For a wide variety of digital data repositories, there's Cambridgeshire Insight
This site is more focussed on the kind of data we'd want to collect in real-time, and your 'climate change' question is likely to include that sort of thing, i.e. the Air Quality sensor data we've collected as opposed to the more 'static' information available elsewhere.
this is all a work-in-progress so we've build the tools that allows you to browse what data we're collecting (i.e. this web site) and all the data on it is available to the public, but to actually get the data you need to request it via email@example.com. As a short hacky alternative you can just 'view source' of any 'plot' page and you'll see that day's data in there.
Of course we're planning on improving this but we have other immediate priorities (to improve the display of travel information, particularly including the buses) but the general agreement is when we've made progress there (Spring this year) we'll provide a web-based API to enable people to access the data without the bureaucratic overhead.