Carbon dioxide is being accumulated in the atmosphere at the fastest rate since records began, as scientists warn that the oceans and forests may have absorbed so much CO2 that their crucial function as “carbon sinks” is now severely threatened.
The jump in atmospheric CO2 is partly the result of rising carbon emissions as the world burns ever-more fossil fuels, according to the latest World Meteorological Organisation report, which finds the concentration of carbon increased by nearly three parts per million (ppm) to 396ppm last year.
But, crucially, preliminary data in the report indicates that the jump could also be attributed to “reduced CO2 uptake by the Earth’s biosphere” – the first time the effectiveness of the world’s great carbon sinks has been scientifically called into question.
Scientists said they were puzzled and extremely concerned by prospect of reduced absorption of the world’s oceans and plants, which they cannot explain and which threatens to accelerate the build-up of heat-trapping greenhouse gases in the atmosphere if the trend continues.
“That carbon dioxide concentrations continued to surge upwards last year is worrying news,” said Professor Dave Reay, of the University of Edinburgh.
“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,” Professor Reay added.
“If they begin to fail in the face of further warming then our chances of avoiding dangerous climate change become very slim indeed.”
The plants and the oceans each typically absorb about a quarter of humanity’s CO2 emissions every year, with the other half going into the atmosphere, where it can remain for hundreds of years.
The last time there was a reduction in the biosphere’s ability to absorb carbon was in 1998, a year in which extensive forest fires and dry weather killed off lots of plants, dealing a blow to the world’s carbon sink.
But Dr Oksana Tarasova, chief of the atmospheric research division at the WMO, said this time it is much more worrying because there have been no obvious impacts on the biosphere this year.
“This problem is very serious. It could be that the biosphere is already at its limit, or it may be close to reaching it. Or it may be that it just becomes less effective at absorbing carbon. But it’s still very concerning,” said Dr Tarasova.
The worst-case scenario in which the carbon sink ceased to function at all would double the rate at which CO2 emissions accumulate in the atmosphere, significantly increasing the fallout of climate change, such as storms, droughts and temperature increases, Dr Tarasova said.
The latest WMO survey packed a second environmental punch – revealing that the oceans are currently acidifying at a rate that is unprecedented in the past 300 million years.
This is because they are absorbing about 4kg of carbon dioxide for every person on the planet, the report says.
The WMO’s findings intensified calls for co-ordinated global action to limit global warming to 2C, beyond which its consequences become increasingly devastating.
“We are running out of time. Past, present and future CO2 emissions will have a cumulative impact on both global warming and ocean acidification. The law of physics are non-negotiable,” said the WMO’s secretary-general Michel Jarraud. He added that, rather than rising, fossil fuel and other emissions badly need to come down.
In pictures: Changing climate around the world
In pictures: Changing climate around the world
Calved icebergs from the nearby Twin Glaciers are seen floating on the water in Qaqortoq, Greenland
Oroumieh, one of the biggest saltwater lakes on Earth, has shrunk more than 80 percent to 1,000 square kilometers in the past decade. It shrinks mainly because of climate change, expanded irrigation for surrounding farms and the damming of rivers that feed the body of water
A boat navigates among calved icebergs from the nearby Twin Glaciers in Qaqortoq, Greenland. Boats are a crucial mode of transportation in the country that has few roads. As cities like Miami, New York and other vulnerable spots around the world strategize about how to respond to climate change, many Greenlanders simply do what theyve always done: adapt. 'Were used to change, said Greenlander Pilu Neilsen. 'We learn to adapt to whatever comes. If all the glaciers melt, well just get more land
The Svalbard Global Seed Vault is seen after being inaugurated in Longyearbyen, Norway. The 'doomsday' seed vault built to protect millions of food crops from climate change, wars and natural disasters opened deep within an Arctic mountain in the remote Norwegian archipelago of Svalbard
A technician preparing to drain a vast underground lake at the Tete Rousse glacier on the Mont Blanc Alpine mountain, to avert a potentially disatrous flood. Some 65,000 cubic metres (2.3 million cubic feet) of water have gathered in a cavity, dangerously raising the pressure beneath the mountain, a favourite spot for holiday makers in Saint-Gervais-les-Bains
