As Sudbury faces a hotter, drier future, we need planning policies that help to mitigate climate change, as well as adapt to the realities that the change in the weather will bring, says a Laurentian University scientist.
Dr. David Pearson, who prepared a report in November 2012 entitled Climate Change and Sudbury’s Official Plan, was reacting to similar report that will go to the city’s planning committee Feb. 25. Mitigating policies focus on such things as maximizing energy efficiency in new city buildings and building compact communities with strong public transportation systems.
“Cities can set an (energy-efficient) standard with their own buildings that act as a benchmark for the entire community,” he said. “We can be further ahead in planning than other cities or the province.”
For example, structures could be built to minimize heat loss through walls and incorporate solar energy and other renewable energy systems in their own buildings.
Such measures will help Sudbury prepare for weather that is forecast to be drier on the one hand, and more extreme on the other, according to a report prepared by the city’s planning staff.
“According to data published by the Ontario Centre for Climate Impacts and Adaptation Resources, Greater Sudbury’s climate has gotten warmer and wetter, with warmer and slightly drier summers and warmer and wetter winters, in the last 50 or so years,” the report reads.
Winter mean temperatures have already increased by 2.4 C since 1956, while summer mean temperatures have risen one degree at the same time. If current trends continue, Sudburians can expect winters to warm by another 3.4 C by 2050, with a five- to 10-per-cent reduction in the amount of rainfall we receive in winter and summer.
“Because (winters) are warmer, the precipitation itself will change with less snow and more rain/freezing rain,” the report reads. “It is also expected that we will see more frequent occurrences of extreme weather events.”
The consequences of the climate change will translate into a number of new challenges for Sudbury, including:
-Increased risk of drought, forest fires and insect outbreaks.
-Heat stress and extreme weather events affecting vulnerable groups; infectious diseases; and smog events.
-Floods and extreme rain events; fire frequency and duration due to droughts making residential areas more vulnerable; increased building maintenance costs; and, more frequent road and culvert repairs.
-Lower water levels and decreased water supply; changes in water quality; changes in lake ecosystems; impact on shoreline wetlands and other critical habitats; less hydropower production; and, impacts on recreational activities such as boating and fishing.
-Mining operations may be impacted by decreased water supply; forestry sector could be impacted by insect outbreaks; and, agriculture sector could be affected by droughts.
Despite the dire predictions, Pearson said Sudbury’s decades-old regreening programs are already helping us adapt to extreme weather events. For example, the barren rock along Martindale Road has been reclaimed and vegetation there plays a key role in keeping people safe.
“When severe rainstorm water fell on Martindale 40 years ago, that water rushed straight off into the street,” he said.
"But with the vegetation coming back, we have restored an ecosystem service. The trees and the vegetation soak up the water and prevent it from flooding Martindale. And it prevents it from rushing into Junction Creek and flooding homes downstream on Copper Street, for example."
When Sudbury was largely covered in barren rock, whenever there was a big rainstorm, large amounts of soil would get washed into area lakes because there was little vegetation to absorb it. That led to frequent flooding downtown in the 1930s and 1940s.
“The soils that were washed off the slopes is all sitting in Kelly Lake — tens of thousands of tonnes of it is sitting at the bottom of the lake.”
And it’s essential to make that connection in planning policies, he said, because protecting water quality is more than just making sure no one dumps toxins in the lake. Protecting vegetation around the lake – especially within 10 metres of the shore – ensures that when it rains, the runoff into the lake isn’t full of the sorts of nutrients that cause blue-green algal blooms.
Since we know that in the future, there will be more evaporation and area lakes will be warmer, the water will be particularly prone to the toxic blooms. And for a lake that provides drinking water such as Ramsey, the effects could be disastrous.
“Fifty thousand people drink that water,” Pearson said. “For a lake like Ramsey, which is not fed by a river flowing in at one end and another river flowing out at another … there is a really, really serious risk of lower water levels plus warmer water leading to blue-green algal growth. We’ve already had some of that in Ramsey in isolated bays. I’ve seen them.”
He has also seen examples in which the algal blooms rapidly engulf a lake, rendering the water undrinkable.
“If that were to happen to Ramsey, we would have a very, very serious problem,” he said. “Ramsey is on a knife edge. So the planning policies around the lake need to take into account climate change, and the vulnerability of the lake.”
Since the amount of phosphorus needed in the nutrients to trigger the blooms is very low, restricting development on the lake is the only way to protect the water quality. Phosphorus comes from such things as lawn fertilizer, disturbance of soil due to construction, and from septic systems.
“There are still private septic systems around (Ramsey) Lake, the responsibility for which are in the hands of homeowners,” he said. “As long as we drink that water, we have to be very careful, because climate change will affect the water whether we like it or not.”
As far as the city’s infilling policy is concerned, Pearson said it makes sense to limit the amount of energy and greenhouse gases it takes to get around the community by having everyone live closer together and using public transit.
But that doesn’t mean groups who are fighting development to preserve greenspaces are wrong.
“Part of what one has to do when looking at the infilling policy is to look at what function the greenspace serves,” he said.
For example, development near Lily Creek should be restricted as much as possible, because it acts as a giant bathtub for the city when we get heavy rain.
“Water absorbed by Lily Creek is not flooding Junction Creek and homes downstream. Lily Creek acts as a shallow bathtub that holds water back,” he said.
“If the greenspace simply looks nice, then that’s a different sort of a decision than, say, if it’s a pond that absorbs floodwater, protecting lives and saving property. So it’s a different decision that has to be made.”