Jude, SimonGill, AndrewBirchenough, Silvana N. R.Willsteed, Charles Edward Allan2023-10-122023-10-122019-06https://dspace.lib.cranfield.ac.uk/handle/1826/20367The challenges of assessing and managing the cumulative impacts of human activities on the environment remain major obstacles to sustainable development. This challenge is highlighted by the worldwide expansion of marine renewable energy developments (MREDs) in areas already subject to multiple activities and where climate change is rapidly changing the environment. Cumulative effects assessments (CEAs) in theory provide decision makers with adequate information about how the environment will respond to the incremental effects of licensed activities and are a legal requirement in many nations. In practise, however, such assessments are beset by uncertainties that, in context of MREDs, resulting in substantial delays during the licensing process that limit progress towards meeting carbon emission reduction targets. At a broader level, poor CEA practice risks developments and activities being permitted that contribute to environmental degradation with negative implications for connected human societies. This thesis investigates the origins of CEA to understand why improved practice remains challenging and to identify key CEA considerations that need to be addressed to improve CEA. Shortcomings in current practice were evaluated to refine the key CEA considerations. A conceptual analysis of the underpinnings of CEA was completed that resulted in a tiered conception of CEA being proposed to support regional coherence between CEAs, and the elaboration of principles and a CEA pathway to support consistent CEA practice. The CEA pathway was tested by defining and collating evidence to populate the steps of the pathway, which was then applied to a case-study to investigate the potential for novel approaches to support improved CEA. Insights and directions for future research were discussed to contribute to the evidence base required to improve CEA and to advocate for a change in CEA, from being a sub-discipline of project- and plan- level assessments, to becoming the overarching purpose of such assessments.en© Cranfield University, 2019. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.Cumulative effects assessmentenvironmental assessmentsocial-ecological systemsmarine renewable energyenvironmental impact assessmentecosystem approachmarine managementmarine spatial planningThesis or dissertation