When Was Climate Change Discovered and How Long Has It Been an Issue?

Thanks to Earth-orbiting satellites and modern-day technology, scientists have been able to provide unequivocal evidence that the world is warming. But the concept of climate change has been known to humans for centuries.

Climate change first became front-page news in 1988, after a dire warning from James Hansen, who served as director of NASA's Goddard Institute for Space Studies, clearly linking human activity to global warming. His statement was built on decades of research into the planet's climate systems.

"It has not been one eureka moment, but rather a gradual awareness," Yves Plancherel, a climate change researcher and affiliate with Imperial College London's Grantham Institute for Climate Change and the Environment, told Newsweek. "The first calculations of the atmosphere increasing temperatures on the Earth were in the early 1800s...Very early on they discovered that there would be significant warming if carbon dioxide levels were to increase."

French physicist Joseph Fourier first described the greenhouse effect in 1824, whereby light energy from the sun passes through the atmosphere and is converted into heat energy that is trapped in the lower atmosphere. He suggested that there must be something in the atmosphere acting like an insulating blanket to keep the heat energy in.

Just over a decade later, American scientist Eunice Foote concluded that this blanket likely contained carbon dioxide and water vapor, and that an increase in these gasses in the Earth's atmosphere would lead to considerable global warming. Her conclusions were later confirmed by Irish physicist John Tyndall in 1861.

Since the late 19th century, Earth's average temperatures have been steadily increasing, although most of this warming has occurred in the last 40 years. Throughout its history, the Earth's climate has changed considerably, with eight cycles of ice age in the last 800,000 years alone. However, the current warming trend is proceeding at a rate not seen for millennia and 97 percent of scientists agree that this trend is a direct result of human activities.

In 1896, 10 years after the invention of the first true automobile, the Motorwagen, Swedish chemist Svante Arrhenius predicted that atmospheric carbon dioxide, brought about by the burning of fossil fuels, could lead to a substantial increase in average global temperatures.

"At the time it wasn't really an issue as we'd just started to use fossil fuels," Plancherel said.

It was not until 1938 that British engineer Guy Callendar was able to demonstrably link global warming with rising levels of atmospheric carbon dioxide. Even then, meteorologists at the time largely dismissed his work.

"In the 1950s and '60s, the first measurement programs started to be put in place," Plancherel said.

In the 1960s, Syukuro Manabe of Princeton University led the development of the first physical models for climate change, for which he jointly won the Nobel Prize in Physics in 2021. "He developed the first robust predictions of Earth's climate that actually included the role of water vapor in the atmosphere," Plancherel said. "And from that moment on, people started to work on climate modeling with increasingly better predictions."

Today, data is gathered from ancient and contemporary sources, from ice cores and tree rings to satellites and weather balloons. "The data help the modeling community refine the models that they are developing so that they are increasingly accurate," Plancherel said. "The early models were scientific curiosities...Nowadays, climate models are becoming tools that we can use for business decisions."

Plancherel and his team have been using AI to make comparisons between different models and improve model resolution to make even more accurate predictions. "Nowadays, we are at a stage where we don't really need to convince the world that climate change is real because the effects are being felt already," he said. "The goal now is not so much to predict but to adapt."