Human activities have transformed the planet at a pace and scale unmatched in recorded history, causing irreversible damage to communities and ecosystems, according to one of the most definitive reports ever published about climate change. Leading scientists warned that the world’s plans to combat these changes are inadequate and that more aggressive actions must be taken to avert catastrophic warming.
World is on brink of catastrophic warming, UN climate change report says
A dangerous climate threshold is near, but ‘it does not mean we are doomed’ if swift action is taken, scientists say
By Sarah Kaplan
March 20, 2023
A
Chinese state-owned coal-fired power plant near a solar farm project
under construction on a lake caused by a collapsed and flooded coal mine
in Huainan in 2017. (Kevin Frayer/Getty Images)
At our current global pace of carbon emissions, the world will burn through its remaining “carbon budget” by 2030.
Doing so would put the long-term goal of keeping global warming to 1.5
degrees Celsius (2.7 degrees Fahrenheit) irrevocably out of reach.
Why the goal of 1.5 degrees Celsius?
Keeping warming below this threshold would help save the world’s coral reefs and preserve the Arctic’s protective sea ice layer. It could also stave off dramatic sea level rise by avoiding further destabilization in Antarctica and Greenland.
So where do we stand now?
The world has already warmed more than 1.1 degrees Celsius (2 degrees Fahrenheit) above preindustrial temperatures. We charted over 1,200 different scenarios for climate change over the coming century; of those, 230 pathways achieve the warming goal — although only 112 may be realistic.
What can be done?
Not
all hope is lost. Tackling global warming is an enormous feat, but
there are many people, organizations and activists making bold strides.
We’re tracking their stories in our Climate Solutions section.
The report released Monday from the United Nations’ Intergovernmental Panel on Climate Change found the world is likely to miss its most ambitious climate target — limiting warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial temperatures — within a decade. Beyond that threshold, scientists have found, climate disasters will become so extreme people cannot adapt. Heat waves, famines and infectious diseases will claim millions of additional lives. Basic components of the Earth system will be fundamentally, irrevocably altered.
Monday’s assessment synthesizes years of studies on the causes and consequences of rising temperatures, leading U.N. Secretary General António Guterres to demand that developed countries like the United States eliminate carbon emissions by 2040 — a decade earlier than the rest of the world.
With few nations on track to fulfill their climate commitments and with the developing world already suffering disproportionately from climate disasters, he said, rich countries have a responsibility to act faster than their low-income counterparts.
The world already has all the knowledge, tools and financial resources needed to achieve its climate goals, according to the IPCC. But after decades of disregarding scientific warnings and delaying climate efforts, it adds, humanity’s window for action is rapidly closing.
“Climate change is a threat to human wellbeing and planetary health,” the report says. “The choices and actions implemented in this decade will have impacts now and for thousands of years.”
Calling the report a “how-to guide to defuse the climate time-bomb,” Guterres announced on Monday an “acceleration agenda” that would speed up global actions on climate.
Emerging economies including China and India — which plan to reach net zero in 2060 and 2070, respectively — must hasten their emissions-cutting efforts alongside developed nations, Guterres said.
Both the U.N. chief and the IPCC also called for the world to phase out coal, oil and gas, which are responsible for more than three quarters of global greenhouse gas emissions.
“Every country must be part of the solution,” Guterres said. “Demanding others move first only ensures humanity comes last.”
A stark scientific outlook
Already, the IPCC’s synthesis report shows, humanity has fundamentally and irreversibly transformed the Earth system. Emissions from burning fossil fuels and other planet-warming activities have increased global average temperatures by at least 1.1 degrees Celsius (2 degrees Fahrenheit) since the start of the industrial era. The amount of carbon dioxide in the atmosphere hasn’t been this high since archaic humans carved the first stone tools.
These changes have caused irrevocable damage to communities and ecosystems, evidence shows: Fish populations are dwindling, farms are less productive, infectious diseases have multiplied, and weather disasters are escalating to unheard of extremes. The risks from this relatively low level of warming are turning out to be greater than scientists anticipated — not because of any flaw in their research, but because human-built infrastructure, social networks and economic systems have proved exceptionally vulnerable to even small amounts of climate change, the report said.
The suffering is worst in the world’s poorest countries and low-lying island nations, which are home to roughly 1 billion people yet account for less than 1 percent of humanity’s total planet-warming pollution, the report says. But as climate disruption increases with rising temperatures, not even the wealthiest and most well-protected places will be immune.
The researchers say it’s all but inevitable that the world will surpass 1.5 degrees Celsius of warming by the early 2030s — pushing the planet past a threshold at which scientists say climate change will become increasingly unmanageable.
In 2018, the IPCC found that a 1.5C world is overwhelmingly safer than one that is 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than the pre-industrial era. At the time, scientists said humanity would have to zero out carbon emissions by 2050 to meet the 1.5-degree target and by 2070 to avoid warming beyond 2 degrees.
Five years later, humanity isn’t anywhere close to reaching either goal. Unless nations adopt new environmental policies and rapidly shift their economies away from fossil fuels, the synthesis report says, global average temperatures could warm by 3.2 degrees Celsius by the end of the century. In that scenario, a child born today will live to see several feet of sea level rise, the extinction of hundreds of species and the migration of millions of people from places where they can no longer survive.
“We are not doing enough, and the poor and vulnerable are bearing the brunt of our collective failure to act,” said Madeleine Diouf Sarr, Senegal’s top climate official and the chair for a group of least developed countries that negotiate together at the U.N.
She pointed to the damage wrought by Cyclone Freddy, the longest-lasting and most energetic tropical storm on record, which has killed hundreds of people and displaced thousands more after bombarding southern Africa and Madagascar for more than a month. The report shows that higher temperatures make storms more powerful and sea level rise makes flooding from these storms more intense. Meanwhile, the death toll from these kinds disasters is 15 times higher in vulnerable nations than in wealthier parts of the world.
