Tag Archives: How to lie with graphs

The Amazing Decelerating Acceleration of Velocity Curve Of Global Cooling! #FauxPause

In 2009 someone wrote a blog post about climate change that made all the usual science denialist claims. Hurricanes have reduced therefore global warming is not real. In this case, hurricanes are one of the main threats of climate change (a straw man) and since they are not as common these days in the Atlantic as alarmists claimed the would be (cherry picking) global warming is not a concern. There were stronger storms in the past. Katrina wasn’t really all that bad. Etc. etc.

The Ice Caps (he called sea ice “Ice Caps”) are not really melting that bad and besides we don’t really know what they were doing before 1970 so we can use anecdotal evidence that sea ice was less extensive and ignore anecdotal evidence that sea ice was more extensive in the past.

El Nino was supposed to do somehting rather specific and unusual (that El Nino researchers were never very sure of) and instead did something else rather unusual therefore there is no global warming. Climate models don’t really work, Carbondioxide is a plant food, global temperatures are experiencing a hiatus in increase, it’s really the sun, etc. He called concern over climate change hysteria and called discussion of changes to climate alarmism.

This was Matt Rogers, who at the time, and who is still now, with the Capitol Weather Group. Perhaps Matt was confused five years ago. Perhaps he was a climate change skeptic in the days when it was reasonable to question the mainstream science, before the consensus formed and climate scientists started working more on details. But no, that doesn’t really explain what he was saying then because consensus was already established. He was, in truth, spouting denialist creed. But still, perhaps these days Matt, who is actually a trained meteorologist, has shaken off the denialism.

Maybe. But just the other day he came out with a post that is very much worhy of admonishment, in part because of a graphic it uses. Have a look at the graphic, which is about Global Temperature Change in recent years. Tell me what you think this graph shows?


Decrease, decline, flatness, hiatus. Cooling. Climate getting cooler. Global warming must be wrong.


This is a change in the rate of acceleration of the velocity of global temperatures. We’ll get back to that in a moment.

Matt starts his post with:

The recently-released National Climate Assessment (NCA) from the U.S. government offers considerable cause for concern for climate calamity, but downplays the decelerating trend in global surface temperature in the 2000s, which I document here.

No it doesn’t. The NCA addresses the topic in the FAQ and in the body of the report rather prominently.

Matt then notes:

Many climate scientists are currently working to figure out what is causing the slowdown, because if it continues, it would call into question the legitimacy of many climate model projections (and inversely offer some good news for our planet).

This is a misstatement. This verbiage implies that many climate scientists accept the idea of a “slowdown” and are trying to figure it out. This is simply not true. There is secular variation in the commonly used surface temperature measures, which are an incomplete estimate of global temperature and warming/cooling over time, ignoring the largest heat reservoir on the planet (the ocean) and highly dynamic changing effects such as the Arctic. It is like an index, useful but nothing like perfect. Imagine using only one of several indexes of the economy to stand in for all of them? You wouldn’t Actually, these temperatures series are much better measures of global warming than any of those economic indexes are of the economy, but you get the point; it is a good estimate. Emphasis on both “good” and “estimate.” Anyway, most of this variation has been explained in the past. A few studies recently explained more of the variation. But overall the march of global surface temperatures have tracked with expectations and gone up over time. Scientists are not scrambling to explain a thing that is not happening. Matt should know this.

Now about his graph. Matt first tells the people reading his post that they could create their own graph of global temperatures and make one, but no, Mat will do it for you:

You can see the pause (or deceleration in warming) yourself by simply grabbing the freely available data from NASA and NOAA. For the chart below, I took the annual global temperature difference from average (or anomaly) and calculated the change from the prior year.

He’s referring to the chart I show above, but implying in the text that this is a chart of global temperature anomalies (differences above or below a baseline) just like any other temperature change over time chart. He doesn’t exactly lie, but he made a very obscure graph of a very obscure measure with questionable statistical validity or usefulness and seems to do everything he can to pass it off to the unwary as a graph showing global temperature decreases over the last several years.

More subtly, why did he smooth the line? It makes it look like a mathematical function (giving it undue credence?) when it is really multi-cause variation from year to year in a derivative.

Also, by setting the start of the graph at a recent arbitrary point, the graph can not show the long term trend. That would probably be a more or less flat line with short term up and down trends. It would be a very uninteresting graph. Only by focusing on this close up does it look like it is showing something. At the moment I’m writing this blog post from the middle of the Great North Woods so I don’t have access to the data but maybe I’ll make that graph for you and show you at a later time.

The “sign of data validation” he refers to in his post, that both data sets have the same trend, is bogus. They are not two separate data sets. They are two overlapping sets of data measuring the same thing. So, here, “Data Validation” means that no one accidentally inserted their checkbook balancing data into the wrong spreadsheet cells.

Matt notes “…the warm changes have generally been decreasing while cool changes have grown.” This is not a graph of warm or cool changes. It is a graph of the rate at which changes have happened. So by stating it this way, the essence of the graph is lost. This is a graph of change in rate of change.

Then, “To be sure, both sets of data points show an mean annual change of +0.01C during the 2000s. But, if current trends continue for just a few more years, then the mean change for the 2000s will shift to negative.”


Nice to admit that the trend is an increasing temperature, but suggesting that this could shift to negative (for more than a brief moment) is insane. This is like looking at the increase in maximum rate of human travel over a century, from horse to car to aircraft to space ship and predicting that at some point we will be going faster than the speed of light. You can’t go faster than the speed of light. You can’t add greenhouse gasses to the atmosphere and cool off the planet short of a very serious negative feedback mechanism which apparently does not exist. Warp drives in the news lately notwithstanding, we will not cool the planet by, effectively, turning up the effects of the sun’s energy.

Then, “The current +.01C mean increase in temperatures is insufficient to verify the climate change projections for major warming (even the low end +1-2C) by mid-to-late century.”

There is not a “current +.01C increase.” There is a poorly made graph combined with an apparently poor understanding of the science possibly made with the intent of minimizing concern over global warming covering only a short period of time being misinterpreted as a valid measurement. This is like cold fusion or faster than light neutrinos invalidating the Standard Model in physics. But less interesting.

The rest of Matt’s post is him tossing softballs at himself in the form of the usual objections people make when someone advocates for the #FausPause. Like that Matt or his friends might be cherry picking. Like they do. Or noting that it is warmer now than ever. Like it is.

In the end, literally, Matt notes that the slow down is not real, is only temporary, and will go away. But this is only after a majorly misleading graphic and a lot of verbiage with an entirely different message. Is this a new kind of denialism and what do we call it?