By Nina Chestney
LONDON (Reuters) - Greenhouse gas emissions in 2030 will exceed by 12 billion to 14 billion tons what is needed to keep global warming to an internationally agreed target, the United Nations said on Thursday.
A day before the global Paris Agreement climate pact formally comes into force, the annual U.N. Environment report analyzed countries' current pledges for emission cuts and whether they are enough.
It found they are not.
Emissions in 2030 are expected to reach 54-56 billion tons of carbon dioxide equivalent, far above the level of 42 billion tons needed to have a chance of limiting global warming to 2 degrees Celsius (3.6 degrees Fahrenheit) this century.
Last year, UN Environment estimated that the gap between pledges and emissions cuts that scientists estimate are needed was up to 12 billion tonnes.
Even if emissions cut pledges under the Paris agreement are fully implemented, predicted 2030 emissions could put the world on track for a temperature rise of 2.9 to 3.4 degrees Celsius this century, the report said.
"If we don't start taking additional action now, beginning with the upcoming climate meeting in Marrakesh, we will grieve over the avoidable human tragedy," Erik Solheim, head of UN Environment, said in a statement.
Delegates from signatory nations meet in the Moroccan city of Marrakesh from Nov. 7-18 to start turning their many promises on tackling climate change into action and draw up a "rule book" for the accord reached last December and which comes into force on Friday.
"The growing numbers of climate refugees hit by hunger, poverty, illness and conflict will be a constant reminder of our failure to deliver. The science shows that we need to move much faster," Solheim added.
The Paris Agreement promises to limit global warming to "well below" 2 degrees Celsius above pre-industrial times. But current pledges for limiting emissions are too weak and will allow temperatures to rise by perhaps 3 Celsius or more by 2100.
The report said the private sector, cities and regions could reduce emissions by several billion tonnes by 2030 in areas such as agriculture and transport, as well as increased energy efficiency.
(Editing by Jeremy Gaunt)