Our children will never experience a childhood as cool as ours. And our childhood wasn’t that cool.
“What really inspired [that graphic] was showing the consequences of the choices and actions taken now in reducing [greenhouse gas] emissions for generations now and in the future, for our children,” said Christopher Trisos, a member of the core writing team for the synthesis report and helped with the graphic.
The report released Monday emphasizes that overall, the degree of warmth — and the subsequent health of the environment, wildlife and ourselves — can still be altered depending on policies and actions taken today. The current implemented policies would put global temperatures around 3.2 degrees of warming by 2100 — somewhere in the range of the “intermediate” or “high” pathway of future emissions scenarios depicted in the graphic, said NASA climate scientist Alex Ruane, who is a member of the core writing team for the synthesis report and helped with the overall concept and science content of the figure.
The graphic is centered around a popular visual called climate stripes that show global temperature increases with vertical colored lines. The climate stripes were created in 2018 by climate scientist Ed Hawkins, using inspiration from previous scientists and even a crochet pattern. While creating the new IPCC report, graphic designer Arlene Birt proposed a visual that, alongside the stripes, would depict temperature changes across generations.
The visual shows that a person born in 1950 entered the world when there was around 0.25 degrees of warming compared to the late 1800s, said Ruane. Today, a 70-year-old has experienced 0.85 degrees of warming in their lifetime so far, or around 0.12 degrees per decade, he said.
A person born in 1980 first experienced around 0.4 degrees Celsius of warming above preindustrial times, experiencing 0.75 degrees of warming in about 40 years to date (approximately 0.19 degrees per decade, according to Ruane). The rate of warming to date was nearly 50 percent faster for those born in 1980 compared to those born in 1950, he said.
For a person born in 2020, the extent of warming highly depends on society’s response. In the higher emission scenarios, Ruane said those born in 2020 would experience average decadal warming rates about three times higher by the time they are 70, compared to what those born in 1950 have experienced. Yet, if warming is limited below 2 degrees or 1.5 degrees (seen in the low and very low scenarios), he said the 2020s generation could see climate stabilization before they are 30 years old.
Ruane added that average decadal warming does not necessarily capture acceleration but does convey a core climate message: Each generation has had a different set of experiences already, and future generations are set to experience warming beyond what those alive have yet to see.
“It’s not just that this can be warmer. It’s that there are going to be different experiences in terms of human health and ecosystems and the extreme events that you might experience,” said Ruane.
Today’s average global temperature has grown by 1.1 degrees Celsius (2 degrees Fahrenheit) since the beginning of the industrial era, mainly due to human activities like burning fossil fuels that emit heat-trapping gases into the atmosphere. Researchers have called to reduce fossil fuel consumption and limit Earth’s future warming to ideally 1.5 degrees Celsius, stating that further warming will make climate disasters significantly more extreme and impossible to adapt to.
Nations will need to fulfill their current climate commitments and introduce new environmental policies to limit warming to levels that communities can reasonably adapt to.
The report outlines several effects from the rapid global warming: Population declines and extinctions, increased risk of heat stroke and reduction in crop and fishery production.
While the graphic shows observations and future pathways for the average global temperature, differences appear regionally. Some locations have already warmed by 2 degrees. Many of the world’s poorest nations have and will continue to feel the brunt of increasing global temperatures.
Trisos, who is also director of the Climate Risk Lab in the African Climate and Development Institute at the University of Cape Town, said a person born in 2020 in southeast Asia could face up to 150 days per year of deadly heat when they are 70 years old at the end of the century. Their counterpart in Florida, meanwhile, would see 50 days of deadly heat per year.
Many of the pathways remain fairly similar for the next decade or so but start to prominently diverge around 2040 and 2050. The very low and low greenhouse gas scenarios show carbon dioxide emissions declining to net zero around 2050 and 2070, respectively. A high greenhouse gas emissions scenario illustrates that carbon dioxide emissions will double from current levels by 2100. A very high greenhouse gas emissions scenario depicts carbon dioxide emissions would double even faster, by 2050.
“In all cases the impacts will be more severe than there are already today. So, climate change doesn’t go away it only becomes worse slower,” Niklas Höhne, a scientist at the NewClimate Institute who has contributed to several IPCC reports, including this one, said in an email. “We can slow down the change by acting immediately to reduce greenhouse gas emissions. The report also says that we have all means to do so.”
Sarah Kaplan contributed to this report.