Gardner variety: climate change vs. global warming
Climate change. Global warming.
It’s easy to confuse the two terms. They’re often used interchangeably by members of the media. In reality, however, they describe separate, though related, descriptions of global climate phenomena.
When scientists use the term “climate change,” they are referring to significant and lasting changes recorded in global weather patterns over periods ranging from decades to millions of years.
The phenomenon — the main area of concern in the field of paleoclimatology — is well documented throughout Earth’s history — e.g., the various ice ages and period following the mass extinction of dinosaurs.
Researchers are able to assess past climate conditions by obtaining data previously preserved within rocks, sediments, ice sheets, tree rings, corals, shells and microfossils, among others.
Each of these entities contain preserved physical characteristics, enabling researchers to reconstruct climate patterns for periods far preceding human existence.
Global warming, on the other hand, is used to describe the current change in Earth’s climate. Since the early 20th century, the global air and sea surface temperature has increased by approximately 1.4 degrees Fahrenheit, with roughly two-thirds of the increase occurring since 1980.
The most important distinction between the two terms revolves around us, incidentally.
Global warming, when described by scientists, reflects the current changes in climate believed to have been caused by human activity, according to a recent study presented to the United Nations by the Intergovernmental Panel on Climate Change.
I want to shift the focus to climate change, however, because it shouldn’t be controversial. It’s treated as if it were a dirty word, and I think that’s mostly a result of misinformation.
Drastic shifts in weather patterns have been well documented throughout the Earth’s approximate 4.5 billion year history. So what do we have to account for such dramatic changes?
In short, a ton.
Earth’s climate system can generally be divided into five sections, which include the atmosphere, or the layer of gases surrounding the Earth; the hydrosphere, or combined mass of water found on the planet; the cryosphere, all frozen water on Earth; the lithosphere, which is restricted to the surface soils, rocks, and sediments; and the biosphere, which represents the global sum of all living ecosystems.
Natural changes to any of these components results in climate variability, or short-term conditions that deviate from expected weather patterns.
For example, when a volcano erupts, an excess of gases and particle matter are released into the atmosphere, inhibiting the amount of solar energy reaching the surface of the Earth. The resulting effect is a cooling of temperatures.
The eruption of Mount Tambora in Indonesia in 1815 led to temperatures falling by roughly 0.7-1.3 degrees Fahrenheit, depending on the region.
This doesn’t sound like a dramatic shift, but the event — dubbed the “Year Without a Summer” — led to widespread agricultural disaster, famine, and hundreds of thousands of deaths.
Many of these shifts, whether you’re looking at short-term changes in oceanic temperatures or gradual, long-lasting transitions, such as the melting of ice caps, directly affect one another. When the cryosphere begins to melt, the hydrosphere grows larger, in effect altering certain member’s of the biosphere’s ability to survive.
That, in turn, can affect the atmosphere through fluctuating oxygen and carbon dioxide levels resulting from photorespiration.
In that sense, the Earth can almost be viewed as a living, breathing organism in and of itself. The Earth, like our species, is constantly evolving. It will adapt. It will survive.
The same cannot be said about the living organisms it contains. Drastic changes in climates have decimated global populations in the past. We may think we’re special, but we’re not. So let’s start paying attention.
Wesley Gardner can be reached at firstname.lastname@example.org