparatory dialogue, thematic workshops and other events (more than 450 participants in POLIMP workshops and events), questionnaire elaboration and targeted interviews with stakeholders (90 respondents to questionnaires, stakeholders dialogue).The stakeholders-users of the climate policy platform have expressed their content for the creation of a user centric database that users can use to search, view and extend the resources collected.They highlighted that it creates the right environment, provide a useful tool and information in a user-friendly way for key policy stakeholders to share knowledge and practical experience on climate policy, fostering collaborative knowledge exchange.
However, further features are needed to be implemented to the existing database to improve methods for assessing and comparing the existing knowledge on climate policy.More specifically, it would be helpful to develop a voting procedure for each information resource already included in the database, which can be used to evaluate the effectiveness of strategies for managing the impacts of climate change policies.This would facilitate comparisons of policy making effort in the near term-in advance of any official policy surveillance or benchmarking.Moreover, independent researchers could further analyze and synthesize these data to create some of the more challenging but informative climate policy decisions.This would allow stakeholders and other users to provide feedback on the feasibility, integrity, and precision of the database's shared information, which could be used to further refine the current pathways and options and to inform ongoing deliberations concerning climate change policy.
The Climate Policy Database could undergo further development, being enhanced through characteristics, such as a hierarchical structure of the database users.Not all users of a database system will have the same accessing privileges.For example, one user might have read-only access (i.e., the ability to read a file but not make changes), while another might have read and write privileges, which is the ability to both read and modify a file.For this reason, the database could provide a security subsystem to create and control different types of user accounts and restrict unauthorized access.
In addition, it would be useful to create an event notifications service, through which information about events in the database could even be sent via email to the users.The user would then log and review changes or activity occurring on the database.

Conclusions
An effective response to climate change is currently high on the political agenda among the world's nations.Climate change mitigation efforts are currently intensified at an international level, as parties focus and coordinate their efforts towards an international agreement, while adaptation to climate change is in the spotlight of climate negotiations.
However, this changing and versatile political scenery of negotiations creates a wide range of possible directions and potential implications of policies on EU level, thus impeding solid policy and decision making.It necessitates further access to improved knowledge transfer and uptake for policy and decision makers, in order to render them capable of developing clear understanding of current regimes, their possible directions, implications and consequences and to support them in taking well-informed, consolidated decisions based on up-to-date reliable facts.The first step towards enhancing understanding of possible directions of climate policies among policy makers and other stakeholders is the identification of knowledge needs.In this way stakeholders are facilitated and enabled to form well-informed, consolidated decisions.
In this article the design and development of a climate policy database was presented, containing all the resources that can cover the climate policy knowledge gaps.Knowledge needs on EU and international climate policy implications were identified through POLIMP's methodology and participatory process and were presented to selected stakeholders during thematic POLIMP workshops, for feedback analysis, results review and validation.The purpose of the database is to create an ontology for interpreting and organising information associated with climate policies and to provide a platform that allows exploration, editing and extension of the concentrated knowledge.
Managing information using a database allows to become strategic users of the available data, a fact especially helpful in climate policy making, where the vast number of existing research and knowledge needs to be effectively gathered and structured.The Climate Policy Database allows regulatory agencies, governments and policy makers in general to evaluate the current regimes and their implications and impacts, and provides scientists the ability to probe and understand the outcomes of climate negotiations.The database model can be used by local governments, national, regional and international communities and academia.
The Climate Policy Database is proved to be the key element of this approach.This practical web-based application serves as a database on issues related to climate change mitigation and adaptation, technology transfer, and market mechanisms, providing numerous functionalities to make knowledge transfer as easy and accessible as possible for decision makers in policy, business and civil society.The implementation of a running living database, for annotating and structuring the knowledge related to climate policies and provision of a platform, allows exploration, editing and extension of the concentrated knowledge facilitating the decision and policy makers.The developed platform facilitates the search of information related to climate policies based on specific keywords, which in turn lowers the barrier for data re-use and integration.

