Mind manipulations with trends and fluctuations

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Fluctuations.. all of us are familiar with them. Yes, because we (us, and everything else living in our planet) are not perfect machines. Everything in the natural world fluctuates, some more than other. 

Let's use a mondane example to explain fluctuations - weight. In this world obsessed with looks and weights and diets we are all overly familiar with that feeling when we step on the scale. Some of us (me included, guilty as charged!) weight themselves at a too high frequency (daily or multiple time per week). If you are anything like me you would have noticed, and perhaps have been surprised, by the great fluctuations the body goes through on a daily basis - my weight for example can go through changes of up to 2kgs in just one day, and no I am not getting 2kg fatter in a day - it's just not possible.

In terms of data, if we look at today's point (116.7 lbs) it could be used to compare me against a pool of other women my age and height, or perhaps a regional comparison. But if we want to look at how my body is changing, one point is actually not enough. We should choose a before and after. But what before? If we look at the "weekly" data it looks as if i got slimmer and then fatter again. But I still fit in the same trousers,

So perhaps a 'weekly' measurement is not the most accurate for weight. Perhaps we should choose a scale based on the measurement that we are interested in. 
And this does not just apply to weight, which I am just using as an example. If we want to understand how the world around us is changing, overall, we need to look behind fluctuations. Measure the temperature outside your house for example, from winter leading to spring and summer, you would expect it to increase, yet at times it decreases (if you live in the north like me right now, for example, you would easily say that no we are not in summer according to the temperature, however a week or so ago we were...). So what do you do? Is this a fluctuation? Or is temperature going down now all the way to winter? And is it the same outside my house than it is outside yours? 





First thing to do is to look at longer time scales to individuate trends. But a timeline is often arbitrary (and I will be coming back to this, very important point, shortly). 
If we (again and I promise just for one last time) look at my weight, if we choose a month view, you could say that I have been more or less the same, the trendline would be flat. Over 3 months, slightly decreasing, over 6 months definitely decreasing.

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Similarly to my weight, the climate around us is fluctuating. And we need to look past these fluctuation if we want to see what the climate is doing overall. And this is where the battle between climate change 'believers' and climate change 'deniers' arises from. It's all about looking at the right scale, and looking past the fluctuations. 

Source: Met Office

If you choose two arbitrary points to compare from this graph you could choose two points that show similarities, suggesting that there is no climate change afterall, or you could choose two points that show alarming differences. However, if you look at the trend, there is no hiding behind doors - there is a trend for increasing global average temperature anomalies. 
I guess the point i am trying to make is beware - when you are shown data. Try and understand where are those data coming from, try to see the bigger picture. Don't blindly trust. Data are numbers and many nowadays use these numbers at their conveniences.
Not just talking about climate change, or weight loss. This applies to just about anything. Data are numbers and the presentation of these numbers in graphs can be used to manipulate people's mind. People like you and me, who sometimes blindly read the latest articles. Always questions, always read behind the line..