Five global oil giants — Chevron, ExxonMobil, Saudi Aramco, Gazprom and BP — likely contributed to the deadly 1998 heatwave in India, the worst among the preceding 50 years, according to a new study.
The five companies caused the intensity of the five hottest days to increase by 0.08°C, the paper published in Nature noted.
The event caused heavy economic losses. Chevron, for example, was responsible for causing losses amounting to $1.9 billion from the 1998 heatwave.
Further, the companies were also responsible for increasing the intensity of heatwaves of 2003 in France and Russia in 2010, and in United States in 2012, increasing the intensity of the five hottest days by 0.11°C, 0.27°C, and 0.09 °C, with Chevron also causing losses of $3 billion, $2.8 billion, and $28.8 billion, respectively.
The oil, coal and gas extracted by fossil fuel companies have released substantial emissions of carbon dioxide and methane over the past century. Between 1920 and 2020, Saudi Aramco, Chevron and ExxonMobil produced a cumulative total of 16.6, 14.2 and 13.2 Gigatonnes in CO2 emissions, respectively.
The analysis was done using a tool developed by researchers at Dartmouth College in the US to trace specific climate damages back to emissions from individual fossil fuel companies. It could find applications in climate liability cases, which have increased in recent years, with over 100 climate-related lawsuits filed since 2017.
“As extreme events intensify and losses accumulate — and as political action on climate change lags the urgency of the crisis — more people are turning to the legal system for relief.
There is talk of a ‘coming wave of climate legal action’ for which courts are woefully unprepared,” the researchers wrote in the paper.
According to Callahan, much of attribution science has focused on quantifying the effect of climate change writ large – for example, how much hotter a heat wave was because of historical greenhouse gas emissions. "But knowing the role of overall global warming doesn’t necessarily tell you the role of any individual emitter. Our study goes a step further by specifically simulating the contributions of fossil fuel firms to global warming, and therefore the impacts of warming," the expert told Down To Earth.
To develop this tool, the researchers combined climate modelling with publicly available emissions data to compare the current climate and a scenario without the heat-trapping gases a company’s activities released into the atmosphere.
They found that the top five emitters were Saudi Aramco, Gazprom, Chevron, ExxonMobil and BP, responsible for global economic losses from intensifying extreme heat amounting to $2.05 trillion, $2 trillion, $1.98 trillion, $1.91 trillion and $1.45 trillion, respectively.
Investor-owned companies like Chevron, ExxonMobil, and BP and state-owned enterprises, for example, Saudi Aramco and Gazprom are each collectively responsible for roughly $14 trillion in losses.
The analysis also finds that the global economy would be $28 trillion richer in a world without the extreme heat caused by 111 major carbon emitters. Of this, $9 trillion in losses can be traced back to the top five top-emitting firms.
The extreme heat from the top five emitting companies has caused the annual Gross domestic product (GDP) per capita reductions exceeding 1 per cent across South America, Africa and Southeast Asia. However, USA and Europe, home to Gazprom, Chevron, ExxonMobil and BP are headquartered, have seen milder costs from extreme heat.
This can be explained by how warm a place is to begin with. "There is an inherent geophysical inequity in climate change — low-income, tropical regions that are the least culpable for warming exist at the warmest latitudes. As such, a marginal change in extreme heat has the largest economic impacts for those regions," Justin Mankin, associate professor of geography at Dartmouth College told DTE.
The study only focuses on extreme heat, but this tool, the authors add, can be applied to other climate hazards such as extreme rainfall or drought. "However, given the myriad costs of climate change that we don’t yet know how to count up, any such effort will inherently underestimate the total impact of global warming,” Callahan explains.
“Extreme heat is indelibly linked to climate change itself, and the losses from it have been an instigator for legal claims. So, it’s an obvious place to illustrate the broad application of our approach,” Justin Mankin, associate professor of geography at Dartmouth College explained.