Post by Tony Cooper
I've lived in tornado- and hurricane-prone parts of the US, but
never where cyclones might be expected. I thought it was Kansas
where cyclones occur.
But, I'm currently being informed that the (US) East Coast can
expect "bomb cyclones". "Cyclone" is scary enough, but "bomb
cyclone" is enough to make you jump out of your ruby red slippers.
I've noticed that the current northern hemisphere freeze is bringing the
climate change deniers out in droves. "If it's that cold, then obviously
there isn't any global warming." They can't see the difference between
the global temperature rise and local coolings.
In their defence, I should see that it's not easy to see the connection.
Cold winters in Western Europe are easier to explain. That region relies
for its heating on a flow of warm water across the Atlantic. Melting
arctic ice is changing the salinity of the gulf stream, and that can
change the flow. If a tipping point is reached -- and everyone is hoping
it won't be -- then global warming could cause an ice age in Europe.
For North America, the critical factor seems to be the northern jet
stream. Warming in Alaska causes that boundary to move, meaning that a
lot of cold air gets dumped on regions further south. If the global
temperature rise can't be halted, then extreme winters could become a
regular feature in the US and Canada.
We don't seem to have those complications in the southern hemisphere,
apart from the problem of tropical storms moving further south. For us,
warming just means too much heat. Both our winters and summers are
getting hotter. Perhaps that's because there's no land, except in South
America, in the critical boundary zones.
Peter Moylan http://www.pmoylan.org
Newcastle, NSW, Australia