Climate Crisis or a Bit of Stormy Weather?

We hear about climate a lot now. Have you ever wondered about the difference between climate and weather? Weather is a word used to describe the state of the atmosphere with respect to heat, cold, wetness, dryness, calm, storm, etc., and climate describes long-term weather, for example, tropical climate.

Recently there has been interest in historical accounts of weather recordings by monks over date ranges spanning ~400 to 1600 A.D. In some cases, these accounts tell us about past weather and climate. Through science, we do not have to rely on accounts of medieval monks because many scientific methods provide reliable information concerning the past climate. The scientific term for this is proxy (climate proxies).

There are many kinds of proxies. Simple examples include certain types of chemical indicators and pollen. Almost all chemical reactions vary in progression based on temperature. Pollen tells what types of plants are around, and we know that some plants grow in warm climates and some grow in cooler climates.

We have an excellent idea that reconstruction of past climate using proxies is valid. First, we know this because, simply speaking, the laws of physics and chemistry govern proxies. Second, we know this because we can compare proxy results to human records, including those of medieval monks. Proxies give a record of past climate going far back. They can also provide clues about influencing factors. For instance, scientists have analyzed tiny air bubbles trapped in ice that formed in the distant past to understand how the concentrations of gases in the atmosphere have changed over time.

Of course, the gases in the atmosphere are not the only thing that controls climate, but they do have a large effect. A former colleague at the Meadows Center described the effect in terms of clothes. Some clothes are insulating and provide warmth, and some the opposite. Like clothes, having the right combination of clothing layers, that is, gases in the atmosphere, is crucial to optimum temperature regulation. Carbon dioxide, CO₂, is a gas now famous for carrying heat energy and “warming.” The graph below shows how concentrations of CO₂ have changed over the past ~250 years, as measured in ice and in recent times at the Mauna Loa observatory in Hawaii. This warming gas is associated with temperature changes, as the next graph shows.

Global atmospheric CO₂ concentrations from 1700 to 2021. The wiggles in the graph represent seasons. We do not see seasons in long-term measurements due to averaging. Source: Met Office.

Global temperature anomalies averaged and adjusted to early industrial baseline (1881-1910).
Source: NASA, GISS, NOAA, NECI, ESRL

The science is clear that CO₂ and some other gases are greenhouse gases, increasing in the post-industrial age, and the global average temperature is increasing. A view of the Grinnell Glacier taken from the summit of Mount Gould in Glacier National Park, Montana, in 1938, 1981, 1998, and 2006 (left to right below) tells one story about this. Reluctantly, based on the science alone, I cannot help but agree with the Habanero Irregular Contributor, who recently pointed out that biological organisms have a long history of changing the atmosphere of the Earth (note: this contributor’s science content has been trustworthy, but our staff has still not been able to determine the identity, and therefore the exact credentials, of this irreverent contributor). We would not be the first organisms to change the atmosphere.

A series of photographs of the Grinnell Glacier, in (from left) 1938, 1981, 1998, and 2006. In 1938 the Grinnell Glacier filled the entire area at the bottom of the image. By 2006 it had largely disappeared from this view. Source: Encyclopedia Brittanica 

The graph above showing temperature and CO₂ dates back to the mid-1850s. This date range represents only a small part of a much longer story. Scientists recently published the proxy-based temperature history shown below in the prestigious journal Science. This data gives a very different perspective on past temperature. Going back 66 million years, the Earth was warmer, much warmer. It was a hothouse. As you will also see from the labels that our staff added, it was a hothouse unoccupied by humans. Humans have been around in coolhouse times. Hominids date back to icehouse times.

Earth’s climate dynamics over the last 66 million years.
Source: Dr. Thomas West­er­hold, Center for Marine Environmental Sciences

Organisms have their climates for thriving. Most orchids cannot be found growing in Canada, and Canadian wheat is not a crop for the tropics. Humans are organisms, too; our environment affects us, and we can affect our environment. For instance, NASA has recently been working on developing the capability to divert asteroids from hitting Earth. An asteroid impact could eradicate life as we know it. What do you think about climate? Is it as important? Let us know in the comments →

This post is a simplified version of an original article on the topic of the Greenhouse Effect and Climate Change. Readers interested in additional scientific discussion can read the original article here.

Further Reading:

• A Medieval Weather Report (Medievalists.net)
• Medieval monks’ records, volcanoes and climate (Washington State University Insider)
• Earliest known English report of rare weather phenomenon found in medieval text (Yahoo!)
• Strange Weather, Volcanoes, and a Roof Collapse: Secrets of the Medieval Chronicle (Medieval Fragments)
• The Anglo-Saxon Chronicle: Eleventh Century (Yale Law School)
• Global Warming Natural Cycle (OSS Foundation)
• Causes of Global Warming (Britannica)
• Paleoclimatology: How Can We Infer Past Climates? (Carleton College Science Education Resource Center)
• What Are Proxy Data? (National Centers for Environmental Information)
• Westerhold et al. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. 2020. Science, Volume 369, Issue 6509, pages 1383–1387. https://doi.org/10.1126/science.aba6853.