Atmospheric greenhouse gases have hit record highs after global carbon dioxide concentrations rocketed at the fastest rate since records began, an international report has revealed.
The latest Greenhouse Gas Bulletin shows levels of carbon dioxide (CO2), the main driver of global warming, rose more sharply between 2012 and 2013 than at any time since 1984.
Scientists from the World Meteorological Organisation (WMO), which produced the report, have warned the world is “running out of time” to cut emissions and reverse temperature rises.
“We know without any doubt that our climate is changing and our weather is becoming more extreme due to human activities such as the burning of fossil fuels,” said WMO secretary- general Michel Jarraud.
“Far from falling, the concentration of carbon dioxide in the atmosphere actually increased last year at the fastest rate for nearly 30 years.
“We must reverse this trend by cutting emissions of CO2 and other greenhouse gases across the board. We are running out of time.
“Carbon dioxide remains in the atmosphere for many hundreds of years and in the ocean for even longer.
“Past, present and future CO2 emissions will have a cumulative impact on both global warming and ocean acidification. The laws of physics are non-negotiable.”
A target of keeping earth’s average temperature from rising more than 2°C above pre- industrial levels was widely agreed at a United Nations climate change conference in 2009. This equates to a rise of no more than 1.3°C above today’s average temperatures.
The WMO report does not measure emissions released from burning fossil fuels. It assesses the quantities of warming gases that remain in the atmosphere after natural interactions between the air, land, seas and all living things have taken place.
It suggests long-lived gases such as CO2, methane and nitrous oxide remaining in the atmosphere have increased warming by a third since 1990.
Concentrations of CO2 recorded in 2013 were 142 per cent higher than in 1750, while methane and nitrous oxide rose by 253 per cent and 121 per cent respectively.
Around a quarter of all emissions are absorbed by the oceans and another quarter by the biosphere, cutting gases remaining in the atmosphere.
Experts suggest warming is accelerating because of a drop in CO2 uptake by the Earth as well as steadily increasing man-made emissions. Professor Dave Reay, chair in carbon management at the University of Edinburgh, said: “That carbon dioxide concentrations continued to surge upwards last year is worrying news. This is the litmus test when it comes to our efforts to reduce emissions, and on this evidence we are failing. Of particular concern is the indication that carbon storage in the world’s forests and oceans may be faltering.
“So far, these ‘carbon sinks’ have been locking away almost half of all the carbon dioxide we emit. If they begin to fail in the face of further warming then our chances of avoiding dangerous climate change become very slim indeed.”
A section on ocean acidification has for the first time been included in the bulletin. It showed how the world’s seas are becoming acidic more rapidly today than at any time over the last 300 million years.
Mr Jarraud added: “We have the knowledge and we have the tools for action to try keep temperature increases within 2°C to give our planet a chance and to give our children and grandchildren a future.
“Pleading ignorance can no longer be an excuse for not acting.”