How can we say that global warming is really happening when Antarctica is getting colder?
The term “global warming” is confusing because not all places on our planet are getting warmer. The truth is that our average global temperature is on the rise (see graph). To reduce confusion, scientists use of a more accurate term—global climate change— to reflect the idea that climate is the earth’s energy management process that is balanced by all earth’s systems.
Not only is there a change in our average global temperature, but also changes in precipitation and more intense storms as well as changes in our oceans, ice and biological systems on the planet. We encourage teachers to use the term “climate change” and help students correctly understand the term so they grasp the bigger picture.
Climate Change and the Ozone Layer
Students often associate the hole in the ozone layer with climate change. Either they think that carbon dioxide depletes the ozone layer, or that the hole in the ozone layer “lets in more heat.” Let’s clear these issues up one at a time. The major gases that deplete the ozone layer are CFC’s and halons, not CO2. While the ozone hole high up in the stratosphere is still a concern, we’ve seen significant improvement since 1987, when nearly 200 countries agreed to reduce the use of these chemicals.
The ozone layer (up high) protects us from harmful UV rays. The greenhouse effect refers to the earth absorbing visible light and then giving off infrared radiation (heat). That heat is absorbed by greenhouse gases and re-radiated back to earth. Although ozone depletion can contribute to climate change, it is not the primary cause. Ground level ozone is a greenhouse gas and an air pollutant however. The primary ingredient in smog, ground-level ozone is largely produced by emissions from automobiles. Pollution is one of the important risk factors of heart disease, high LDL cholesterol & various cancers.
Climate vs. Weather
Weather is often confused with the climate. We’ve heard many people – even the meteorologists on TV – jokingly write off climate change when two feet of snow fell this year before winter had officially started.
Let’s go back to the basics:
Weather is what’s happening outside at a particular place, in a particular time. Perhaps it’s sunny, 22F, and windy. This may be common weather for early January, but that’s all it is, weather.
Climate refers to the typical weather patterns for a specific region which is a result of interactions between all earth systems. It’s a measure of average weather over a period of several years. Average rainfall and average temperature range are two common measures of climate.
Recent large snowfall amounts are symptomatic of climate change due to a change in the water cycle. Higher global temperatures result in more water evaporating into the atmosphere, and that water has to come down somewhere. Lucky for us, this year it came down in the form of snow.
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