llustration: Sarah Grillo/Axios

Models that climate scientists used in recent decades to project temperature changes have generally been very accurate, a new peer-reviewed study concludes.

Why it matters: It serves to rebut conservative opponents of proposals aimed at cutting emissions, who have long argued that models haven't gotten it right as part of broader attacks on climate science.

What they found: The study in Geophysical Research Letters reviewed the performance of 17 models published between 1970 and 2007.

  • "We find no evidence that the climate models evaluated in this paper have systematically overestimated or underestimated warming over their projection period," the paper states.
  • "In general, past climate model projections evaluated in this analysis were skillful in predicting subsequent [global mean surface temperature] warming in the years after publication."
  • Some, however, showed too much and others too little.

The big picture: Climate models look at the physical relationship between greenhouse gas emissions and temperature, as well as other factors including human-influenced emissions variables like economic growth and technology change.

  • As Vox puts it, it's about "predicting physics vs. predicting humans."
  • If you simply look at how well the models predicted temperature changes that later occurred, 10 of 17 were essentially spot-on — "virtually indistinguishable from observations," as this Washington Post story notes.
  • But if you look at how well models did at assessing the relationship between changing greenhouse concentrations and temperature, they did even better.
  • 14 of the 17 were "consistent with observations," the paper notes, and "statistically indistinguishable from what actually occurred," co-author Gavin Schmidt writes in a blog post.

Go deeper:

Go deeper

Updated 41 mins ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 10 p.m. EST: 32,135,220 — Total deaths: 981,660 — Total recoveries: 22,149,441Map.
  2. U.S.: Total confirmed cases as of 10 p.m EST: 6,975,980 — Total deaths: 202,738 — Total recoveries: 2,710,183 — Total tests: 98,481,026Map.
  3. Politics: House Democrats prepare new $2.4 trillion coronavirus relief package.
  4. Health: Cases are surging again in 22 states — New York will conduct its own review of coronavirus vaccine.
  5. Business: America is closing out its strongest quarter of economic growth.
  6. Technology: 2020 tech solutions may be sapping our resolve to beat the pandemic.
  7. Sports: Pac-12 will play this fall despite ongoing pandemic — Here's what college basketball will look like this season.
  8. Science: Global coronavirus vaccine initiative launches without U.S. or China — During COVID-19 shutdown, a common sparrow changed its song.
4 hours ago - Sports

Pac-12 will play football this fall, reversing course

A view of Levi's Stadium during the 2019 Pac-12 Championship football game. Photo: Alika Jenner/Getty Images

The Pac-12, which includes universities in Arizona, California, Colorado, Oregon, Utah and Washington state, will play football starting Nov. 6, reversing its earlier decision to postpone the season because of the coronavirus pandemic.

Why it matters: The conference's about-face follows a similar move by the Big Ten last week and comes as President Trump has publicly pressured sports to resume despite the ongoing pandemic. The Pac-12 will play a seven-game conference football season, according to ESPN.

Dave Lawler, author of World
4 hours ago - World

Global coronavirus vaccine initiative launches without U.S. or China

Data: Gavi, The Vaccine Alliance; Map: Naema Ahmed/Axios

A global initiative to ensure equitable distribution of coronavirus vaccines now includes most of the world — but not the U.S., China or Russia.

Why it matters: Assuming one or more vaccines ultimately gain approval, there will be a period of months or even years in which supply lags far behind global demand. The COVAX initiative is an attempt to ensure doses go where they're most needed, rather than simply to countries that can produce or buy them at scale.

Get Axios AM in your inbox

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Subscription failed
Thank you for subscribing!