Views and debates on climate change policy
Home | Panelists | Staff Blog | RSS

Donald F. Boesch
President, University of Maryland Center for Environmental Science

Donald F. Boesch

Donald F. Boesch, an oceanographer, is president of the University of Maryland Center for Environmental Science and Vice Chancellor for Environmental Sustainability for the University System of Maryland. ALL POSTS

Climate change, not change in the weather

Q: If we're so worried about global warming why has it been so cold here in the U.S., in Europe and other parts of the globe? What do weather statistics say has happened during the past 50 years? And how does weather differ from climate (is there a difference)?

Simply stated, weather is what we experience from one day to the next; climate is what we would normally expect. Both vary. Last Thursday the high temperature in Denver was a bone-chilling 14 F, but this Tuesday Denver approached a shirtsleeve-wearing 60 F. Does this demonstrate global cooling or global warming? Neither, of course, and both proponents of global warming and contrarians should avoid overhyping specific weather events.

Similarly, some years are decidedly cooler or warmer than others, not just in Denver but in many parts of the world. Many variations in climate are caused by cycles, or oscillations, that take place over months, years or even a decade. Some are influenced by currents
in the oceans, the principal medium of heat storage on the planet. The most prominent is the often-cited El Niño oscillation in the Pacific Ocean. Unusually warm water in the eastern Pacific brings El Niño and warmer global average temperatures, while the opposing La Niña results in cooler average temperatures.

The cold winter thus far in many parts of the U.S. and northern Europe has been caused by another oscillation, the Arctic oscillation. A strong high pressure over Greenland deflects cold air of the jet stream farther to the south than
usual. But Arctic temperatures have been quite a bit warmer than usual, as are temperatures around the Mediterranean, most of Africa, South America and south Asia.

With so much variability in climate throughout the world, over seasons and from year to year, how do we know if the Earth's climate is really changing? One approach is to evaluate the changes in annual temperature averaged over the entire planet, including surface waters of the ocean. Global average temperature has shown a clearly increasing trend since the 1950s, of course still with increases or decreases from one year to the next because of climate variability. The last decade was the warmest since temperature measurements began, as were the 1990s, and the 1980s before them. We are unequivocally advancing toward the 2 degrees Celsius increase in global average temperature that the Copenhagen Accord commits to avoid.

By Donald F. Boesch  |  January 13, 2010; 9:10 AM ET Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   StumbleUpon   Technorati  
Previous: The weather belongs on the evening news | Next: Look beyond preconceptions


Please report offensive comments below.

Simple system. There have always been ways that the Earth recycles stuff. Water from ground to river to ocean to evaporation to clouds to the ground. Carbon from CO2 to living things which die, get buried and rot... back to CO2. Other stuff in rock gets buried and eventually burps back out in volcanoes. Natural processes that allow the atmosphere to change and climate to change too (along with oscillations, axis rotation, etc.). None are man-made. But wait! Now man comes along and digs up all the oil and coal buried by nature and releases it. That is unnaturally causing a natural thing. In addition, man is removing forests, another natural process to pull carbon from the air. Things are changing because we are screwing with nature. Any person who doesn't believe it is a goofball, to be kind.

Posted by: steveboyington | January 15, 2010 9:00 PM
Report Offensive Comment

Corrct me if I'm wrong, but sea level change is a fail-safe indicator of global warming because it is an accumulator.

So what is the sea level change over the last 50 to 100 yrs and how do you measure it? It would seem to be a tough measurement for small changes but, if global warming is happening, then it should start to be well above the noise and easily measurable.

Posted by: jdwrock | January 15, 2010 8:14 PM
Report Offensive Comment

The problem with global warming theory is that its proponents have much too high an opinion about the current ability of sciemtists to understand all the factors that affect climate.

Scientists utilize software programs to create predictive models. They have continually tweaked these models when unexpected weather events or trends occur that the models didn't predict. This has occurred more than once. Until they verify that no more twaeks will be required, they should not claim "the science is settled."

