By the end of the century, if warming stops at 1.5 degrees, the sea level rise may be almost four inches lower than if it stops at 2 degrees.
"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. We need to make to make major changes in transportation, buildings, industry, and how we use land.
The authoritative Intergovernmental Panel on Climate Change said in a report released Monday that urgent, global action is required to stave off the devastating implications of climate change.
The authors said global warming is likely to reach 1.5 deg C as early as 2030 if it continues to increase at the current rate.
Even if warming is kept at or just below 1.5 degrees C, the impacts will be widespread and significant.
'The faster governments phase out coal, embrace the renewable energy revolution and move to protect communities at risk, the more lives and livelihoods will be spared'. Coral reefs would decline by 70 percent to 90 percent with global warming of 1.5 degrees Celsius, whereas virtually all would be lost with 2 degrees Celsius.
The world has only a few years left to deal with climate change - or face blistering heat waves, rising seas and a 'shocking rise in hunger, ' a United Nations report has warned.
If emissions can't be cut to a sufficient degree, researchers will need to devise effective methods of removing Carbon dioxide from the air, such as devoting land to growing trees and biofuel crops, Erik Solheim, executive director of the UN Environment Program, tells The Washington Post.
Friends of the Earth Scotland director Dr Richard Dixon said: "The bill doesn't commit to the action necessary to limit warming to 1.5C, it doesn't deliver on the Paris Agreement, and it doesn't deliver on Nicola Sturgeon's promise to ensure that Scotland plays our full part in tackling this global problem".
"We need to extend this kind of progress on renewables to other areas".
The report is seen as the main scientific guide for government policymakers on how to implement the 2015 Paris Agreement, which aims to limit the rise in global average temperatures to "well below" 2C above pre-industrial levels, while seeking to tighten the goal to 1.5C.
The IPPC report represents "sobering assessment of the challenge we face, and of the risks and costs of a warming planet", Caroline Theriault, a spokeswoman for Environment Minister Catherine McKenna, said. "Several regional changes in climate are assessed to occur with global warming up to 1.5 degree Celsius compared to pre-industrial levels, including warming of extreme temperatures in many regions (high confidence), increases in frequency, intensity, and/or amount of heavy precipitation in several regions (high confidence), and an increase in intensity or frequency of droughts in some regions (medium confidence)". "Climate change represents a huge risk for all our futures". Scientists acknowledged that some set of actions could require a trade-off with sustainable development (a proxy word used for sustainable growth, poverty eradication and better living standards for the poor).
Sea level rises would be 10cm lower with a 1.5C temperature rise compared to 2C by the end of the century.
"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 IPCC report is a wake-up call for slumbering world leaders".
The Scottish government is to seek fresh independent advice on its climate change targets after the latest warning on rising global temperatures. This will require acting on all fronts to rapidly reduce emissions by 2030.
Using carbon capture and storage (CCS) technology, the share of gas-fired power would need to be cut to 8 percent and coal to under 2 percent.