If the world stays on its current warming track, the IPCC says, global flood damages will be as much as four times higher than if people limit temperature rise to 1.5 degrees Celsius.
“The world cannot ignore the human cost of inaction,” Sarr said.
The price of delay
Though much of the synthesis report echoes warnings scientists have issued for decades, the assessment is notable for the blunt certainty of its rhetoric. The phrase “high confidence” appears 118 times in the 26-page summary chapter. Humanity’s responsibility for all the warming of the global climate system is described as an unassailable “fact.”
Yet the report also details how public officials, private investors and other powerful groups have repeatedly failed to heed those warnings. More than 40 percent of cumulative carbon emissions have occurred since 1990 — when the IPCC published its first report on the dangerous consequences of unchecked warming. The consumption habits of the wealthiest 10 percent of people generate three times as much pollution as those of the poorest 50 percent, the report said.
Decades of delay have denied the world any hope of an easy and gradual transition to a more sustainable economy, the panel says. Now, only “deep, rapid and … immediate” efforts across all aspects of society will be able to stave off catastrophe.
“It’s not just the way we produce and use energy,” said Christopher Trisos, director of the Climate Risk Lab in the African Climate and Development Initiative at the University of Cape Town and a member of the core writing team for the synthesis report. “It’s the way we consume food, the way we protect nature. It’s kind of like everything, everywhere, all at once.”
But few institutions are acting fast enough, the report said. November’s U.N. climate conference in Egypt ended without a resolution to phase down oil, gas and coal — a baseline requirement for curbing climate change. Last year, China approved its largest expansion of coal-fired power plants since 2015. Amid soaring profits, major oil companies are dialing back their clean-energy initiatives and deepening investments in fossil fuels.
Humanity is rapidly burning through the amount of pollution the world can afford to emit and still meet its warming targets, the IPCC said, and projected emissions from existing fossil fuel infrastructure will make it impossible to avoid the 1.5-degree threshold.
Yet even as environmental ministers met in Switzerland last week to finalize the text of the IPCC report, the U.S. government approved a new Arctic drilling project that is expected produce oil for the next 30 years, noted Hans-Otto Pörtner, a climatologist at Germany’s Alfred Wegener Institute and a co-author of a dozen IPCC reports, including the latest one.
“These decisions don’t match reality,” he said. “There is no more room for compromises.”
Failure to act now won’t only condemn humanity to a hotter planet, the IPCC says. It will also make it impossible for future generations to cope with their changed environment.
There are thresholds to how much warming people and ecosystems can adapt to. Some are “soft” limits — determined by shortcomings in political and social systems. For example, a low-income community that can’t afford to build flood controls faces soft limits to dealing with sea level rise.
But beyond 1.5 degrees of warming, the report says, humanity will run up against “hard limits” to adaptation. Temperatures will get too high to grow many staple crops. Droughts will become so severe that even the strongest water conservation measures can’t compensate. In a world that has warmed roughly 3 degrees Celsius (5.4 degrees Fahrenheit) — where humanity is currently headed — the harsh physical realities of climate change will be deadly for countless plants, animals and people.
‘It does not mean we are doomed’
Despite its stark language and dire warnings, the IPCC report sends a message of possibility, said Friederike Otto, a climate scientist at Imperial College London and a member of the core writing team for the report.
“It’s not that we are depending on something that still needs to be invented,” she said. “We actually have all the knowledge we need. All the tools we need. We just need to implement it.”
In many regions, the report says, electricity from renewable sources like solar and wind is now cheaper than power from fossil fuels. Several countries have significantly reduced their emissions in the past decade, even as their economies grew. New analyses show how efforts to fight climate change can benefit society in countless other ways, from improving air quality to enhancing ecosystems to boosting public health. These “co-benefits” well outweigh the costs of near-term emissions reductions, even without accounting for the long-term advantages of avoiding dangerous warming.
Report authors say the IPCC’s assessment comes at a moment of truth for climate action. Starting this year, nations are required to start updating the emissions-cutting pledges they made in Paris in 2015.
The pledges are far from sufficient to fulfill the goals of the Paris agreement, the IPCC says, and most nations are not on track even to meet even those targets. Countries must cut their greenhouse gas emissions by almost half before 2030 for the world to have a 50-50 chance of limiting warming t0 1.5 degrees, the report said.
Unless the world commits to much deeper and faster emissions this decade, it will probably be impossible to limit warming to 1.5 or even 2 degrees Celsius, the IPCC said. People will live with consequences of that failure for hundreds, if not thousands, of years.
“This is a truly a unique moment to be alive," said Kaisa Kosonen, a climate expert for Greenpeace International who represented the nonprofit at the synthesis report approval meeting last week. “The threats are bigger than ever before, but so are our opportunities for change.”
The need to consider climate change’s unequal impacts is a through line in this latest IPCC report. costs of climate change. At last year’s U.N. climate conference, nations agreed to establish a fund that would help pay vulnerable communities for irreversible harms. By the time diplomats meet again in Dubai in December, they are expected to hash out the details of that fund, determining who deserves compensation and who should be on the hook for the bill.
The need to consider climate change’s unequal impacts is a through line in the latest IPCC report. Stronger social safety nets and “redistributive policies that shield the poor and vulnerable” can help build support for the kind of disruptive changes needed to curb carbon emissions, it says. Sharing resources with low-income countries and marginalized communities is necessary to enable them to invest in renewable energy and other forms of sustainability.
“It gives a goal to work towards, to a world that looks different,” Otto said of the report. “It does not mean we are doomed."