The latest issue is that scientists, including one of the primary authors of the UN climate chnge report, have recently "discovered" a 30-year warming and cooling cycle. If the "science is settled" as global warming theorists have shouted for the past decade or more, then why has this cycle only recently been discovered? The answer is that the science is not settled. We really don't know how many more adjustments the computer climate models will have to undergo. Climate is just such a complex system that we lack the tools to predict accurately.

That dosn't mean there is no global warming. It does, however, mean that global warming proponemts have alienated a lot of people and lost some of their credibility as experts by not admitting their own limitations.

The other area of concern with climate prediction is the same for any compter generated report. Its called the "Garbage in. Garbage out." Rule. Whether its financial projections or sciemtific data, the conclusion will be wrong if the data isn't accurate.

Global warming proponents have done very little to assure critics that their temperature readings are measured reliably and consistently on a worldwide basis. In a legal trial the prosecution must prove the reliability of the devices used to obtain data to be introduced as evidence (eg the speed gun was properly callibrated, the officer knoew how to use it, the breath analyzer was not contaminated by another source). The prosecution must also prove the chain of custody, which means that third parties didn't have the opportunity to change the evidence after it was collected. Without these procedures, you can't admit evidence in court, because it it illogical to assume that data proves anything if you can't verify the data is real.

If you apply the legal standards for data to temperature readings used by global warming proponents, the evidence would not be admissible. Not enough has been done to safeguard the temperature reading equipment or to verify the chain of custody of the data. Its not an easy task given the worldwide collection and constant econonomic, social and political changes.

All this was known long before the disturbing news about the UK climate group and their data loss. You don't have ot assume they lost the data on purpose to question their results. The results were already questionable because its so difficult to collect massive amounts of temperature data and ensure the integrity of that data even to the degree that we require for a speeding ticket or DUI charge. Global warming proponents are guilty of massive negligence that would get the local police chief or DA fired if they failed to develop a better evidentiary system.

The real issue is not whether weather should affect our analysis of climate. The real questions are:
(1) Do we really understand all the factors affecting climate?
(2) How reliable is data collection and retention?

Posted by: jfv123 | January 15, 2010 5:46 PM
Report Offensive Comment

The most sensitive and accurate data for climate changes is the ice core samples from glaciers and polar caps that show the weather for the Earth since the glaciers and ice poles were created. These samples show the weather patterns on an annual basis. They can look at ice core samples for hundreds of thousands of years back and tell when there was a volcano, how much CO2 or methane was in the air, how much snow occurred, and many other things. These ice core samples show a very disturbing phenomenon now occurring that is unprescedented and exponentially accelerating. Mother Nature is not yet compensating very well, but when it happens it may be sudden and severe. The Earth is either going to continue to warm and may eventually turn into a dust bowl--like Mars, or we may have another ice age. Perhaps Mars was once vastly inhabited by humans who eventually self-destructed. Naaaaaaaa. In either case, human civilazation will not fare well.

Posted by: maphound | January 15, 2010 4:19 PM
Report Offensive Comment

Thats funny. Weather doesn't count when it doesn't support the hyped false hypothesis of Global Warming now morphed into "climate change".

I thought that the weather showed a warming trend. That is from the extremely limited amount of data over only about 100 years.

Now that these so called "scientists" don't have data that supports a warming trend, the ignorant excuses start to flow.

There is no Global Warming. CO2 from people breathing, Animal Flatulence, and SUV's is not doing anything to change the Weather or the Climate.

Weather, and Climates are intertwinned despite what these lame brained fools are saying.

The Weather and Climates around the earth change just like the seasons. CO2 doesn't cause the earth to warm and cool, the earths relationship to the Sun does.

Most of these so called scientists / global warming apologists, are still waisting money stolen from the taxpayers and citizens from around the world.

Just think what would be accomplished if they would be looking into something worthwhile like cancer research.

CAP AND TAX and Global Warming is solely a ploy to control and tax the masses. Global Warming is a complete myth.

Posted by: ignoranceisbliss | January 15, 2010 12:48 PM
Report Offensive Comment

Post a Comment

RSS Feed
Subscribe to The Post

© 2010 The Washington Post Company