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Have you noticed the trees this year? The city's canopy of green appears fresh as springtime. Along with the luxurious plants tumbling out of their boxes and the improved air quality, the lush treetops are a happy consequence of what will most likely be Toronto's wettest summer on record.
As Environment Canada senior climatologist David Phillips reminds us, there's never been a wetter January-to-July period, and Toronto has already far surpassed precipitation for all of 2007. "My God, we have five months to go," says Phillips. There have been 674 millimetres of rain as of Friday morning, compared to a total of 592 in 2007.
The rain has not been constant, but unnervingly erratic, like a guest who can't make up his mind whether to go or stay. There's been rainfall, or at least traces of rain, on more than half the days (39 out of 69) since June 1. While this unpredictable summer has spoiled many a cottage weekend or planned outing to a local park (not to mention delaying building projects), it has also brought a miscellany of benefits:
Trees: Toronto trees are greener and less stressed this year, says Richard Ubbens, director of forestry for Toronto. "You see them framed against the sky and they look terrific."
There's lots of photosynthesis going on, he says. "So it means they are storing lots of sugar and starches in the root system. It bodes well for the forest." The rain is especially beneficial for the city's older trees, which are weaker and can succumb more readily to drought.
Lake levels: Up, up, up compared to the well-below-average levels of recent years. It's been a boon for shipping, recreational boaters and marinas. Shipping loads – cargo such as grain and iron ore – in the Great Lakes returned to normal this year after reduced capacity in 2007, when loads were 500 to 1,000 tonnes lighter, the Shipping Federation of Canada reports.
The relationship is sensitive: for every centimetre decline in water level, shipping loads are reduced by 50 tonnes. Lake Ontario water levels increased 33 centimetres over last year, and Lake Superior, 42.
Air Quality: The air is cleaner when pollutants – ground level ozone, nitrogen dioxide and fine particulate matter – are washed away by the rain and fresh breezes. In 2005, the worst on record, Toronto had 48 smog-warning days. By this time last year, Toronto had recorded 24 smog-advisory days. This year there have been just 10, according to Environment Canada.
Apples, Peaches, Pears: There's been great growth on fruit trees, as long as orchards haven't been in the path of hailstorms, which devastated this year's crop for some growers. The 2008 pear crop should be double last year's. Peaches and apples are expected to be larger than average this year because of abundant rain.
"But we've had enough," says Brian Gilroy, of Ontario Apple Growers. "It can stop. What we need now is a bit of heat and sunshine to raise the sugar levels in the fruit."
Apple trees in Simcoe have grown about a metre this season. "Tremendous, some of the greatest I've seen," says John Cline, associate professor of horticulture at the University of Guelph.
Irrigation: Fruit trees need about 25 millimetres of rain a week to thrive, and rain is more effective than the same amount of irrigation, Cline says. On cool, rainy days less moisture is lost through evaporation – it's generally hotter and dryer when irrigation is required.
Brenda Lammens, an asparagus grower in Norfolk County, says not having to irrigate has helped offset the increased cost of fuel. Lammens, chair of the Ontario Fruit and Vegetable Growers' Association, estimates that laying irrigation pipes and other costs involved could add 20 per cent to a farmer's expenses in a dry summer.
Forest Fires: This has been one of the lowest seasons in 50 years. There were 181 fires from April to August in Ontario this year, compared to 799 during the same period in 2007; 410 hectares have burned in 2008 compared to 40,000 hectares in 2007. However, there are some ecological benefits to forest fires, notes fire information officer Lindsay Munroe, of the Forest Fire Management Centre in Sudbury: a species like the Jack pine needs fire to open its cones and spread its seeds, and fire can stimulate new growth in tall-grass prairie and oak savannah areas while controlling invasive pests.
West Nile Virus: With the cooler temperatures linked to all the rain, the risk of the virus – transmitted by infected mosquitoes – is low this year, says Dr. Howard Shapiro, associate medical officer of health for Toronto. There have been no cases of West Nile in humans so far in 2008, no birds have tested positive, and only two samples of mosquitoes have tested positive.
Power: Each degree above 35°C can increase demand for electricity by 450 megawatts, the energy needed to illuminate 4.5 million incandescent light bulbs. Cloud cover can reduce demand by 1,000 MW – the energy to run 500,000 energy-efficient air conditioners. Peak demand for electricity in 2008 is 3,000 MW less than the peak demand in 2006, the Independent Electricity System Operator (which monitors electricity consumption) reports – that's about the electricity demand for a city twice the size of Mississauga. The wet weather – and more water in dams – has also contributed to increased production from Ontario's hydroelectric providers. Hydro production this May, June and July was 2.2 million megawatt-hours higher than the same three months in 2007. That's enough electricity to power a city 1.5 times the size of Barrie for a year.
Wildflowers: Wildflowers have evolved to cope with changes in moisture and sunlight in their native area, says Carole Ann Lacroix, a botanist and curator of the Ontario Agricultural College Herbarium in Guelph. Generally, they are tolerant and hardy. With lots of rain, it's been a good year for moisture-loving plants like ostrich ferns. But wild geranium and wild phlox, now in bloom, are also doing well, as are the purple-flowered New England astor and goldenrod. She's been digging them out of her garden, along with wild bergamot. "They are huge, producing as much seed as possible – they've been taking over and overshadowing a lot of other plants."
Gardeners: Joy all around. "The vegetables have done incredibly well," says Cathie Cox, director of horticulture at the Toronto Botanical Garden. "I have potatoes the size of my feet in my allotment garden." She notes vegetables that haven't traditionally done well in southern Ontario, such as broad beans, are thriving. At the botanical garden, the flowers are magnificent, she adds, and trees that appeared doomed have found new life. "We were considering replacing the Amur cork tree – it had dieback – but no matter how much you irrigate, it's not the same as a cleansing downpour."
