In the EPA EF reconsideration document there is a section on p62 where they attempt to make the argument that the CO2 endangerment finding would also apply to direct water vapor emissions to the atmosphere, which is (according to them) obviously absurd. But both claims are bogus.
[Read more…] about Are direct water vapor emissions endangering anyone?Climate Science
The Endangerment of the Endangerment Finding?
The EPA, along with the “Climate Working Group” (CWG) of usual suspects (plus Judith Curry and Ross McKitrick) at DOE, have just put out a document for public comment their attempt to rescind the 2009 Endangerment Finding for greenhouse gas emissions.
[Read more…] about The Endangerment of the Endangerment Finding?National Climate Assessment links
For some reason, it has become hard to locate the various National Climate Assessments (NCAs) that have been produced by the USGCRP over the decades (and it’s pretty hard to find the USGRCP as well…). However, the reports are still accessible if you know where to look. So for future reference, here are all the links (and we’ve downloaded the pdfs locally so that they will always be available here).

NCA1 (2000)
- Full report (via the internet archive) (via gov archive) (local pdf)
NCA2 (2009)
- Full report (via the internet archive) (via gov archive) (local pdf)
NCA3 (2014)
- Full Report (via the NOAA library) (local pdf)
- Climate Science Supplement (via the internet archive) (local pdf)
NCA4 (2017)
- Volume 1 Climate Science Special Report (via the NOAA library) (local pdf)
- Volume 2 Impacts, Risks, and Adaptation in the United States (via the NOAA Library) (local pdf)
NCA5 (2023)
- The NCA5 Atlas (via ESRI)
- Full report (via the NOAA Library) (local pdf)
NCA6
There is no ongoing NCA6 process, even though it is mandated by Congress to be completed over the next few years. We’ll let you know if that changes.
Ocean circulation going South?
Some intriguing new measurements of salinity in the oceans around Antarctica have set off reams of sensationalist speculations. Maybe some context is helpful…
[Read more…] about Ocean circulation going South?Melange à Trois
In honor of the revelation today, that Koonin, Christy and Spencer have been made Special Government Employees at the Dept. of Energy, we present a quick round up of our commentary on the caliber of their arguments we’ve posted here over the last decade or so.
TL;DR? The arguments are not very good.
[Read more…] about Melange à TroisUnforced variations: July 2025
Unforced variations: Jun 2025
Predicted Arctic sea ice trends over time
Over multiple generations of CMIP models Arctic sea ice trend predictions have gone from much too stable to about right. Why?
[Read more…] about Predicted Arctic sea ice trends over timeThe most recent climate status

The Arctic Council’s Arctic Monitoring and assessment Programme (AMAP) recently released a Summary for PolicyMakers’ Arctic Climate Change Update 2024.
[Read more…] about The most recent climate statusUnforced variations: May 2025
This month’s open thread. Note that the Nenana Ice challenge break up date graph has been updated, and the Yukon river ice break up is imminent (or may have already happened! [Update – it already had]). Please stay focused on climate issues.