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| A man stands in a flooded street in Miami on Sept. 10, 2017, as Hurricane Irma hits the area. (Matt McClain/The Washington Post) |
Consider how climate change risk is expressed in key reports like those from the U.S. National Climate Assessment (NCA) and the U.N. Intergovernmental Panel on Climate Change (IPCC).
The NCA says there is at least a two-thirds chance that your asthma or hay fever will get worse because of climate change. There’s a more than 90 percent probability that extreme precipitation (think flooding) will increase in frequency and intensity. What about heat waves increasing? There’s a 99 percent probability. In fact, heat waves kill more people than any other weather-related event in the United States.
What about rising sea level? Under our current emissions trajectory, the NCA says there is a 2 in 3 chance that between $66 billion and $106 billion of real estate will be underwater by 2050. And we mean literally underwater.
How do we handle these risks from climate change? Not very well. We want more data, more proof that the risks are real before acting.
Let’s contrast that with how businesses handle risks. Companies would not be content with a 66 percent chance that a fire will start in their building, or a 66 percent chance that the wheels will fall off a new car they release to production. That’s an untenable level of risk.
How do we know this? Because we know of the tools companies use and the level of risk they are willing to tolerate. One tool used extensively is a Failure Modes and Effects Analysis (FMEA). An FMEA is used to assess the risk of failure of every component in a product (like every bolt), and the consequences of that failure to the overall product (like the car).
The FMEA scale goes from 1 to 10, with 10 being worst case and one being what the engineers and designers shoot for. A 10 rating corresponds to a 10 percent or greater probability, a nine to a 5 percent probability and a two rating corresponds to a 0.0001 percent probability or lower. A one rating corresponds to zero probability. So the automotive designers strive for a 0.0001 percent probability of failure, or better. Wow! Meanwhile, we are talking 66 percent, 90 percent and 99 percent probabilities with climate change, and we have done little so far to mitigate these risks.
In contrast to the automotive world, it seems like we want climate scientists to strive for 100 percent certainty. It’s like saying, “I want you to be 100 percent certain the wheel is going to fall off my car before you take any action.”
Risk is generally expressed as the probability multiplied by the impact. It is the combination of these two variables that determines the level of risk. So a high probability risk with a small impact might not be a significant concern. But a high probability risk with big impact is a real problem.
The wheel falling off your car has a big impact. So is your house being underwater. In both cases, we want to drive the probability as low as possible. And there is one big difference between the wheel falling off your car and climate risk. When the auto company makes a mistake and a risk occurs, they can recall the vehicles and fix the problem. You cannot recall the sea lapping at your front door or the air that your asthmatic child is breathing.
It’s like we are speaking two different languages. I guess the risk of destroying the climate, and a good part of Earth, is not as worrisome to us as the risk to an individual car.
One of the most worrisome risks of all with climate change is that the Antarctic and Greenland ice sheets will start to collapse this century, triggering up to eight feet of rising sea level by 2100 and putting the fate of our low-lying coastal cities in peril. Can you imagine trying to relocate millions of people inland? How many people will suffer? Who will pay the cost?
What’s that probability? Nobody really knows for sure, but a recent survey of climate scientists who specialize in rising sea level put it at 5 percent. Multiply that by the cost of all the infrastructure in harm’s way. The same study indicated almost 200 million people would be displaced. Nothing to worry about, right? No need to take action.
Let us make it clear: We are not criticizing scientists for the way they express risks. We certainly want scientists to have high confidence before we accept a new wing design on a plane or that new prescription drug. But climate change is different. We have already gone way beyond what the business industry would react to. We can’t recall the planet if we mess up. So let’s get on with it and stop asking the scientists for ever higher certainty in their predictions. That’s a recipe for beyond disaster.
Links
- How Will Companies Respond to the Risk of Climate Change?
- PM's bushfire response must include climate change: experts
- Climate risk and response: Physical hazards and socioeconomic impacts
- Long shaped by fire, Australia enters a perilous new era
- Fourth National Climate Assessment
- Excessive Heat Conditions
- Ice sheet contributions to future sea-level rise from structured expert judgment
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