From the NY Times:
Gavin Schmidt of NASA GISS has an article in a recent issue of Nature about how scientists can't explain the recordbreaking temperatures seen in the last nine months (or so), and about why that's a problem. I don't think it's paywalled. He wrote that he doesn't think it's a decrease in aerosols (which cool the planet), as James Hansen has been speculating in recent months. Gavin writes:
Much of the world’s climate is driven by intricate, long-distance links — known as teleconnections — fuelled by sea and atmospheric currents. If their behaviour is in flux or markedly diverging from previous observations, we need to know about such changes in real time. We need answers for why 2023 turned out to be the warmest year in possibly the past 100,000 years. And we need them quickly.
I don't understand how teleconnections could cause an increase in global heat. Regional, sure. But the entire planet? How does that work?
7 comments:
Absorbed energy = solar insolation - albedo.
It is well known that ENSO leads to changes in weather patterns right around the planet That is teleconnection.
It is generally accepted that to increase the global average temperature by 1C would require the amount of absorbed energy flux to increase by about 4W/m^2. The 0.2C observed jump suggests that absorbed energy increased quite suddenly by about 1W/m^2.
With solar insolation constant, that suggests that a decrease in albedo is responsible. We should be looking for changes/mechanisms such as a decrease in low cloud cover or, as has been suggested, the decrease in sulphur emissions by ships.
Given the suddenness and persistence of the change, perhaps we have crossed a tipping point without noticing the cause.
Yes, thanks, but what Gavin wrote is that after correcting for ENSO, the volcano in Tonga, changes in solar irradiance, and new regulations on shipping emissions, they're still short by 0.2 C. They don't have sufficient data on global aerosols...
Or am I missing your point?
Never mind, I think I understand your comment better....
But the problem is this large spike in temperatures. Did albedo or clouds suddenly change enough to create this spike of about 0.4-0.5 C.
Therein lies the problem. None of the observed changes in water vapour, ice albedo etc, alone or in combination, explains the 2023-24 temperature increase.
Something unexpected and so far unexplained is happening.
I understand. Thanks EM.
https://skepticalscience.com/how-extreme-temperature-2023.html
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