Get ready for a smoking 2024, when global warming will make a big jump
This year's been really hot, even during a cool phase of the normal 3-7 year up and down temperature cycle. We'll be in the high phase by 2024, with the world hotter than we've ever felt it before.
Columbia University’s Jim Hansen, former NASA scientist and noted expert on climate, puts out a monthly update on what’s been going on with Earth’s climate. It’s a must-read to understand where the Earth’s climate is now, and how it has responded to all recent climate forcings, human or otherwise. Recently, Hansen released his group’s analysis of the August temperature anomaly — the global average Earth surface temperature relative to what is was on pre-industrial times, roughly in the period 1880-1920. This temperature anomaly is the figure often mentioned in discussions of goals for limiting planetary warming.
Hansen’s groups analysis should set alarm bells ringing for what is coming in the near future. By 2024, they expect, temperatures will likely surge to levels we have never experienced before. If you thought this summer was scorching, just wait two years.
Almost by convention, many scientists have long suggested that it would be disastrous if we pass through the limit of 2.0C warming over pre-industrial times. More recently, governments behind the Paris climate agreement stated that we should be more ambitious and really aim to limit warming to no more than 1.5C, if we hope to have a liveable world. Right now, the global temperature stands at somewhere around 1.1-1.2C above pre-industrial times.
The figure below, borrowed from Hansen’s report, shows the temperature record over the past 140 or so years. Clearly, there’s been a gradually upward trend in global temperatures over the past century — this is global warming. Its accelerated in the past 30 years. But one very interesting feature of this temperature record is that its not just smoothly going upward, but shows a marked wiggling, up and down, over a period of every roughly 3-7 years.
This wiggle reflects the influence of a famous and important climate phenomenon known as the El Niño-Southern Oscillation (ENSO). It’s not at all a simple thing, and many aspects of it are still not understood. But, empirically, the term refers to a long-standing periodic oscillation in the temperatures of the central and eastern tropical Pacific Ocean — an immense body of water capable of storing vast quantities of heat. There’s a warm phase, the El Niño phase, and then a colder phase, the La Niña phase. These two phases also affect patterns of rainfall all over the globe, as well as global temperatures. During an El Niño phase, the Earth’s surface temperatures tend to be warmer, and then they grow cooler in a La Niña phase. The cycle repeats, even as the overall temperature of the planet shows a steady rise.
Why does this matter? Because, as Hansen points out (and has been pointing over for the last two years), we have been in a cooler La Niña phase of this oscillation for the past 2-3 years. The extreme temperatures we experienced this past year came about despite the overall cooling effect of La Niña, and would have been much worse had we been in a warmer El Niño phase. But we’re headed toward such a phase now. Back in 2017 we were in an El Niño phase, and, according to Hansemn, one result was that 2017 ended up being the fourth hottest year on record. Based on recent data, he projects that 2022 will end up being essentially in a dead heat with 2017. Then, 2023 will be warmer still, as we move into the coming El Niño phase.
And then we will come to 2024, which could be epic. Here, it’s worth mentioning, that the ENSO oscillations aren’t completely regular. The process doesn’t work with the precision of a clock. The ups and downs always come, but predicting the timing isn’t easy. With this in mind, Hansen’s projections for 2024:
…we suggest that 2024 is likely to be off the chart as the warmest year on record. Without inside information, that would be a dangerous prediction, but we proffer it because it is unlikely that the current La Nina will continue a fourth year. Even a little futz of an El Niño – like the tropical warming in 2018-19, which barely qualified as an El Niño – should be sufficient for record global temperature. A classical, strong El Niño in 2023-24 could push global temperature to about +1.5°C relative to the 1880-1920 mean
That’s big news. No, its huge news. The future of climate is already here. Or will be very soon. While many people still hope we can limit warming to some temperature rise less than 1.5C — still a goal of the Paris Agreement — scientists for some time have been suggesting we’re getting close to bursting through that barrier. Some estimates from earlier this year suggested a 50% chance of going past 1.5C in the next five years. Experts increasingly think we’ve more or less missed our chance to keep temperatures within this zone in the long run.
As a report by the United Nations Environment Programme recently put it,
We had our chance to make incremental changes, but that time is over. Only a root-and-branch transformation of our economies and societies can save us from accelerating climate disaster.