The targets rely on increased use of renewable energy, to the point that they product 70 to 85% of electricity supplies by 2050.
The report, which encompasses more than 6,000 scientific references, has found that some of the most severe climate change scenarios could be felt at an even lower temperatures of global warming, occurring decades earlier than expected.
Most worryingly, the IPCC's report claims that this 1.5°C increase could be reached in as little as 11 years, and nearly certainly within 20 years.
Carbon emissions need to reach "net zero" by 2050 and almost halve from 2010 levels by 2030.
The IPCC warns, however, there is a stark difference between 1.5 and even 2 degrees Celsius of warming. Switching away rapidly from fossil fuels like coal, oil and gas to do this could be more expensive than the less ambitious goal, but it would clean the air of other pollutants.
These are just a few examples taken from a depressingly long list of climate change threats that would be made significantly more unsafe if the temperature were to rise by 2°C or beyond by the end of the century. This means any remaining emissions would need to be removed by planting forests, or using carbon capture and storage technology, where emissions from power plants and industry are captured and stored deep underground.
When the target was put into the Paris Agreement, relatively little was known about the climate risks that would be avoided in a 1.5C warmer world compared with a 2C warmer world, or about the action needed to limit temperature rises to that level.
"We need to extend this kind of progress on renewables to other areas".
India hadn't made any scientific contribution - in terms of modelling possible climate change-impact to its agriculture, monsoon, urban dwellings - to this report but gave critical inputs to the scientific basis underlying these assessments.
The Paris Agreement adopted by 195 nations at the 21st Conference of the Parties to the UNFCCC in December 2015 included the aim of strengthening the global response to the threat of climate change by "holding the increase in the global average temperature to well below 2 °C above pre- industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C above pre-industrial levels".
He admitted the report showed that "limiting warming to 1.5°C is barely feasible and every year we delay the window of feasibility halves".
Time is running out: the IPCC report is unequivocal that the world - including Australia - needs to take unprecedented action, and it needs to do it soon.
He warned the world was already seeing the beginning of "massive displacement and a shocking rise in hunger" - and unless temperatures stayed below 1.5C, island nations would disappear beneath rising seas.
Negative impacts of climate change occur on a continuum, and defining a point at which climate change becomes unsafe is hard and contentious.
Keeping the Earth's temperature rise to 1.5 degrees Celsius means making rapid, unprecedented changes in the way people use energy to eat, travel and live or we risk even more extreme weather and loss of species, a United Nations report said on Monday.
"The US is pretty much on target to reach its (climate) targets at least in the short-term - the market is driving this", said McCarthy, who ran the EPA under Trump's predecessor, Barack Obama, from 2013 to 2017.
The co-leader of the Scottish Greens, Patrick Harvie, called on the first minister to convene a summit of political and civic leaders throughout Scotland to discuss further action. This would require all countries to enhance their existing emission reduction targets under the agreement for the period starting 2020.
It is thought that by 2100, global sea rise levels would be 10cm lower that if global warming were to be at 2C. The agency removed its section on climate change from its website a year ago for an "update" that has yet to materialize.