Global Warming-Do We Understanding the Changes?

By: Hubert Crowell

Reading through the reports from NOAA, National Oceanic & Atmospheric Administration, I became aware of just how little we understand our climate. We appear to be doing a good job of collecting data, but a long way from understanding that data.

It is clear that change is on the way and that it will be good for some and bad for others. Of course this is nothing new, there has always been change and it has helped some and hurt others.

At this point we don't know if the changes caused by man are good or bad and we don't know how much of the change was caused by man. We had better understand our climate and what affects it before we start thinking about what kind of climate we want. Or maybe it should be the other way around we had better think about what kind of climate we want before we start trying to change it. We used to seed clouds to bring on rain until we ran into problems causing too much rain. Now you don't hear anything about cloud seeding. If we start trying to control the changes, somebody is not going to like it.

It looks like the earth is a huge climate regulator, as it gets too warm, the ice melts creating more moisture for rain and snow. Fresh water runs into the oceans changing the currents and causing cooling periods, like the *Younger Dryas. Our largest climate controller is the Great Ocean Conveyor Belt. We need to understand more about what effects this large world wide circulation of water between the major oceans. Studies are being made too more define this river in the ocean.

If we try to slow the current warming trend, do we know the result? I don't think so. It is obvious that we have a lot to learn.

We are getting commercials on TV warning us about Global Warming, when they should be telling us how to prepare for the next ice age. 1989 and 2006 were the warmest years on record for the United States main land, but what about the rest of the world? I hope that they enjoyed the warmth also.

High CO₂ levels in recent years may be due to the large forest fires that have occurred. **Some believe that higher levels of CO₂ are the result of a warmer climate and not the cause of it. A warmer climate equates to more plant growth, thus a larger source of CO₂ when burned or decayed. If we could prevent all forest fires, CO₂ levels would slowly come down. However the evidence does show that green house gasses have caused the recent warming trend. Visit realclimate.org for ongoing discussions on our climate.

We should all be thankful for Global Warming, If all the burning of fossil fuels over the past 1300 years had not kept the temperature up, we would have been in another ice age by now. It looks like that there is a tug of war going between the cycle of ice ages and the influence that humans caused. If you stabilized our planet to the known mean temperature for the past that we know of, we would be living in a continuous ice age. I for one prefer the current warm climate with all the storms and rising sea levels to another ice age.
***Human activity over the last 8,000 years may have headed off the next ice age, new research suggests.

* http://science.nasa.gov/headlines/y2004/05mar_arctic.htm A Chilling Possibility.

**http://www.realclimate.org/index.php?p=13 What does the lag of CO2 behind temperature in ice cores tell us about global warming?

*** http://www.worldclimatereport.com/index.php/2005/01/28/disaster-averted/ Disaster Averted.

Quotes and Charts:

Are we barreling down a runaway route toward climatic catastrophe, or will the future bring relatively benign changes that will not threaten society?

The accumulation of greenhouse gases in the atmosphere will almost certainly cause Earth's surface temperature to rise. But we do not know how quickly the planet will warm or how that warming will affect different regions of the globe.

Answers to such questions will only come through intense research into the mysteries of Earth's climate system."

-- from Reports to the Nation on Our Changing Planet

Will Melting Ice Trigger an Ice Age? Not likely. But, remember the Younger Dryas? Melting polar ice may have poured fresh water into the North Atlantic and interrupted the deep ocean circulation pattern, which may have sent the Northern Hemisphere into a 1,000-year cold period. Today, fresh water flow into the Arctic Ocean from Siberia's four great rivers has increased, and oceanographers observe a slight decrease in the salinity of the North Atlantic. Although climate models do not project that these trends will lead to anything like an ice age, some indicate that over the next few hundred years deep ocean currents may be disrupted, which would affect regional temperature and precipitation patterns over North America and Europe.

Because saltwater is denser and heavier than freshwater, this "freshening" of the North Atlantic would make the surface layers more buoyant. That's a problem because the surface water needs to sink to drive a primary ocean circulation pattern known as the "Great Ocean Conveyor." Sunken water flows south along the ocean floor toward the equator, while warm surface waters from tropical latitudes flow north to replace the water that sank, thus keeping the Conveyor slowly chugging along. An increase in freshwater could prevent this sinking of North Atlantic surface waters, slowing or stopping this circulation.

In summary, we know that the rise in atmospheric CO₂ is entirely caused by fossil fuel burning and deforestation because many independent observations show that the carbon content has also increased in both the oceans and the land biosphere (after deforestation). If the oceans or land had contributed to the rise in atmospheric CO₂, they would hold less carbon. Their response to warming may be real, but it is less than their response to increasing CO₂ and other climate changes for the moment.

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hubertcrowell@comcast.net