By City Sustainability Staff
Is it climate change or global warming?
Climate change and global warming both refer to the increase in overall, long-term global temperatures that have been occurring since the industrial revolution. “Global warming” is a term specifically referring to the overall long-term warming trends and predicted continued global warming into the future. “Climate change” is the all-encompassing term that describes changes in wind, precipitation, extreme weather events, and length of seasons as well as temperatures.
What is Anthropogenic (human) Global Warming (AGW)?
To start off, the Earth has a natural greenhouse effect with four major gases in its atmosphere: water vapor, carbon dioxide, methane and ozone. When solar radiation from the sun reaches Earth’s surface it becomes infrared thermal radiation (heat). Some of this thermal radiation escapes into outer space, while the rest is reflected back to Earth by greenhouse gases, keeping the planet warm enough for life. Human activities such as the burning of fossil fuels, agriculture and deforestation all add greenhouse gases into the atmosphere. This rapid increase in atmospheric greenhouse gases reflects more thermal radiation back to Earth’s surface causing temperatures to rise.
But it snowed a lot in Beaverton this winter!
Doesn’t that prove global warming is wrong? No, because Beaverton’s short-term weather does not represent global climate averages. Even if all of North America is abnormally cold for a month, the rest of the Earth could still be experiencing warmer than average temperatures. It is important to look at AGW at a global-scale, as well as to look at long-term climate trends compared to averages and not just specific regions or weather events.
Please look for our next climate change series article next month and learn more about what Beaverton is doing to address climate change by visiting our sustainability page here: http://www.beavertonoregon.gov/399/Sustainability.
Category: Community Stories