Four Kinds Of Killer Weather Extremes: An Achilles Heel Problem For Climate Predictors. 

Originally published on Forbes.com on October 15, 2024

Globally, the killer quad of weather extremes have not worsened in the last 50 years, even though the oil and gas industry now produces around 50% of global emissions.

An Exxon study done in 1982 focused on global warming by increasing greenhouse gas (GHG) emissions. Remarkably, thirty-seven years ago Exxon accurately predicted that by 2019, the earth would hit a carbon dioxide concentration of 415 ppm and a temperature increase of almost 1C degree since the industrial revolution.

The presently largest U.S. oil and gas company predicted four decades ago almost the exact global warming situation the world had in 2019 and that we have today.

ExxonMobil has been taken to court many times, including in Massachusetts in 2019 and in California in 2023, for knowing about climate change but ignoring the consequences on society in later decades.

In the ultimate irony, Exxon knew the GHG levels were increasing over time, and must have modeled the major contribution from the burning of fossil fuels including their own production of oil and gas. Fossil fuels today contribute roughly 73% of all global greenhouse gas (GHG) emissions.

Uncertainties in predicting climate change.

But Exxon’s predictions were about global warming, not climate change. Prediction of the effects of climate change is another big step and is fraught with uncertainties.

Most of Exxon’s work in the 1970s and 1980s focused on predicting global warming. But they did acknowledge potential effects this might have on climate and the uncertainties. For example:

“Let’s agree there’s a lot we don’t know about how climate will change in the 21st century and beyond,” Exxon’s CEO Lee Raymond said in his speech before the World Petroleum Congress in Beijing in October 1997.

What is the difference between global warming and climate change?

Since 1973, the last 50 years have been a period when global temperature rise has been consistent and very strong, rising 1.0C degrees. If the world were sensitive to 0.2C or 0.5C, or even 1.0C global warming, climate change indicators should show up in long-term data trends.

There are worldwide consequences of global warming. These direct indicators include Arctic and Antarctic ice melting, glaciers retreating, sea levels rising, corals bleaching, and some biodiversity habitats changing. These have been serious, but not generally associated with human lives lost, destroyed infrastructure, famines, mass migrations, or government collapse.

Each of these direct indicators, on a global basis, has worsened in the last 50 years, and long-term data have proven this. For example, coral bleaching in the Great Barrier Reef has reached an all-time high.

But there also exist indirect indicators of climate change, such as the so-called four killer weather extremes of droughts, wildfires, floodings, and hurricanes. These are often catastrophes, as the US found out recently from hurricanes Helene and Milton. These are often short- or long-term catastrophes that have major effects on human lives: famines, migration, and the stability of governments.

But the four killer weather extremes have not worsened in the past 50 years. Long-term data such as hurricanes show numbers of worldwide events that, although fluctuating, reveal no long-term trend. The events were reliably recorded and carefully counted.

It’s the same for the global tally of droughts, wildfires, and floodings. On a global basis, none of these four killer weather extremes have worsened over the past 40-50 years — even though global temperature has risen by 1.0 C degrees in this period.

One thing has to be made clear. The above refers to global numbers or averages that haven’t changed over 50 years. If hurricanes in the southeast U.S. have increased over 50 years, then hurricanes somewhere else in the world must have decreased, to keep the total hurricane numbers the same. This is a subtle point but an important one since we are focused here on global warming.

What this means for climate change.

The global data are saying that these four killer weather extremes, which have not worsened, are not sensitive to a relatively large rise of 1.0 C degrees that has taken place over the past 50 years. This comes as a jolt for climate modelers.

If the four killer weather extremes haven’t shown any global worsening trends over the past fifty years, even though the global temperature has risen 1.0C in this time, why should the world be worried about future worsening? Stated in another way, why should we be worried about the next 0.3C rise in global warming that will reach the danger number of 1.5C above preindustrial times, as designated by the Paris Agreement of 2015?

Based on the dominant dangers of droughts, wildfires, floodings, and hurricanes, the urgency to reduce GHG emissions, though still significant, is not as dire as often presented by climate modelers, the media, and the press.

Last, the oil and gas industry is not worsening the killer quad of weather extremes, even though the companies now produce around 50% of global GHG emissions. The industry may be culpable for direct indicators of global warming, but not these indirect killer extremes.

Back to ExxonMobil. Until climate models can explain why there has been no worsening of the “killer quad” of extreme weather events over the last 50 years, ExxonMobil would not be wrong in saying that climate change, and its effect on humanity, are too uncertain to be predictable by models in these respects. 

For example, Exxon’s chief executive Rex Tillerson said in 2013, “The facts remain there are uncertainties around the climate… what the principal drivers of climate change are.” 

Nevertheless, ExxonMobil seems to be saying that climate change may become more serious (direct indicators not indirect ones) because they are embarking on strong actions to reduce or bury their GHG emissions – all of them by 2030. But perhaps not serious enough for ExxonMobil to begin to diversify from the production of oil and gas to the production of wind and solar or other renewable energies.