Global warming of 3 degrees Celsius would destroy the planet

There is a very real opportunity the planet will heat up by an average of 3 degrees Celsius (5.4 degrees Fahrenheit) this century, which would be disastrous.

In such an incredibly hot world, scientists agree, deadly heat waves, horrible fires and damaging showers will come much more often and will be much harder than they are today. The ocean will also be warmer and more acidic, causing fish declines and is likely the end of coral reefs. In fact, a quarter of the species on Earth or may disappear in such conditions or to follow that path. Our coasts would be reshaped as a result of rising sea level on foot, for centuries, places of drowning such as Charleston, South Carolina Market Street, downtown Providence, Rhode Island and the Houston Space Center.

All of this, as climate scientist Daniel Swain of the University of California, Los Angeles, said, would be. bad: “Bad for humans. Bad for ecosystems. Bad for the stability of the Earth’s systems that we humans depend on for everything. ”

Experts cannot say exactly how far this future will go, as it depends on what humans do to alleviate the deterioration of the climate crisis, especially over the next decade. But for world leaders meeting in Glasgow this weekend for the 26th United Nations Climate Change Conference (COP26), that future could become inevitable if they do not comply with more aggressive and immediate measures to limit greenhouse gas emissions.

According to the Paris Climate Agreement, the global collective goal is to ensure that global temperature rises do not rise by more than 2 degrees Celsius (3.6 Fahrenheit) to a perfect 1.5 degree (2.7 Fahrenheit). But today we are on our way to almost double – 3 degrees which could be a disaster.

“I fear that without a science-based policy, and without achieving that ambitious goal, we will be facing a world of 3 degrees Celsius by the end of this century,” said Kim Cobb, a climate scientist and author at Georgia Tech. The latest report from the Intergovernmental Panel on Climate Change (IPCC) told BuzzFeed News. “It’s almost unimaginable, to be honest.”

So what can it be like to warm up to 3 degrees Celsius?

Starting point Measuring future warming is not the case today; It is the late 1800s, when reliable records of global temperature began to become available. More than a century later, the planet has already warmed slightly more than degrees Celsius (1.8 degrees Fahrenheit) due to the accumulation of fossil fuel pollutants in the atmosphere, such as carbon dioxide and methane. That’s average, though some places have already made it much hotter.

Adding 2 more degrees to more than one degree we have already added would make our world much hotter and disproportionately dry. Here’s why: About 70% of the planet is covered in water, and water heats up more slowly than Earth.

“If the whole world is to heat to 3 degrees Celsius,” Swain explained, “every area of ​​the earth must heat much more than that.”

That would probably be about 1.5 degrees Celsius warmer on average above ground, or collectively 4.5 degrees, according to Zeke Hausfather, a climate scientist and energy systems analyst at Breakthrough Institute. And it will probably be even hotter in the Arctic, that is heated approximately three times the rest of the planet.

One way to see what this might look like in the places we live in is to consider the number of days that the local temperature is 95 degrees Fahrenheit (35 degrees Celsius). At the beginning of this century, Arizona experienced about 116 days with high temperatures, Texas about 43 days, Georgia about 11 days, Montana about 6 days, and Massachusetts only one day. Climate Impact Lab modeling.

If global temperatures were to rise by an average of 3 degrees Celsius by 2100, those numbers would rise by approximately 95 degrees Fahrenheit between 179 and 229 days in Arizona, 135 to 186 days in Texas, and 85 to 143 days. Georgia, 46 to 78 days in Montana and 26 to 66 days in Massachusetts, according to the same analysis.

Only this summer, Northwest Pacific heat waves brought temperatures similar to Death Valley to British Columbia, Oregon and Washington, hundreds of people die would be at an event agreed by scientists “almost impossible”Without climate change. Then a he set a record for rain It fell about 9 inches in central Tennessee, killing about two dozen people. And last weekend, They fall more than 5 inches a day In the California capital Sacramento, setting a new record.

“What I’m thinking is, what would be a shocking event in a warmer 3 degree world?” said Swain.

It is impossible to know the exact answer. But the general contours of what it may look like are already clear: more common and intense extreme heat events, as well as frequent and intense showers, are also expected to be drier in that world. This is true almost anywhere on the planet.

“There are very few people on Earth who won’t see an increase in maximum precipitation intensity,” Swain said, “and it’s very likely that there will be zero spots that won’t increase on the hottest days.” ”

Statistics Final IPCC report supports this. What was considered a 10-year extreme heat event in the late 1880s, such as the heat wave, was more than 5.6 times more likely to occur in a world 3 degrees warmer. The result may be higher power costs as a result of an air conditioning explosion, which can lead to power supply problems. Those who do not have access to cooling may be exposed to more heat illness. And then there is the issue of water scarcity; along with constant heat waves, they can cause major crop failures.

Also, what was considered an extreme 10-year extreme rainfall event would be more than 1.7 times more likely. These types of disasters have historically flooded clean roads, homes and businesses and destroyed power lines.

Meanwhile, disasters in the region will also increase in frequency and intensity. Think of longer droughts and higher fires on the West Coast and stronger hurricanes on the Gulf Coast and East Coast. Worse, a phenomenon called “compositional catastrophe” could tell what happened to these events in succession or at the same time. It was a new example of this. Lake Charles, Louisiana, which suffered multiple disasters declared by the federal government last year: hurricanes, including a devastating Category 4 storm, a winter storm and then severe flooding.

In a 3 degree warmer world, the present-day coasts will largely disappear, and will be steadily reduced in the coming centuries by rising seas.

By the end of 2100, sea levels are expected to rise by an average of about 2 feet. That would be almost a disaster for the nations of the small islands. Most of the Maldives, large parts of the Bermuda archipelago, and some Seychelles islands, including its airport, may be flooded. So can large parts of the Thai capital Bangkok, where more than 5 million people live; The cities of Amsterdam, The Hague and Rotterdam in the Netherlands, combined, are home to about 2 million people; and much of the U.S. Gulf Coast, including parts of major cities like New Orleans and Galveston, Texas. These examples are based on mapping By the Climate Central research team, whose projections do not take into account current or future defenses built to deal with rising water levels.

The water will continue to rise for the next century and so on. So by jumping to 2,000 years in the future, Robert Kopp, a climate scientist at Rutgers University, expects water levels to be between 13 feet and 30 feet above the current level. This water, assuming no defense against rising levels, would likely flood parts of California Bay and Los Angeles and reconfigure many coasts in Texas, Louisiana, Mississippi, Alabama and Florida, according to Climate Central. mapping.

“About 12% of the world’s population living on Earth could be threatened by a 3-degree Celsius scenario in the long-term future sea level,” said Scott Kulp, a leading computational scientist at Climate Central. “So that’s 810 million people.”

The forecast for 2100 does not take into account the potential for rapid melting of the world’s ice sheets, and even longer-term estimates do not imply a complete rapid collapse, although it is possible. “The more we push the system above 2 degrees Celsius, but we don’t know how much, the more likely we are to launch layers of ice that can rapidly increase sea level rise,” Kopp explained in an email.

Most maybe The scary thing about a 3 degree warmer world is the uncertainty about how our so-called natural carbon sinks (think plants and trees, land, and even the ocean) will affect the way we regularly and consistently extract carbon dioxide from the air. . If one of these emissions stopped absorbing more carbon, more carbon would remain in the atmosphere, which would drive global warming.

Or one of the longer-term carbon sinks is likely to disappear. Right now, for example, there is a layer of frozen earth called permafrost, distributed in various parts of the planet, including the poles. Collectively, all this permafrost it stores more carbon than what is in the atmosphere today. As the planet warms, the permafrost layer will thaw, releasing some of that carbon into the atmosphere along the way and feeding more warming in a dangerous feedback loop.

“Right now they throw half of our emissions into the ground in a decade, natural carbon sinks that have operated at the same levels of service for a decade,” said Cobb of Georgia Tech. “So from now on, as a climate scientist, it’s very worrying to start to understand that there is a real risk that these natural carbon sinks will stop working even at higher heating levels.”

As Hausfather of the Breakthrough Institute said, “The thing is, even though we believe we are on our way to a 3 degree warmer world under current policies, we can’t rule out a 4 degree warmer world.” ●