The BBC article goes on to say…
If a trend meets the 95% threshold, it basically means that the odds of it being down to chance are less than one in 20.
Last year’s analysis, which went to 2009, did not reach this threshold; but adding data for 2010 takes it over the line.
“The trend over the period 1995-2009 was significant at the 90% level, but wasn’t significant at the standard 95% level that people use,” Professor Jones told BBC News.
“Basically what’s changed is one more year [of data]. That period 1995-2009 was just 15 years – and because of the uncertainty in estimating trends over short periods, an extra year has made that trend significant at the 95% level which is the traditional threshold that statisticians have used for many years.
“It just shows the difficulty of achieving significance with a short time series, and that’s why longer series – 20 or 30 years – would be a much better way of estimating trends and getting significance on a consistent basis.”
Professor Jones’ previous comment, from a BBC interview in February 2010, is routinely quoted – erroneously – as demonstration that the Earth’s surface temperature is not rising.
What a difference a year can make!!! 1995-2009 was not a statistically significant warming trend.
One year later… We now have a statistically significant warming trend!
So… Does this mean that if the cooling trend since 2001 is still present in 2016, that we will then have statistically significant global cooling?