At the start of the last decade, Kallan Benson was 5 years old, her favorite story was “The Secret Garden,” and Earth was in the midst of its warmest year on record. Benson had heard about climate change (her mother is an environmental scientist), but she didn’t know world leaders had just signed an agreement calling it “one of the greatest challenges of our time.” She cared about Earth, but she trusted adults to protect it.
She doesn’t feel that way anymore.
By the final year of the decade, the planet had surpassed its 2010 temperature record five times. Hurricanes devastated New Jersey and Puerto Rico and floods destroyed the Midwest and Bangladesh. Southern Africa was gripped by a deadly drought. Australia and the Amazon are ablaze. Global emissions are expected to hit an all-time high this year, and humanity is on track to cross the threshold for tolerable warming within a generation.
The 2010s were a “decade of disappointment,” said Benson, now 15 and a national coordinator for the youth climate organization Fridays for Future. If the world is to stave off further disasters, the next decade must be one of unprecedented climate action, she said.
“This decade that we’re going into now will be the most important of our lives,” Benson said. “We’re kind of running out of options. And we’re running out of time.”
Ten years ago, the United Nations released its first “emissions gap” report detailing the disparity between commitments made by nations to reduce greenhouse gases and what is needed to meet global temperature targets. It estimated that countries should be curbing emissions about 3 percent per year.
But that hasn’t happened, said Surabi Menon, vice president for global intelligence at the ClimateWorks Foundation and a steering committee member for the U.N.’s emissions gap reports. “We’ve left ourselves with a very narrow window to take the kind of action that needs to be taken,” she said.
Promises fall short
The 2015 Paris Climate Accord — the first-ever global agreement to limit warming to “well below 2 degrees Celsius” — was important, Menon said. But the promises made at that meeting fell short. According to the latest emissions gap report, temperatures can be expected to rise 3.2 degrees Celsius above pre-industrial levels by the end of the century, unless the world’s top emitters increase their Paris commitments.
Right now, most aren’t on track to meet even their most modest targets. The world is already about 1 degree Celsius warmer than it was before humans started burning fossil fuels. Global annual emissions have increased 4 percent since the Paris agreement was signed. And the average concentration of carbon dioxide in the atmosphere — “the only number that matters,” in the words of Phil DeCola, chief scientist for the World Meteorological Organization’s greenhouse gas monitoring program — is the highest in human history.
Meanwhile, improved scientific models found that even 2 degrees of warming — once thought to be a reasonable target — could be practically intolerable in parts of the world. To get on track to achieve a less disastrous 1.5 degrees temperature rise, a landmark U.N. report found that nations must nearly halve emissions by 2030.
The U.N.’s 1.5 degree analysis provoked widespread alarm after it was published in 2018. Politicians referred to the report at rallies, teenagers quoted it during school walkouts. “If we don’t do something by then,” 14-year-old climate activist Alexandria Villasenor said in February, referring to 2030, “it will be the end of my world.”
But climate scientists caution against treating 2030 as a deadline, and 1.5 degrees as a threshold for extinction.
“Climate change is not a cliff, it’s not a pass-fail course,” said Georgia Tech researcher Kim Cobb. “If we meet the 1.5 target, there may still be tons of ugly surprises. And if we don’t meet it, it’s not that everybody’s going to die.”
According to Cobb, the report is better understood as a road map for navigating the perilous path to sustainability.
“Our decisions over the next 10 years will affect the magnitude of climate change for centuries to come,” she said. “I don’t think it can get more sobering than that.”
The first and most important step will be to reduce fossil-fuel consumption, experts say. According to the latest emissions gap analysis, the past 10 years of inaction have more than doubled the rate at which emissions must fall; to meet the 1.5 degree goal, emissions must be cut by 7.6 percent each year.
Such action would require “unprecedented transformation of society,” the report acknowledged.
But many of the solutions needed — both economic and technological — already exist. The report called on the global community to replace coal power with renewable energy, decarbonize transportation and manufacturing, and help developing nations build green infrastructure to meet their growing power needs.
Ending subsidies for fossil fuels could reduce global emissions 10 percent by 2030, the U.N. has found. And eliminating “short-lived” greenhouse gases — including methane, black carbon and fluorinated gases, which linger in the atmosphere less than carbon dioxide but trap more heat — over the next 20 years could help Earth avoid between 0.6 and 0.8 degree of warming by 2050, research suggests.
