What does this mean?

Sustained above-average temperatures, as the planet has seen so far this century, can affect the ice sheet, global sea levels, ecosystems, agriculture, coastal development, ocean acidification, rainfall and a number of cyclical rhythms. “In February 2020, we saw the worst ever coral bleaching event in the Great Barrier Reef – the third mass bleaching event in just five years – and a direct result of increased sea water temperatures…”. Source: Science X, 6 April, 2020.

Organisations such as CSIRO, the International Energy AgencyNASA, the Intergovernmental Panel on Climate Change (IPCC)  and the US National Oceanic and Atmospheric Administration (NOAA) all agree that we must drastically reduce greenhouse gas emissions if we are to prevent catastrophic climate change into the future.