Illustration: Rebecca Zisser/Axios

A new analysis could take a step toward resolving a fiery debate: how to think about — and describe — likely levels of future emissions and warming in light of current trends and planned policies.

Driving the news: Two scientists, in a lengthy post via the Breakthrough Institute, conclude Earth is on track to warm by roughly 3°C above pre-industrial levels by 2100.

  • "This is a far cry from the 1.5°C and 2°C targets enshrined in the Paris agreements, but is also well short of the 4°C to 5°C warming in many 'business as usual' baseline scenarios that continue to be widely used," write Zeke Hausfather and Justin Ritchie.

Why it matters: 3°C means a world far hotter than today.

  • But it's also far less than would likely be enabled by models using high and even unchecked emissions growth — scenarios that they argue, based on extending the International Energy Agency's 2040 analyses through 2100, are no longer in the cards.
  • Hausfather and Ritchie see the most likely outcome from current policies is 2.9°C-3.4°C, but that falls to 2.7°C-3°C if nations meet their existing pledges under the Paris deal.

The big picture: 3°C would mean a lot of damaging outcomes, and even warming to date is causing major harms. A big UN-led report last year explored the consequences of breaching 1.5°C (which is quite likely).

But, but, but: They argue that some commonly cited future "pathways" used in climate literature that bring much higher warming levels are looking quite unlikely for several reasons, including efforts over the past decade to move away from coal.

One level deeper: "Even a current policies scenario where emissions continued to steadily grow rather than leveling off after 2040 would still end up well-below the commonly used RCP8.5 (SSP5-8.5) scenario, which represents the highest end of the range of no-policy baseline scenarios examined in the literature."

The intrigue: Needless to say there's plenty of variables because gaming out the future of technology, policy and economic trends is really dicey. There's also uncertainty about the sensitivity of the climate to rising emissions concentrations.

Go deeper:

Go deeper

Judge orders Eric Trump to testify in New York probe before election

Photo: Ira L. Black/Corbis via Getty Images

A judge on Wednesday ordered Eric Trump to comply with a subpoena to testify in a New York probe into his family business before the presidential election.

The state of play: New York Attorney General Letitia James (D) last month said her office had filed a lawsuit to compel the Trump Organization to comply with subpoenas related to an investigation into whether President Trump and his company improperly inflated the value of its assets on financial statements.

28 mins ago - Podcasts

Reid Hoffman and Mark Pincus on the rise of Silicon Valley SPACs

Silicon Valley venture capitalists are no longer content with investing in startups and then eventually handing them off. Instead, many are now forming SPACs, or blank-check acquisition companies, to ride tech unicorns into the public markets themselves.

Axios Re:Cap digs into this trend with the co-founders of a new tech SPAC called Reinvent Technology Partners: Reid Hoffman, a co-founder of LinkedIn and partner at Greylock, and Mark Pincus, the founder and former CEO of Zynga.

Updated 42 mins ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 2:30 p.m. ET: 31,717,955 — Total deaths: 973,014 Total recoveries: 21,795,005Map.
  2. U.S.: Total confirmed cases as of 2:30 p.m. ET: 6,913,046 — Total deaths: 201,319 — Total recoveries: 2,646,959 — Total tests: 96,612,436Map.
  3. Health: CDC director says over 90% of Americans have not yet been exposed to coronavirus — Supply shortages continue to plague testing.
  4. Politics: Fauci clashes with Rand Paul at COVID hearing: "You're not listening" — FDA chief vows agency will not accept political pressure on coronavirus vaccine.
  5. Vaccines: Johnson & Johnson begins large phase 3 trial — The FDA plans to toughen standards.
  6. Sports: Less travel is causing the NBA to see better basketball.

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