There's been an interesting series of articles in The Vancouver Sun about climate change threats to the Lower Mainland. The low-lying Fraser River estuary is particularly vulnerable. It's a witches' brew of sea level rise, storm surges and rivers in flood being backed up by the sea.
“If you have a warmer atmosphere, you’re probably going to get more
rain, so in the mid-latitude you could get a sequence of big storms,”
said Gordon McBean, professor at Western University and director for
research at the centre for environment and sustainability.
“The first couple of them could deposit all of their rain over the
Interior of B.C., making the flow down the Fraser even larger, then at
the same time, the winds blow the ocean over Georgia Strait, then you’ve
got this extra water in the Fraser River running past New Westminster
and hitting Ladner, the airport and areas under the Oak Street Bridge.
“This water is coming down the river at the same time as the wind is
pushing the water from the Georgia Strait towards it so you get this
kind of double effect.”
“The level of insured losses is going up so rapidly from flooding
that the insurance industry has gone from thinking of itself as a fire
mitigation agency to a flood mitigation agency,” said Deborah Harford,
executive director of the Adapt to Climate Change Team (ACT) at Simon
“Half of every dollar that the insurance
industry spends in Canada right now is on basement inundation, either
because of greywater backup or because of somebody’s sump pump failing.
Heavy precipitation is causing those damages. Even without insuring
overland flooding, they’re already taking a catastrophic level of loss.”
Water seems to be the main problem with climate change, Harford said.
“It’s either too much, too little or there or not there when you really need it,” she said.
That heavy precipitation is likely to get worse as the pattern of storms changes in B.C.
getting different kinds of storms, we’re getting different intensities
of storms, different forms of precipitation at different times and in
different forms,” said Stephen Sheppard, professor in landscape
architecture and forest resources management at the University of B.C.,
who works with Collaborative Advanced Landscape Planning (CALP) engaging
communities on climate change. “We used to get a lot of snow in the
mountains, now we get rain on snow, which is disastrous for the streams
because they get huge amounts of run-off."
Sea level rise also raises the threat of saltwater inundation of the rich Fraser Valley agricultural zone which could undermine the urban Greater Vancouver region's food security.
[UBC professor] Stephen Sheppard said agriculture in the area could be profoundly
affected by rising water tables, increased salinity, and the effect of
climate change on crops, such as different growing seasons or
“All of these things together will probably change the face of
agriculture as we know it in the Lower Mainland in this century,” said
Sheppard, professor in landscape architecture and forest resources
management at UBC.
Given that much of the land in the Agricultural Land Reserve, used to
grow food in the Metro region, is in regions like Delta, Richmond and
Surrey, which are low-lying, increasing salinity could have significant
effects on the region’s food supply.
“Communities like Delta provide about one-third of the local food for
the whole of Metro Vancouver,” Sheppard said. “There’s a knock-on
effect for everybody because if agriculture is affected, it may be that
the adaptation is to switch to different kinds of crops or different
kinds of farming or different locations for farming.
“Maybe we have to move some of the farms into urban areas that are
not at risk of flooding, so I think you will see a lot of interest in
alternative forms of food production as a response to these kinds of
Lower Mainland municipalities are planning to meet the combined impacts of river flooding, sea level rise, storm surges and saltwater inundation but there is a reluctance to incur massive spending on problems that might be decades off.