2 Nature of the threat |
13. "Space weather" is a naturally
occurring phenomenon that can impact upon the Earth's environment
in ways that are detrimental to key technologies in operation
in space, the atmosphere and the surface of the Earth. "Space
weather" generally refers particularly to changes in the
space environment near Earth, caused by varying conditions in
the sun's atmosphere. Solar activity adheres roughly to an eleven
year cycle, with solar activity increasing during a "solar
maximum", making space weather events more likely. The next
solar maximum is predicted to occur in 2013. However, space weather
events do not necessarily obey this cycle; the Carrington event
of 1859 (see below) occurred in the middle of a cycle. Space weather
events are an everyday occurrence. Indeed, the well-known phenomenon
of the aurora borealis, or "Northern Lights", is an
effect of charged particles originating from the sun colliding
with the Earth's atmosphere.
14. The following table summarises some of the
different types of space weather and their potential impacts.
1: Categories of Space Weather
|Coronal Mass Ejections (CMEs)
||Plasma ejected violently from the outer atmosphere of the sun
||Fluctuations in the Earth's magnetic field (geomagnetic storms), driving additional current into power grids, disrupting satellites, GPS (global positioning system) and radars
|Solar Energetic Particle (SEP) events
||High energy particles expelled from sun during solar events like CMEs
||Damage to electronics, computer chips and power systems in spacecraft [and aircraft] (possibly at ground level too), raised ground radiation levels
|Solar radio bursts
||Intense bursts of radio noise produced by solar events like CMEs
||Interference with low power wireless radio technologies such as mobile phones, wireless internet and GPS receivers
|Solar flares||Outburst of radiation and energetic particles
||Modest effects on Earth
Data Source: Science and Technology Committee,
Scientific Advice and Evidence in Emergencies, para 18
15. The largest ever recorded space weather event
occurred in September 1859. It is known as the Carrington Event
after Richard Carrington, the British astronomer who observed
a solar flare so strong that it could be seen with the naked eye.
The huge coronal mass ejection (CME) that followed induced enormous
electric currents that surged through telegraph systems, causing
shocks to telegraph operators and setting fire to papers.
Operators were able to disconnect their batteries and continue
to send messages using only this induced current. The impact was
so wide-ranging that auroras, normally limited to polar regions,
were observed as far South as Hawaii and the Caribbean.
16. The Carrington event is thought to have been
up to ten times larger (depending on what effect is being measured)
than anything seen in the past 50 years.
There have been less significant, but still destructive, events
in the more recent past. In March 1989 a large CME caused the
Canadian province of Quebec's power grid to collapse within 90
seconds, after stabilising equipment failed to cope with the effects
of the geomagnetic storm. Around six million people were subsequently
without power for nine hours. The same storm caused a transformer
to fail in New Jersey and various other effects across the North
American grid. It is also thought to have been the cause of damage
to two transformers in the UK. The adverse effects of extreme
space weather on modern technology are therefore well documented.
17. Resilience to space weather events is routinely
built into some components of infrastructure, such as satellites,
which are frequently exposed to its effects. However, events vary
in intensity, and the potential impact of a severe event could
18. Space weather events have the potential adversely
to affect human health in some cases. Exposure to even very high
levels of electromagnetic activity is not thought to have any
direct ill-effects on humans or any other living organisms. However,
there could be potential implications for patients with implantable
cardiac devices, as highlighted to the Committee by the Royal
College of Physicians.
Solar energetic particle events may lead to increased exposure
to radiation for workers such as pilots and flight attendants
on long-haul flights.
19. The Government told us that the likelihood
of a severe space weather event (not necessarily, of course, a
Carrington-magnitude event) over the next five years was assessed
as being moderate to high, with the potential to cause damage
to electrically conducting systems such as power grids, pipelines
and signalling circuits.
POTENTIAL IMPACT ON ELECTRONIC INFRASTRUCTURE
20. The maximum possible severity of a space
weather event is, of course, impossible to estimate, but witnesses
use the Carrington event as a reasonable worst case possibility.
Since 1859 the reliance of the world on electrical power has increased
enormously. As a result, as the Met Office put it, "the potential
effects of space weather are growing rapidly in proportion to
our dependence on technology".
The impact of an event on the scale of the Carrington Event occurring
today would be huge; the US National Research Council estimated
the wider societal and economic costs of a severe geomagnetic
storm occurring today to be around $1-2 trillion.
