Lord Lilley

The assumption of stationarity of the residuals is well established in the peer reviewed literature. Recent examples of this can be found in the following papers:

Kew, Sarah F., Sjoukje Y. Philip, Geert Jan van Oldenborgh, Gerard van der Schrier, Friederike EL Otto, and Robert Vautard. "The exceptional summer heat wave in southern Europe 2017." Bulletin of the American Meteorological Society 100, no. 1 (2019): S49-S53.

Yiou, Pascal, Julien Cattiaux, Davide Faranda, Nikolay Kadygrov, Aglae Jézéquel, Philippe Naveau, Aurelien Ribes et al. "Analyses of the Northern European summer heatwave of 2018." Bulletin of the American Meteorological Society 101, no. 1 (2020): S35-S40.

Leach, Nicholas J., Sihan Li, Sarah Sparrow, Geert Jan van Oldenborgh, Fraser C. Lott, Antje Weisheimer, and Myles R. Allen. "Anthropogenic influence on the 2018 summer warm spell in Europe: the impact of different spatio-temporal scales." Bulletin of the American Meteorological Society 101, no. 1 (2020): S41-S46.

Further to the written answer provided on 6 October (HL8377), the plot placed in the Library of the House shows that the GEV distribution is a good fit to the data, which supports the assumption that the distribution of residuals may be adequately modelled as stationary.

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.

The analysis does not assume that all the months of June during 1926-2020 have the same statistical distribution for the highest of their daily temperature maxima at Verkhoyansk. Instead, the method involves modelling secular changes in the data by a covariance with smoothed Global Mean Surface Temperature (GMST) and first removing this to create a set of residuals that may be assumed to be stationary and to which a Generalized Extreme Value (GEV) fit is then made. This method, based on peer-reviewed literature, is set out in the linked methods document which accompanies the report.

I have arranged for a copy to be placed in the Libraries of the House, along with explanatory text and supporting documents.

The report’s sample size is large enough to justify the fitting method used in the analysis as daily temperature data at approximately one-year intervals are not significantly correlated from year to year over continental regions. The maximum daily temperature in a particular month or season in a particular year in a continental region does not serve as a good predictor of the maximum daily temperature in the same month or season in the following year (over and above the long-term effect of climate change) due to natural variability of the climate system. The June-July daily maximum temperature data over timescales from 1 day upwards shows no significant autocorrelation (correlation with itself across a period of time) above 1 week timescales and confirms that the 94 data points used in the report are independent, a sufficiently large number to justify the fitting method used in the analysis. The analysis in the report is based on peer reviewed methodology as set out in a paper by Van der Wiel et al. referenced in the report, which applied this fitting method to a dataset of a comparable size.

Sir James Bevan’s speech was underpinned by published evidence from a variety of national and international reports that includes the UK Climate Projections 2018 announced by the Secretary of State for Defra in November 2018. The Environment Agency has recently published research showing an upward trend in extreme floods at two-thirds of their river level monitoring stations and that this trend is 90% certain at over a fifth of locations.

The UK is party to a number of international agreements that provide for obligations and recommended practices around customs procedures and declarations, such as the Revised Kyoto Convention.

Obligations as to the precise form of the UK customs declarations for imports are established by the UK’s domestic legislation. There is no general exemption regarding the contents of customs declarations for goods being imported under a free trade agreement, including imports that are tariff free and quota free.

The assessment of the capture rate was made from a mathematical model developed by Public Health England (PHE). The 7% capture is for those infections in asymptomatic travellers that were infected before travel and were incubating infection during travel.

This finding is for asymptomatic travellers irrespective of the prevalence of infections in the country that the traveller is arriving from and is independent of the period of the year that it is applied to. This is based on the high sensitivity and specificity of current laboratory-based Polymerase Chain Reaction (PCR) and PHE has not identified any technology that has better detection rates that would change these findings.

Testing in care homes is an important part of keeping staff and residents safe in the COVID-19 response. It means those who test positive can be isolated, reducing the number of people who can spread the virus and protecting the most vulnerable.

PHE has conducted a number of prevalence studies in health care workers using reverse transcription-PCR which informs assessment of potentially infected staff. The assessment of the risk posed by visitors to care-homes is part of the SAGE social-care sub-group’s purview and will be reported in due course.

The development of a COVID-19 vaccine is at the early stages but progressing rapidly. The Government is working to ensure the United Kingdom has the manufacturing capability to produce these vaccines at the levels the UK needs. To do this, a new cross-Government vaccines taskforce has been set up, reporting to the Secretaries of State for Business, Energy and Industrial Strategy and Health and Social Care as well as Sir Patrick Vallance. It brings together Government, industry, academics, funding agencies and other partners to make rapid decisions in order to accelerate vaccine development in the UK.

The UK Government does not offer advice on this specific matter to British travellers.

All passengers arriving in the UK at passport control are checked against Home Office databases. The majority of these are checked against our systems before they even travel, through the collection of advanced passenger information (API).

Border Force defines General Aviation (GA) and General Maritime (GM) as any arrival into the UK that is not operating to a specific and published schedule and departing at both small airports and marinas with no Border Force presence, and at major airports where Border Force officers are located. Both EU/EEA citizens (1) and visa nationals (2) may arrive at General Aviation or General Maritime ports

There is a requirement for advance passenger information to be submitted for General Aviation and General Maritime arrivals. When the relevant information is received, and there is a requirement to examine the passenger, Border Force Officers will be deployed.