A major UN report says an "unprecedented" response is needed to limit global warming.
The Intergovernmental Panel on Climate Change (IPCC) says we're already seeing the impact of human-influenced global warming - such as increases in extreme weather and rising sea levels.
Its new report, agreed following a meeting in South Korea over the weekend, says that limiting global warming to 1.5ºC - rather than 2ºC or higher - will require significant international action.
For example, Scientists estimate that a 1.5ºC change would see coral reefs decline by up to 90% - but at 2ºC that would increase to 'virtually all' reefs.
Now, the IPCC is calling for "rapid, far-reaching and unprecedented changes in all aspects of society".
UN Secretary General Antonio Guterres said that while limiting climate change is possible, "there is no time to waste".
Reacting to the report, Irish climate change expert Prof John Sweeney observed: “For Ireland, overshooting 1.5°C would accentuate our emerging problems of climate extremes and damage the economic prospects of our current young people.
"The report confirms that only by undertaking radical steps today to decarbonise our societies can we leave a legacy of a sustainable world for the next generation.”