21. The cause of the damage would be geomagnetically
induced currents (GICs). These are electric currents driven by
electric fields that are induced in the surface layers of the
Earth crust by rapid changes in the geomagnetic field (such as
those occurring during magnetic storms). These currents are most
evident in long metal structures, such as power grids, pipelines
and railway circuits, with earth connections to the surface layers,
so that currents can flow between the Earth and these structures.
Research Councils UK highlighted in particular the risk of GICs
causing damage to electrical grid transformers:
GICs pose a threat to electricity distribution grids
extending over long distances which can cause blackouts and damage.
Permanent damage to transformers caused by GIC is a major concern.
Transformers are costly, not available as "off-the-shelf"
items, and replacing one is a major exercise. The consequences
of a prolonged loss of electrical power are potentially catastrophic
as the infrastructures and services that modern developed societies
rely on are entirely dependent on electricity. Examples include
heating, lighting, refrigeration, communications, pumping of fuel,
water and sewage. 
22. The US National Academy of Sciences has estimated
that if a magnetic storm that occurred in May 1921 was repeated
today then 130 million people in the US would lose their electricity
and more than 350 transformers would be at risk of permanent damage.
Avi Schnurr, Chair of the EIS Council added that the Federal Energy
Regulatory Commission (FERC) had estimated that the duration of
the impact would be five to 10 years.
He thought it would be fair to say that the conclusions about
the UK would not be better.
23. While experience of, and forecasts about
the likely impact of, severe space weather on the USA, are relevant,
it cannot automatically be assumed that the effect of the UK would
be the same. FERC wrote "while the threats posed by EMP and
the vulnerabilities of electrical infrastructure to EMP are not
unique to the US, differences between the US and UK power grids
should be considered when reviewing the applicability of these
responses to the UK".
Chris Train of National Grid thought that the consequences in
the UK would be less because the UK infrastructure was differently
We have been working along with our partnersthe
BGS and Manchester University and otherslooking at what
the potential impacts would be here in the UK.
Because of the meshed infrastructure here in the
UK, we believe that the impact would not be as great here. The
effort that we have been putting in has been around operation
mitigations following a coronal mass ejection to understand how
we might manage the system to minimise the impact of the potential
in such an event. But I do not think that it would have the same
catastrophic cascading effect that would happen in the United
States because of the different nature of the configuration and
development of the networks.
24. In response to Chris Train, Avi Schnurr made
clear that he thought that the National Grid assessment was, for
a variety of reasons, too optimistic.
Both witnesses did, however, agree that there was more work to
be done on the modelling.
25. National Grid, while noting that contingency
plans were in place to react to damage, admitted that in the event
of an extremely severe storm, long-term blackouts could be a possibility:
If all transformers at a node are damaged then, depending
on the location of the node within the network, this could result
in a local area being disconnected until replacement transformers
could be installed. Replacing a transformer can take two or more
months depending on the availability and location of spares. In
this extreme event scenario National Grid estimates that the probability
there would be a disconnection event is 62% for England and Wales
and 91% for GB as a whole.
26. If, as might be expected, several countries
were affected simultaneously and needed new transformers, this
would, presumably, affect the availability of spares and hence
extend the delay in restoring power supplies.
27. As noted by several commentators, including
Research Councils UK, modern developments in technology have actually
led to greater vulnerability to the effects of space weather,
as microchips become smaller and more advanced. This is a particular
hazard for satellites which are exposed to the greatest effects
of space weather.
28. The risks posed by space
weather are known and significant, though there is argument about
the likely extent of their impact: a severe event could potentially
have serious impacts upon UK infrastructure and society more widely.
It is essential that this hazard is sufficiently recognised and
addressed by the Government and relevant civil bodies.
29. We recommend that work proceed
as a matter of urgency to identify how seriously a future Carrington
event would affect the UK infrastructure. It is clear that more
modelling is required to establish the likely effect of a major
space weather event on the National Grid. This should be independently
validated and compared with the results of observations of Grid
behaviour during space weather events.
High Altitude Nuclear EMP Weapons
30. Space weather events have always been with
us, though their likely effects have become more significant as
technology advances. A newer threat, though one which has been
the subject, until recently, of more research, is the possibility
of deliberate attack, perhaps with little or no warning. A single
nuclear weapon detonated between 25-500 miles above the Earth
could create an electromagnetic pulse (EMP) - i.e. a high density
electrical field-- with the potential to cause severe damage to
technology over a wide geographical area, the area depending on
the height of the detonation.
31. The effect of such a high-altitude nuclear
EMP (HEMP) burst would not be identical to those of severe space
weather because it would create a series of electromagnetic "waveforms"
that each has a slightly different effect on Earth. The overall
effect, however, would be similar in nature to the effects of
naturally occurring space weather, but faster and more intense,
which makes HEMP potentially highly destructive.
