(WFLA) — It’s quite the claim; This week, Earth broke a record for its hottest day in 120,000 years. Actually on concurrent days — Monday, with another jump on Tuesday. The black line in the image below is 2023.
El Niño (a natural cycle) is just getting started. As it gets stronger, adding more heat to Earth’s system, this summer will continue to set new all-time record hot global days. And along with that, many other records will be shattered as well.
But no matter how hot it gets this summer, as the steady drum beat of human-caused climate heating beats on, the summer of 2023 will soon be considered a “cool” summer in a couple of decades.
How can we be so confident of any of these bold assertions? As a climate specialist, I’ll do my best to explain. It is fairly simple and fully expected by the climate science community.
First, we know using observations that temperatures over the past decade have been warmer than any we have seen since record-keeping began in the 1800s. Since then, Earth has warmed by 1.2 degrees Celsius (2 degrees Fahrenheit).
We also know through sophisticated methods of examining copious climate clues in proxy data like tree rings, ice cores, ocean sediments, etc. that Earth’s average temperature has not been this warm since the ice age ended 20,000 years ago.
Take a look at the visual below. The message is quite simple and stark. On the scale of 1,000s of years, this visual illustrates that Earth’s temperature is now shooting straight up. Here are a few takeaways from the visual.
The rate of warming today is unprecedented in the 20,000 years shown. In fact, coming out of the last ice age, it took 10,000 years for the Earth’s average temperature to warm 3 degrees C.
Astonishingly, humans — due to the burning of fossil fuels and greenhouse gas emissions — will likely cause the same amount of warming in 200 years. That means our current warming rate is 50 times that of the natural warming rate that proceeded the most recent ice age.
Between 10,000 years ago and today’s rapid manmade warming, Earth’s average temperature was relatively constant, allowing human civilizations to thrive. There were disruptive regional cooling episodes like the disparate Little Ice Age events, but the impact on overall global temperature was relatively minor.
Since at the peak of the last ice age, Earth’s average temperature was about 10 degrees cooler than today, we know that it has not been this warm since before the last ice age. We call that time the “last interglacial” (in-between glacial periods) which peaked around 125,000 years ago.
Proxy data tell us that the average global temperature during the last interglacial was about 1 degree Celsius warmer than today. During that time, scientists estimate sea level was 30 feet higher than today. With continued warming, the past warns us that future generations may very well have to deal with that kind of sea level rise.
In fact, we can expect to gain another degree of warming by mid-century, putting us on par with the temperatures of the last interglacial. And by the end of the century, if we don’t curb our carbon emissions, we may very well experience the hottest temperatures in over 1 million years.
But taking a step back, once we get past 2050, our future warming becomes a lot more uncertain. That’s because we can’t possibly know how much humans will reduce emissions and we also can’t be certain of the Earth system feedbacks to warming. We also don’t know if Earthlings will embark on some sort of geoengineering project to try to reduce the heating.
The latest best estimate, assuming current government policies on emissions, is that Earth is set to warm ~2.7 degrees C by 2100. But betting on governmental policies is a big assumption and significantly greater warming is possible if we continue to emit as we are now.
Admittedly, this may all seem hopeless. But unlike a terminal illness, we know exactly what the problem is, we know exactly how to fix it, and we have all the solutions we need now. What is required is that we pay attention and get serious, quickly. Our future depends on it.
If you are interested in learning more about climate, follow my Twitter account here. It is a comprehensive day-by-day documentation of our changing climate.
