What are the current impacts of climate change on marine life according to the UN Environmental Program?

According to the UN Environmental Program, the situation is deteriorating rapidly due to very hot ocean temperatures in recent years. The impact is so severe that projections indicate a quarter of all marine life will be gone by the end of the century if current trends continue. This alarming data reflects the unprecedented rate of warming since the mid-20th century, which is causing significant biodiversity loss in our oceans. While 'An Inconvenient Truth' had some incomplete or overstated elements, the fundamental climate warnings appear to have been accurate or even understated compared to current reality.