THE EMP COMPONENTS
- "E1" or "Fast"
component occurs within a few billionths of a second of detonation.
It produces a very brief but intense electromagnetic field that
can induce very high voltages in electrical conductors. Unlike
naturally occurring geomagnetic storms, which pose the greatest
risk to long electrical conductors like power line transformers,
this effect has the power to disrupt or damage micro-electronic
systems, electronics-based control systems, sensors, communication
systems, protective systems, computers and similar devices. Damage
and disruption could occur almost simultaneously over a very large
- "E2" covers roughly the same geographic
area as the first component and is similar to lightning in its
effect, though far more geographically widespread and somewhat
lower in amplitude. In itself this component would not be an issue
for critical infrastructure systems since they have existing protective
measures for defence against lightning strikes. The most significant
risk derives from the fact that this component follows a small
fraction of a second after the first (E1) component, which may
have already impaired or destroyed protective and control features.
The energy associated with the second component therefore may
be allowed to pass into and damage systems.
- "E3", or "slow" component
is a slower-rising, longer-duration pulse that creates disruptive
currents in long electricity transmission lines, similar in effect
to that of a severe geomagnetic storm.
32. The sequence of E1, E2, and E3 components
of EMP is important because each can cause damage which can allow
subsequent components to cause greater damage than they might
independently. The combined effect of a nuclear EMP is therefore
very difficult to mitigate,
and witnesses agreed that such an event would be "a different
kettle of fish" from a Carrington-sized event, and a "truly
33. In July 1962, the United States conducted
an experiment with the detonation of a 1.4 megaton nuclear weapon
(Starfish Prime) 250 miles above the Pacific Ocean, around 900
miles from Hawaii. The effect of this explosion was the generation
of an electromagnetic pulse that was far larger than expected.
The EMP caused damage to electrical equipment in Hawaii, knocking
out streetlights, setting off fire alarms and damaging telephone
equipment. There were also visible auroras in the sky following
the detonation. In 1962, the Soviet Union also performed a series
of three high-altitude nuclear tests in space over Kazakhstan.
The weapons used were smaller than that of the US's Starfish Prime
test, but the EMP effects were reportedly more significant, as
the detonations occurred over a populated area. While there is
little information available about these tests at least in the
public domain, what there is suggests . that there was significant
damage to telephone wires and power cables.
POTENTIAL IMPACT ON ELECTRONIC INFRASTRUCTURE
34. An EMP Commission was established in the
United States in 2001 to look expressly at the potential impact
of a high altitude EMP attack on key US infrastructure. It published
a preliminary report in 2004 which established the nature of the
threat being faced, followed by a final report in 2008 which went
into much greater detail as to the potential impact on critical
national infrastructures and recommended courses of action to
address the threat. Its overall conclusions were that US society
is vulnerable to an EMP attack, the consequences of which might
be long-term, widespread and catastrophic, and because of the
interdependency of the systems which are likely to be affected,
the current recovery plans may be of little value.
35. National Grid's written evidence reiterated
the concerns of the EMP Commission:
The effect of E1 and E3 pulses from HEMP would be
considerably more extreme [than space weather events]. For these
effects we have no practical experience to fall back on, although
the Commission to Assess the Threat to the United States from
EMP Attack did conduct a number of experiments on E1 and its effect
on SCADA. They concluded that "Large-Scale load losses in
excess of 10% are likely at EMP threat levels" and that "widespread
collapse of the electrical power system [...] is virtually inevitable.
36. While the probability of a HEMP attack is
judged by the Government to be low, it is accepted that its impact
would be high, and in view of this the Government includes it
in the second tier of priorities for UK national security.
37. The Government does not differentiate in
its risk assessment between HEMP and other elements of a nuclear
The National Security Strategy and National Security
Risk Assessment assessed the risk from a nuclear attack and thus
HEMP, as part of the risk of an attack on the UK by another state
or proxy using CBRN (chemical, biological, radiological and nuclear)
weapons. This risk was judged to be low likelihood but in view
of the impact, to be considered in the second tier of priorities
for UK National Security.
It views the threat as potential rather than actual.
Currently no state has both the intent to
threaten our vital interests and the capability to do so
with nuclear weapons. MOD's view is that over the next decade,
existing space launch vehicle technology could theoretically be
adapted by states to deliver a nuclear device; however, the
MOD does not currently see the UK or Western Europe as a target
for such an EMP attack. MOD does not believe that any non-state
actors can currently produce improvised nuclear devices and none
are likely to be able to make a sufficiently robust warhead for
missile delivery in the foreseeable future.
