## 7 Conclusions: Changing Climate, Changing EO Needs  
ECVs are critical for understanding and monitoring the Earth's climate system. These variables provide important information about the Earth's biogeochemical processes and help to improve our understanding of the climate system and its response to natural and human-induced changes. In a changing climate, ECVs provide an important example on the possibility to create coherent timeseries of temperature, ocean colour and many other variables. But lake extent, lake colour, and ocean colour in small oceanic regions are still not possible. By monitoring these and other ECVs, scientists and policy makers can better understand the causes and consequences of climate change and develop strategies to mitigate its impacts. However, there is a spatial and radiometric resolution gap to monitor small yet very important habitats. Privately own satellites are integrated into services such as Copernicus but, currently, there is no public access to long-time series derived from such data. The same algorithms and processing methods used for ocean colour can be applied to data from other sensors to assess the water quality and phytoplankton abundance in lakes and other small water bodies [25]. The lack of VHR1 and VHR2 resolution imagery provides a significant limitation not only on the science that can be done in the two use cases (lakes and MPAs) but also a potential operational water quality monitoring system in high resolution. Effective ecosystem-based management (EBM) in MAPs offers a variety of factors not restricted to sustainable fisheries and conservation measures [30]. The capabilities of high-resolution data, specifically in terms of detection of Harmful Algal blooms, euphotic depth, CDOM and organic matter might contribute to a more pressing view of MPA monitoring, but the literature is not yet mature in terms of use cases. However, the applications of EO data in the scope of MPAs are vast and due their remoteness, satellites are vital to monitor such zones. A previous study identified 21 policy statements for EO data, identifying that most of the current policies abide for some type of free and open data access. Nonetheless, when all the exceptions are outlined across all these policy statements, the situations are extensive and potentially very restrictive. In most cases, the application of these restrictions is too broad to be applied [33]. As seen before, VHR is needed for effective environmental monitoring. There are three main arguments, protecting VHR satellite owners and concerns surrounding security threats, considering that the provision of the creation of a long time series from VHR imagery of the ocean is not time critical:  
1. The maritime picture, being highly dynamic and constantly changing, is not subject to the same risks and threats posed by land imagery. 2. Creation of timeseries on water quality parameters could be specific to MPAs where military activities are in principle not foreseen. 3. Although the images themselves could still be protected by user rights, their scientific derived products do not need to be, especially considering these data are not sensitive. The usage of EO data for lakes and MPAs is currently only possible via some privately owned satellites especially considering the necessary EO data characteristics (higher spatial, spectral, and temporal resolutions). The EO methods necessary to perform analysis on an environmental basis (such as the retrieval of algorithms) are not suitable to produce long timeseries, with the biggest disadvantage being scientists needing to purchase an entire collection of privately owned data to study these small environments. However, the challenges are clear: studying small lakes and monitoring MPAs over long timespans is crucial. Albeit not addressed in this article, LiDAR (\"light detection and ranging\") is capable of detecting Chlorophyll in water, though it is not as commonly used as an optical remote sensing method.