General · 7th September 2010
Whether to mention the weather is an odd uncertainty given that weather is a nearly compulsive subject of conversation these days. But people don't really want to give it serious attention. So they discuss it superficially. Yes, it's been very hot and dry lately. Yes, it was cold. Yes, it was rainy. Yes, it's been quite unusual. So the weather is dismissed as a passing and innocuous anomaly.
But the dismissal is more of an evasion than a conviction, like an awkward moment when shared desires are recognized but not explored. So most people are uncertain what to say when the platitudes seem so inadequate. "Unusual" is too vague. "Scary" is too extreme. And anything else is too definitive. By common agreement, the unspoken strategy is don't say too much, don't speculate, don't jump to conclusions and don't think about the future.
Predictability, of course, is the difference between weather and climate. For any given day or week, weather variability can be so fickle that the best of forecasting can't predict it. But climate is different. It has general characteristics that make predictability relatively reliable – we may never be entirely confident about the Antarctica weather on any particular day but we can be almost certain that it is not a good place to grow palm trees.
Variability also answers the question of the climate change skeptics. "If global warming is occurring," they ask, "then why are some places getting colder weather?" Because weather can be more extreme while average temperatures continue to rise. This is why statistics on weather are more important than local anecdotal reports – specific locations can always furnish exceptions to a general trend.
This is precisely what has been happening during the last few months. Temperatures for Vancouver's Winter Olympics were 4-5°C above records set in 1937, and the warmest in 115 years. Then coastal British Columbia experienced an unusually cold April and May. Then June arrived, setting heat records and positioning the year to be the warmest yet recorded. More records were set when scorching heat arrived in July and August. July was a record dry month for BC. For the first time, serious forest fires threatened the province's northwest as well as its interior.
Alberta had its driest spring since the 1930s while Saskatchewan had its wettest in history – 200 mm in June, two-thirds of its annual quota in one month. An estimated 3 to 5 million hectares of Prairie fields were under water from the record rainfall and could not be planted. Production losses are about $3 billion. In contrast, last year the Prairies had one of its worst droughts. Climatologists are now advising farmers to expect a future of unpredictable weather.
Colder weather has also been common – 400 such records were set in the US in January alone – but the trend has been toward warming. Statistically, every measure of colder weather has a counterpart in twice as many examples of warmer weather – in the US in June, record highs were five times as frequent as record lows. The Canadian Arctic had an average spring temperature that was 6°C above normal, a measurement that Environment Canada officials described as "unprecedented" and "extraordinary".
On average, the Arctic has been 3°C warmer than pre-industrial levels while the planet is 0.8°C warmer. July was the second hottest month since humans have been recording temperatures, and 2010 is set to become the hottest year ever measured, without the assistance of a warm ocean cycle in 1977.
The heat brought droughts to Honduras and India. "Unprecedented" was again used to describe the dust storms from 100 km/h-plus winds that blanketed eastern Australia, fanning bush fires, cancelling flights and ferries, and slowing Sydney's traffic to a crawl – a "hell of earth, fire and wind" as one commentator described it. Southern China's longest drought in a century ended with torrential rains that washed away 64,000 homes and caused an estimated $2.4 billion in damage. Despite the drought, China is reporting a seven-fold increase in deluges. Brazil and France joined China in rainfalls that reached 500 mm in 24 hours. Manila, in the Philippines, flooded when it received 430 mm of rain in 12 hours. Turkey also suffered floods from torrential rains. Pakistan suffered the worst flooding in its 80 year history – horrendous damage with one-fifth of the country under water and 20 million people affected.
Meanwhile, Russia has experienced its worse drought since the 11th century. Temperatures stayed at 38-40°C for weeks, forest fires were unstoppable, many villages and uncounted homes were burned, peat bogs blazed, acrid air was killing 700 people per day, and wheat crops have been so damaged that food security has prompted Russia to curtail its exports this year. The economic damage is estimated at $15 billion.
Oxfam notes that weather-related disasters have quadrupled during the last two decades, from 120 per year to over 500. The number of people affected by these events has risen from 174 million to 254 million per year. Weather now accounts for 90 percent of human disasters.
Some climatologists speculate that 2010 might be a "Pearl Harbour" moment for global climate change. But, as everyone knows, weather is characteristically unpredictable, records are always being broken somewhere, and more people on the planet mean that larger numbers will be affected by unusual weather. Besides, a serious conversation about the weather might go beyond platitudes. And most people, it seems, are not yet ready for that conversation.