@GoddersUK: The Y axis is the global surface temperature anomaly. I do not know what the base years are that are used to calculate the anomaly, and I don't know if this is land surface only or if it includes sea surface temperatures as well.
The average temperature of the earth is approximately 14 or 15 degrees Celsius (288 Kelvin)
It looks like this chart starts around when the UN IPCC says humans started to have an influence on temperatures due to CO2, generally around 1940 - 50, when levels started to rise. Prior to that date any temperature rise is considered to be from natural variability and not from anthropological sources.
So when you see or hear about how the globe warmed such and such amount since 1880, when the first thermometers were invented and started taking temperatures, keep in mind that all the temperature rise from 1880 to about mid 20th century was natural warming. Most people are not made aware of this fact.
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The fitted data that you allude to is actually from tuning climate models, but unfortunately there is no way to verify, as there are so many different ways that you can change the various variables that go into climate models to get the same fitted results. Only future data can verify if the climate models actually work, or provide some guide into how accurate they are. As you probably know weather models are good at most to about 7 to 8 days before they are completely unreliable. The chart shows that the climate models that are used to predict / project future temperature have been on the high side when compared to actual observations.
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What you may not know, as you say "Come back to me in a decades time with a consistent drop in rate of warming", is that there has been no global warming from 16 to 23 years depending on which UN IPCC approved data set you use. :
There is also a 68 page report on this standstill in temperatures here you can download:
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There is an interesting idea of using an statistical model for climate that might show some promise: