Climate Change and Long Range Planning

It's not unusual for water utilities and state water resource agencies to develop long-rang plans looking ahead 10, 20 and even 50 years. Long range planning is a good thing. You know your infrastructure is going to age in stages, that your population is likely to grow, that areas of growth will shift geographically over time, and that your water resources are finite and need to be managed.

A funny truth is that most long range plans are based on past experience – you look at what has happened in the past and transfer that knowledge into predictions for the future. Another truth is that long-range plans are never perfect; pipe might not last as long as you expected, or the economy tanks and your customer base declines. Still, you adapt the plan as you move through time and circumstances change.

But I struggle with the concept of planning for climate change. How do you plan for something outside your experience and with a completely unpredictable outcome?

Let me start by saying that I believe that the world's climate is changing. Change is a given. It would be news if climate was stable. I can accept that the world is getting warmer even though we had a very cold winter last year. It might have been colder in Tulsa, but the global average temperature went up.

Whether man has played a role in warming the planet has been debated endlessly and makes my head hurt. I don't know. Maybe.

But one thing is certain from what little I know about weather patterns: Global temperatures have risen and fallen dramatically over the millennia. There have been many periods in world history when temperatures have been warmer than now. And periods when it was much, much colder. Sometimes the changes were sudden; sometimes they stretched over centuries.

Let's assume that the earth will continue to warm over the next century. It's also, sadly, safe to assume the human race is not going to cut back on burning fossil fuels. So, how do those assumptions help you in long range planning?

Maybe the Southwest will get drier and the Northeast will see larger, more violent storms. How much drier? How much more rain? What do we really know that we can plan for? Could you reasonably upscale your stormwater collection system based on climate change predictions?

I found an interesting document online prepared by the Met Office, the UK's National Weather Service, that looked at a wide assortment of climate models collected from around the world. The results were almost funny in how dramatically they varied. As an example, when looking at the potential of flooding in the UK caused by climate change, estimates ranged from a 56% reduction in flood risk to a 180% increase.

For the US, they looked at 21 different climate models. As a group, the projections were evenly balanced between increasing and decreasing flood risk in the early 21st century.

Ultimately, I think planners will have to rely on experience and understand that any long range plan is a best guess and subject to change – just like the climate!

James Laughlin, Editor