How "Space Weather" Could Knock Out Services Here On Earth and What Can Be Done to Prevent It

"There is no dispute that electric grids worldwide are vulnerable to potentially catastrophic damage from solar-generated EMP."

So said former Maryland Republican congressman and Howard University professor Roscoe Bartlett in 2011.  According to Britain's Daily Mail, an electromagnetic pulse (EMP) expelled from the Sun nearly slammed into Earth.  Humanity missed calamity by a narrow two weeks.

EMPs are accelerated and highly charged streams of particles.  They can come naturally from the Sun, or artificially from nuclear weapons blasts.  Such an explosion in the atmosphere could create an electromagnetic field that could fry unprotected electronics and electrical systems. 

According to the Heritage Foundation, "effectively, the U.S. would be thrown back to the pre-industrial age following a widespread EMP attack."  Presumably a natural EMP blast could produce similar effects.  A one in eight chance exists that Earth may suffer such an event by 2020.

Heritage in 2010 laid out suggested preparations to protect against EMPs

Step No. 1: Require the Director of National Intelligence (DNI) to Produce a National Intelligence Estimate (NIE) Describing Which Countries Are Capable of Launching an EMP Strike. The NIE should review not only the weapons systems themselves but the delivery systems and platforms capable of carrying the weapons. Additionally, Congress should obtain from the NIE the intelligence community’s assessment of how EMP-capable countries are incorporating those weapons into their broader military strategies.
The latter assessment would permit the President and his advisors to determine how the U.S. could respond to EMP threats as they arise. Such planning is an essential part of providing an effective defense against these threats.
Step No. 2: Press the Obama Administration to Prepare to Protect the Nation’s Cyber Infrastructure Against the Effects of EMP. Congress should direct the Department of Defense and the Department of Homeland Security to manage this effort, which should incorporate the recommendations of the commissions. For instance, the commission has determined that preparedness measures must account for the fact that the cyber infrastructure is quite dependent on the power grid. Thus, contingency planning must explore ways to keep the cyber system functioning without primary power.
Further, it recommends identifying the most critical elements of the cyber system that must survive an EMP attack. Finally, the commission recommends that preparedness planning account for the interdependency between the nation’s cyber infrastructure and other elements of the broader infrastructure. Overall, the key to preparing to counter the effects of EMP is to put barriers in place to prevent cascading failures in the nation’s infrastructure.
Step No. 3: Require the Navy to Develop a Test Program for Sea-Based Interceptors with the Capability to Intercept and Destroy Ballistic Missiles Carrying EMP Weapons Prior to Detonation. It is clear that ballistic missiles offer an ideal delivery system for an EMP weapon. For instance, an enemy of America could launch a short-range missile carrying an EMP weapon from a cargo ship off the U.S. coast. Clearly, the terminal-phase ballistic missile defense systems currently in the field or entering the field, such as the Patriot system and the Terminal High Altitude Area Defense system, will not reliably intercept such ballistic missiles prior to the detonation of an EMP warhead. The Standard Missile-3 Block IA (SM-3 Block IA), as a midcourse defense system, may be able to do so.
What the U.S. really needs to address this threat, however, is a version of the SM-3 that will intercept these kinds of missiles in the boost or ascent phase of flight. The Independent Working Group has recommended developing and fielding what it calls an “East Coast Missile Defense” to address this emerging threat.[3]
Accordingly, Congress should require the Navy to demonstrate the capability to produce new versions of the SM-3 interceptor that are capable of destroying a short-range missile in the boost or ascent phase of flight, prior to its reaching the preferred detonation points for an EMP warhead. This will require that Congress also provide the Navy with the funds necessary to undertake this test program.
If it chooses to do so, Congress could also direct the Air Force to undertake a companion program that would permit operational use of the Airborne Laser system to defend against an attack from a short-range missile.

EMPs have caused disruption before.  In 1989 they knocked out parts of Quebec's telephone infrastructure.  130 years prior, they interfered with telegraph operations not long after the invention of the device.