"Alan Murphy" wrote:

....
The work of Lorenz on the
chaotic nature of weather was to suggest that very small
changes in the initial conditions of a chaotic system could cause
huge and unpredictable variations on the final outcome. Amazing
that his work has fallen out of fashion so quickly :-)

I think perhaps we're getting mixed up here between weather and climate (I
know that's a bit of a cliché now). When Krakatoa and to a lesser extent,
Pinatubo, had a detectable cooling effect on the planet for several years,
that was a change in climate (albeit relatively short-lived).

The work of Lorenz you refer to is probably more to do with the chaotic
nature of day-to-day weather, popularised by the term 'butterfly effect'.
On the basis of the extreme sensitivity to initial conditions that you
mentioned, a nuclear explosion in one part of the world could conceivably
result in a storm somewhere else that wouldn't otherwise have happened, but
that's still just weather.

I'm not sure that long-term climate is chaotic in the same kind of way - I
think it's more deterministic, which is why scientists can make projections
of climate climate 50 or 100 years away, but weather forecasts are limited
to a few days. The beat of a butterfly's wing might change the weather but
it won't change the climate.

That's how I understand it, anyway.