We haven’t checked much lately on climate science, so it is time to catch up, starting with some recent items about oceans worth a note.
As everyone in California knows, it’s a big El Nino year. El Nino is the phenomenon where liberals go crazy when Antonin Scalia says something. No, okay, so that’s not it, but that Nino (his nickname to his friends) also causes huge storms.
El Nino is the periodic occurrence of warm water in the Pacific Ocean that typically changes winter weather patterns around the world. Naturally it gets wrapped up with climate change, because El Nino years also correlate to spikes in the global average temperature. 1998, which saw a big El Nino, was the previous high temperature year until 2015, whose record temperature is bringing smiles to the desperate climatistas. It is important to keep in mind that although the phenomenon has been recognized for more than a century, comprehensive and accurate data, from satellites, have only been around for about 40 years, so statements about “strongest El Nino ever recorded” are misleading.
Retired NASA scientist Roy Spencer, whose website is worth checking regularly, offers a long treatment of the issue:
Dick Lindzen suggested to me recently that this might be a good time to address the general question, “what causes the global-average warmth during El Nino?”
The short answer is that, during El Nino, there is an average decrease in the vertical overturning and mixing of cold, deep ocean waters with solar-heated warm surface waters. The result is that the surface waters become warmer than average, and deeper waters become colder than average. The opposite situation occurs during La Nina.
Importantly, the change shows up in global average ocean computations, based upon ocean temperature data (see our Fig. 3, here); this means that the changes centered in the Pacific are not offset by changes of the opposite sign occurring in other ocean basins. . .
In a sense, the deep ocean provides an air conditioner for the climate system, and during El Nino the air conditioner isn’t working as hard to cool the atmosphere. During La Nina, it’s working harder than normal, leading to global-average coolness.
From here things get complicated, as you would expect with something a complex as the earth’s climate. Dr. Spencer decodes it into plain English:
The consensus opinion of El Nino and La Nina is that it is just a quasi-periodic oscillation of the climate system that has no long-term impact on global temperature trends.
But we demonstrated that as El Nino develops there is an increase in radiative energy input into the global-average climate system which precedes peak El Nino warmth by about 9 months. This is mostly likely due to a small decrease in low cloud cover associated with the changing atmospheric circulation patterns during El Nino (La Nina would have increased cloud cover).
Thus, if the climate system goes through a multi-decadal period of increased El Nino activity (and decreased La Nina activity), like what happened after the 1970s, there can be a multi-decadal natural warming trend that is entirely natural in origin as more solar energy is absorbed by the system. This complicates identification and quantification of the human greenhouse gas-forced portion of climate change, leading (in my opinion) to overestimates of the anthropogenic warming effect.
You can expect that as El Nino heavy weather increases, you’ll hear the exact opposite of this. It will be taken as proof of human-caused climate change.
More to come on ocean news. Several more interesting items in the stack.