Three decades until carbon budget is eaten through | RenewEconomy

Three decades until carbon budget is eaten through

If the planet’s carbon budget was a giant cake, then we’d all be running out of dessert — fast.


Climate Central

If the planet’s carbon budget, which is the amount of fuel we can burn, concrete we can pour and forest we can fell without blowing global warming goals, was a giant cake, then we’d all be running out of dessert — fast.

We’ve got about a third left. Credit: Michael May/flickr

We’ve been eating into the carbon budget since the Industrial Revolution. Just nibbling at first, but now with record relish. Figures published Sunday warn delegates attending Tuesday’s U.N. Climate Summit in New York that, at the rate we’re going, in nearly 30 years we’ll run out of our metaphorical carbon cake. That’s when we would start gorging our way to a future where warming exceeds the internationally agreed-upon goal of 2°C, or 3.7°F.

Scientists writing in Earth System Science Data Discussions on Sunday calculated that all the planet’s residents will have released about 37 gigatonnes of climate-changing carbon dioxide in 2014 by burning fossil fuels and, to a far lesser extent, by producing concrete (which involves carbon dioxide-releasing chemical reactions) by the time the ball drops in Times Square. That’s up 2.5 percent from 2013, and up 65 percent from 1990. Another 3 gigatonnes will have been released this year from deforestation, the researchers calculated. Taken together, that will bring our historical grand total of CO2 emissions to 2,000 gigatonnes.

For a two-thirds shot at keeping warming to within the 3.7°F goal, scientists writing in Nature Geoscience on Sunday say we have to keep to a carbon budget of 3,200 gigatonnes. So it could be said that we have 1,200 gigatonnes of carbon budget left to eat through. (Though it wouldn’t hurt the climate to leave some of that on the plate.)

If recent greenhouse gas trends continue, that carbon budget will have been devoured 22 years after a new climate treaty takes effect in 2020, the scientists calculated based on a review of global financial forecasts and the new emissions data. If climate-changing pollution levels remain stable at 2014 levels, the carbon budget would last for nearly an extra decade.

“Every day we eat more than the previous day,” said University of Exeter professor Pierre Friedlingstein, who led the research published in Nature Geoscience. “If every day you take more cake, it goes out faster.”

Most of the growth in annual emissions is occurring in China and India as their economies expand. The new figures show that U.S. emissions are expected to fall by less than 1 percent this year following a slightly larger rise last year.

Credit: Roland Peschetz/flickr

Friedlingstein warned that carbon budget projections are “conservative” because they don’t account for other greenhouse gases or for climate feedbacks — such as carbon dioxide and climate-changing methane that’s escaping from melting permafrost.

The carbon budget figures are normally updated annually and released in the lead-up to late-year U.N. climate negotiations. This year, publication was coincided with this week’s climate summit.

At the summit, which is an informal prelude to climate negotiations planned in Lima in December and in Paris a year later, countries are being asked to explain how they plan to reduce greenhouse gas pollution rates. The new papers highlight the urgency of such efforts.

“The most important aspect of this paper is how increasingly difficult it will be for us to keep global temperatures at a reasonable level unless we act quickly,” said Stanford University professor Rob Jackson, co-chair of the Global Carbon Project, which helps coordinate the carbon budget research. He was not directly involved with either of the new studies.

“Despite all of the actions; all the activities around the world; all the increases in renewables, carbon dioxide concentrations are still going up,” Jackson said. “They’re going up faster than anyone expected 20 years ago.”

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  1. Diego Matter 6 years ago

    Just having spent the weekend at the Climate Action Summit 2014 in Brisbane and listening to the enormousness and the urgency of the problem, this doesn’t make me very happy.

    Only seeing many thousand citizens marching together at the People’s Climate March demanding governments to get active on climate change is an encouraging sign.

    One thing is clear. It will take all our efforts to win this battle, or we will all lose,

  2. Alex Hromas 6 years ago

    What this global snapshot fails to identify is the need for wealthy well developed economies such as Australia, USA, Europe etc. to de-carbonise their economies much faster than others. This will provide the breathing space for developing econmies to improve their standards of living without the high initial costs of renewables. Australia has excelent solar recouses and we can convert our stationary power generation systems to supply all our needs using solar thermal plants (with heat storage), wind, solar, hydor and biomass at a cost of 3% of GPD over 10 years and we need to start now!
    Unfortunately the present federal government appears to believe that climate change is a Communist/ Green allinance plot to destroy our democracy and the opposition is too concerned re voter back lash.
    The Greens have a sensible policy and it may be a good idea to vote for them even if you only do it once to rattle the chain on the others.
    We cannot afford to sit back and wait.
    The 2degree C global temperature rise is generally quoted as the safe guide rail. All of those who use this statistic have failed to read the rest of the report 2degrees gives us a 50% chance of avouding uncontrolled climate change when positive feed back mechanisms i.e. permafrost melting, take control.
    Its akin to playing Russian Roulette with a 6 round revolver with 3 rounds in the chamber, anyone care to join me?

  3. Ben Courtice 6 years ago

    This is very optimistic. Looking at things like the arctic sea ice, melting ice shelf in Antarctica, ocean acidification, coral bleaching etc gives a sense that maybe we’ve already blown the budget.

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