It's titled, "The Global Warming Statistical Meltdown: Mounting evidence suggests that basic assumptions about climate change are mistaken: The numbers don’t add up." It begins
At the recent United Nations Climate Summit, Secretary-General Ban Ki-moon warned that “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees [of warming] will soon close forever.” Actually, this window of opportunity may remain open for quite some time. A growing body of evidence suggests that the climate is less sensitive to increases in carbon-dioxide emissions than policy makers generally assume—and that the need for reductions in such emissions is less urgent.and concludes
This slower rate of warming—relative to climate model projections—means there is less urgency to phase out greenhouse gas emissions now, and more time to find ways to decarbonize the economy affordably. It also allows us the flexibility to revise our policies as further information becomes available.which is, of course, exactly what the WSJ wants to hear.
As you probably know by now, that paper uses a simple model for temperature change and finds that
...median estimates are derived for ECS of 1.64 K and for TCR of 1.33 K. ECS 17–83% and 5–95% uncertainty ranges are 1.25–2.45 K and 1.05–4.05 K; the corresponding TCR ranges are 1.05–1.80 K and 0.90–2.50 K.where ECS is the equilibrium climate sensitivity and TCR is the transient climate response.
The Lewis & Curry numbers are significantly lower than the IPCC 5AR's numbers (ECS: 1.5°C to 4.5°C, TCR: 1.0°C to 2.5°C), especially for ECS.
The paper has been criticized because it didn't use the latest data for ocean heat content, surface temperatures (Cowtan & Way), or aerosols. These are easily understood points that seem difficult to dispute. Hence, on RealClimate, Nic Lewis flatly refused to address these issues:
I will not waste time arguing in this venue about the validity and/or relevance, or lack of it, of Shindell (2014), Cowtan and Way (2013) or the Allen and Stocker TCR/TCRE relationship.On Twitter Gavin Schmidt said a preliminary calculate of ECS using Lewis and Curry's method but with the most recent ocean heat data (Durack et al) raises their ECS upper limit to 6.1 C -- much higher than the 5AR upper limit (which also did not use data that came out after the 5AR cutoff date of 5/15/13, so the upper limit will likely increase). (Added 10/10: a commenter says this has been revised to 4.7 C.)
But, in her WSJ op-ed, Judith Curry wrote:
Using an observation-based energy-balance approach, our calculations used the same data for the effects on the Earth’s energy balance of changes in greenhouse gases, aerosols and other drivers of climate change given by the IPCC’s latest report.This is sneaky. It's technically true, and makes her paper look like something on equivalent grounds as the IPCC, and something the IPCC missed. But it fails to mention that the Lewis & Curry method doesn't use the most recent data available. It doesn't even acknowledge that they exist, which is at least worth a caveat in the article. Without that, it misleads the reader.
Judith Curry is fond of criticizing others on ethical grounds. I wonder what she would say about the ethics of an IPCC-ish scientist who wrote an article without using the best and most recent data available -- and who even ignored its existence.
I think we all know the answer to that.
PS: The Durack et al changes to ocean heat content (OHC) are indeed significant. Their study found a large addition to the 0-700 meter OHC numbers of (2.2 to 7.1) x 1022 J/35 years. This works out to an average of 20 to 64 terawatts. The existing NOAA OHC numbers for the 35-year change for the 0-700 m region gives 140 TW. So the Durack addition is another 14-46%. That's why their abstract ends with "These adjustments...have important implications for sea level, the planetary energy budget and climate sensitivity assessments." (Emphasis mine.)