Perhaps you’ve heard people in power on the news trying to claim that we stopped using the term “global warming,” because the Earth isn’t getting warmer. This is far from the truth. In order to understand why we went from saying “global warming” to “climate change,” we need to understand how the two terms differ and a bit about where each term came from.
What’s the difference between global warming and climate change?
Think of global warming like one piece of climate change. According to NASA, “Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere.”
NASA states that since 1880, Earth’s average surface temperature has risen by about 1 degree Celsius, or 1.8 degrees Fahrenheit, with the trend currently sitting at a 0.2 degrees Celsius increase every decade.
The key to the term “global warming” is that it describes warming that is caused by human activities.
On the other hand, climate change refers to both human and naturally produced warming and the effects that this warming has on our planet. NASA defines climate change as, “a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates. These changes have a broad range of observed effects that are synonymous with the term.”
This is an important distinction, because we can observe climate change in several ways. Some of the key indicators of climate change include:
- Rising sea levels
- Ice loss at Earth’s poles
- Global land and ocean temperature increases
- Receding mountain glaciers
- Changes in the frequency and severity of extreme weather
Why did we start calling global warming “climate change”?
Now that we understand the difference between global warming and climate change, why did “climate change” replace “global warming” as the mainstream term to describe this scientific phenomena?
According to The Guardian, in 1896, Swedish scientist, Svante Arrhenius, studied ice ages, and whether fluctuations in atmospheric CO2 levels could be the cause. He found that if the amount of carbon dioxide in the atmosphere were cut by half, then the average global surface temperature would decrease by about 4 or 5 degrees Celsius. At the same time, he also introduced the idea that a 50% increase in global atmospheric CO2 levels would result in a global average temperature increase between 5 and 6 degrees Celsius.
Around the same time, the United States and many European countries were powering the industrialization of their economies with coal, and pumping carbon dioxide into the atmosphere at a rate way beyond natural levels, contributing to a rise in the global average temperature.
Flash forward nearly 100 years later to 1988. According to the New York Times, the term “global warming” was popularized after Dr. James Hansen, director of NASA’s Institute for Science Studies in Manhattan, testified before the Energy and Natural Resources Committee of the United States Senate that the record high temperatures were the result of human activity.
In a now famous testimony, Dr. Hansen stated: “the earth is warmer in 1988 than at any time in the history of instrumental measurements. The global warming now is large enough that we can ascribe with a high degree of confidence a cause-and-effect relationship to the greenhouse effect … Our computer climate simulations indicate that the greenhouse effect is already large enough to begin to affect the probability of extreme events such as summer heat waves.”
The switch in preference from global warming to climate change occurred gradually. The Washington Post identifies a few key events that helped the switch:
In a 2005 pamphlet, the National Academies of Sciences stated that, “the phrase ‘climate change’ is growing in preferred use to ‘global warming’ because it helps convey that there are changes in addition to rising temperatures.”
Then in 2006, the Environmental Protection Agency retitled its website on the issue from “global warming” to “climate change.”
The Bush administration also preferred to use the term “climate change.” As the Washington Post reported, there could have been political motivations for the preference. In a 2002 memo, Republican consultant Frank Luntz wrote, “‘climate change’ is less frightening than ‘global warming. While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge.”
Though climate change has surpassed global warming as the more popular term, both are still an accurate depiction of the increase in Earth’s average surfae temperature. Yes, the Earth is still warming, and yes, measures need to be taken by individuals, corporations, and governments if we are going to have any hope of curbing the rise of the average surface temperature.