Oceans act as a sponge for the ill effects of the climate change by absorbing heat and CO2 generated by greenhouse gas emissions . However these same oceans are likely to unleash their wrath on a global scale. According to a draft report of United Nations Intergovernmental Penal on Climate Change destructive changes have already been set in motion. The draft report says that even with most optimistic emission reduction scenario , by the year 2050 many low lying megacities and small island nations will experience extreme sea level events every year. Report says that the big four - United States of America, China, India and European Union will face most devastating fall out of the ocean and ice related impacts of climate change.  IPCC has meanwhile said that final report will be released in September after a thorough discussion with all stakeholders.