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Sunspots play a role in the weather

The speaker was looking out of the window at yet another bitterly cold spring day. He was implying that since the winter and spring that we had been enduring was so abnormally cold, global warming must therefore be the “myth” that the occasional climate science denier asserts it to be.

“. . . global warming b___s___” — Anonymous comment overheard at work a couple of months ago

The speaker was looking out of the window at yet another bitterly cold spring day.

He was implying that since the winter and spring that we had been enduring was so abnormally cold, global warming must therefore be the “myth” that the occasional climate science denier asserts it to be.

What the speaker didn’t seem to know was that there are many other factors that affect our weather besides carbon dioxide and methane.

The Jack Frost that was mostly to blame at that time was actually a “baby girl”.

In Spanish, it is known as “La Nina”, a pattern of colder weather due to a particular shift in the Pacific Ocean currents.

La Nina’s opposite is, of course, El Nino, or the “baby boy” (more precisely, the “Christ child”, since when the El Nino ocean current is active, it hits the Peruvian coast around Christmas time). El Nino is also a very strong weather force.

In 1998, it was responsible for the largest forest fire in Alberta’s history.

But we are now back in neutral territory, since La Nina lost most of her oomph back in April (though May and June have still seen a bit of a chilly hangover now and then).

The curious thing is the general silence in the media over it.

The only mention about it that I came across was by David Phillips (Senior Climatologist for Environment Canada) on the Weather Network.

The other cooling factor that had been affecting our weather related to an alarming lack of sunspots over the last year or so.

The media has been slightly more responsive on this one, as both Peter Mansbridge from the CBC and Bill Greenwood from the Advocate had brought up the subject.

Sunspot activity usually goes up and down on an eleven-year cycle. When there are a lot of sunspots, the planet heats up ever so slightly.

And when the sunspots disappear, things cool down.

The effect can be significant. The normal sunspot cycle tends to heat or cool the planet’s surface by about 0.1 per cent compared to the average energy the Earth receives from the sun. The absence of sunspots in the 1600s that Bill Greenwood wrote about lowered the sun’s energy by about 0.25 per cent.

On the warming side of things, greenhouse gases are heating the planet by about 0.2 per cent (when converted to the same radiative forcing measurements that are used to determine the effects of sunspot activity).

On the surface, it looks as though we may have more to fear from a potential cooling effect than a potential warming effect.

However, whereas La Nina’s and sunspots come and go (and in fact, the latter are now finally starting to appear again), greenhouse gases keep on building up in the atmosphere — and now at an accelerating rate.

Part of this is due to China and India aspiring to our middle-class lifestyle.

But what is truly scary are the various natural feedback effects that are starting to cause a runaway warming of the planet.

I have written about these feedback effects in previous columns, so if you’re still in the dark, just type “positive feedback” and “climate change” into a search engine.

But that’s in the long term. In the short term, our farmers in eastern Alberta could use some more heat and moisture.

The good news is that Environment Canada is forecasting above average precipitation and above average temperatures for the next three months.

The bad news is that it may already be too late for some crops.

As for global warming, we may be too late there also.

For that, we can thank the climate science deniers, since I fully expect that their forecasts will turn out to be about as accurate as Wall Street was on the economy.

Evan Bedford is a local environmentalist. Direct comments, questions and suggestions to wyddfa23@telus.net.