Nav: Home

A lower limit for future climate emissions

February 24, 2016

In a comprehensive new study published in the journal Nature Climate Change, researchers propose a limit to future greenhouse gas emissions--or carbon budget--of 590-1240 billion tons of carbon dioxide from 2015 onwards, as the most appropriate estimate for keeping warming to below 2°C, a temperature target which aims to avoid the most dangerous impacts of climate change.

The study finds that the available budget is on the low end of the spectrum compared to previous estimates--which ranged from 590 to 2390 billion tons of carbon dioxide for the same time period--lending further urgency to the need to address climate change.

"In order to have a reasonable chance of keeping global warming below 2°C, we can only emit a certain amount of carbon dioxide, ever. That's our carbon budget," says IIASA researcher Joeri Rogelj, who led the study. "This has been known for about a decade and the physics behind this concept are well-understood, but many different factors can lead to carbon budgets that are either slightly smaller or slightly larger. We wanted to understand these differences, and provide clarity on the issue for policymakers and the public."

"This study shows that in some cases we have been overestimating the available budget by 50 to more than 200%. At the high end, this is a difference of more than 1000 billion tons of carbon dioxide," says Rogelj.

Estimates for a carbon budget consistent with the 2°C target have varied widely. The new study provides a comprehensive analysis of these differences. The researchers identified that the variation in carbon budgets stemmed from differences in scenarios and methods, and the inclusion of other human activities that can affect the climate, for example the release of other greenhouse gases like methane. Previous research suggested that the varying contribution of other human activities would be the main reason for carbon budget variations, but surprisingly, the study now finds that methodological differences contribute at least as much.

The proposed budget accounts for warming of all human activities and greenhouse gases and is based on detailed scenarios that simulate low-carbon futures.

Rogelj says, "We now better understand the carbon budget for keeping global warming below 2 degrees. This carbon budget is very important to know because it defines how much carbon dioxide we are allowed to release into the atmosphere, ever. We have figured out that this budget is at the low end of what studies indicated before, and if we don't start reducing our emissions immediately, we will blow it in a few decades."
-end-


International Institute for Applied Systems Analysis

Related Climate Change Articles:

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
More Climate Change News and Climate Change Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...