Commentary: 2005 Hottest Year on Record

By Paul Reitan

Buffalo, NY – 2005 was the warmest year on record.
Well - maybe. Maybe 1998 still holds the record. Actually they were so close that the experts disagree, but the disagreement is about a few 100ths of a degree - so, as far as you and I are concerned, they are tied for the hottest year since humans began keeping records. And 2002 and 2003 were so close that they are virtually tied, too, for the hottest.
So, are things really getting hotter? Or are these just a few oddball years. Not likely. 19 of the 20 hottest years on record have occurred since 1980. That's a very high frequency of exceptionally hot years.

But, you know, that really shouldn't surprise us. Temperatures for the last century have been on a climbing trend. And the upward trend has steepened in the last 30 years - about three timers steeper. That rate of increase, incidentally, is about 20 times as fast as when the world emerged from the last Great Ice Age, and that was a dramatic warming by all that we know about Earth temperatures over the last 200,000 years.

So far I've been talking about global averages. In the higher latitudes of the Northern Hemisphere - places like Scandinavia, Russia, Alaska, and Canada - the warming trend has been twice as steep or even steeper.

Arctic sea ice is melting fast. There is recent evidence that the West Antarctic Ice Sheet may be starting to disintegrate - a surprising rate of sliding into the sea - and that could raise sea levels by 16 feet. Winter snow isn't lasting as long as it used to. Spring is arriving earlier - at least springtime temperatures are. Spring sunlight, of course, isn't changing, so organisms that respond mainly to temperatures are getting ahead of those that respond mainly to daylight change - a recipe for disruption of finely tuned and nicely adjusted ecosystems. And, then, patterns of rainfall are changing, too. Some places are drier, some are wetter; storms are expected to be more severe.

This is beginning to sound serious! In fact, it is. Every time the world's leading climate scientists get together to compare notes and understandings a few things become clear - or clearer. One is that the understanding of Earth's climate system is getting better and better. Two is that the confidence in models used to project the future consequences of our abuse of the atmosphere is getting greater and greater. And three is that the prospects for the future get grimmer; with new and improved insights the problems seem to be more severe.
This sounds serious. Very serious. So what should we do? We know the cause. The CO2 content of the atmosphere is now higher than it has been for over 400,000 years because we have burned up the legacy of fossil fuels that were formed over many, many millions of years - and this we've done in just s few hundred years.

The Earth's climate system responds, or course, but it generally changes slowly. It's a little like a large ocean liner with a built-in inertia resisting change. We humans have been nudging the Earth's climate for thousands of years with little noticeable effect. Then we got more serious about it when we began to burn oil and gas. And finally, in the last 100 years or so we can begin to see the effects. A whole degree warmer in the 20th century, but beginning to heat up more rapidly in the last 30 years. So we've finally put climate change onto a new track - and that's scary. Down this road we see big problems ahead. So the question is, how can we reverse this, with all of its built-in inertia - that tendency just to keep going? What can we do?

Incremental changes - little nudges - can work, if we have a thousand years or so to wait to see the change. No, little incremental changes won't do it; what we need is transformational change. Really significant changes in the way our society and the rest of the world's societies work, if we want to begin to turn dangerous climate change around and get it leveled off and back to where we and the rest of the Earth's biological systems have been thriving for thousands of years.

Where can that change come from? I drive a hybrid, and that little nudge makes me feel good, but it won't do much. To change the way societies work calls for very strong, daring policy leadership and international cooperation. Dramatic reductions in the amount of carbon dioxide and other greenhouse gases produced by humans is really the only answer. Step one has to be a crash course in how to cut our use of coal, oil, and gas. Without that the prospects are terrifying. I see terror when I look ahead to when my little grandson is a mature man. Yes, we need a war on terror - that terror.

Listener-Commentator Paul Reitan is a professor emeritus in the Department of Geology at UB.