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Speaker: Prof. Dr. Martin Herold, Chair of Remote Sensing, Center of Geo-Information, Department of Environmental Science, Wageningen University, The Netherlands
Information on where and how change is happening is in high demand in particular on issues related to tropical forests. Prominent policy processes and land-based activities are causing or trying to influence how forest changes occur for many societally relevant areas. The world of Earth Observations is aiming to deliver some of that information: thematically rich, accurate and consistent in space and time over large areas. Significant parts of remote sensing scientist’s interests remains in field of sensor and technology-driven approaches, evolving tools for signal processing and image analysis, and developing fields of application. However the field is evolving in particular since it is trying to better track dynamics and changes, and works more closely with policy processes and through engagement of wider communities. Monitoring tropical forest change is such a worldwide issue of broad relevance since both the drivers causing forest loss and the resulting impacts are related to both local and global scales and linked to major policy and societal engagements (i.e. Reducing Emissions from Deforestation and Forest Degradation – REDD+). This is driving also the Earth Observation community and I will try to highlight five of the factors that change the way that related science and impacts.
First, there is increasing amount of free-and-open remote sensing datasets for the past and in the future. This creates increasingly longer and denser time-series of observation data available to allow for synoptic, more consistent and transparent global view on the human activities on the land surface and related changes on a detailed local level. For example, the new Landsat-8 and the European Sentinels, provide the most important improvements in temporal revisit and continuity, and thus allow for improved assessments of dynamics on the space-time scales where many important human-induced changes on the land surface occur; also in near-real time.
Secondly, this level of information and transparency created by satellite observations will offer unprecedented interactions of satellites, science and society. This goes beyond citizen observer networks that play an increasing role in the improvement of remote sensing studies through providing local information and knowledge. Citizen’s and society’s motivations and interest to participate in monitoring are related to:
• personal and locational details since there is a fundamental interest on where things are, how and why things are the way they are in their personal sphere of influence;
• the notion of the self-aware world that is stimulated by the criticism on restricted data, and the related need for transparency in information;
• the delta-driven information priorities: information on dynamics and change are commonly more interesting than stability,
• specialized science interests.
We are starting to create remote sensing data streams that go beyond expert users but offer avenues to engage broader and provide more direct contributions and benefits than before. There are first experiences with the Google Earth Engine that reduces some of the complicating issues in using remote sensing for a wider societal audience, and show examples how near-real time satellite monitoring can stimulate broad participation and interest in forest monitoring and assessments.
Thirdly, the need for robust ground data is increasing the more quantitative and detailed remote sensing analysis become. This is probably the largest data gap today for remote sensing science but many ground-surveying strategies do not have the integration with remote sensing observations in mind; and vice versus. Such integrated monitoring concepts are just evolving and the use of terrestrial laser scanning and the community/local expert monitoring are relevant examples for tropical forest monitoring.
A fourth point to raise is that technological progress and methodological sophistication alone is often not sufficient to implement forest assessments effectively; both nationally and globally. It is as much about the process than the product and more emphasis is needed on fostering more saliency and legitimacy in addition to technical credibility. The REDD+ process has triggered more serious experiences in the engagement with prominent political processes, the gathering of observation requirements providing technical policy advice, the definition of observation strategies and priorities, evolving international technical consensus, the specification of implementation guidelines, and implementation of dedicated case studies fostering technical progress, operations and applications. I will use the example Global Observation of Forest Cover and Land Dynamics (GOFC-GOLD) REDD Sourcebook working group as case.
A final argument is suggesting that REDD+ is an important catalyst for interdisciplinary collaboration; also in the domain of measuring and monitoring. While the scope, scale and pace of REDD+ to work best remains unclear, the discussions and proposed solutions are increasing in complexity. For example, multi-disciplinary perspectives argue about whether and how REDD+ monitoring systems can include co-benefits; strengthening countries’ technical and governance capacity for REDD+; defining preconditions for successfully incorporating co-benefits into REDD+; linking REDD+ to other policy areas such as forest management certification and timber legality; and identifying and managing the environmental and social impacts of varied REDD+ activities. Interdisciplinary research on REDD+ monitoring can help to distill the lessons learned from REDD+ efforts currently underway and can provide concrete recommendations for improving the impacts of REDD+.