Show an ad over header. AMP

I am the FIRST

The IPCC's journey from "probable" to "unequivocal" on human-caused warming

Out of the more than 3,000 pages in Monday's landmark climate report, one word stood out: "unequivocal."

What they're saying: "It is unequivocal that human influence has warmed the atmosphere, ocean and land," the report stated.

  • This is how solid the tie is between a warming planet and human emissions of greenhouse gases, scientists and government representatives agreed.

Why it matters: It's the strongest description the U.N. IPCC has used to attribute climate change to human activities, but it's far from the first time the word has been used in its reports.

  • Looking over time at the panel's past assessments sheds light on just how much of a departure the latest one is.

Context: The use of the word in Monday's report is part of a pattern of IPCC language used in its "Summary for Policymakers" sections that date to its first assessment report, issued in 1990.

  • Along with a series of remarkably prescient climate projections through 2030, that 1990 report stated: "The unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more."
  • Jump ahead to 1995, when the IPCC came out with what was then a bombshell finding, stating: "The balance of evidence suggests a discernible human influence on global climate."

Be smart: That demonstrated the high stakes associated with individual word choices in these summaries.

Between the lines: Next, fast-forward to the IPCC's fourth assessment in 2007. By then, the science had advanced sufficiently — as had global warming's effects, for the panel to state: "Warming of the climate system is unequivocal." However, it didn't attribute that warming to human emissions of greenhouse gases in such strong terms.

  • Before Monday's report, the most recent full IPCC assessment of climate change was in 2013. That report expressed climate attribution in more confident language than prior assessments, but still not with the same impact:
  • "It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century," the report stated.

The big picture: The IPCC's evolution on these statements is slow and methodical, in part because consensus-based science is inherently somewhat conservative.

  • Also, the IPCC is unique in that scientists and governments together approve the summaries word by word, since they get the most attention from the media and world leaders.

The bottom line: There is actually an even stronger attribution statement in Monday's report, hidden in the technical summary but noticed by the AP's Seth Borenstein.

  • It states that the "Human influence on the climate system is now an established fact." It also describes the human influence on extreme weather and climate events as an "established fact."
  • Case closed.

Why the startup world needs to ditch "unicorns" for "dragons"

When Aileen Lee originally coined the term "unicorn" in late 2013, she was describing the 39 "U.S.-based software companies started since 2003 and valued at over $1 billion by public or private market investors."

Flashback: It got redefined in early 2015 by yours truly and Erin Griffith, in a cover story for Fortune, as any privately-held startup valued at $1 billion or more. At the time, we counted 80 of them.

Keep reading... Show less

Scoop: Facebook's new moves to lower News Feed's political volume

Facebook plans to announce that it will de-emphasize political posts and current events content in the News Feed based on negative user feedback, Axios has learned. It also plans to expand tests to limit the amount of political content that people see in their News Feeds to more countries outside of the U.S.

Why it matters: The changes could reduce traffic to some news publishers, particularly companies that post a lot of political content.

Keep reading... Show less

Scoop: Amazon quietly getting into live audio business

Amazon is investing heavily in a new live audio feature that's similar to other live audio offerings like Clubhouse, Twitter Spaces and Spotify's new live audio platform, sources tell Axios.

Why it matters: As with Amazon's efforts in podcasting and music subscriptions, the company sees live audio as a way to bolster the types of content it can offer through its voice assistant, Alexa, and its smart speaker products.

Keep reading... Show less

Hurricane Ida exposes America's precarious energy infrastructure

The powerful hurricane that plunged New Orleans into darkness for what could be weeks is the latest sign that U.S. power systems are not ready for a warmer, more volatile world.

The big picture: “Our current infrastructure is not adequate when it comes to these kinds of weather extremes,” Joshua Rhodes, a University of Texas energy expert, tells Axios.

Keep reading... Show less

"We must go further": 70% of adults in European Union are fully vaccinated

About 70% of adults in the European Union are fully vaccinated against COVID-19, Ursula von der Leyen, the president of the European Commission, said Tuesday.

Why it matters: The milestone makes the E.U. one of the world's leaders in inoculations, after an initially lagging vaccine campaign, the New York Times notes.

Keep reading... Show less

What Elizabeth Holmes jurors will be asked ahead of fraud trial

Jury selection begins today in USA v. Elizabeth Holmes, with the actual jury trial to get underway on Sept. 8.

Why it matters: Theranos was the biggest fraud in Silicon Valley history, putting both hundreds of millions of dollars and thousands of patients' health at risk.

Keep reading... Show less



Get Goodhumans in your inbox

Most Read

More Stories