[ExI] Comment for Scientific American

[Keith Henson]

I wrote this as a comment to "Climate Model Shows Limits of Global
Pollution Pledges" on the Scientific American web site.

Alas, the comment system seems to be down.

If anyone sees a good place to post it, welcome to use some or all of it.

Keith

Why is it so hard to get agreement about cutting CO2?  The
consequences of not doing so are clearly bad.  We expect weather
disruptions and rising sea level to cause awful problems in the
future.  But those problems are in the relatively long-term future.
Sharply reducing the CO2 output will cause huge problems in the
near-term future.  Reducing CO2 emissions will cause the cost of
energy to rise, and anyone who remembers 1974 knows what that does to
the economy.  Governments are not going to cause their economies to
crash in the short term to cope with a long term problem.  Most of the
people who are in power today count on being gone to the grave before
the "CO2 chickens” come home to roost.

So what could we do?  The only way that I can see that makes sense is
to find a cheaper replacement for fossil fuels.  The current
candidates--PV solar and wind--are too expensive, too limited or both.
They both require very expensive storage.

Nuclear is carbon free (more or less).  It won't last forever, but it
would be good for a number of decades to centuries.  If we can solve
the cancer problem (which seems likely) we can put up with an
occasional meltdown.  It takes about 15,000 one GW reactors to
displace fossil fuel.

Two ways (at least) might be able to get the cost of solar down.  One
of them is StratoSolar where you put the collectors on buoyant
platforms at 20 km and use massive weights (gravity storage) to supply
power at night.  That high, you never are troubled with clouds making
sunlight completely predictable.

The other is solar power satellites.  Invented in 1968, they have seen
a lot of study, but the economics just didn't work.  With recent
developments in low cost transport to LEO and low-cost, beamed-energy,
electric propulsion to GEO they could provide electricity about 25%
cheaper than coal.

It would take about 3000 five GW power plants in GEO to displace
fossil fuel with less expensive, abundant energy from space (and there
is room for a lot more).  On a fast track humans could be off fossil
fuel soon enough (early 2030s) to keep the temperature rise down.
Further, with oceans of cheap energy, we could take CO2 out of the
atmosphere to any level we want.

I am not particular as to which way we replace fossil fuel except that
it needs to be less expensive.  If there was a less expensive source
of energy, there would not be concerns or the need for international
agreements.  People would just quit using expensive fossil fuel and
switch without being forced.

Examining low-cost, no carbon energy solutions is not part of the
mandate of the IPCC.  Perhaps it should be.