The flooding in Texas courtesy of Hurricane Harvey makes clear how powerless we are against the forces of nature. Also obvious is the fragility of our built environment, particularly in popular coastal areas.
At least 22 people have died and cost estimates already amount to tens of billions, with a full assessment still weeks and months away.
Reports and images from the area put in perspective the scale of natural disasters seen in this area – the flood in June was minor and isolated, as was a tornado that touched down earlier this month.
That’s not to downplay the impact on those affected, but we are lucky to be relatively free of major risks. We are far removed from the hurricanes – save for the occasional rain that pushes this far inland – earthquakes, mud/rock slides and even sweeping forest fires seen elsewhere. Tornadoes can and do happen, but with nothing like the frequency and intensity of the U.S. Plains, for instance. Nowhere near large bodies of water, we are unlikely to see the kind of flooding that seems to be increasingly commonplace.
In the case of Houston, what’s going on there is unprecedented in size, but represents the third straight year the area has been hit by a 500-year flood. The odds for such storm/rainfall events are deemed to be 0.2 per cent in any given year, thus the 500-year moniker. Whether the last few years are a statistical anomaly or an indication that there’s more to come remains to be seen.
Still, it’s a troubling trend, as extreme weather is in evidence globally. The June 23 flooding in Woolwich, though fairly limited, was the result of a very heavy – and very much unexpected – rainfall that hit the northern part of the Grand River watershed, wreaking havoc downstream. The tornado, too, was the result of a quick-developing storm cell, providing little warning. Similar examples abound worldwide.
We’re not to confuse today’s weather with the big picture of climate, but every anomaly adds to the evidence.
If climate models are on target, we can expect more extreme weather days ahead, even putting aside the human contribution to global warming/climate change.
These changes would significantly decrease the duration of the annual snow season and lengthen the growing season. They could increase the frequency and severity of extreme heat events in summer.
If the models hold, we can expect more than just rising temperatures. Greater impacts could include changes in precipitation patterns, in soil moisture, and possibly in the frequency and intensity of severe weather events.
Such extremes would have consequences for the property insurance industry and possibly for disaster-relief agencies. Health impacts could affect the insurance and pension industries.
Additional damage to forest ecosystems by pests and diseases, and increased frequency and intensity of fires may occur. Species currently threatened with extinction face the greatest risk of fading away in a changing climate.
Ontario falls prey to a number of natural hazards: drought, heat waves, floods, rain, snow and ice storms, tornadoes and even hurricanes, although they’re rare. Small changes in average climate conditions are expected to generate significant changes in extreme events.
From very local flooding such as June’s event in West Montrose and Conestogo to the devastation of Harvey, Katrina and Sandy, it’s likely we can expect more such new flashes.