Greenhouse gas levels hit a new record in

WMO said methane levels reached a new high of about 1,833 parts per billion in 2014.

By 2030 the INDC pledges will cut 11GT of greenhouse gases from the atmosphere, 12GT short of what is needed to give the world a two-thirds chance of limiting warming to two degrees, it calculates, further fuelling fears any Paris agreement will struggle to tackle escalating climate risks.

Even if the summit does limit warming to just 2C, large swathes of the world’s most heavily populated cities are set to be flooded by surging sea levels, according to new research by scientists in the US. Higher temperatures lead to more atmospheric water vapour, which in turn traps even more heat.

The WMO said Monday that concentrations of carbon dioxide (CO2), methane and nitrous oxide once again broke records previous year. American researchers detected carbon dioxide levels above 400 parts per million in March.

Scientists have been stressing that the planet should seek to avoid warming more than 2 degrees Celsius (3.6 Farenheit) above pre-industrial levels, but diplomats have said recently that it is unlikely such a goal will be achieved in Paris.

Greenhouse gas concentrations have hit a new record every year since reliable records began in 1984, according to Reuters.

“We will soon be living with globally averaged Carbon dioxide levels above 400 parts per million as a permanent reality”, Michel Jarraud, WMO secretary general, said in a released statement.

The World Meteorological Organization’s annual greenhouse gas bulletin found a 36 per cent rise in warming from 1990 to 2014, with the body warning time is running out to curb emissions. Not too much, since greenhouse gas remains in the atmosphere for hundreds of years. “Past, present and future emissions will have a cumulative impact on both global warming and ocean acidification”. “The laws of physics are non-negotiable”, he said.

“It’s an invisible threat but a very real one”.

“We’ve had similar natural events in the past, yet this is the first time we’re set to reach the 1 degree C marker and it’s clear that it is human influence driving our modern climate into uncharted territory”, said Stephen Belcher, director of the Met Office Hadley Centre for climate science.

“Two degrees will be bad enough but it will be better than three degrees”, said Jarraud. These values constitute, respectively, 143%, 254% and 121% of pre-industrial (1750) levels.

“We can’t see CO2”. About a quarter of the total emissions is taken up by the oceans and another quarter by the biosphere, reducing in this way the amount of Carbon dioxide in the atmosphere.

[Photo By Lintao Zhang / Getty Images]Greenhouse gas fuels climate change, the most unsafe among them carbon dioxide since it has a long life cycle.