Ms Nova wrote a
on 2014/12/04 criticizing the Australian Bureau of
Meteorology (BoM) which had reported that the Spring of 2014 was the hottest
Ms Nova's graph, which she used to illustrate her point, is shown on the
Ms Nova stated that she obtained the data she used in the graph from the
University of Arizona at Huntsville (UAH) who had interpreted it from
(There is an interesting examination of this data set in
|Ms Nova's graph
Does Jo Nova understand science?
Anyone with any knowledge of science would be aware that several sets
of measurements of a complex system, using entirely different methods of
data collection, will come up with slightly different results.
One would certainly expect satellite temperature data to differ somewhat to
data collected using thermometers on the Earth's surface.
Does Jo Nova understand her own graphs?
What does Jo Nova's graph show us?
That, according to satellite data, this last Spring might have been the
forth hottest in the last 35 years rather than the hottest.
Even using Ms Nova's graph, seven of the hottest springs in the last 35 years
have occurred in the last nine years.
This graph, and the three others that Ms Nova gave for the other seasons,
shows a warming trend; a trend that became especially strong in the last
twenty years and yet Ms Nova claims "there hasn't been much climate
change in the last 15 years".
The graphs that Ms Nova used provide strong evidence for climate change and
suggest that the rate of warming is increasing!
It certainly does not back up Ms Nova's criticism of the Bureau of
|Ms Nova's graph with a trend line added
|The mathematically calculated trend line indicates rising
I added a mathematically calculated trend line to Ms Nova's graph; the result
is shown on the right.
Not only does the trend line show that the temperatures recorded by the
satellite are rising, but it shows that the rate of rise is itself
The trend line was a 'power' curve generated by Open Office spreadsheet.
Ms Nova's qualifications in climate science
It is worth noting that Ms Nova has no formal qualifications in climate
science and has not published anything in peer-reviewed
journals, yet claims to know the facts on climate science better than most
qualified and published climate scientists; see
Ms Nova seems to believe that we should accept the satellite as interpreted
by UAH and ignore the Bureau of Meteorology data.
In fact, if we are to get the clearest possible picture of historical
climate change, we must look at many data sets.
First, the science:
- About 99% of papers published in peer-reviewed climate journals
accept the fact of ACC;
- The vast majority of climate scientists accept the reality of ACC;
- I doubt that there is any scientific organisation that has any interest in
climate, anywhere in the world, that does not accept ACC.
More on this on
another page on this site.
- Almost every national government in the world
accepts the reality of ACC;
- I doubt that there any respectable university in the world that teaches
that ACC is not true;
- The world's mainstream churches are pushing for serious action to slow
The most reliable data are the actual temperature measurements recorded by
organisations such as the Bureau of Meteorology.
Satellite data is also very valuable, but as mentioned in the
Wikipedia article, satellites do not measure temperatures directly.
The data that they record has to be interpreted to obtain temperatures.
And, of course, while satellite data goes back to around 1980, Bureau of
Meteorology temperature records go back well over a century further.
Temperatures interpreted from indirect observations, such as the satellite
data that were used in Ms Nova's graphs, are called proxies.
There are a number of other ways of implying past temperature: they include
tree-ring data and oxygen isotope data from ice cores.
These can tell us about the temperatures much further into the past than
direct temperature recordings.
A graph of temperatures from the last 1000 years interpreted from proxies
is given in Wikipedia.