To generate more widespread damage from EMP, a nuclear
warhead would have to be detonated at high altitude to generate
the EMP from the interaction between the radiation from the weapon
and the outer layers of the atmosphere. This could only be achieved
by launching a device by missile to an altitude of several tens
of kilometres. A limited number of States possess this capability.
38. The US EMP Commission found that some "rogue
states", including Iran and North Korea, are aware of the
potential of such an attack. Iran, in particular, is reported
to have been conducting what appear to be missile tests to simulate
a nuclear EMP strike.
According to US Senate testimony,
an Iranian military journal
publicly discussed using EMP against the West: 
Once you confuse the enemy communication network
] you will, in effect, disrupt all the affairs of that
country. If the world's industrial countries fail to devise effective
ways to defend themselves against dangerous electronic assaults
then they will disintegrate within a few years.
39. We asked Avi Schnurr if Iran had the capability
to launch a weapon to an altitude of several tens of kilometres.
He replied that there was a serious risk that rogue states and
nations, some of which already possessed the launch capacity,
would acquire the necessary weapons:
There are only two things that stand right now between
usby "us" I mean the United Kingdom, the United
States and other alliesand having this level of catastrophe.
One is that although they have the ships and the missiles, terrorists
groups and rogue nations do not today, necessarily, have access
to nuclear weapons. That is a very thin boundary, because, for
example, North Korea has nuclear weapons. Could North Korea sell
its nuclear weapons? Could there be destabilisation in a state
that has nuclear weapons? I could name a few. Those are things
that could happen in the future. The other thin boundary is will.
We are dependent on keeping any warhead of any size out of the
hands of transnational terrorists or rogue nations and on their
good will if they acquire them.
40. We asked the Ministry of Defence if Iran
could launch a missile from a ship. Following a rather confusing
exchange, we asked
for written clarification. They explained:
A number of elements are required to enable a state
or non-state actor to successfully launch a nuclear EMP attack:
A delivery system capable of adequate range
and altitude, with the capacity to carry a significant payload.
A ballistic missile is, therefore, the most likely delivery system
and, given the weight of a HEMP device, it must be capable of
carrying a payload significantly heavier than a high explosive
A nuclear device is also required to deliver
a HEMP. Successful uranium enrichment and sophisticated weapons
engineering are required to manufacture a viable nuclear device.
To be delivered at high altitude to generate a HEMP, the nuclear
device must also be ruggedised sufficiently to withstand: the
harsh conditions of launch; the high velocity journey through
the atmosphere and into space; and, perhaps, depending on where
on the flight path the nuclear device is detonated, a period of
As well as manufacturing a robust nuclear device,
it must then be successfully integrated into the ballistic
missile to create a weapon system.
The development of all these elements is technically
very challenging and expensive, with progress likely to be made
in small incremental steps over a period of many years, and we
judge this to be within the grasp of only a limited number of
41. Consistent with its view of the threat of
an HEMP attack as potential rather than actual, the policy of
the Government is to try to ensure that no attack occurs. David
We are very much focused on trying to ensure that
that event does not occur in the first place, which is all about
counter-proliferation action to prevent the acquisition of nuclear
weapons or ballistic missile capabilities. Deterrent capability
is one of the areas that we make absolutely certain is protected
against EMP, in terms of our ability then to retaliate against
such an aggressive act.
42. On the basis of the evidence
received, it seems likely that at present only those states with
a known nuclear capability would be able to utilise an HEMP weapon.
However, certain states such as Iran could potentially pose a
realistic threat in the future, even if it does not currently
do so, if nuclear non-proliferation efforts are not successful.
Non-state actors could also pose a threat. While the risk may
at present be low, the potential impact of such a weapon could
be devastating and long-lasting for UK infrastructure. The Government
cannot therefore be complacent about this threat and must keep
its assessment of the risk under review. It is therefore vitally
important that the work of hardening UK infrastructure is begun
now and carried out as a matter of urgency.
43. It is also possible to build non-nuclear
devices which can disrupt electronic systems, though so far only
over a limited area. The Chair of the US EMP Commission wrote:
Non-nuclear EMP weapons, like radiofrequency weapons,
can damage and destroy electronics locally. Such weapons have
short ranges, kilometers for some military systems to meters for
devices improvised by terrorists or criminals. Industrial EMP
simulators, intended to test commercial systems for hardness against
interference from stray electronic and radio emissions, are on
the open market and can be purchased by anyone. At least one such
EMP simulator is designed to look like a suitcase, can be operated
by an individual, and is powerful enough to damage or destroy
the electronic controls that regulate the operation of transformers
and other components of the power grid. Armed with such a device,
and with some knowledge about the electric grid, a terrorist or
lunatic could blackout a city.
