Thursday, January 21, 2016

More Heat, Less Ice

St. Nora Lake has frozen over, finally. The ice was five inches thick at the start of this week. Great news for the snowmobile crowd and winter anglers.

That’s the latest freeze-up in the 30 years that I have known the lake. If this winter continues to be relatively mild, breakup could come earlier than usual. The earliest ice off was a couple of years ago when blue water appeared the last week of March.

Later freezes and earlier openings are becoming more frequent for Haliburton County lakes and raise concerns about what is happening with the world’s climate.

New research indicates that freshwater lakes are warming at twice the rate of the oceans. They get warmer as the length of winter ice cover time gets shorter.

The consequences of warmer lakes are being seen already: the decline of native fish, the arrival of invasive species, more algae and other changes that bring problems. St. Nora was a great lake trout lake when I first saw it in 1985. Today it is considered a better bass lake.

More than three in four lakes above the 40th parallel (roughly the latitude of New York) have had summer temperatures rise 2.7 degrees Fahrenheit between 1985 and 2009. Some lake temperatures have risen more than twice that.

This information comes from a the Global Lake Temperature Collaboration, a new international research group. 

As of last week total ice cover on the Great Lakes was only 3.8 per cent. It was 22.5 per cent at the same time last year, 38.3 per cent in January, 2014.

The fastest warming Great Lake is Superior, which is 1,330 feet deep and holds 11 per cent of our world surface water supply. It has warmed 6.3 degrees Fahrenheit in the past 100 years. Most of the warming has occurred in the last 30 years.

Global warming non-believers say fluctuating temperatures and ice cover are normal and point to last year’s brutal winter. I remember it well – five consecutive mornings of minus 35 Celsius at St. Nora Lake. The previous year was no picnic either.

Temperatures do fluctuate but evidence continues to mount showing that the world is becoming seriously warmer.

Much the global warming focus has been on the Arctic where sea ice is becoming increasing thinner and younger. Air temperatures in the Arctic between October 2014 and September 2015 were more than three degrees above average in all seasons. The highest annual air temperature over land was plus 1.3 Celsius, the highest since 1900.

Land snow cover in the Arctic has decreased every year since 1979 and river discharges have increased during that time.

Looking at the weather forecast every day gives us an inaccurate picture of what is happening. For instance, the daily highs in Haliburton County for much of this week will be below the normal of minus five Celsius.

We consider that quite cold because the temperatures are below normal. However, that normal is based on records going back only 30 years to1985. If you looked at records going back 30 years before that, and even 30 years before 1955, you would find that the normals were much colder than now.

The world’s 20 warmest years recorded all have occurred since 1981. The 10 warmest years have occurred in the past 12 years.

The United Nations climate change conference in Paris last month agreed to do something to stop the rapid ice melt. The 196 nations at the conference accepted a 12-page document agreeing to reduce their carbon output "as soon as possible" and to do what they can to keep global warming "to well below 2 degrees C".

Don’t hold your breath. The Paris conference was all about politicians and bureaucrats.

Real change will come when citizens become alarmed by the mounting evidence, become willing to change lifestyles and demand that politicians take action.

Paris made enough noise around the world to create some hope that all that might begin to happen.

Here’s hoping. It’s nice to see St. Nora Lake open in December and March, but it’s not nice to think about the reasons why.


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