Suddenly the apocalyptic version of science fiction where the machines start breaking down and there is nobody left who can fix them is looking just a teeny bit more plausible. An out-of-control-reactor has the effect of concentrating the mind, and freaking it out.
On the plus side, you have real heroes risking their lives and health to wrestle the thing back to stability. On the other hand you have authorities saying oops, we didn’t think of that. You have aging, dangerous technology. And a natural tendency to let things slide. Throw in a new now-near-complete dependency on an interconnected computer system that is still pretty new and not in the aging-infrastructure category, YET. And for extra credit, the thought that when the international network of computers breaks down, the response will be something like your emergency call to the office IT department.
Okay, and now just to complete the nightmare fantasy, throw in a social breakdown caused by food and/or fuel shortages. Just look what a bit of food cost inflation has done in the Mideast.
Now imagine what a five-year drought that cuts worldwide food production by a third might look like in this mix. Now what could cause such an unprecedented climate shift as THAT, you might ask....