44. Avi Schnurr said:
The biggest issue with non-nuclear EMP weapons is
that the complexity and threshold required to produce them is
minimal, to say the most. At the summit meeting in Washington
DC, for example, there were two Assistant Secretaries of Defence,
a Deputy Under-Secretary and the Pentagon's chief lawyer, all
of whom expressed grave concerns over this riskthe non-nuclear
EMP risk in particular, but the risk of EMP in general. The non-nuclear
EMP risk is much shorter-range. However, that range, which could
be 100 metres, a fraction of a kilometre or a kilometreunder
certain circumstances, which I could discuss separately, it could
be multiple kilometresincludes the risk of having a field
strength that would be even greater, although limited in extent,
than a nuclear EMP [...]. We had a speaker at that summit who
described, to the extent he was allowed to describe it, a device
that he built from hardware he acquired from retail stores in
the United States, which he had built into a van.
45. A number of nations are thought to be undertaking
research into the development of non-nuclear EMP attack weapons,
but the Government does not currently regard them as a serious
risk. Nick Harvey
said "it is certainly considered a potential threat. It is
not considered a particularly likely one, certainly in the foreseeable
future; but we keep that constantly under review. It is a material
risk that we need to consider, but we do not think there is any
imminent likelihood or threat from it".
46. While in the UK material relating to non-nuclear
EMP is highly classified, other nations, particularly in the EU,
are apparently much more open about devices in existence and in
development. We asked the MoD why the UK kept information about
non-nuclear EMP under a higher security classification than did
other countries, and whether this affected its ability to share
best practice with allies. The response was:
We collaborate with our allies on non-nuclear EMP
effects, including research and development into countermeasures,
through the NATO research and technology organisation which has
a working group looking at those issuesso that is quite
a close linkage.
In terms of classification, there is quite a bit
of material on the internet. We routinely monitor that and assess
it. Some of the devices are potentially viable; some are not.
Most of them are rather short-range; for instance, with modified
microwave sources, you are talking about ranges in the category
of hundreds of metres. We keep an eye on those threats. Is it
classified? There are some classified areas. We do not want to
share our view on what viable devices might be at the high end
of non-nuclear EMP, so we protect that very sensitive area, because
we do not wish to see further proliferation of those competent
devices. That is the classification reason.
47. While existing non-nuclear
EMP devices may be crude and limited, the fact that viable devices
could be produced by non-state actors is a cause for concern.
Even localised damage could have the potential to disrupt activity,
especially if combined with other forms of attack.
6 "A Super Solar Flare", NASA Science
News, 6 May 2008, science.nasa.gov/science-news/science-at-nasa Back
Severe Space Weather Events - Understanding Societal and Economic
Ev 22 Back
Ev 46 Back
Ev 30 Back
Q 17 Back
Ev 50 Back
Severe Space Weather Events - Understanding Societal and Economic
Impacts, p 4 Back
Ev 25-26 Back
Severe Space Weather Events - Understanding Societal and Economic
Impacts, p 3 Back
Q 3 Back
Ev 48 Back
Q 4 Back
Ev 41 Back
Q 5 Back
Ev 26 Back
Report of the Commission to Assess the Threat to the United
States from Electromagnetic Pulse (EMP) Attack, Volume 1: Executive
Report, 2004, p 5 Back
Ibid., pp 5-7 Back
Q 90 Back
Report of the Commission to Assess the Threat to the United
States from Electromagnetic Pulse (EMP) Attack, Volume 1,
preface vi-vii Back
Ev 27 Back
Ev 52 Back
"Global Single Point Failure: The EMP threat", the
EMP Awareness Coordination Taskforce (EMPACT), 2009 Back
Statement from Dr. Peter Vincent Pry, EMP Commission Staff, before
the United States Senate Subcommittee on Terrorism, Technology
and Homeland Security, March 8, 2005: Foreign Views
of Electromagnetic Pulse (EMP) Attack Back
"Electronics to determine the fate of future wars,"
Nashriyeh-e Siasi Nezami, December 1998-January 1999 Back
Q 29 Back
Q 41 Back
Ev 51-52 Back
Q 90 Back
Ev 54 Back
Q 33 Back
Ev 20 Back
Q 72 Back
Q 111 Back