The report makes it evidently clear that a 1.5°C world would witness greater sea level rise, increased precipitation and increased frequency of droughts and floods, more hotter days and heatwaves, more intense tropical cyclones, increased ocean acidification and salinity.
While an extra half a degree over that limit of 1.5 degrees might seem insignificant‚ a shocking landmark report just released by the United Nations has taken the world by storm‚ showing how hitting a 2 degree rise would spell doom.
Working through the night, the closed-door huddle in rain-soaked Incheon, South Korea, was to convene a plenary later in the day to hammer through a "Summary for Policymakers".
The planet's surface has already warmed by 1 degree Celsius - or 1.8 degrees Fahrenheit - and could see a catastrophic 1.5 C - 2.7 F - increase between 2030 and 2052, scientists say. On current trends the 1.5°C threshold could be reached as early as 2030.
The report elicited dramatic response, with leaders such as Andrew Steer, president and CEO at World Resources Institute, calling it "a wakeup call for slumbering world leaders".
She highlighted the construction of the Norwich Northern Distributor Road and Norfolk County Council's ambition to build the Western Link, which would connect that £205m road to the A47 to the west of Norwich, as examples of projects which would generate further carbon emissions.
This is hard, and would require rapid and unprecedented economy-wide transformation in each country.
A rise in global temperatures by another 0.5 degree Celsius would increase, deepen and spread the impacts wider, the scientists concluded. But U.S. states led by California and many cities are living up to their commitments to cut greenhouse gas emissions, WMO's Taalas said.
Following the United Nations report, Steve Waygood, from Aviva Investors, said it was estimated that, without action, climate change would cost the global economy 43 trillion USA dollars (£33 trillion) in today's prices. It is based on more than 6,000 scientific references and contributions from thousands of experts and government reviewers around the world.
According to the latest study, the half-degree difference can have a huge impact.
Florida, Alabama bracing for 'monstrous' Hurricane Michael
Hurricane conditions have spread over portions of western Cuba this afternoon, where a hurricane warning is now in effect. The National Hurricane Center has warned that a "life-threatening" storm surge is likely to strike the Panhandle.
"There will be 420 million people less suffering because of climate change if we would be able to limit the warming to 1.5°C level and we have certain areas in the world which are extremely sensitive", Petteri Taalas, secretary-general of the World Meteorological Organization, said today.
Scientists have been sounding the alarm on climate change for decades, yet global emissions are expected to rise again in 2018.
Panmao Zhai, co-chair of the IPCC Working Group I (which assesses the science of climate change), said: "One of the key messages that comes out very strongly from this report is that we are already seeing the consequences of 1°C of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice, among other changes".
"The report shows we only have the slimmest of opportunities remaining to avoid unthinkable damage to the climate system that supports life as we know it", said Amjad Abdulla, IPCC board member and chief negotiator for an alliance of small island states at risk of flooding as sea levels rise.
"It will take government resolve", he said.
At the Paris Agreement in 2015‚ 2ºC was set as the ceiling we should aim to stay under‚ but that has now been changed to 1.5ºC. Countries need to undertake massive de-carbonisation while the developed countries must also address consumption in their countries.
Allowing the global temperature to temporarily exceed or "overshoot" 1.5 °C would mean a greater reliance on techniques that remove Carbon dioxide from the air to return global temperature to below 1.5 °C by 2100.
But the report said the efficacy of measures, such as planting forests, bioenergy use or capturing and storing CO2, were unproven at a large scale and carried some risks. Climate Change Conference, scheduled for December in Katowice, Poland, which marks the deadline for nations implementing the 2015 Paris agreement.
But really whacky ideas, such as blocking out the Sun, or adding iron to the oceans have been dismissed by this IPCC report.