When talk of global warming first started, many people welcomed it, thinking that it would mean warmer winters and longer, pleasantly hotter summers.

When the variable nature of global warming became apparent, scientists started calling it climate change. Now they are starting to call it "climate weirding", which is an alarming step indeed.

The ice and snow storms currently affecting half of the US are attributed to the polar vortex, a prevailing wind pattern that circles the Arctic, flowing from west to east all the way around the Earth. It normally keeps extremely cold air bottled up toward the North Pole.

Mark Fischetti, writing in Scientific American last month, says: "If the vortex weakens, it allows the cold air to pour down across Canada into the US, or down into eastern Europe.


"But why does the vortex weaken? Now it gets interesting. More Arctic sea ice is melting during the summer months. The more ice that melts, the more the Arctic ocean warms. The ocean radiates much of that excess heat back to the atmosphere in the following winter, which disrupts the polar vortex.

"Data taken over the past decade indicates that when a lot of Arctic sea-ice disappears in the summer, the vortex has a tendency to weaken over the subsequent winter, if related atmospheric conditions prevail over the northern Atlantic Ocean (see graph).

"Although the extent of the summer sea-ice varies from year to year, overall it has been disappearing to a notable degree since 2007 and it is forecast to vanish even further. This could mean more trouble for the polar vortex, and more frigid outbreaks - a seeming contradiction to "global warming" perhaps, but not for 'global weirding', also known as 'climate change'."

The Arctic is warming faster than the rest of the planet, almost twice the global average.

These events could give rise to the growth of glaciers in some areas, and increased warming in other areas - and it is this that gives rise to the term "climate weirding".

If you search the internet for news on climate, more and more you will find scientists using "may" when predicting future events.

In past ages, global warming and cooling took place over thousands of years. The present global warming has taken place over only around 200 years, so it is difficult to predict events from the previous records.

We have had 10,000 years of temperate climate, from about 9000 BC to 1800 AD. This was, scientists think, partly caused by the start of agriculture.

Whatever, it is now obvious that the balance of the earth's climate has been disrupted.

I, for one, wish that all people, governments, corporations and groups would adopt a strictly sustainable attitude to agriculture and the use of the Earth's resources.

My dears, hold on to your hats, you ain't seen nothin' yet ...

Sara Dickon is a founder member of Sustainable Whanganui; a member of the Environment Standing Committee NCWNZ; and a committee member of UNANZ, Wanganui branch