Question to the Department for Business, Energy and Industrial Strategy:

To ask Her Majesty's Government, further to the Written Answer by Lord Callanan on 6 October (HL8377), whether they will place a copy of a quantile-quantile plot of a GEV distribution against the distribution of June maximum temperatures at Verkhoyansk during 1926–2020, that includes data from 2020 in particular, in the Library of the House.

Further to the written answer provided on 6 October (HL8377), the plot placed in the Library of the House uses data over 1926 – 2019. The 2020 value is not included in the fit of the GEV itself, as is standard scientific practice to avoid biasing the fit by the extreme value of interest. It is well established that the selection of a series in which a very large extreme has occurred means that the return time of this value is likely to be much larger than the length of the dataset itself. This means the time series would give an artificially low view of the return time compared to reality. However, as requested, we have provided an additional quantile-quantile plot that does include the 2020 value in the fit – which we provide subject to these caveats.