May 15, 2018

Rethinking the carbon budget message

Smoke billows from a large steel plant in Inner Mongolia, China. Photo: Kevin Frayer/Getty Images

Two new analyses argue that a widely cited idea in climate policy and academic circles — to impose a carbon budget — has outlived its usefulness.

The argument: While the idea of a carbon budget has gotten a lot of traction in recent years, two pieces published Monday in Nature Geoscience say the specifics underpinning carbon budget studies have become so complicated and nuanced as to render the tool useless for actual policymaking.

Background: The concept of a “carbon budget” seems relatively simple. It’s the notion that one can only “spend,” or emit, a certain amount of greenhouse gases without exceeding global warming targets.

The details: The studies, one by Glen Peters of Norway’s Center for International Climate Research and the other by Oliver Geden of the Max Planck Institute for Meteorology in Germany, take different approaches but reach the same idea.

  • Geden argues that from a political science perspective, the carbon budget needs to be reframed as an “if, then” problem to say that goals are only possible if policymakers take particular, ambitious steps.
  • Peters says the conflicting assumptions behind recent studies renders the concept useless for policymakers.
  • However, they both arrived at similar conclusions — ditch the carbon budget talk as it has been used to date.

Why it matters: Shifting estimates and assumptions behind these studies are confusing policymakers — and perhaps preventing them from taking the ambitious actions needed to limit global warming’s severity, both authors conclude.

“The concept of a global carbon budget has been shaping how the broader climate community looks at the core of the climate mitigation problem today. But carbon budgets have only been able to influence climate policy talk, not decisions, let alone actions,” Geden told Axios.

One level deeper: Both Geden and Peters cited a recent study that found nations might be able to emit a considerably more greenhouse gases and still meet the ambitious Paris agreement target of limiting global warming to as low as 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, above pre-industrial levels.

  • But they argue such a goal is only possible if policymakers were to take drastic actions now, including steps that are not currently technically feasible — like deploying large-scale carbon removal technologies.
“And irrespective of the temperature target, carbon budgets are beside the point. They are too academic,” Peters told Axios.
“What does 500GtCO2 mean?” Peters said, referring to 500 gigatons of carbon dioxide-equivalent. “I don’t think many would know, you have to map it to a language people can understand, such as 40% below 1990 levels by 2030 (to take an EU example), net zero by 2050, etc.”

The bottom line: How global warming is discussed, even if it’s mostly within the world of policy wonks and science geeks, matters because it helps steer policy.

Go deeper

U.S. coronavirus updates: Death toll hits 3,900

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Andrew Witherspoon/Axios

The U.S. death toll from the novel coronavirus has just hit 3,900, per Johns Hopkins data.

Details: Tuesday night's grim milestone came hours after President Trump said it's "going to be a very painful two weeks," with projections indicating the novel coronavirus could kill 100,000–240,000 Americans — even with strict social distancing guidelines in place. "They are going to be facing a war zone," he said of medical workers.

Go deeperArrowUpdated 14 mins ago - Health

World coronavirus updates: UN warns of recession with "no parallel" to recent past

Data: The Center for Systems Science and Engineering at Johns Hopkins, the CDC, and China's Health Ministry. Note: China numbers are for the mainland only and U.S. numbers include repatriated citizens and confirmed plus presumptive cases from the CDC

The novel coronavirus pandemic is the "greatest test" the world has faced together since the formation of the United Nations just after the Second World War ended in 1945, UN chief António Guterres said Tuesday.

The big picture: COVID-19 cases surged past 858,000 and the death toll exceeded 42,000 Tuesday night, per Johns Hopkins data. Italy reported more than 12,000 deaths.

Go deeperArrowUpdated 19 mins ago - Health

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 10 p.m. ET: 857,957 — Total deaths: 42,139 — Total recoveries: 178,091.
  2. U.S.: Leads the world in confirmed cases. Total confirmed cases as of 10 p.m. ET: 188,547 — Total deaths: 3,899 — Total recoveries: 7,068.
  3. Business updates: Should you pay your rent or mortgage during the coronavirus pandemic? Find out if you are protected under the CARES Act.
  4. Public health updates: More than 400 long-term care facilities across the U.S. report patients with coronavirus — Older adults and people with underlying health conditions are more at risk, new data shows.
  5. Federal government latest: President Trump said the next two weeks would be "very painful," with projections indicating the virus could kill 100,000–240,000 Americans.
  6. Coronavirus in custody: Inmates in all U.S. federal prisons are set to enter a 14-day quarantine on April 1. A federal judge on Tuesday ordered U.S. Immigration and Customs Enforcement to release 10 detained immigrants who are at risk of contracting COVID-19 while in confinement.
  7. U.S.S. Theodore Roosevelt: Captain of nuclear aircraft carrier docked in Guam pleaded with the U.S. Navy for more resources after more than 100 members of his crew tested positive.
  8. What should I do? Answers about the virus from Axios expertsWhat to know about social distancingQ&A: Minimizing your coronavirus risk.
  9. Other resources: CDC on how to avoid the virus, what to do if you get it.

Subscribe to Mike Allen's Axios AM to follow our coronavirus coverage each morning from your inbox.