Mike Nelson: Global Warming - It's about the science

Climate Talks being held in Paris

DENVER - With the International Climate Talks now being held in Paris, the topic of Global Warming is high on the list of topics in the news. In that light, there is plenty of buzz going on social media about "climate change" from many different points of view.

Here are my thoughts and comments. My only request to those who choose to comment is that you first take the time to read this and consider before simply typing a talking point.

I address this topic at some peril! In many ways, the job description for a TV "weathercaster" is to be the nice friendly person who tells you what the high will be, how much snow will fall and what to expect for the weekend. I have found that the topic of global warming can stir up emotions and can bring some rough responses via e-mail and Facebook.

I appreciate the fact that viewers have differing views and opinions on many issues and climate change is one of those topics that can bring a strong reaction. There are quite a few of my "Broadcast Brethren" that choose to avoid even addressing climate change so as to not anger some of their viewers. I think we have a responsibility to try and teach the basics of climate change. TV meteorologists are often asked to provide insight and explanations on earthquakes, meteors, tsunamis and volcanoes. For many Americans, we are as close to a scientist as they will get, and they invite us into their living rooms.

I hope that, even if you do not agree with my comments and explanations, you will appreciate the attempt and still choose to watch my weather reports. With that said, here we go!

Weather is NOT Climate!

WEATHER is one play in a football game / CLIMATE is the history of the NFL!

Experts at the National Center for Atmospheric Research (NCAR) feel that 90 to 95 percent of what we see in the wide variety of weather is due to natural variability.The remaining 5 to 10 percent is due to the warming of the planet due to an increase in various greenhouse gases. Another sports analogy is to consider the impact of steroid use by a professional athlete.

The talent and work ethic of the athlete is responsible of 90-95 percent of what we witness on the playing field. The added "juice" of the steroid accounts for that extra power that can result in faster times or more home runs.

Of course, 5 to 10 percent of the change may not seem like much, but consider what that can mean in terms of tangible measurements:

  • A 5 to 10 percent drop in crop yields would have a huge impact on agri-business in our state and across the nation.
  • A 5 to 10 percent drop in snowpack in future decades would be a major concern for Colorado and the West.
  • A 5 to 10 percent increase in insurance losses from weather would amount to billions of dollars over the long term.

Even though an individual severe weather event cannot be blamed on Global Warming, a warmer climate "juices" the atmosphere and may bring more frequent severe weather events in the future. Warmer average temperatures in the western United States will likely be manifested in more drought and fire concerns in the decades to come.

Because we are far away from large bodies of water, higher temperatures here are not usually associated with increased humidity - in fact, just the opposite.

With a gradual warming of the planet, our regional climate is likely to become drier on average over the next 100 years. The result will be more wildfires, lower reservoirs and more frequent droughts.

One cold winter does not mean there is no global warming!

There are often comments and questions about global warming when unusual regional weather events occur - such as snow in Las Vegas or extreme cold weather bringing a hard freeze to Florida.

Extreme episodes of cold and snow in southern areas is due to a southern bulge in the circumpolar vortex (the dreaded POLAR VORTEX), bringing chilly air down from Alaska and Canada into the lower 48 states.

Often, while portions of the lower 48 states are shivering, Fairbanks enjoys very mild weather for their area. When that vortex drifts back to the north, Fairbanks returns to very cold and the lower 48 warm back up.

The key here is that we are talking about regional weather events. Things tend to even out - if one area is unusually warm, another is cold. But on a global average, we are seeing a warming of the planet by about 1.5 degrees Fahrenheit since 1900.

The world has not warmed in the past two decades - but it has!

There is an often quoted issue of 1997 being the warmest year and that global temperatures have cooled since that time. This information is misleading. In 1997, the world climate was influenced by one of the strongest El Nino events ever recorded.

The very warm Pacific Ocean water bumped global air temperatures higher. Temperatures have remained warmer than the long term average in the years since 1997 - just not quite as warm as that one spike.

It is important to also note that 2014 was warmer than 1997 and this year is on track to be even warmer!

The oceans have an enormous capacity to absorb heat and much of the global warming we are seeing is going into the oceans. This is causing sea levels to rise and the increase in CO2 is changing the chemistry of the water – making it more acidic.

Back in the 1970s, they said Earth was cooling...

I did my meteorology training at the University of Wisconsin at Madison in the 1970s. At that time, Dr. Reid Bryson, one of the founders of the UW Meteorology Department was lecturing about the prospect of a "New Ice Age". The cause, Bryson theorized, was due to the increase in tiny particles of smoke and dust during the Industrial Revolution.

The increase in atmospheric aerosols would block incoming sunlight like a dirty window. It was from that theory that several magazines ran feature articles about "Global Cooling." It stands to reason that folks would be concerned about such an about face in 40 years.

In fact, even at the time, most researchers, including Bryson, felt that the increase in CO2 would eventually offset this "dirty window" effect and the climate would begin to warm.

This is an important point, as many anthropogenic global warming (AGW) skeptics still bring up the "1970s Global Cooling Theory" as an argument that the current consensus among climate scientists has been an "about face" form the 1970s.

Here is a link to an article about the Bulletin of the American Meteorological Society...

What about Climate-Gate?

The release of private e-mails from the University of East Anglia in late 2009 raised some questions about a hidden agenda among the leading climate scientists around the world. The timing of the release of the e-mails came just before the International Climate Conference in Copenhagen and did divert the focus of the agenda of that conference.

