Cycling not related to global warming?

It being Sunday, and morning, and my brain not being full into gear yet, I was idly playing with data visualisation tools, as you do, getting ideas for the design of something I'm trying to make...

I compared 'bicycle' and 'cycling' on Google's trends engine with 'Global Warming (see the picture); and the result really surprised me.

Firstly, both the 'bicycle' and 'cycling' graphs peak sharply in July, indicating to me that interest in the TdF, by itself, outstrips interest in all other cycling activities put together (this is more true if you look at the data from just the US, slightly less true if you look at the data from just the UK).

But secondly, even ignoring the July anomaly, I can see no correlation whatever in that graph between 'cycling' and 'global warming'. For the average person in the UK, private car usage accounts for 21% of their personal carbon footprint, second only to domestic heat and power. So for the average person, switching journeys from car to bike would be one of the most significant ways they could reduce their carbon footprint. We seem to have completely failed to get that message across.

By contrast, there's vastly better match in the UK between 'bicycle' and 'congestion charge', but that could be coincidental because for some reason 'congestion charge' also seems to peak annually in July.

Conclusions:

We haven't got the message across about cycling as an ecologically responsible choice (or people just don't care).

Taxes do far more to encourage interest in cycling than social responsibility.