Impact of Climate Change on Global Wave Energy Resource

The Intergovernmental Panel on Climate Change (IPCC) is the main organization about the analysis of climate changes. This organization collects studies and processes all the information obtained with the aim of producing final reports, the last IPCC report is the "Fifth Assessment Report" (AR5) which was published in 2014. In the Fifth Assessment Report are also discussed some future climate projections, in which different rate of greenhouse gas emissions are expected, assembling different climate models. The projections are called Representative Concentration Pathways (RCPs) and in AR5 four of these are examined and they represent three different kind of scenarios with different rates of changing. Wave energy is a field of renewable energy which try to extract the energy stored in wind waves. In the years many attempts to produce energy from waves was made using prototype that benefit from waves using different methods such as their kinetic energy, the motion of swinging or rotation that caused by waves to floating devices and also the pressure inducted by the oscillating sea level into closed chambers moored on shore. Potentially, marine energy is considered as a powerful resource despite the majority of technologies are still in an experimental state, in fact it is estimated that energy extractable from oceans could cover the entire global energy requirement. Between the technologies developed until now there are some which try to obtain energy from waves, tidal, currents, ocean thermal gradient and osmotic power. The five data model used for this work provide a total of twenty files output, ten for wave heights and ten for peak wave periods, where each set of ten is divided into five output of past period (1979-2005) and five of future period (2081-2100). The used models are the following: BCC-CSM1.1, EC-EARTH, GFDL-ESM2M, INMCM4, MIROC5. For the process of assessment of wave energy between all the point available in the models, only a 1310 have been selected, forming a grid all over the sea surface with a point every 5° of latitude and longitude, so that the distance between two following models vary depending on the latitude and has a mean length of 400 km. The results of the global wave power averaged on every points for the entire time interval of twenty year in the past (1986-2005) and in the future (2081-2100) show that all the five models agree on considering the southern hemisphere, particularly in the Indian Ocean's area to the south west of Australia, the powerful area with peak of mean wave power around 180-200 kW/m. Secondly, the northern hemisphere is also considered by all the five models as a high power area, with some models estimating the North Atlantic as little more powerful than Pacific Ocean (BCC-CSM1-1 and EC-EARTH) while other models (INMCM4 and MIROC5) estimate the last one more powerful than Atlantic Ocean. All the models seems to agree with the computation of the difference between past and present conditions, considering a little increase of wave power in the center of Indian Ocean and an high increase in the South area of it. All models also estimate, but with different rates, an increase of power in the East area of Pacific Ocean and a decrease in the northern hemisphere of Atlantic Ocean.