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Blowin' in the Wind, Issue #104 CO2 400 ppm and Climate Change -May 30, 2013
May 30, 2013
Hello ,

Climate Change and Carbon Dioxide at 400 ppm

A dreaded environmental milestone has been reached. With our first readings of 400 ppm for CO2 in May this year, our attention has once again turned to the subject of climate change. What kind of results do we expect from Climate change?

Tornadoes. Wild fires. Floods, droughts, hurricanes and such.

Massive hurricanes?

After Sandy hit the east coast of the USA last year, a lot of people started to wonder if there is a real connection to be made here. We can't know for certain if Sandy is really a part of it, but it certainly does look that way.

We have seen significant and quick changes and people are taking note of this. A few years ago there was much talk of the subject of climate change in the form of global warming in the wake of Al Gore's film, An Inconvenient Truth. And then with the election of Obama and the concurrent slip in the economy and political strife, this issue took a back seat for a number of years.

Where did it go? Nowhere really. It's still with us. Still creeping up on us. As Obama noted in a recent speech, our 12 hottest years on record have occurred in the last 50. The skepticism we may all have considered at some time in the past is looking quite weak these days.

The world average-temperature gains made in the 1980's and 90's have not disappeared. Even if they levelled off somewhat since then (that is the rate of temperature increase slowed to nearly zero for a number of years) they have not returned to previous levels. Did anybody expect them to? Why not? They always did before THIS time.

Other observations attributed to Climate Change

We have seen it warm when it's supposed to be cold, cold when we're expecting increased warmth (e.g., March and April, 2013). As famous CBS forecaster David Bernard put it, "Weather is your mood, climate is your personality." This phenomenon is not new. It's just statistical "noise", even though it always shocks someone.

We look for a trend instead. Consistency. Something like the Mauna Loa observations. That curve you may have seen plotted in various scientific news programs and the like looks like a little roller coaster track, except it keeps going up and up with each successive hill. This thing, called the Keeling Curve shows the concentration of carbon dioxide in the middle of the Pacific Ocean, away from immediate major anthropogenic influences (aside from relatively small Hawaiian cities).

It shows a trend. Up and up. From less than 300 ppm about a century-and-a-half ago to over 400 now, with no end in sight. Other greenhouse gases, notably methane and nitrous oxide have similarly-shaped concentration curves. So what?

At the same time the global average temperature has been on a one-way trip upwards. There is been a lot of dispute over how much and how accurately it has been monitored, recorded and displayed (think hockey-sticks), but the existence of a trend is indisputable. And thus is a correlation.

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