SPOILER: sent in by Steve H. who explains...
There are eight main characters in "State of Fear":
George Morton: An extremely rich philanthropist, placing most of his money toward environmental concerns. His pet charity is NERF, the National Environmental Resource Fund
Peter Evans: A young, gawky and oftentimes wussy lawyer for George Morton
Sarah Jones: George's attractive assistant and eventual love interest for Peter
Nick Drake: Head of NERF and key contact for George and Peter; Drake turns out to be a bad guy who's part of a global conspiracy to generate artificial weather-related disasters. These disasters are meant to stimulate awareness and interest in the Global Warming Catastrophe. To what end, the reader is not really sure. Does Drake really care about the environment that much and has gone off on the deep end? Or is he just trying to get a handle on all the donation funds that will roll in to NERF once the general populace panics over the abrupt climate changes going on?
Jimmy Bolden: A NERF henchman, out in the field, orchestrating the weathers of mass destruction
John Kenner: Mysterious know-it-all and seeming lone wolf in a crusade to stop NERF's nefarious activities, taking Sarah, Peter and Sanjong along for the ride
Sanjong Thapa: Kenner's dutiful assistant
Jennifer Haines: Kenner's niece and lawyer working on a NERF lawsuit; her role is one part anti-Global-Warming-evidence-provider and one part possible love interest for Peter
The relationship between George Morton and Nick Drake / NERF is a good one at the beginning of the book, until John Kenner comes along and fills Morton in on what NERF is really doing. Almost immediately after Morton halts his NERF funding following this news, he disappears when his car wrecks on a coastal California road, seemingly lost to the ocean currents. The reader is meant to think Morton's dead, but you never actually believe that given the absence of a body and the fact that Morton's assistant, Sarah Jones, a few weeks earlier, purchased a duplicate car of the one Morton supposedly crashed. Regardless, Kenner swoops in and takes Sarah, Peter Evans, and Sanjong off on a whirlwind adventure to stop NERF's four planned major disasters.
(Keep in mind that each...and...every...single...time the characters board an airplane during the rest of the book, they and the reader are treated to a discourse from Kenner on why Global Warming is load of nonsense. Though these conversations never seem to end, the evidence against Global Warming does seem reasonable.)
The first calamity involves the creation of a 100-mile wide iceberg from the detonation of a chain of explosives in Antarctica. In the process, Sarah and Peter get stuck by Jimmy Bolden in a gigantic ice crevice. The two just barely manage to scrape their way out and make it back to base, suffering cuts, bruises and frostbite. Kenner had gone out on his own and disabled key explosives, neutering this disaster.
Back in L.A., the foursome continue along their merry way, investigating this and that. In the process, Kenner and Sarah get caught in a giant lightning machine (used to test airplane parts) by Bolden. The two just barely manage to escape, with Sarah suffering burnt hair and partial nudity. (She has to take her clothes off so they don't get burnt while on her person.)
Off to disaster number two: flash flooding in the American Southwest. Bolden and his buddies fire up a pre-existing storm with a web of hundreds of rockets and wires. This amped-up storm creates flash floods that sweep through populated areas. Thanks to Kenner's forethought, the potential victims are warned in time and escape, but not before Sarah and Peter have their car struck by lightning several times (NERF can kind of control lightning strikes). Sarah manages to take a hit herself but survives (with lightning-induced scarring across her torso), thanks to Peter's CPR. The pair gets back in their SUV, only to wind up in a raging, flooded river that sweeps them along. The two just barely escape when the SUV lodges against a pile of debris before falling down a tremendous waterfall.
Disaster number three -- a NERF-directed hurricane -- never happens because the conditions aren't right. So Sarah is spared at least little bit of further bodily damage.
Somewhere around this point, Peter is ganged up on by a bunch of thugs in his apartment, who then paralyze Peter by (and I am not making this up) forcing a golf ball-sized octopus to bite him in the armpit. Peter is rescued, just in time, by Sarah. Peter recovers after a few hours in a local hospital.
The fourth disaster is an eerily coincidental, massive tsunami, originating in roughly the same area where the December 2004 tsunami struck in the real world; this time aimed toward the coast of California. Bolden and his friends plan to use "cavitators" on the coast of a key island to boil the earth, sending a massive landslide into the sea, helped along by another series of (submerged) explosive devices. Kenner takes along the same crew to this island, with the addition of an actor, Ted Bradley ("who used to play the President on TV"). Ted, a staunch but uninformed environmentalist, is along at Drake's behest to keep an eye on Kenner and crew. Jennifer Haines has also joined up.
In the course of trying to reach the cavitators on the coast, the group (less Sanjong) gets captured by sadistic, cannibal rebels. Though Bradley (and I am not making this up) gets sliced, diced, and eaten by the cannibals, the rest -- again -- just barely escape, this time with the help of the "surprise" appearance by George Morton, who apparently has been roaming the island over the past nine days since his car crash. Storming the coast, with an exchange of gunfire (Jennifer gets shot in the leg here and just barely survives), the team disables one or two of the cavitators. Peter tussles with Jimmy Bolden and Jimmy winds up underneath one of the cavitators and gets vaporized in a largely dissatisfying comeuppance. The explosions go off anyway (thanks to Sanjong's incompetence) and do trigger a tsunami, just not one big enough to harm the U.S. coast. At best, it turns into a wave about six feet high in some parts that gets American surfers excited.
The heroes fly back to the U.S., where Morton takes a turn at going on about the environment. This time he offers solutions on how to properly approach the problem of securing unbiased research. Morton announces that he's going to start up a new company to undertake this research and wants Sarah and Peter to run it.
Nothing happens to Drake and the book is done.
By the way, "State of Fear" is a phrase meant to capture the state the American public always needs to be in, in order for the government to have control over society. Before environmental concerns, the country was worried about communism and nuclear war. When the Berlin Wall fell in 1989, environmentalism rose to take its place. This fear, according to Crichton, is fed by the government, the media, and lawyers.