You might not think so but climate has a complicatedness about it. I gotta tell you, though. As much as I know about climate there is much on the topic I still haven’t learned.
All of which has got me thinking today about how the Air Quality Matters blog can be an added and invaluable resource where the spread of the all-important climate message is concerned.
In the interest of brevity talk today is limited to that pertaining to a climate continuously undergoing change and its link to greenhouse gas (GHG) emissions.
Right off the bat, it’s important to not get climate and weather confused. Climate represents weather patterns taken or collected over an extended period of time like over decades.
Climate diversity
Take the Golden State. California is what is called climate diverse. The six different climates the state has are alpine, desert, Mediterranean, oceanic, subarctic and temperate and all are pretty much self-explanatory. It is also fairly easy to notice the transition in going from one to the next.
However, in California, there is also evidence that climate here has gone through a change or changes over broad stretches of time. Yosemite National Park in the high Sierra Nevada Mountain range, for example, was formed by a glacier and near the town of Fairmead located in the central San Joaquin Valley, woolly mammoth bones have been unearthed, both of which suggest that the region was far, far colder than what it is today.
Climate changes
Okay, on to climate change. Now, when we talk about climate change, it relates to the notion of the change in climate or climatic conditions one period compared to another.
So, what is GHGs’ connection? (Disclosure: This is where there is much disagreement).
Before we start, this needs to be prefaced by mentioning that there are seven atmospheric greenhouse gas (GHG) emissions in all: carbon dioxide, fluorinated gases (hydrofluorocarbons, nitrogen trifluoride, perfluorocarbons, sulfur hexafluoride), methane, nitrous oxide and even water vapor can be considered a greenhouse gas.
Okay, so next there is a concept or phenomenon known as climate forcing. Because GHGs trap and retain heat – different GHGs retain the heat they trap for different lengths of time – experts agree that this action has an influence on planet warming – or cooling – outsized or otherwise. Carbon dioxide is said to have the smallest. This has to do with what’s referred to as Global Warming Potential or GWP. The fluorinated gas group has some of the largest GWPs.
At this point it’s too easy or maybe convenient to shift the conversation from climate to temperature when catchphrases like “Global Warming Potential” are introduced. I think it’s a mistake many sources discussing climate change make. Sure, climate change and global warming – and cooling – are related. However, they should never be confused as being one and the same thing.
Which now has me thinking about another part of the exchange of ideas that this and other similar platforms facilitate and further and, that is, in how we know climate change can be caused by human-forced or prompted influence.
While this example might not be thought of in the conventional or customary sense, it does suggest a strong-to-direct connection.
The excerpts are from “Falling levels of air pollution drove decline in California’s tule fog,” Apr. 20, 2019 Air Quality Matters post.
“Tule fog, named for a sedge grass that populates California’s wetlands, is a thick ground fog that periodically blankets the Central Valley during the winter months.
“To find out why the fog is fading, the researchers analyzed meteorological and air pollution data from the Central Valley reaching back to 1930. They found that while yearly fluctuations in fog frequency could be explained by changes in annual weather patterns, the long-term trends matched those of pollutants in the air.
“The results help explain the puzzling decades-long rise and fall in the number of “fog days” affecting the region, which increased 85 percent between 1930 to 1970 and then decreased 76 percent between 1980 to 2016. This up-and-down pattern follows trends in air pollution in the valley, which rose during the first half of the century, when the region was increasingly farmed and industrialized, and then dropped off after the enactment of air pollution regulations in the 1970s.”
“The link between air pollution and fog also explains why southern parts of the valley — where higher temperatures should suppress the formation of fog — actually have a higher occurrence of fog than northern parts of the valley.”
“And it makes sense, given what we know about how clouds and fog form, Gray says. Oxides of nitrogen (NOx) react with ammonia to form ammonium nitrate particles, which help trigger water vapor to condense into small fog droplets. Emissions of NOx have declined dramatically since the 1980s, resulting in a decrease in ammonium nitrate aerosols and fog.”
I rest my case.
An earlier version of this article misstated perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride and nitrogen trifluoride as fluoridated gases. This misstatement has since been corrected.
Last updated on Jun. 23, 2023 at 6:47 a.m. Pacific Daylight Time.
Above and corresponding, connected home-page-entry images: Jeff Schmaltz, NASA
– Alan Kandel
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