At the beginning of November the previous year, the Intergovernmental Panel on Climate Change (IPCC), which I am privileged to chair, released its Synthesis Report which is part of the Fifth Assessment Report of the Panel.  There was detailed assessment of options by which the world would need to mitigate emissions of greenhouse gases (GHGs), such that temperature increase by the end of this century would not exceed 2 ^oC.  Essentially, the pathway by which there would be high assurance of the 2 ^oC target being adhered to would require a 40–70 per cent reduction in GHG emissions by 2050 over the levels recorded in 2010, and zero or negative emissions by the end of this century.  These targets would certainly not be easy to reach. An important element of action that would be required involves greater use of renewable energy.  In fact, as early as 2050, the world would need trebling or quadrupling of low-or zero-carbon sources of energy supply.

The IPCC brought out a special report in 2011 with the title “Special Report on Renewable Energy Sources and Climate Change Mitigation” (SRREN).   In that report it was stated that “Ocean energy offers the potential for long-term carbon emissions reduction but is unlikely to make a significant short term contribution before 2020 due to its nascent stage of development. In 2009, additionally installed ocean capacity was less than 10 MW worldwide, yielding a cumulative installed capacity of approximately 300 MW by the end of 2009. All ocean energy technologies, except tidal barrages, are conceptual, undergoing research and development (R&D), or are in the pre-commercial prototype and demonstration stage. The performance of ocean energy technologies is anticipated to improve steadily over time. Whether these technical advances lead to sufficient associated cost reductions to enable broad-scale deployment of ocean energy is the most critical uncertainty in assessing the future role of ocean energy in mitigating climate change. Though technical potential is not anticipated to be a primary global barrier to ocean energy deployment, resource characteristics will require that local communities in the future select from multiple available ocean technologies to suit local resource conditions.”

Relatively few assessments have been conducted on the technical potential of various ocean energy technologies and such potentials will vary based on future technology developments. Whilst some potential ocean energy resources, such as ocean currents and osmotic power from salinity gradients, are globally distributed, other forms of ocean energy have complementing distributions.

According to SRREN, the theoretical potential for ocean energy technologies has been estimated at 7,400 EJ/yr, well exceeding current and future human energy needs.  Hence, it is perfectly appropriate to state that the oceans on this planet quite, apart from providing substantial other benefits, can also be treated as oceans of energy.  Decision makers now have to provide adequate resources for research and development by which the potential of energy from the oceans can become a reality.