October 5, 2021
TORONTO — Younger generations will be more severely threatened by climate change and extreme weather events compared to older generations, exposing inequities in intergenerational exposure to climate extremes a climate study says.
The study, published last week in the journal Science, says that under global warming, extreme events such as heat waves will “continue to rise in frequency, intensity, duration and spatial extent over the next decades,” meaning younger generations will experience far more of them.
The study estimates that under current climate policy pledges, children born in 2020 will experience two to seven times more extreme weather events, particularly heat waves, compared with people born in 1960.
“Our results highlight a severe threat to the safety of young generations and call for drastic emission reductions to safeguard their future,” the study authors state.
Canada, alongside the U.S. and Europe, has raised greenhouse gas emission targets ahead of the COP26 climate summit in Glasgow, Scotland in November.
Canada announced in July that it was raising its target to cut 40 to 45 per cent of its emissions below 2005 levels by 2030.
A UN report released in September said that current pledges to reduce emissions will still result in levels 16 per cent higher in 2030, pushing global warming close to 2.7 degrees Celsius by 2100.
The Paris Agreement, which Canada signed, was ratified around the goal of keeping global warming around 1.5 C to avoid catastrophic climate change.
The study posits that the land area affected by heat waves will increase from 15 percent to 22 per cent by 2100 under a scenario in which the Paris Agreement goal of limiting warming to 1.5 C is reached, but that figure jumps to 46 per cent when in line with current emission reduction pledges from nations.
When examining how younger generations will be faced with an increase in global warming and extreme events, the study combined life-expectancy data from different countries, climate models of extreme weather event projections and future global temperature trajectories from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5 C.
The results allowed researchers to examine lifetime exposure to climate extremes across birth cohorts – or generations – globally.
One example cited in the study is that a person born in 1960 will on average, experience two to four heat waves (defined by the study’s extreme heat wave classification) across their lifetime.
However a child born in 2020 will experience approximately nine to 30 heat waves under a scenario in which current climate pledges are honoured. The study authors say that number is reduced to seven to 22 heat waves if warming is limited to 2 C, or eight to 18 heat waves if pledges follow the Paris Agreement goal of limiting warming to 1.5 C.
The study authors applied their approach to other extreme events they analyzed — such as wildfires, crop failures, droughts, river floods, heat waves and tropical cyclones – generating a total of 273 global-scale projections.
“Our results highlight that lifetime exposure to each of the extreme events consistently increases for higher warming levels and younger [generations],” the study says.
If global warming increases by 3 C, the study approximates that a six-year-old in 2020 will experience twice as many wildfires and tropical cyclones, three times more river floods, four times more crop failures, five times more droughts and 36 times more heat waves compared to someone born in the 1960s.
Under a 3 C global warming simulation, children under the age of eight will face an “almost five-fold” increase in extreme weather even exposure, the study says.
The study also analyzed which global regions will see the biggest increase in exposure to extreme climate events, with a “particularly strong” increase in the Middle East and North Africa, with at least seven times higher exposure on average for all generations younger than 25 in 2020 under current emission reduction pledges.
The study says its findings “highlight the strong benefits” of countries following the Paris Agreement emission targets to “safeguard the future of current younger generations.”