Climate change and escalating environmental degradation risk becoming key constraints to economic growth and human development. Poor women and men in developing and transitional countries are disproportionally affected by pollution, land degradation and other environmental problems due to high dependence on natural resources and high exposure to risks. Managing the environment is important for the well-being of all citizens, particularly for the least well-off. There has been progress in terms of policies and creation of environmental authorities and international environmental commitments. However, there is a growing gap between the environmental commitments made and the actual implementation to improve environmental outcomes. Environmental policy design is embedded in a political context with multiple actors and interests. In many cases measures that strengthen important human rights principles, such as the rule of law, transparency and public participation, may be equally or more important than specific environmental policies or projects in order to improve environmental management. It is increasingly recognised that technical solutions to environmental problems are not sufficient to obtain sustainable development. Instead, there is a growing attention to the importance of governance to manage the wide range of environmental challenges and impacts.The purpose of the report is to explore the linkages between governance and the implementation of environmental legislation (including multilateral environmental agreements) and other environmental measures. The report is intended as a source of information and inspiration to individuals and organisations working with environment and development. It attempts to demystify the concept of governance and show how greater attention to specific governance aspects can help improve environmental outcomes. The report is divided into three parts: one theoretical part providing an overview of research on linkages between environmental governance at different levels (international, national, sub-national) and environmental outcomes. The second part provides examples of the linkages between the environmental implementation challenge and different governance aspects, particularly transparency, participation, integrity and accountability. The third part highlights issues to consider for environmental authorities in developed countries interacting directly or indirectly with environmental authorities in transition or developing countries through development cooperation or multilateral environmental agreements.The work has been performed as a desk study, with an extensive review of research literature and assessment reports, as well as interviews with a number of experts.The report presents the following key conclusions: overnance aspects need to be considered when aiming at improving implementation of environmental legislation and other environmental measures. There is a growing consensus emphasising that governance aspects have a strong effect on environmental actions and outcomes. Measures that strengthen important human rights principles such as the rule of law, transparency and public participation may be equally or more important than specific environmental policies or projects in order to improve environmental outcomes. Improving environmental outcomes is thus not only dependent on legal frameworks and the capacities of the environmental authorities and sector ministries, but also largely on external factors that provide the ‘enabling environment’. Good governance is needed to manage large flows of environmental and climate change finance. The urgency of addressing the environmental challenges, particularly related to climate change, and the associated large flows of funds that are envisaged as a response to these challenges, provide additional arguments for the need of good governance. Large flows of financial resources, coupled with an imperative to spend, can create conditions prone to corruption. Good governance is acknowledged as an important factor to prevent social ills such as corruption, social exclusion, and lack of trust in authorities.Fragmented international governance frameworks are badly suited for addressing the implementation deficit. While several international agreements as well as non-legally binding instruments are in place, each agreement deals with specific environmental issues. The national action plans developed in line with the different international agreements are often poorly implemented, project oriented and not well integrated in national or sectoral planning and decision-making processes. Ownership can be strengthened by linking environmental outcomes to developing and transition countries’ priorities, such as economic development, poverty reduction or job creation. Furthermore, the international environmental financing is often supply-driven and fragmented, and the funders are seldom aligned with the developing or transitional country’s national systems e.g. for planning, monitoring and budgeting. The need for a bottom-up approach is increasingly recognised, where governments are accountable to the citizens. For improved implementation, country systems need to be strengthened, and the international environmental governance system more efficient.Factors related to corruption, impartiality and government effectiveness are influential to reach positive environmental outcomes. Poor women and men, who often bear the heaviest costs of environmental degradation, tend to be dispersed and weakly organised in comparison to interests benefitting from the current – often unsustainable – growth path. Where, for instance, vested interests work against reforms for controlling industrial pollution or deforestation, there are often also weaker constituencies, such as affected communities, unions and environmental organisations, pushing for reform implementation. Accountability mechanisms, such as ensuring the rights to access information, public participation and access to an impartial justice system, are essential for enabling these constituencies to demand environmental improvements. Efforts to improve environmental policies must go hand in hand with efforts to reduce corruption if they are to have the intended effects. Improved accountability, transparency, public participation and integrity can reduce the risk for corruption and create trust and legitimacy which facilitates implementation of different policy instruments. Environmental governance is cross-cutting, relates to international, national, and sub-national levels, and involves many actors. Global governance mechanisms are needed to address global challenges. However, implementation at national and sub-national level must be led by the developing and transitional countries themselves. While the public sector has a key role in the formulation and implementation of governance mechanisms, such as policies and regulations, the active participation of many other actors, free flow of information, accountability and integrity are crucial aspects for improved environmental outcomes. The important governance role of communities and other actors in between the state and the market are increasingly recognised. Many countries have decentralised natural resource management for enhanced community level participation, transparency and strengthened accountability. However, with decentralised responsibilities must follow sufficient resources - for instance information, training and financing - needed to carry out the new functions. Context specific analysis is needed to identify key governance bottlenecks and priority interventions for environmental management. There are a wide range of potential environmental governance mechanisms, and the specific circumstances in each country will determine what needs to be strengthened and in what order. Example of context specific conditions that vary greatly are financial resources, monitoring capacity, government effectiveness, integrity of the judicial system, voice and accountability, as well as public awareness on environmental and development risks and opportunities. A context specific analysis will help identifying the steps that are possible to take to improve governance in the short, medium and long term. Improving governance is a process, and each step can be important. Environmental authorities in OECD countries can help raise attention tobroader governance issues for better environmental outcomes. There is a large need for improved capacity for environmental management. As participants in international negotiations and actors in international development cooperation, environmental authorities influence frameworks and approaches. When involved in development cooperation, a broad governance perspective should be used during identification of capacity strengthening needs. Furthermore, governance tools such as participation and transparency should be considered as means to reach intended results while promoting governance more broadly. When contributing to international environmental frameworks, opportunities to promote the use of country systems for planning, budgeting and monitoring should be explored.