Global Warming: Time’s Almost Up
With climate change, the world is approaching several tipping points. Experts say there’s still time to prevent existential collapse, but some damage is already permanent.
If 2030 is truly the year when some effects of the climate crisis become irreversible, the world is at T minus 8 and counting down. That’s the dire word from the United Nations and its recent report on the world’s “climate emergency,” one of three reports the UN Intergovernmental Panel on Climate Change (IPCC) has been tasked with crafting before the end of 2022.
Each looks to be more cautionary than its predecessor. “IPCC Sixth Assessment: Impacts, Adaptation and Vulnerability” lays it out in a no-BS manner: “Unless we act now, multiple crucial planetary systems are on the cusp of permanent damage.”
For several decades, scientists have set a 1.5 degrees Celsius (2.7 degrees Fahrenheit) global temperature increase as the threshold at which the planet can survive, and perhaps repair any environmental damage. That increase originally was expected to be reached by 2100, but more-recent research reveals the process is happening faster and more severely than expected.
Mid-century is now the likely point at which climate change can’t be reversed, and some permanent negative effects could begin to appear in as little as eight years, under the world’s current 1.1 degree C increase, IPCC notes.
“The cumulative scientific evidence is unequivocal,” says Maarten van Aalst, a climate scientist who heads the Red Cross Red Crescent Climate Centre in Enschede, the Netherlands, and a co-author of the report. “Any further delay in global action on adaptation and mitigation will miss a brief and rapidly closing window of opportunity to secure a livable and sustainable future for all.”
There are nine essential systems in Earth’s environment that are threatened by the climate crisis, the collapse of any of which could throw the planet into functional chaos. Several collapses in quick succession could be catastrophic. Click image to see a larger version. Source: Carbon Brief
Although the world’s response window is quickly closing, there’s still time to avoid the worst, according to the report’s authors. A lot depends on whether the planet reaches a series of “tipping points” within the next few years. These sinister benchmarks include:
Death of the Coral Reefs
Coral reefs protect coastlines from storms and erosion, are the source of new medicines, and provide food to millions of people. But they can survive only within a narrow temperature band, the report notes.
The coral that build them get much of their food from algae living in their tissues. When the seawater is too warm, the coral expel algae, causing the coral to turn white or “bleach.” If it lasts too long, the coral starve and a thriving ecosystem becomes a graveyard of dead shells. An unrelated 2021 IPCC report revealed that almost 15 percent of the planet’s reefs have vanished since 2009, largely due to climate change.
Melting of the Ice Sheets
The Antarctic and Greenland ice sheets are melting quickly. Loss of the Antarctic sheet could result in up to an 11-foot rise in ocean level; loss of the Greenland sheet could mean an increase of 23 feet. Though a total meltdown with that kind of damage is projected to take more than a century, it will still mean having to relocate coastal cities worldwide before then.
The Atlantic Ocean’s Circulation Stops
The Atlantic Thermohaline Circulation impacts global weather patterns dramatically. A complete collapse could result in a European and North American ice age, accompanied by higher sea levels in coastal cities.
A process known as the Atlantic Meridional Overturning Circulation (AMOC) keeps warmer tropical water flowing north along the coast of northern Europe to the Arctic, where it cools and sinks to the bottom of the ocean. That cooler water is then pulled back southward along the coast of North America.
This circular cycle keeps northern Europe several degrees warmer than it would otherwise be. Some recent research indicates the AMOC system has gradually weakened over the past few decades, and it may soon be “critically unstable,” collapsing in 50 to 250 years.
The “Snow Forest” Disappears
Cold-weather boreal forests that run across the Western United States, Canada, and Alaska store more than 30 percent of all forest carbon on the planet. Without them—a distinct possibility over the next 50 years due to warmer temperatures, fire, and insect-induced damage—huge amounts of greenhouse gasses would be released into the atmosphere, worsening global warming. Dead trees are also fire hazards and would be replaced by grasslands, which are less productive at CO2 storage.
The Amazon Rainforest Becomes a Savanna
Similar to the fate of the snow forest, the 2.5 million square mile Amazon rainforest—home to an estimated 30 percent of the world’s species, and capable of creating its own rainfall—is dying due to rising temperatures, drought, fires, and clearcutting. Anything destroyed will be replaced by grasslands with few trees.
A March 2022 report by British and German researchers estimates that 75 percent of the Amazon is headed toward its own tipping point, although no exact date of that status has been determined—yet.
Any of these collapses, even partial, would be disastrous for life on Earth, experts note. And, systems that become unstable will affect others, leading to more instability and potential collapse. “I’ve seen many scientific reports in my time, but nothing like this,” says UN secretary-general António Guterres. “It is a damning indictment of failed climate leadership.”
Call to Action
An estimated 3.6 billion people—more than 40 percent of the world’s population—are highly vulnerable to climate change, according to the study. From 2010 to 2020, 15 times more people died from floods, droughts, and storms in very vulnerable regions, including parts of Africa, South Asia, and Central and South America, than in other parts of the world.
“Any more delay in climate action is going to close off opportunities to head off the worst impacts of climate,” says report co-author Sarah Cooley, director of climate science at the Ocean Conservancy in Washington, D.C. “But the good news is, there are more details than ever about how the global community can meet the challenge effectively, despite our slow start.”
Adaptation is crucial. Feasible solutions already exist, but more support must reach vulnerable communities, the report notes. At least 170 countries’ climate policies now include adaptation, but many have yet to move beyond planning into implementation.
The good news is that existing adaptation options can reduce climate risks if they are sufficiently funded and implemented with more speed and urgency.
These options include ecosystem-based adaptation, which includes the protection, restoration, and sustainable management of ecosystems to more sustainable agricultural practices like integrating trees into farms, increasing crop diversity, and planting trees in pastures.
Ecosystem-based adaptation can reduce already-present climate risks—including droughts, extreme heat, floods, and fires—while aiding biodiversity, livelihoods, health, food security, and carbon sequestration.
New technologies are another factor. Combining nature-based solutions with engineered options such as flood control channels may help reduce water-related and coastal risks, particularly in cities, the report notes. Access to better technologies can also help strengthen resilience.
Experts note that this is where upgraded methods of clean energy such as wind and solar, more-efficient use of building materials, and earth-friendlier structural design can boost resistance to a raging climate. They might even reduce and perhaps reverse the environmental damages that are expected to come.
The Ross Ice Shelf, Antarctica’s largest at 500 miles wide, 350 miles long, and 500 feet tall, is among those threatened by climate change. Credit: Michael Van Woert/NOAA
Deforestation has occurred in 20 percent of the Amazon rainforest—shown in the rectangular light green and brown regions—to the benefit of cattle ranchers and food farmers. Meanwhile, society could lose the planet’s largest supplier of clean air by the century’s end. Credit: Sentinel Hub/Flickr
Boreal forests, such as this one in Alaska, could be nearly extinct within 50 years, threatening the planet’s ability to decarbonize 30 percent of its CO2. Credit: Kristine Sowl/USFWS-YDNRW
Coral reefs, which protect coastlines from storms and erosion, are on the verge of starvation due to warming waters. Credit: prilfish/Flickr
Climate change poses a risk to life-supporting systems, from ecosystem structure to length of time between ecological events. Source: UN Intergovernmental Panel on Climate Change (IPCC) “IPCC Sixth Assessment: Impacts, Adaptation and Vulnerability” report