Flood? Fire? Flu? Alien invasion? There is one group of people at City Hall whose job it is to know, and to help us prepare. They're the London Resilience Team, staffed by London Resilience Officers, and they do all sorts of things behind the scenes to keep the capital hazard-ready. Planning for Mass Casualties. Promoting Business Recovery planning. Coordinating Electricity Disruption workshops. Updating the London Recovery Management Protocol (which is a disaster recovery plan you'd probably rather not be thinking about).
It should therefore come as no surprise to hear that London has an official risk register. That's the London Risk Register v7.0, a list of potential perils which might beset the capital, ranked by likelihood and impact. Dozens of "Reasonable Worst Case Scenarios" are considered, each relating to an unplanned event. Communities and businesses are invited to give due consideration to the register's contents so that they remain resilient in the face of heaven knows what. And that's why the plan is shared publicly, providing visibility for forward planning, and scaring the heebeegeebees out of those of a nervous disposition. [pdf]
So, what are the biggest threats to London? The London Resilience Team work this out by rating each risk on a 1 to 5 scale for impact and likelihood, then combining the scores. Impacts rank from Limited (1) to Catastrophic (5), while likelihoods are rated by how likely something is to happen over the next five years (1 in 20000 chance for the lowest category, a 50/50 chance for the highest). This produces a four-point categorisation by colour, with green for the lowest risks and red for the highest. London has eight risks in the red zone, eight that worry the authorities above all others.
Below is a grid showing a summary of the ratings for the risks in London's Risk Register. The scale up the side is Impact, and the scale along the bottom is Likelihood. The nearer the top right-hand corner, the scarier.
London's Risk Register 2018 - Summary of Risk Ratings
» Coastal Flooding
» Unconventional Attack
» National Electricity Failure
» Toxic Chemical Release
» Volcanic Ash
» Inland Water Pollution
» Food Chain Contamination
» Influx of British Nationals
» Building collapse
» Public Disorder
» Large road accident
» Cyber (Data Confidentiality)
The most pressing risk facing the capital (medium high Likelihood, catastrophic Impact) is Pandemic Disease, with a 1 in 20 chance of occurring over the next five years. This is the threat of a major worldwide influenza outbreak, possibly affecting 50% of the UK population and causing up to 750,000 fatalities. As well as sickness and death, the risk register warns that absenteeism might become significant, affecting business continuity, and that pandemics often come in several waves, each lasting around three months. The last really bad pandemic was the Spanish Flu of 1918, which killed 2% of those infected, and scientists have long feared a mutated rerun.
As catastrophic, but less likely, is National Electricity Failure. If the National Grid went down, for whatever reason, the most serious problem would be how to reboot the UK's power stations without a supply of electricity. Rest assured there are well-laid contingency plans, codeword Blackstart, using a handful of power stations with emergency generators on site to eventually kickstart all the others. But the risk register warns of total civilian blackout for up to 5 days, with London reconnected late in the process, and "possible loss of life support machines, civil unrest, no alarms, street lighting, gas heating, rail transport, water supplies and mobile telecommunications etc." A slightly less serious version of the risk is Regional Electricity Failure, which south east England successfully survived after the great storm of 1987.
Central London's not at risk from Toxic Chemical Release, but it could affect those living within three kilometres of "a large industrial complex or bulk storage of chemicals". A few such sites exist within the M25, where a serious incident could lead to up to 50 fatalities and 2000 casualties. Contaminants vary, but as well as immediate impacts on air quality, water pollution and agriculture, expect longer term environmental repercussions and prolonged demands on health care services.
Coastal Flooding refers to the risk of inundation from the sea, specifically a tidal surge running up the Thames estuary. The worst impact would be on the east coast of England, the Thames Flood Barrier (hopefully) mitigating much of the damage in the capital, although low-lying areas of London remain vulnerable, and there could be widespread structural damage including disruption to transport, power and water treatment infrastructure. Fluvial Flooding travels in the opposite direction, downstream, and could follow a sustained period of heavy rainfall across the Thames basin. The risk register suggests prolonged flooding might affect 363,000 residents, with a few hundred fatalities and over 10,000 casualties. London's most recent serious flood occurred in January1928 when thawing snow combined with exceptionally heavy rain overtopped the Embankment in multiple locations.
I'm afraid Unconventional Attack isn't very cheery. This relates to a mass impact terrorist attack, either against a nuclear or chemical facility or by obtaining and dispersing chemical, biological, radiological or nuclear materials. This stuff is exceedingly hard to come by so the likelihood of such an event remains low, but is not negligible. Any outcome involving widespread dispersion and contamination would have a severe impact on London's ability to function, and on Londoners themselves. Smaller scale attacks only make it into the orange section.
And finally there's Severe Space Weather. That's not weather as such, but refers to variable conditions on the sun and in space which can influence the performance of technology we use on Earth. Global Navigation Satellite Systems are particularly susceptible to major solar flares, which could lead to electrical blackouts, GPS outages, disruption to aviation and lengthy interruptions to civilian mobile communication. A huge geomagnetic storm in September1859, the so-called Carrington Event, merely managed to knock out a few days' telegraph signals. A similar-sized coronal mass ejection today, if pointed directly towards the Earth, would damage many of the electronic systems on which we now rely and full recovery might take several years.
The remaining 43 risks in the register are either less likely or of lower impact, probably both. That doesn't mean they're of no consequence at an individual level, just that the overall effect on the capital would be lower. Nobody wants to see Attacks on Infrastructure, Disruption to Water Supply or even Effusive Volcanic Eruption, but at least they're only orange, yellow or green, not red. For further details of what each of these risks entails, see the pdf. It's interesting to note that Brexit doesn't appear, only one or two of its potential consequences, but maybe a few more economic risks will appear when the register is next updated next year.
It's reassuring to know that, even if we're not worrying about every negative possibility every day, someone else is keeping an eye on them. All we can do is stay alert and be prepared, and hope that some of the really terrible things never happen. As a minor step you could follow London Prepared on Twitter to keep up with what's going down, or read their 30 top tips to boost your own household's resilience at time of need. And it's probably best not to download a copy of the London Resilience Partnership: Mass Evacuation Framework (v2) for bedtime reading... although somewhere out there, thousands have.