What are the chances they'll increase the probability of an impact?

....not even Bruce Willis.

My radio station had a guy on talking about the dangers of EMP. A small(ish) nuclear devise blown up in our atmosphere could essentially knock out all of the electronics on the continent. This is projected to wipe out 90% of the population within 12 months.

I guess the good news is, this doesn't sound like any of the tribulation calamities.

A high-altitude nuclear detonation produces an immediate flux of gamma rays from the nuclear reactions within the device. These photons in turn produce high energy free electrons by Compton scattering at altitudes between (roughly) 20 and 40 km. These electrons are then trapped in the Earth’s magnetic field, giving rise to an oscillating electric current. This current is asymmetric in general and gives rise to a rapidly rising radiated electromagnetic field called an electromagnetic pulse (EMP). Because the electrons are trapped essentially simultaneously, a very large electromagnetic source radiates coherently.

The pulse can easily span continent-sized areas, and this radiation can affect systems on land, sea, and air. The first recorded EMP incident accompanied a high-altitude nuclear test over the South Pacific and resulted in power system failures as far away as Hawaii. A large device detonated at 400–500 km over Kansas would affect all of CONUS. The signal from such an event extends to the visual horizon as seen from the burst point.

90% is a very pessimistic estimate.

Read "One Second After" for a description of a post-EMP world.

That's the guy that was on, the author of "One Second After".

50% of the nuclear weapons used in war did not even hit their target cities. (The Nagasaki bomb missed the target by miles!) I doubt that AQ, the PLO or the NEA could do better than the US Army did in 1945 with regard to accuracy.

On the morning of August 9, 1945, the U.S. B-29 Superfortress Bockscar, flown by the crew of 393rd Squadron commander Major Charles W. Sweeney, carried the nuclear bomb code-named "Fat Man", with Kokura as the primary target and Nagasaki the secondary target. The mission plan for the second attack was nearly identical to that of the Hiroshima mission, with two B-29s flying an hour ahead as weather scouts and two additional B-29s in Sweeney's flight for instrumentation and photographic support of the mission. Sweeney took off with his weapon already armed but with the electrical safety plugs still engaged.
Observers aboard the weather planes reported both targets clear. When Sweeney's aircraft arrived at the assembly point for his flight off the coast of Japan, the third plane, Big Stink, flown by the group's Operations Officer, Lt. Col. James I. Hopkins, Jr. failed to make the rendezvous. Bockscar and the instrumentation plane circled for 40 minutes without locating Hopkins. Already 30 minutes behind schedule, Sweeney decided to fly on without Hopkins.

By the time they reached Kokura a half hour later, a 70% cloud cover had obscured the city, prohibiting the visual attack required by orders. After three runs over the city, and with fuel running low because a transfer pump on a reserve tank had failed before take-off, they headed for their secondary target, Nagasaki. Fuel consumption calculations made en route indicated that Bockscar had insufficient fuel to reach Iwo Jima and would be forced to divert to Okinawa. After initially deciding that if Nagasaki were obscured on their arrival the crew would carry the bomb to Okinawa and dispose of it in the ocean if necessary, the weaponeer Navy Commander Frederick Ashworth decided that a radar approach would be used if the target was obscured.

At about 07:50 Japanese time, an air raid alert was sounded in Nagasaki, but the "all clear" signal was given at 08:30. When only two B-29 Superfortresses were sighted at 10:53, the Japanese apparently assumed that the planes were only on reconnaissance and no further alarm was given.

…

At 11:01, a last minute break in the clouds over Nagasaki allowed Bockscar's bombardier, Captain Kermit Beahan, to visually sight the target as ordered. The "Fat Man" weapon, containing a core of ~6.4 kg (14.1 lbs.) of plutonium-239, was dropped over the city's industrial valley. It exploded 43 seconds later at 469 meters (1,540 ft) above the ground exactly halfway between the Mitsubishi Steel and Arms Works in the south and the Mitsubishi-Urakami Ordnance Works (Torpedo Works) in the north. This was nearly 3 kilometers (2 mi) northwest of the planned hypocenter; the blast was confined to the Urakami Valley and a major portion of the city was protected by the intervening hills. The resulting explosion had a blast yield equivalent to 21 kilotons of TNT (88 TJ). The explosion generated heat estimated at 3,900 degrees Celsius (4,200 K, 7,000 °F) and winds that were estimated at 1005 km/h (624 mph).

Casualty estimates for immediate deaths range from 40,000 to 75,000. Total deaths by the end of 1945 may have reached 80,000.

I played the "home game" in the 1980's in Grenada and Beirut, as a Marine.

;-)

So was Nagasaki hit or missed by an atomic bomb in 1945?

It seems the answer was both.
[snip]
Looking at the BDA photos at the link, I’m not sure that I’d call it a complete miss: