I want to talk about this picture.
Because it triggered for me something that has been banging around in the back of my head for a few years, and I have not really known how to relate it. When it arrived a few years ago thoughts like this were too catastrophic to fit into our world view. Maybe our world view is changing, but I’m not sure about it.
At the time, I was on the Metro Vancouver Utility Committee, which is a committee of local elected officials that get together to discuss the operations of the water and sewer infrastructure of the region and review capital plans for the Metro Vancouver Board. (This has been replaced after the 2018 election with separate Liquid Waste and Water committees). As was our mandate, we were doing long-term planning for the region’s water supply. Really long-term, like 50 – 100 years.
This is important, because major water infrastructure like our three big reservoirs, the dams that support them, and the pipes and pumps and stuff that move a billion litres of water around every day is really expensive stuff. Once installed, it may be in the ground for a century or longer. In a rapidly-growing region with land constraints like Greater Vancouver, big decisions about how, where, and when we invest in this infrastructure are important.
To inform that planning, we needed to include projections about climate change. Beyond just being hotter in the summer, and the potential for less snowpack, we need to consider impacts on ENSO and other global climate systems that may drastically shift when and how much rain falls in our watersheds so we are capable of storing the right amount. We had science types who study this stuff in universities for a living providing models for us.
The subject matter experts were able to, I think, provide a pretty good summary of what we know, what we don’t know, and what we don’t know we don’t know about the climate are we project to 2100, about 80 years in the future. There were several chuckles around the table from comfortable elected people “I’ll be dead then! Har Har!” which is its own telling moment, but I digress.
Scientists being science types, they spent a lot of time talking about uncertainty. There are a variety of models, none of them perfect, and subtle adjustments of what we put into the model can have big impacts over decades. Will the world meet the Paris Agreement goals? Will the economic growth of the last decades continue? Will Elon Musk invent the Mr. Fusion? All of these are external things climate scientists cannot predict, but they can make projections based on different amounts of greenhouse gasses going into the atmosphere. From those they can infer the impact on temperatures, sea and air circulation patterns, feedbacks positive and negative. They have several different models, and into each they can add several emissions scenarios, and they end up with scores or hundreds of different results.
These projected results are not random, though. They cluster. They reinforce each other as often as they differ. In the report we were given, there were three distinct clusters in projecting the temperature impacts of Anthropogenic Climate Change on Greater Vancouver. As is the wont of planners and engineers, they hope for the “best case”, plan around the “middle case”, and have contingencies for the “worst case”.
Looking at a “middle case” for 2100, they made some iterations around our watersheds, how the hydrology of them will be impacted, how spring rains vs. summer rains impact storage need. All to figure how we will assure we can supply water to a City of (I can’t remember the number now, but for the sake of moving the discussion along let’s say it was) 4 Million people. Great, we put our stake in the ground, and have something to plan around. If things change, we will adjust, but this is the point we adjust from.
I put my hand up. “If the annual temperature increases by that much, what does that mean for the trees we are protecting in the watersheds? Can they tolerate that change?”
The answer was “outside of our current scope”. Not the topic of this discussion. We moved on to reservoir design options.
But it doesn’t take much research to discover that, even in the “middle scenario” provided, we are looking at temperatures that are outside of the habitat range of the Douglas fir, the western hemlock, the sitka spruce, the red cedar. The trees will likely die.
Sitting in Metro Vancouver’s offices, you could look over at the North Shore Mountains. It was hard to imagine what Vancouver will look like in 2100 with those trees dead or dying. To most of us, those green mountainsides reaching to rocky peaks define Vancouver. So much so that the City has expensive and complicated “view cone” programs to assure that people’s view of that green expanse is protected by policy. I’m not sure anyone is really thinking about what it means if they are gone.
Maybe it’s too hard to imagine. Just another bummer on the pile, and I’ll be dead by then. Or maybe our current sepia-toned sky should prompt us to imagine why we have made this choice.
Thanks to Mr. Mathew Bond for permission to lament over your photo.