However, you can't make
a plausible prediction of future survival without an estimate of present population size: not even today's worst journalists would buy it, nor should they.
Without a successful validation procedure, no model should be considered to be capable of providing
a plausible prediction of future behaviour of the climate.
Not exact matches
The main reason climate models run into the
future are not really
predictions is that it is very expesnive to run each scenario, and so there are far too many
of them to run every
plausible case.
«As a process committed to acceptance
of deep uncertainties,» they say, «CIDA does not attempt to reduce uncertainties or make
predictions, but rather determine which decision options are robust to a variety
of plausible futures.»
This raises an interesting question, which is how should the IPCC (or anybody else for that matter) falsify hypothesis II and III, which although they are at least
plausible, make no testable
predictions, unlike hypothesis I. Has anybody made projections for
future climate with an unambiguous statement
of uncertainty that would allow the projections to be falisfied by the observations?
Therefore, the AASC recommends that policies related to long - term climate not be based on particular
predictions, but instead should focus on policy alternatives that make sense for a wide range
of plausible climatic conditions regardless
of future climate.
Many
of the
predictions end up spelling out Mad Max - ish scenarios for
of the country's
future that seems at once fantastic and uneasily
plausible.
More usefully in terms
of future predictions, a recent paper in PNAS by Van Vuuren and co-workers (including a friend
of mine, Tom Wigley, who is an Adjunct Professor at the University
of Adelaide), assessed the impact on climate change
of some
plausible real - world actions.