In August 2005 Hurricane Katrina hit continental United States, flooding New Orleans, and devastating coastal towns. In December, my house insurance increased 25%.
Katrina was the 7th most intense hurricane ever recorded in a season that included 2 other hurricanes in the top 6 most intense hurricanes ever documented. The 2005 hurricane season made many believers out of skeptics about global climate change.
Scientists have been watching a significant increase in concentration of carbon dioxide in our atmosphere for several decades now. Carbon dioxide levels now exceed 400 ppm. Greenhouse gases absorb (and release) heat energy from the sun, and science predicts that as greenhouse gases increase in concentration temperatures in the atmosphere, and on land and oceans, will increase. You might expect that natural forces will equalize these differences, most noticeably and rapidly in the atmosphere. The result will be increased wind, both in frequency and in velocity. But it’s not as simple as that. We also find systems of extreme weather develop so that we get pockets of intense rain in some areas, but prolonged droughts in others. In the larger picture, global climate change actually means global weather change.
There still are many skeptics about whether global climate change is a real phenomenon. They point out that most weather events, for instance, wind and rain, occur within the normal ranges previously recorded. Other external events, such as volcanoes or sun spots cause periodic aberrations. In most cases, such arguments are intended to deny that the change in climate or weather are caused by mankind. It is no coincidence that often proponents of the “natural causes” concept are connected to petroleum industries, automotive industries or other industries that would be impacted if governments decided to do something to reduce the discharge of carbon dioxide to our atmosphere. But there are many other skeptics as well. Why is there so much confusion?
Part of the problem might be the way we discuss weather. Mostly weather is described by statistics. The nightly news tells us how the forecast temperature or rainfall compares to historical highs or lows. Or “normals” for a particular day, which is just a statistical mean of all readings. When you compare readings relative to “normal”, you find a lots of readings not in the normal range. But, that’s normal. Then we report unusual events with terms like “one-in-one hundred year flood’. But what does it mean when we get another “one-in-one hundred year flood” in the same year? Somehow, our reporting normalizes all weather events.
The past year has had many weather events outside the normal. There were record numbers of tornadoes moving through “tornado alley” (Texas, Oklahoma, Kansas). There’s drought in Texas and California. In the last few years there’s been record forest fires in Australia. And a record flood in Australia. This fall saw more than 2 meters of snow fall on Buffalo, New York. Then wash away a few days later. Locally, we’ve experienced the second cold weather snap in November. But between the snap some high temperature records were set! The conditions that caused the cold weather included a couple of high pressure systems sitting in north-central Canada, which sucked cold Arctic air south, affecting most of the continent. This event included conditions that stalled systems that normally move along the jet stream, making conditions last longer than expected. Similar events occurred last year resulting in a new weather term: “polar vortex”. And this year the Farmer’s Almanac predicts a special followup they call the “polar vortex from hell’.
Whether its colder than normal days in November, missed ferry sailings due to high winds, costlier fruits and vegetables in the supermarket due to droughts in California, or (heaven forbid) higher coffee prices due to drought in Brazil, I do know that the extreme weather conditions around the world are going to affect every one of us!