Gareth wrote:
> On Feb 8, 7:07 pm, James Annan <[EMAIL PROTECTED]> wrote:
>> What adaptation do you think is required?
>>
>> As Michael says, there isn't really much preparation to do. Few
>> decisions need to be taken more than a decade out and those that do,
>> there are probably much larger uncertainties than climate change anyway.
>
> It's more about giving ourselves the tools to enable adaptation. If we
> can make multi-year forecasts of climate excursions, they become
> relevant for all sorts of short-term adaptation. In the case of
> Australia, if models suggested prolonged drought in a given area, then
> early steps to save water might prevent severe hardship later.
> Equally, it might help to prevent government compensating farmers for
> drought losses when it might be better to assist them to move to other
> land uses.
>
> The primary early adaptation I see is agricultural. It doesn't take
> big shifts in climate to change the economics of crop yield/quality.
> Winter chilling is important to fruit set in many crops - reduce it,
> and you reduce growers income directly. And it doesn't have to a
> permanent shift: a change from one year in ten with poor fruit set to
> four in ten might be enough to make growing that crop uneconomic. With
> grapes, for example, excessive summer heat changes wine quality
> markedly for the worse (unless you like drinking alcoholic jam).
OK, but this is more a question of adapting to the existing climate, as
preparing for 20 years hence. Crops are grown on an annual cycle,
machinery only last a few years (in fact astonishingly little time on
efficient agribusiness, as reliability and peak performance are critical
factors).
I can see how it could add a bit of impetus to (eg) relocation rather
than compensation for losses, if it was thought that the losses were
going to mount rather than just being a one-off. But still, there are
few government policies that last more than 5 years and the trend in
climate change is really very small over that sort of time scale.
[To be clear, I'm talking not about pushing seasonal forecasting up to
the 5 year time scale, but more like interpolating the 100 year climate
change scenarios down to perhaps 20 years.]
>>> I don't want to downplay it too much - in fact it's an area I'm
>> increasingly interested in for a number of reasons
>
> What are those reasons, James?
>
Partly because I can expect to see if I'm right (which should keep my
honest).
Partly because it's a short enough time scale that there is some
prospect of testing techniques with forecast/validation cycles over
recent history.
Partly because it may have value for some practical decisions (although
not a huge amount).
Partly because it's not been done very well yet.
The papers I alluded to earlier present 90% confidence intervals of
0.3-1.3C and 0.5-1.1C over the 30 year interval 1990s-2020s. That is,
they are centred on 0.8C in 30 years, which I (and indeed the IPCC)
think is unreasonably high - there is no sign of such acceleration yet,
and I don't think a single AOGCM from the IPCC behaves in such a way.
They also give no regional information. Ie, there is room for
improvement here...
James
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