A major UN report has warned that "rapid, far-reaching and unprecedented changes in all aspects of society" are needed to limit the level of global warming.
The Intergovernmental Panel on Climate Change (IPCC) says we are already seeing the consequences of around 1°C change in global temperatures due to human activities.
Researchers have said that effects of global warming so far include more incidents of extreme weather, rising sea levels and diminishing sea ice in the Arctic.
However, the report - which was approved during a meeting of the IPCC in South Korea over the weekend - warns that major international action will be required to limit global warming to 1.5ºC, rather than 2ºC or higher.
It's estimated that a 1.5ºC change would see coral reefs would decline by up to 90% - but at 2ºC that would increase to 99% or more.
Scientists estimate that the lower temperature change would mean the Arctic Ocean would be free of sea ice in the summer once per century - jumping to once per decade if it's higher.
The report also suggests that by 2100, global sea level rise would be 10 cm lower with global warming of 1.5°C compared with 2°C.
It is not impossible to limit global warming to 1.5ºC, according to the new @IPCC_ch report. But it will require urgent, unprecedented & collective #ClimateAction in all areas. There is no time to waste. https://t.co/m3HQkSmAHY
— António Guterres (@antonioguterres) October 8, 2018
The IPCC says that action is needed across societal areas such as land, energy, transport and energy to avoid a higher global temperature change.
According to the experts, human-caused emissions of carbon dioxide (CO2) would need to fall by about 45% from 2010 levels by 2030 - before reaching 'net zero' in 2050, meaning "remaining emissions would need to be balanced by removing CO2 from the air".
"Most important years in our history"
Following their meeting, the IPCC suggested that limiting global warming is possible and many actions are already underway to tackle the issue - but warned that such actions 'need to accelerate'.
Debra Roberts, Co-Chair of IPCC Working Group II, observed: “This report gives policymakers and practitioners the information they need to make decisions that tackle climate change while considering local context and people’s needs.
"The next few years are probably the most important in our history."
The report says that limiting climate change would have major impacts for society - such as helping eradicate poverty and reducing inequality.
Reacting to the report, climate change expert John Sweeney - Professor Emeritus from Maynooth University - suggested failure to face up to the challenge of limiting climate change will have major consequences for both human society and the entire planet.
He explained: "Major extinctions of plants and animals will accelerate and weather related hazards will increase in frequency almost everywhere.
“For Ireland, overshooting 1.5°C would accentuate our emerging problems of climate extremes and damage the economic prospects of our current young people."
He added: "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.”
