Earth’s Energy Imbalance and Implications (click for PDF)
Here’s a portion of the abstract:
Improving observations of ocean temperature confirm that Earth is absorbing more energy from the sun than it is radiating to space as heat, even during the recent solar minimum. This energy imbalance provides fundamental verification of the dominant role of the human-made greenhouse effect in driving global climate change. Observed surface temperature change and ocean heat gain constrain the net climate forcing and ocean mixing rates. We conclude that most climate models mix heat too efficiently into the deep ocean and as a result underestimate the negative forcing by human-made aerosols. Aerosol climate forcing today is inferred to be ‒1.6 ± 0.3 W/m2, implying substantial aerosol indirect climate forcing via cloud changes. Continued failure to quantify the specific origins of this large forcing is untenable, as knowledge of changing aerosol effects is needed to understand future climate change. A recent decrease in ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols and a deep prolonged solar minimum. Observed sea level rise during the Argo float era can readily be accounted for by thermal expansion of the ocean and ice melt, but the ascendency of ice melt leads us to anticipate a near-term acceleration in the rate of sea level rise.
This line is rather odd:
A recent decrease in ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols…
Well I don’t know what he’s talking about, but the Pinatubo eruption happened in June 1991, and I doubt much aerosol remained after about 3 years. Maybe in his mind 15-20 years ago was “recent”? In 1999 the USGS report on Pinatubo said:
The aerosol cloud spread rapidly around the globe in about 3 weeks and attained global coverage 1 year after the eruption. The SO2 release was sufficient to generate over 25 Mt of sulfate aerosol, and peak local and regional midvisible optical depths of up to 0.4 were recorded. Global values after widespread dispersal and sedimentation of aerosol were about 0.1 to 0.15, with a residence time of over 2 years. This large aerosol cloud caused dramatic decreases in the amount of net radiation reaching the Earth’s surface.
So what’s Hansen thinking when he says “A recent decrease in ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols…” ?
But I digress. The good doctor is also talking again about sea level rise, saying that:
…we conclude that the rate of sea level rise is likely to accelerate during the next several years.
And then goes on to talk about Pinatubo aerosols again:
Reasons for that conclusion are as follows.
First, the contribution of thermal expansion to sea level is likely to increase above recent rates. The nearly constant rate of sea level rise since 1993 masks the fact that thermal expansion must have been less in the Argo era than in the prior decade, when ice melt was less but sea level rose 3 mm/year. Solar minimum and a diminishing Pinatubo rebound effect both contributed to a declining rate of thermal expansion during the past several years. But the Pinatubo effect is now essentially spent and solar irradiance change should now work in the opposite sense.
Well…not so sure about that. A recent analysis of tide gauge data published in the Journal of Coastal Research suggests that there’s been no hint of acceleration at all in the past 100 years:
The paper is currently in press at the Journal of Coastal Research and is provided with open access to the full publication. The results are stunning for their contradiction to AGW theories which suggest global warming would accelerate sea level rise during the last century. In fact, the data distribution seems to be slightly towards the deceleration side:
This seem like a perfect time to revisit this story that I did over a year ago that talked about a prediction posted in a salon.com interview where Dr. Hansen said that the “West Side Highway would be underwater in 20 years”. Well Hansen got upset with that report and called up the reporter and told him his memory was wrong, saying that it was actually 40 years.
Willis Eschenbach told me about the disagreement, and I updated the original story about three weeks ago to deal with the shift from 20 years to 40 years. See the corrected title:
The surprise? Even adding 20 years, Hansen’s prediction still doesn’t look promising. Here’s the new additions to that story from October 2009:
UPDATE: Thanks to a tip from Willis Eschenbach, there’s some developing news in that story from Dr. James Hansen. The Salon interviewee and book author, Rob Reiss that I quoted, now admits he somehow conflated 40 years with 20 years, and concedes that Dr. Hansen actually said 40 years for his prediction. However, as the newest analysis shows, it doesn’t make any difference, and we still aren’t seeing the magnitude of sea level rise predicted, now 23 years into it.
See the relevant excerpt below:
Michaels also has the facts wrong about a 1988 interview of me by Bob Reiss, in which Reiss asked me to speculate on changes that might happen in New York City in 40 years assuming CO2 doubled in amount. Michaels has it as 20 years, not 40 years, with no mention of doubled CO2. Reiss verified this fact to me, but he later sent the message:
“I went back to my book and re-read the interview I had with you. I am embarrassed to say that although the book text is correct, in remembering our original conversation, during a casual phone interview with a Salon magazine reporter in 2001 I was off in years. What I asked you originally at your office window was for a prediction of what Broadway would look like in 40 years, not 20. But when I spoke to the Salon reporter 10 years later probably because I’d been watching the predictions come true, I remembered it as a 20 year question.“
Source: this update on Dr. Hansen’s personal web page at Columbia University.
In my [original] story, below, I quoted from Reiss here in the Salon interview.
So I’m happy to make the correction for Dr. Hansen in my original article, since Mr. Reiss reports on his original error in conflating 40 years with 20 years. But let’s look at how this changes the situation with forty years versus twenty.
Per Dr. Hansen’s prediction in 1988, now in 2011, 23 years later, we’re a bit over halfway there … so the sea level rise should be about halfway up the side of Manhattan Island by now.
How’s that going? Are the predictions coming true? Let’s find out. Let’s look at the tide gauge in New York and see what it says.
Here’s the PSMSL page http://www.psmsl.org/data/obtaining/stations/12.php
You can see the terrifying surge of acceleration in the sea level due to increasing GHGs in the 20th century. Willis downloaded and plotted the data to see what the slope looked like, and then plotted a linear average line.
Here it is overlaid with the Colorado satellite data. Note the rate of rise is unchanged:
And add to that, the recent peer reviewed paper from the Journal of Coastal Research that said: “worldwide-temperature increase has not produced acceleration of global sea level over the past 100 years”
As of this update in March 2011, we’re 23 years into his prediction of the West Side Highway being underwater. From what I can measure in Google Earth, Dr. Hansen would need at least a ten foot rise in forty years to make his prediction work. See this image below from Google Earth where I placed the pointer over the West Side Highway, near the famous landmark and museum, the USS Intrepid:
The lat/lon should you wish to check yourself is: 40.764572° -73.998498°
Here’s a ground level view (via a tourist photo) so you can see the vertical distance from the roadway to the sea level on that day and tide condition. Sure looks like at least 10 feet to me.
According to the actual data, after 23 years, we’ve seen about a 2.5 inch rise. There’ s still a very long way to go to ten feet to cover the West Side Highway there.
To reach the goal he predicted in 1988, Dr. Hansen needs to motivate the sea to do his bidding, he’s gonna have to kick it in gear and use a higher octane driver if he’s going to get there.
Thanks to Willis for the two graphs above.
This story I did is also instructive:
Freaking out about NYC sea level rise is easy to do when you don’t pay attention to history
But while Dr. Hansen is looking for acceleration, the ensemble current plot of satellite measured sea level data seems to have a small hiccup in the last year:
And finally, to be fair, I want to show this video. Dr. Hansen produced a video where he briefed colleagues on his new paper, I present it here in full: