The climate has continuously fluctuated over the 4.6 billion years of Earth’s history. The planet has gone through ice ages and interglacial periods, evolving like a living organism. Recently, some experts have downplayed the current climate crisis, arguing that “it was even hotter in the past” and that “today’s climate is just part of a natural cycle.”
The real issue lies in the speed and cause of the warming. How fast temperatures rise is a critical factor because it directly affects the survival of all living organisms, including humans. Rapid climate change can lead to the extinction of species before they have a chance to adapt.
The Guardian recently ran a feature comparing past and present extreme heat, illustrating the severity of the current climate crisis. Matthew Huber, a historical climate expert at Purdue University, explained that the Eocene epoch, lasting from 56 million to 34 million years ago, was about 10 to 15 degrees Celcius1(8 to 27 degrees Fahrenheit) hotter than today.
However, Huber emphasized that the temperature increase during the Eocene was gradual and occurred over a long period. In contrast, today’s climate change is vastly different. Global temperatures have risen by 1 degree Celcius (1.8 degrees Fahrenheit) in just over 100 years—a historically unprecedented event.
Huber noted, “Humans have not faced a climate like this over our long history; we are starting to hit unprecedented temperatures.”
For the past 10,000 years, humanity has lived in a Goldilocks zone, where the climate has been just right for life to thrive. This stable climate allowed humans to evolve, settle, and build civilizations.
“The climate settled on an even keel; people could settle in one place, and civilization started,” Huber said.
This period is known as the Holocene, which lasted from about 12,000 years ago to the present. However, the Guardian reports that many experts believe the Holocene has ended and now prefer the new term Anthropocene. This new era is defined by rapid changes caused by human activity, which has led to unprecedented environmental shifts in a relatively short time.
Paleoclimatologists use data from tree rings, ice cores, and ocean sediments to study past climates. Many experts focus on temperature levels and the rate at which temperatures are rising.
About 55 million years ago, during a period known as the Paleocene-Eocene Thermal Maximum, carbon dioxide (CO2) levels in the atmosphere rose, causing temperatures to increase by at least 5 degrees Celcius (9 degrees Fahrenheit). However, this change occurred slowly over thousands of years, allowing life on Earth to adapt.
In contrast, today’s climate crisis is unfolding much faster. Global temperatures have risen by more than 1 degree Celcius (1.8 degrees Fahrenheit) in just over a century. Lina Pérez-Angel, a paleoclimatologist at Brown University, explained that this 100-year span is “a blink of an eye in Earth’s history,” she noted, “There has never been such rapid change in Earth’s history.”
Jason Smerdon, a Columbia University climate scientist, added that it’s hard to find any historical precedent for such rapid climate change. He compared the rate of post-glacial warming to walking, whereas the predicted 3 degrees Celcius (5.4 degrees Fahrenheit) rise by 2100 would be like driving a car at 257 km/h (160 mph)
Another issue besides the rapid rise in temperatures is the cause of this change. While past climate changes were driven by natural cycles, today’s crisis is primarily caused by human activities. Burning fossil fuels, transportation, and energy consumption have led to a sharp increase in CO2 levels.
It is estimated that the last time CO2 levels were this high was about 3 million years ago. Until about 800,000 years ago, atmospheric CO2 levels never exceeded 300 parts per million (ppm). Today, they have soared past 400 ppm, with NASA’s climate data showing a record of 427 ppm.
Experts calling for the term Anthropocene argue that urgent global action is needed to address the climate crisis. Despite the 2015 Paris Climate Agreement, where more than 190 countries agreed to reduce greenhouse gas emissions, CO2 levels continue to rise.
While experts call for urgent, science-based actions, many governments remain indifferent.
Most Commented