Global carbon dioxide concentrations in the atmosphere surpassed 400 parts per million for the first time since measurements began, according to data collected from over 40 measuring stations around the world, putting pressure on politicians in the lead up to the climate summit in Paris. Elke Bunge reports.
The Synthesis Report of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which was released in Copenhagen in November, is alarming: humans are responsible for climate change. Far-reaching measures to reduce carbon dioxide and nitrogen emissions have to be implemented all over the world by 2050 if we are to have any hope of saving our climate.
Failure to act will result in extreme weather events such as storms, tornados, and heavy rain in some parts of the world, contrasted with devastating droughts in other parts. Our habitat, Planet Earth, will become anything but habitable if our emissions continue unabated.
More than 400 ppm
But not much has happened since those dire warnings just six months ago. On the contrary, a new benchmark is once again sounding off the alarm bells: for the first time since climate measurements began, global CO2 values exceeded the 400 ppm threshold in March of this year, according to measurements analysed by the U.S. National Oceanic and Atmospheric Administration (NOAA). ‘ppm’ stands for parts per million and is the ratio of carbon dioxide molecules to all other molecules in the atmosphere.
CO2 emissions rising rapidly
A total of 40 measuring stations around the world registered CO2 levels above a concentration of 400 ppm, a value that represents a symbolic limit for scientists. “CO2 concentrations haven’t been this high in millions of years,” said NASA scientist Erika Podest. “Even more alarming is the rate of increase in the last five decades and the fact that CO2 stays in the atmosphere for hundreds or thousands of years.”
From 1995 to 2011 alone, CO2 emissions rose each year from 23 to 30 billion tonnes. And even though researchers know that the readings vary widely throughout the year and are particularly high in spring before the plants get new leaves and act to naturally lower CO2, the current levels are still alarming. Only around 40 per cent of the carbon dioxide remains in the atmosphere; the rest is stored not only by plants but also the ground and in particular the world’s oceans – the latter stores around 30 per cent, which is why the world’s oceans are acidifying.
Next round number achieved
Before industrialisation CO2 levels were at 270 ppm. When the global environmental organisation 350.org was founded, it wanted to see carbon dioxide reduce to below 350 ppm – a hope reflected in the organisation’s name and what it calls a ‘safe’ level.
“In some ways, 400 ppm is just a number, another milestone that we are blasting past at a rate that is now exceeding 2 ppm per year,” says NASA climate researcher David Crisp.
“It brings home the fact that fossil fuel combustion, land use practices, and human activities have increased the CO2 concentration in Earth’s atmosphere.”
Politicians’ turn to act
With the Kyoto Protocol in 1997, the United Nations agreed to a framework convention on climate change for the very first time ever. But the Kyoto Protocol dealt only with industrialised countries and has since expired. Concrete measures are now urgently needed to reach a new global climate agreement at the upcoming climate summit in Paris in December.
“The scientists have done their job, now it is again a matter for the politicians. Leaders have everything they need to take action, and clear scientific evidence, a strong business case and a great public support,” said May Boeve, director of 350.org.