Joanne “I never cherry pick” Nova takes to the oceans in her quest to yet again cherry pick only the science that supports her political opinion.
This time she blatantly throws out science that has warming in it … because, er, it has warming in it.
Basic Argo Facts
We first need to help Nova understand the limitations of measuring the ocean which stems mostly from the fact that it’s huge. In volume, it’s about 1.300 billion cubic kilometres.
- Whilst Argo data is much more comprehensive than we used to have, it still works out to one float per 380,000 cubic kilometers. That’s cubic kilometres, not just meters, or litres.
- Argo floats don’t go below 2,000 meters. The average depth of the ocean is almost double that.
- Argo floats don’t measure under ice so they’re not measuring a large part of the Artic, where polar amplification is thought to be causing greater warming and accelerating sea ice loss.
- Argo floats are designed to go up and down in the water, not from side to side so they drift with the current, measuring the same area of water over and over again.
- Argo floats will drift with the current allowing two or more floats to be covering the same patch of water (see animation using actual Argo data), thus leaving even larger volumes unmeasured for many months.
- Argo floats have been slowly deployed over many years (see animation here), from Nova’s cherry picked start year there were only around 1,060 floats, that’s 1 float per 1,200,000 cubic kilometres.
One float per 380,000 cubic kilometres of water (three times that amount in the beginning), half of which is never reached, is not accurate enough to give any precise figure of ocean heat content.
The Argo team themselves say “The global Argo dataset is not yet long enough to observe global change signals.”, yet Nova bases her “science” upon an even smaller cherry picked timeframe and then ignores any science that says otherwise.
Nova Hides the Incline
Joanne “I never cherry pick” Nova places ALL her cherries into the Argo data, however, not all of the Argo data. Nova’s graph (she says it’s from Douglass and Keen 2010, but she’s wrong, it’s from Douglas and Knox) only plots a trend on “filtered” data between 2004 and 2008 and doesn’t consider more recent data. In Douglas and Knox’s words … “Note that the length of the time segment is four years.”.
Here’s the full amount of ocean heat content data including the more recent Argo data, as well as the earlier XBT data.
Nova wants you to discard the XBT data too. I’m betting that would be the case if it showed a downward trend. But it’s foolish to throw away data because it’s less extensive than modern day measurements. Looking at the above graph it’s easy to see that XBT data has more year-to-year variability than the Argo data, but it’s not so “erratic and highly uncertain” as Jo puts it. The long term upward trend is very clear no matter how much Nova tries to wish it away.
In true fashion, Nova only wishes to keep the small section of data showing a slight decline, instead of the full picture which clearly shows long term heat accumulation. An accumulation that fits in with the many pieces of non-cherry picked data showing that the planet is warming.
Can’t see the Data?
Nova makes up a story about how Argo was apparently impossible to get even though it was freely available.
When faced with this easy-to-find data, she then changes her expectations and instead of just the data, she wants it to be gridded, analysed and reported to her as soon as new data becomes available.
Ironic now that more recent analysis of the data shows the Argo data inclining once again as the long term trend overwhelms short term variation, she no long wishes to present it on her graphs, instead sticking with just the 4 years, and just the first 700 metres.
Nova goes on to plot the cherry picked Argo data against her view of “Model Expectations”. Nova fails in a few ways.
1. No model predicts a straight line over any short term period. Trendlines are used to show the average changes over long term periods, it makes no sense to use one on short term data. Doing so means your choice of cherry picked year becomes critical – as discussed by Tamino.
2. Argo’s data, as the Argo team says, is not long enough to provide a long term trend because it doesn’t measure the entire ocean on a resolution that is capable of reporting all heat. On a time scale of a few years the inadequacy of our measurement system ensure that we do not know for certain exactly how much heat there is. Scientists know there is uncertainty in short term data, that’s why they look at long term data for real climate trends.
3. Nova doesn’t compare against all the data. She insists on throwing out data from the deeper readings (see below).
Nova Lacks Depth or Perception
If you wish to measure the heat in the ocean, is it better to measure to 700 meters or down to 2,000 meters? The answer is obvious, the more ocean we cover, the more accurately we can monitor the change.
Not so it seems for Nova; well especially when the addition 1,300 meters shows up more warming than if you just look at the top 700 meters and that’s what Nova’s friend Bob found by comparing the different depths. Once again the denialist mind like Nova/Bob is thinking that the science is “hiding the levelling off of the 0-700m data” rather than simply a graph showing more data. When faced with more data that confirms the well established science showing the world is warming, denialists will go to great lengths in order to pretend the new data doesn’t exist.
Nova complains … “Despite the paucity of measurements below 1000m, the NCDC decided to add the deeper ARGO series to their 1950 -2010 graph on ocean heat. This creates a sudden uptick at the end of the graph“. At least Nova is blunt about why she doesn’t like it. But if you take a look at her friend Bob’s analysis you’ll find this period is where the most amount of deeper samples have been taken. The more detailed, deeper period of sampling shows the heat content is increasing.
On the one hand Nova says she likes Argo data because it’s more accurate than the XBT data, then when the ARGO team delves deeper and the warming trend continues, Nova gets cold feet about going deep.
An Even Deeper Look
That’s not the end of it. One study looks at even deeper data and Nova briefly mentions it … “Purkey & Johnson 2010 look at depths down to 4,000m for the 1990s and 2000s (how is that relevant to CO2 induced warming in the last 10 years?) It’s not like recent coal emissions could have warmed the abyssal depths.”.
Ironic that one moment Nova refuses to use the deeper Argo data, yet now she suddenly claims that there’s no possible reason for looking. A real scientist that has a good skeptical mind would allow the data to do the talking rather than simply assuming the heat could not reach to abyssal depths.
It seems her conviction is born from her previous statement that “The oceans take about 1,000 years to fully churn”, a mistake in thinking that the entire ocean must churn in order for heat to transfer downwards, an assumption on her part which isn’t supported by the science. Not only did Purkey and Johnson find Nova to be wrong, new research show’s Nova’s concept of the slow conveyor belt is simply outdated.
Nova’s View of the Science World
When you choose to ignore data, like the way Nova cherry picks only some bits of data and ignores the rest, then your view of the planet becomes less clear.
Science is about using all of the data, regardless of whether it supports your personal political view or not.
The data that shows warming or cooling is NOT based upon Nova’s cherry picked 4 years of Argo data, the data comes from multiple lines of evidence such as:
- land surface thermometers show the planet has warmed.
- sea surface readings from ships & buoys show an increase in temperature.
- satellite data also shows the planet has become warmer.
- XBT and Argo data both show the ocean heat content is increasing.
- plant and animal species migrating in response to warmer climate.
- sea ice extent and volume decreasing and at an accelerated rate.
- sea level rise showing increased land ice melt and thermal expansion.
- glacier ice decreasing and at an accelerated rate.
For more detail, and links to the science I recommend … http://www.skepticalscience.com/The-many-lines-of-evidence-for-global-warming-in-a-single-graphic.html
Nova’s addiction to cherry picking means she ignores the mountain of evidence showing that our planet is rising in temperature.
update 1 Mar 2012: added 700m vs 2000m comparison graph.