Cracked mud is picture at sunrise in the dried shores of Lake Gruyere affected by continuous drought near the western Switzerland village of Avry-devant-Pont. A leading climate scientist warned that Europe should take action over increasing drought and floods, stressing that some climate change trends were clear despite variations in predictions
Cattle graze on grassland that remains dry and brown at the height of the rainy season in south of Bakersfield, California. Its third straight year of unprecedented drought, California is experiencing its driest year on record, dating back 119 years, and dating back as far as 500 years, according to some scientists who study tree rings
An aerial view shows tents of flood-displaced people surrounded by water in southern Sehwan town. United Nations Framework Convention on Climate Change (UNFCCC) executive secretary Christiana Figueres met with people displaced by last year's devastating floods. Catastrophic monsoon rains that swept through the country in 2010 and affected some 20 million people, destroyed 1.7 million homes and damaged 5.4 million acres of arable land
An aerial view of flooding in North Wagga Wagga. Climate change is amplifying risks from drought, floods, storm and rising seas, threatening all countries but small island states, poor nations and arid regions in particular, UN experts warned
Damages caused by a landslide on the Pan-American highway near La Moramulca, 55 Km south of Tegucigalpa. International highways have been washed out, villages isolated and thousands of families have lost homes and crops in a region that the United Nations has classified as one of the most affected by climate change
A resident sprays water on a peatland fire in Pekanbaru district in Riau province on Indonesia's Sumatra island. Indonesia, an archipelago of 17,000 islands, is one of the world's biggest carbon emitters because of rampant deforestation. US Secretary of State John Kerry Sunday issued a clarion call for nations to do to more to combat climate change, calling it 'the world's largest weapon of mass destruction'
An excavator clearing a peatland forest area for a palm oil plantations in Trumon subdistrict, Aceh province, on Indonesia's Sumatra island. As Southeast Asia's largest economy grows rapidly, swathes of biodiverse forests across the archipelago of 17,000 islands have been cleared to make way for paper and palm oil plantations, as well as for mining and agriculture. The destruction has ravaged biodiversity, placing animals such as orangutans and Sumatran tigers in danger of extinction, while also leading to the release of vast amounts of climate change-causing carbon dioxide
Stagnant rain water with tannery waste make the Hazaribagh area in Old Dhaka as well as Buriganga River the most polluted. Each year during the seven-month long dry season between October and April the Buriganga River becomes totally stagnant with its upstream region drying up and becoming polluted from toxic waste from city industries
Waste water from Dhaka city drained to the River Buriganga contributes to its pollutions. On the World Water Day observed in 2007 under the theme Coping with Water Scarcity, under the leadership of the Food and Agriculture Organization of the United Nations, DrikNEWS explores some of the images of the river. UN-Water has identified coping with water scarcity as part of the strategic issues and priorities requiring joint UN action. The theme highlights the significance of cooperation and importance of an integrated approach to water resource management of water at international, national and local levels
Heavy smog has been lingering in northern and eastern parts of China, disturbing the traffic, worsening air pollution and forcing the closure of schools. China's Environment Ministry said it will send inspection teams to provinces and cities most seriously affected by smog to ensure rules on fighting air pollution are being enforced
“We have the knowledge and we have the tools for action to try to keep temperature increases within 2C 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,” he said.
The total concentration of heat-trapping greenhouse gases jumped to a record 479ppm in 2013, when methane and nitrous oxide is included.
Plants and oceans: The carbon savers
A carbon sink is anything that removes carbon dioxide (CO2) from the atmosphere and stores it, in a process known as carbon sequestration. There are two major carbon sinks in the world – plants and oceans – and each has historically sucked about a quarter of humanity’s CO2 emissions out of the atmosphere and stored it.
Leaves absorb carbon dioxide during photosynthesis, where the sun’s energy is used to separate the oxygen which is released back into the atmosphere and the carbon, which it stores. Half of the tree is made up of carbon.
The ocean absorbs CO2 in diffusion, which is essentially an attempt to reach equilibrium with the atmosphere. Sea life then extracts the carbon and oxygen from the water and combines them with calcium to produce calcium carbonate.Reuse content