Long-term averages are sometimes far easier to predict that short-term
events.

Flip an honest coin once, twice, three times, four times, and you can't
predict with much certainty what pattern of heads and tails you'll get.


Flip an honest coin 1,000 times, however, and almost certainly you'll
get something like a 50/50 ratio of heads and tails -- not a perfect
match, but close.

I submit that predicting the weather and predicting the climate offer
an analogous situation. Predicting what the temperature will be
tomorrow or next week is really tough. But in many place, it's not
that difficult to predict that the average winter temperature will
hover between X and Y degress, and the average summer temperature will
hover between A and B degrees, which will be much higher.

It's that kind of long-term average projection that the global climate
modelers are working with. Some of them will admit that in truth,
global climate and weather patters are really, really complex, and that
the earliest computer models had large blind spots in terms of dealing
with various climate factors (especially the effects of clouds) in any
detail.

However, the climate models keep improving and getting more
sophisticated, and there's a large amount of empirical research going
on in various places -- ice borings taken from Greenland and
Antarctica, probes for temperature and dissolved gas concentrations in
the oceans, observations about changes in the yearly migration patterns
of birds and the yearly blossoming times of plants, etc. -- that the
scientists are using to supplement the computer modeling.

It's that kind of computer modeling and research that the IPCC
researchers have relied on in making their predictions, I think. This
obviously doesn't guarantee that the IPCC is right in every one of its
findings. What possibly could? But we're not just talking about your
local weather reporter gauging an advancing cold front wrong and
falsing predicting scattered showers for Tuesday.

Because I'm something of a "true believer" on global climate, though I
admit I don't understand all of the research models in any kind of
detail, I'd like to add something about the original post in this
string.

And that is that the kinds of long-term, average projections that the
global climate modelers are making -- whether they're right or wrong --
are similar in a way to the average projections that the average farmer
has to make in deciding what to plant, and when, to produce crops
during the next growing season.

Ditto with the corporate planners with the big oil companies, or with
your local electric utility company, who need to make some kind of
guess about how much their customers will be running their furnaces in
December and their air conditioning units in August in order to make
some very practical business decisions regarding how much energy to
have on hand, and when.

Ditto for people who operate ski resorts; ditto for Florida hotel and
restuarant owners who have to have some idea of future weather and
climate patterns in order to prepare for the yearly tourist season.
And on and on.

The greenhouse skeptics can rightly point to crudities in the computer
models that have been used in the past to predict greenhouse-related
climate change, I think, and it's a fact that careful temperature
records using thermometers date back no more than 120 years or so in
the advanced industrialized West.

You can make an argument that we're having to make some guesses based
on information that may be somewhat shakier than we'd like it to be.
But all kinds of farmers, business people, and government planners
already are relying on climate guesswork of just this kind.

Predicting that the global climate won't change, based on 120 years'
worth of thermometer readings, is just as dicey as predicting that it
will. Predicting that the climate won't change based on the policy
preferences of the fossil fuel industry, which doesn't want to lose
sales and revenue because of global warming, is pretty stupid, because
if anyone has an obvious reason for skewing the climate science, the
fossil fuel people do.

When respected scientists associated with the IPCC proclaim that it's
time for people to get worried, then, and when year after year of
hotter-than-average weather seems to confirm the IPCC's scenario, I
think it makes sense to listen.