Figure 1 .
Figure 1.Methodology followed by POLIMP for identifying knowledge gaps on implications of possible directions of EU and international climate policies.

Figure 1 .
Figure 1.Methodology followed by POLIMP for identifying knowledge gaps on implications of possible directions of EU and international climate policies.

Figure 2 .
Figure 2.An ontology for representing the knowledge package resources.

Figure 2 .
Figure 2.An ontology for representing the knowledge package resources.

Figure 3
Figure 3 depicts the schematic view of the Climate Policy Database setup with OntoWiki as a generic tool for viewing and editing the resources of the database and with OpenLink Virtuoso as the backend storage database.

Figure 3
Figure 3 depicts the schematic view of the Climate Policy Database setup with OntoWiki as a generic tool for viewing and editing the resources of the database and with OpenLink Virtuoso as the backend storage database.

Figure 4 .
Figure 4.The Climate Policy Database: (1) Selection of a knowledge base; (2) Selection of a class; (3) Selection of additional properties to be shown as columns in the list; (4) Further restriction of the resources in the list.

4. 4 . 2 .
Extending the Climate Policy database-Creating a New Class and Instances By selecting Edit and then Add Resource here in the navigation component the user can create a new class in the Climate Policy ontology.By creating new classes the Climate Policy ontology can be extended and new tags in the pre-defined hierarchy can be added according to the needs.In addition, new instances of the available classes can be created.This enables the user to add new instances of the Climate Policies Taxonomy and Knowledge Package classes, enriching the Climate Policy Database.Depending on which class is selected in the Navigation component, a list of existing templates for the new instance's creation is presented to the user.

Figure 4 .
Figure 4.The Climate Policy Database: (1) Selection of a knowledge base; (2) Selection of a class; (3) Selection of additional properties to be shown as columns in the list; (4) Further restriction of the resources in the list.

4. 4 . 2 .
Extending the Climate Policy database-Creating a New Class and Instances By selecting Edit and then Add Resource here in the navigation component the user can create a new class in the Climate Policy ontology.By creating new classes the Climate Policy ontology can be extended and new tags in the pre-defined hierarchy can be added according to the needs.In addition, new instances of the available classes can be created.This enables the user to add new instances of the Climate Policies Taxonomy and Knowledge Package classes, enriching the Climate Policy Database.Depending on which class is selected in the Navigation component, a list of existing templates for the new instance's creation is presented to the user.4.4.3.Browsing the Climate Policy database-Viewing the Instance List of a Class By selecting one of the available classes in the navigation component, the user receives a list of resources that are instances of the selected class in the main window area.4.4.4.Browsing the Climate Policy database-Viewing a Single Instance The selection of a resource redirects the user to a generic resource details view in which the representation of the selected RDF triples appears as resource attribute value notation in the user interface.4.4.5.Making changes to the Climate Policy Database-Modifying an Instance or a Class

Table 1 .
Ontologies in various applications.

Table 3 .
Key knowledge needs and priorities.
Vertical integration between decision-making levels.Energy PolicyElectricity market design.Energy price developments in different world regions, and its impacts.Energy efficiencyEffectiveness of existing energy efficiency policy.Possible energy saving obligation schemes and financing options.Energy efficiency measures savings potential.Access to capital for energy efficiency measures.Emissions Trading Further harmonization of emissions trading scheme implementation across the Europe (EU).Price stabilisation mechanisms, backloading, changes to the linear reduction factor.

Table 3 .
Key knowledge needs and priorities.
Climate finance generating mechanisms, innovative climate finance schemes.Types and timescales of climate change mitigation targets.Vertical integration between decision-making levels.Energy PolicyElectricity market design.Energy price developments in different world regions, and its impacts.
TransportIncreasing efficiency through intelligent transport systems.Efficient integration of modal networks.

Table 4 .
Main Classes and Sub-classes of the Climate Policy Ontology.