Changing Climates. The Role of Renewable Energy in a Carbon-Constrained World. A Paper Prepared for REN21

The current paper on renewable energy and climate change is focused on the key characteristics of the climate change challenge, the intergovernmental action to address the challenge, and how current and future renewable energy projects can contribute to global carbon mitigation and adaptation efforts at the local level. The report presents the current and possible different future contributions that renewable energy can make. This is based on analysis of different authoritative global scenarios and their underlying assumptions, and is aimed at providing guidance on what would be required in terms of policy decisions and technological developments if renewable energy is going to significantly mitigate climate change. Although the focus is particularly on climate change and the opportunities for renewable energy, other issues are closely interlinked. Reducing GHG emissions by introducing more renewable energy, for example, will also have positive impacts on the security of energy supply, while potentially compounding the need for investment capital. The report begins with the current global energy demand and the contribution of renewable energy to meeting that demand. Next, different key internationally recognised energy development scenarios are presented from the Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency (IEA), together with selected policy scenarios of very different specific options to mitigate climate change and stabilize CO2 levels in the range of 450-550 ppm. These scenarios are presented with both high and limited penetrations of renewable energy, along with discussions of underlying assumptions leading to these different results, including comparisons of projected technology costs. Existing policies worldwide to promote renewable energy are then analysed for their relative efficiency and results. Guidance is presented on the possible policy tools governments can use to move from the stipulated 'business-as-usual' (BAU) renewable energy expansion to a level where renewable energy makes a major contribution to climate change mitigation over the coming decades. To present realistic recommendations, barriers and opportunities for such a renewable energy expansion are discussed separately. It is not possible to 'translate' the results of the global scenarios directly into requirements for policies at the national level. The aim of the section is therefore to show that action is already taking place, which can be scaled-up. Further, experiences with a wide variety of different policy tools are available, which support the realistic call for stronger policies. The financial implications and requirements related to different short and medium term 'energy futures' are then discussed with analysis of current actions and the specific challenges related to rapidly expanding the renewable energy sector. The specific role that carbon finance can play in this regard is addressed in detail. Linking the long-term forecasts directly to finance requirements or even summing up the costs over 100 years would not provide significant (or meaningful) policy insights. Focus is therefore on the trends for the longer term costs of different technologies. Because all predictions indicate that the Earth will face some level of climate change - even with urgent and decisive action on the mitigation side - the possible role that different renewable energy technologies can play to adapt or reduce the vulnerability to climate change are briefly discussed. More analysis is needed to better identify specific renewable energy contributions, although the chapter does provide some initial indications. It is important to emphasize that the scope here is to examine the contribution of renewable energy to mitigating climate change. The implicit assumption is that this will need to be considered in close connection with activities related to energy conservation and improved efficiency in both energy production and use. This understanding is also embedded in the scenario analysis presented in Chapter 3. Makin g this link explicit would merit an entirely separate investigation since energy efficiency and conservation present challenges of a different nature in terms of technologies, policies and implementation. It is therefore considered beyond the scope of this effort.