A group of researchers at Carnegie Mellon University is trying to get a better understanding of the views of earth scientists regarding various climate change topics. They have set up an ongoing poll to do this, called Vision Prize. It’s a short (10 question) poll, covering topics like the rate of CO2 increase, predicted future temperatures, sea ice and sea level states, and hurricane frequencies. Early participants can designate a $20 donation from the group to a charity of their choice, upon completion. Please take a few minutes to help them out if qualified.
Kevin,
The sea ice decline (using area) shows a decline somewhere between a linear and quadratic fit (neither fits the data too well). I was using a logarthmic fit, which falls to 1 million km2 in 2050.
There is higher uncertainty in the volume calculations than either the area or extent measurements. In theory, they should show much better correlation.
A few journal articles which put the recent changes in longer term perspectives. One must be careful when using short-term changes to extrapolate longer term effects. This is not to say the the ice is not melting – it certainly has been. However, predictions of rapid acceleration in the next few years are not supported by much of the data.
http://bprc.osu.edu/geo/publications/mckay_etal_CJES_08.pdf
http://www.the-cryosphere-discuss.net/5/1311/2011/tcd-5-1311-2011.html
http://www.eurekalert.org/pub_releases/2011-08/uoc-lvi080211.php
Dan H.,
A quadratic gives a significantly better fit than a linear trend, and extrapoates to Ice free conditions in ~2032.
Ray,
I responded to Kevin earlier, but it did not post. I was using a logarithmic fit, which results in 1 million km2 in the year 2050. None of the fits; linear, quadratic, or even logarithmic, are particularly good owing to the large variability in the data. Some research suggests that winds and currents play a large role in both variability and overall melting.
Pete,
There is a big difference between summing up different energy sources and getting the math to close and deploying a working energy infrastructure.
Actually, the problem is probably easier in developing countries where little infrastructure exists than in industrial countries where we must substitute a sustainable infrastructure for a legacy infrastructure.
Then there is the whole problem of transportation–and KAP’s electric golfcarts aren’t going to cut it.
We have a long way to go in terms of energy generation, even further to go in terms of energy transmission and storage, and still further to go in terms of energy sufficiently portable to be viable for transportation. And even once we solve these issues, we have a multi-decade effort for deployment.
And we are pretty much doing bupkes right now to address any of these issues.
> higher uncertainty in the volume calculations than either the area
> or extent measurements. In theory, they should show much better correlation.
What theory?
How does area correlate to extent, and both to volume?
Citation, please?
You write as though you have expertise to share, but without
citations to support what you say.
Ray Ladbury wrote: “… electric golfcarts aren’t going to cut it …”
Calling the Nissan Leaf or the Chevy Volt an “electric golfcart” is really off the mark.
It reminds me a bit of folks who said that the IBM PC was an overpriced, glorified typewriter/adding machine that would never catch on with businesses.
Speaking of which, IBM is developing lithium-air batteries with dramatically increased energy density compared to today’s batteries, that will give electric cars a range of 500 miles per charge. They expect to have production versions within 10 years.
When it comes to electric transportation there are ways evolving
Dan H.: Antarctic Ice Mass Loss, 2002-2009
#51–Appreciate the citations, Dan–though as it happens I’ve read all three previously.
You write “predictions of rapid acceleration in the next few years are not supported by much of the data”–but Maslowski’s date does not require any acceleration, if you trust PIOMAS. (Yes, of course it’s modeled, not measured, and of course there are, as you say “uncertainties.” That doesn’t mean it should be ignored.)
And I think that there is, in fact, some evidence of ‘acceleration’ in this data:
http://img.photobucket.com/albums/v224/Chiloe/Climate/sea_ice_VOL_min_to_date.png
@Hank Roberts #46: Yes, thanks to our advisory group, which includes behavioral researchers, scientists, and science communicators. If you are willing to take the time to give us more feedback but prefer not to use the forum, feel free to email feedback@visionprize.com.
Kevin,
The PIOMAS volume calculations are a product of the observed area and modeled thickness. Since both the area and thickness are decreasing at approximately the same rate, the volume is decreasing much faster. However, the volumetric decrease will necessarily slow even if the rate of area and thickness loss remain constant (an artifact of multiplying). The volume cannot go to zero before the area and thickness. Therefore, using the PIOMAS plot of volume to estimate a loss of area is invalid.
Dan H. –
You have ignored my comment, so let me phrase it as a question: Do you believe that the decline in Arctic ice is accelerating? From what I can find, the most recent information says that it is:
http://www.softconference.com/ACSchem/player.asp?PVQ=HJDL&fVQ=FJKHLL&hVQ=
Jim Galasyn@58 –
I quoted that exact same study to “Dan H.” on another blog a year ago. He did not agree with it then. It will be interesting to see if his opinion has changed.
Dan H.,
Your assertion that volume cannot go to zero before extent ignores the fact that we are talking about models here, not reality. In reality, volume is the correct variable to model–and it should yield a less conservative result based on the physics. There is a lot of really crappy first-year ice–that melts pretty quickly. And multi-year ice is getting thinner and thinner. The trend is clearly accelerating–any reasonable analysis of the goodness of fit favors a nonlinear model. I would say that my estimat of 2034 is probably conservative.
Dan H uses any reply to repeat one of the talking points.
He’s a useful guide to which one’s at the top of the list.
So, where’s the push to ignore ice volume coming from these days?
Ray’s point should be obvious — a thin skim of ice can form over a large area, and break up to spread across an even larger extent — yet goes away quickly. Total volume during such a winter will never be much above zero.
Ask the people running the icebreakers which — volume, area, or extent — matters for shipping. Duh.
Oops. Damn, I should know better than to reply Dan H’s talking points.
Sorry for following the digression.
Note About Question Revisions
Based on feedback from participants in the poll, commenters on this post and other members of the scientific community, we have clarified four of the questions in the Vision Prize poll. The new versions have been posted on the site and are reproduced below.
Question 3: If and when CO2 concentration in the atmosphere reaches 550 ppm, what will be the increase in global average surface temperature relative to the year 2000? (Note that this and the next question ask about temperature at a particular moment in time, without reference to whether or not an equilibrium in temperature change has been reached.)
Question 5: When (if ever) will the Arctic Sea become completely free of summer floating ice? (Note that this question asks when the extent of sea ice will be reduced to zero square kilometers, without reference to whether it remains ice free in subsequent months or years.)
Question 6: What is the likelihood that global average sea level will rise more during this century than the highest level given in the 2007 assessment of the Intergovernmental Panel on Climate Change (0.59m)?
Question 10: What decrease (if any) in the annual global economic growth rate percentage would be required to keep CO2 concentration in the atmosphere from exceeding 550 ppm? (Note that this question is phrased in terms of percentage points. For example, a change from 5% to 4% would be a decrease of 1%.)
Updated Information About 225+ Expert Participants
We also invite you to view updated information about our expert participants, many of whom were introduced to the poll by this post. This includes a geographic visualization by affiliation and position and breakdowns by areas of expertise , as well as the public pages of those participants who have elected to share them.
Your interest, feedback and support are much appreciated. Additional participants are welcome.
–Peter Kriss, Vision Prize Director of Research