The correct options are
A The ocean absorbs most of the excess heat from greenhouse gas emissions, leading to rising ocean temperatures.
B The ocean’s ability to absorb excess heat has shielded humans from more extreme changes in climate untill now.
D The rise in sea surface temperatures is causing the intensification of El Niño events.
Ocean warming is an environmental crisis that has long ranging consequences for marine ecosystems. Oceans absorb excess heat from GHG emissions. Without this oceanic buffer, global temperatures would have risen incrementally. It also leads to deoxygenation, reducing amount of oxygen available for marine life. Rising temperatures affects reef-building species such as corals and mangroves which protect coastlines from erosion. Rising sea levels has led to intense hurricanes and EL Nino events, bringing droughts and floods. Thus, it is important to implement adequate mitigation and adaption strategies.