"The concentration of carbon dioxide in the atmosphere is approaching 410 parts per million. That has already driven global temperatures nearly 1 ˚C above pre-industrial levels and intensified droughts, wildfires, and other natural disasters. Those dangers will only compound as emissions continue to rise." (Temple, 2019)
How often have you read statements like the one presented above and wondered, "How on Earth could a 1°C increase in temperature cause wildfires?!"
Well, if you have, you're not alone.
Plenty of people think that a mere 1°C of warming sounds pretty nice. After all, a 23°C afternoon is lovely... but a 24°C afternoon is simply glorious!
So what's all the fuss about?
In a nutshell, here's the issue. The warming that climate scientists discuss, debate, and set as targets is presented as an average amount of warming observed over the entire planet across an entire year.
Now... if you've lived long enough, you already know that averages do not occur at average rates. As an example, my hometown of Newmarket, Ontario receives approximately 1.5 cm of rainfall, on average, per day. However, nobody would ever imagine that we literally get 1.5 cm of rain each and every day. No. That rain comes in much larger amounts, spread out sporadically across just a few months of the year. That means that we get quite a bit of rain on some days, but probably no rain at all on most other days of the year. Nonetheless, our structures, streets, creeks, sewers, and drainage systems must all be able to handle our peak amounts of rainfall - not the rather innocuous sounding average amount of rainfall.
It's the same thing with heat. The 1°C mentioned in the quote at the top of this article is not for a moment referring to a daily increase in temperature. It's an average temperature that is spread out across the entire planet, over an entire year. Now, just like rainfall, that average will not present itself at average rates. Rather, that heat will come in waves of peak events, and it's those peak events that do all the damage, like melting glaciers, releasing methane from permafrost, causing droughts, and producing the conditions necessary for forest fires to occur. Unfortunately, all of these things lead to an ongoing feedback loop that drives even more warming... but that's another story.
Right now, let me demonstrate the deceptively dangerous, subtly disarming nature of average temperature increases. As a simple example, I thought I would use an extreme temperature that many people could probably relate to around Thanksgiving time: the temperature required to roast a turkey!
And I'm not going to waste your time talking about some small bird, either... no sirreee, Bob. I'm going to use an example of a 20 lb., fully stuffed turkey!
According to the chart illustrated above, such a turkey would require 8 hours at 325°F (163°C) to be perfectly roasted.
Fair enough. So, just to illustrate my point, let's take that amount of heat and spread it out evenly across an entire year. We can do that by dividing 163°C by 365 days. (You will note that I am using the Celcius temperature scale because that is the scale used in climate science.)
Okee dokes. That gets us approximately 0.45°C per day. However, we don't need 24 hours to cook this bird. Nope. We just need 8 hours, or one third of a day. So then, lets divide the 0.45°C daily temperature by 3 to get us just 8 hours of cooking time. That gives us a temperature of 0.15°C.
So, to bring this example all together:
But it is alarming.
The alarming issue is hidden in that one little pesky fact about averages: averages do not occur at average rates. It's the peak events that do all the damage.
Now, of course, we don't get peak events that are nearly as dramatic as the example that I've outlined above... thank God! If we did, we would have all perished long ago.
To be sure, temperature increases on the planet do not occur over just one day. However, the point remains the same: while our temperature increases do not occur over a single 8 or 24-hour period of time, they do not get spread out evenly amongst all the days of the year, either.
Reality is somewhere in between... but that "somewhere in between" is still a very dangerous predicament. Experiencing an average temperature increase of just 1, 1.5, or 2°C, concentrated within a number of peak events that are spread throughout the entire year will still wreak havoc across the globe. And, as I mentioned before, the even scarier issue is the fact that temperature increases give rise to even further temperature increases.
That is precisely why the recent IPCC Report on Global Warming of 1.5°C (IPCC, 2018) suggests that we have just eleven years to get climate change under control.
After that, there will be little chance of regaining any control at all over the roasting oven that we like to call the planet Earth.
Temple, J. (February 27, 2019) One man’s two-decade quest to suck greenhouse gas out of the sky:
Klaus Lackner’s once wacky idea increasingly looks like an essential part of solving climate change.
MIT Technology Review. URL: https://www.technologyreview.com/s/612928/one-mans-two-
IPCC, 2018: Global warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C
above pre-industrial levels and related global greenhouse gas emission pathways, in the context of
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Zhou, M. I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, T. Waterfield (eds.)]. In Press.