The IPCC, the UN's top climate panel, issued the report from Incheon, Republic of Korea, where for the past week, hundreds of scientists and government representatives have been pouring over thousands of inputs to paint a picture of what could happen to the planet and its inhabitants with global warming of 1.5°C (or 2.7 degrees Fahrenheit).
Canada would have to cut its emissions nearly in half over the next 12 years to meet the stiffer targets dozens of worldwide climate change experts say is required to prevent catastrophic results from global warming.
While more than 180 countries have accepted the report's summary, the U.S. (which is the second biggest emitter in the world) said that their acceptance of the report does not "imply endorsement" of the findings.
Greenhouse pollution must be reduced by 45 per cent from 2010 levels by 2030 and 100 per cent by 2050.
Limiting warming to 1.5°C is possible within the laws of chemistry and physics but doing so would require unprecedented changes, Co-Chair of IPCC Working Group III Jim Skea said. The not-so-great news? They need to accelerate.
To limit warming, report authors claim significant actions must be taken to change land use practices, transform the energy sector and curb industry emissions. "Over 187 cities globally participate in that symbolic gesture of switching off your lights for that one hour, to say I really care about this and I want to be part of the solution", Ms Richter said. "This means that any remaining emissions would need to be balanced by removing Carbon dioxide from the air", it says. Coral reefs would decline by a still unsustainable 70 percent to 90 percent instead of being virtually wiped out under the higher increase. "We are already putting all our efforts to ensure that the global temperature does not further increase". "The latter would be used as part of a now nonexistent program to get power from trees or plants and then bury the resulting carbon dioxide emissions in the ground, leading to a net subtraction of the gas from the air - bioenergy with carbon capture and storage, or BECCS".
"The next few years are probably the most important in human history", IPCC co-chair Debra Roberts, head of the Environmental Planning and Climate Protection Department in South Africa, told Agence France-Presse.
The rise has already triggered consequences we are seeing through the seasons such as more extreme weather.
The next major climate discussions are scheduled in December in Katowice, Poland where countries are expected to discuss rules to implement the Paris agreement.
The lower target would also reduce species loss and extinction and the impact on terrestrial, freshwater and coastal ecosystems, the report said.
Developing nations and least developed countries have been asking developed nations, particularly the United States, to take historical and moral responsibility for being one of the largest greenhouse gas emitters.
Joyashree Roy, a professor of economics at Jadavpur University and a co-author of the IPCC report, says: "We have found that the burden of global warming will fall disproportionately on the poor who are not responsible for the problem if we don't meet (the) 1.5 degrees target". Even that more modest goal is out of reach for now despite plans such as the controversial national carbon price, making buildings more energy efficient and eliminating coal as a source of electricity by 2030. That slower rate of rising water would mean that people living in island nations and along coastlines would have more time to adapt. We shall wait and see how much of the world takes up the challenge.