In my opinion, there were about 60 megabytes worth of e-mail exchanges released, but only a small fraction of the private comments truly raised any concern.

Scientists often speak casually among themselves in a short-hand of sorts. In this respect, saying something such as "the trick in this problem" does necessarily mean an actually "trick" or sleight of hand, but rather a method of calculating something.

Granted, it does not sound good when clipped out of context, but there were no comments such as "Boy, are we pulling a fast one on the world. We are going to get rich!"

Another comment that was brought up is, "We cannot show any warming, and it is a travesty that we cannot." In this case, the comment refers to a lack of an adequate monitoring system to show the warming in the deeper waters of the ocean.

We know that the warming is there, we just do not have the instruments covering enough of the ocean to measure it adequately. Once again, it looks bad when taken out of context, but actually had a very different meaning.

The fate of the Arctic ice

Another major complication for our future climate will be the fate of the sea ice in the Arctic. Satellite measurements since the late 1970s have shown that the sea ice has dramatically diminished and has reached a record low as of late summer 2012. In 2015, the ice was slightly greater in coverage, but still well below the long term average.

Although sea ice does grow and shrink due to natural cycles, it appears that the current state of the ice is near historic lows. Anecdotal records from indigenous peoples and 19th century sailors show that the melting of the ice, as well as the surrounding permafrost, indicate a dramatic warming of the northern latitudes.

The sea ice is highly reflective, dark open ocean is just the opposite. As more of the Arctic remains open, the waters will warm and this may play a significant role in altering the phases and intensity of many ocean circulations.

What about the SUN?

There is much discussion about the fact that the sun has by far the largest impact on our climate.
The periodic changes in solar output and the orbital changes are taken into account in the climate studies and modeling. In fact, the current solar output is slightly less than in previous decades - our climate should be cooling, but it is not.

Carbon Dioxide is just a TRACE GAS!

Another comment often heard is that CO2 is just a tiny fraction of the atmosphere. Just because CO2 is a trace gas does not mean that it is not important in the equation. Small amounts do matter - I weigh 200 pounds, I require a certain small amount of Vitamin-D to remain healthy. Too much of this vitamin, however and I will become very ill.

Think of each molecule of carbon dioxide as a feather in a down comforter. If there are not very many feathers, your body's heat will escape through the comforter and you will be cold. If you keep adding feather after feather, the comforter becomes much more efficient at holding in your body heat and you stay warmer.

Our atmosphere behaves in a similar manner and scientists have calculated that each doubling of the CO2 results in a net increase of 4 watts per square meter of stored energy over the entire surface of the Earth.

That is about a night-light’s worth of heat over a square meter, but taken over the vast surface area of the Earth, this is a tremendous amount of energy!

This is not new information, it has been solid science that can be measured in a laboratory! The effect of CO2 in trapping heat has been known since the middle of the 19th Century - check here.

Climate has always changed...

It is absolutely true that the Earth's climate has cycled through great changes over the course of our geologic history. These changes are obvious in the fossil record - Denver was once under a great shallow ocean!

These changes are due to a variety of causes, from volcanoes to continental drift to the shift in the Earth's orbit on its journey around the sun, to changes in the output of energy from the sun.

One of the key components to our Ice Ages has been what are called the Milankovitch Cycles. These long term changes in the shape of our orbit and the shift in the tilt of the Earth work like the complex gears of a clock, gradually switching our planet from Ice Age to warmer periods and back again.

The Milankovitch Cycles are well documented and have been a primary driver of our changing climate for hundreds of thousands to millions of years. Here is a link to learn more...

Now, for the first time in the Earth's history, these gears are being impacted by rapid changes in the atmospheric chemistry - changes that are being caused by human activity.

What about cosmic rays?

The theory that a change in climate might be related to cosmic rays has been in the news recently after the European Organization for Nuclear Research (CERN) published a paper about the relationship between cosmic rays and cloud formation.

The theory is that these invisible, high energy rays could increase cloud cover and thus cause an increase in the reflection of sunlight, thus cooling the Earth during the day. In contrast, the clouds could cause a warming at night by trapping the previous day's heat.

The research is interesting and is well worth considering how an increase or decrease of these rays might impact the Earth's climate, however, the observed changes in cloud nuclei appear to be too small to have a significant effect on climate. In addition, in looking at trends in cosmic ray cycles, there is no connection that would fit with the increase in global temperature.

The CERN research is occasionally brought up by skeptics of human caused global warming precisely because CERN has such a strong reputation for advanced research.

The theory sounds exotic enough to be misrepresented as a legitimate natural cause for the warming we are seeing. Upon further review, it appears that while it is excellent research, it is not a major driver of the current warming.

My personal thoughts

I am not a climate scientist; my expertise lies in a much, much shorter time-frame. However, I spend a great deal of time on-line and at seminars with many of the best climate scientists from NCAR and other research institutes from around the world.

My opinion is that we are indeed having a significant impact on the warming of our climate, and this will make weather events more extreme. With a greater amount of energy in the climate system, there will be drier droughts, heavier rains (although more spotty), bigger winter storms and more powerful severe weather events.

Remember, 90 to 95 percent of what we see is within the normal variability of weather - it is that extra 5 to 10 percent, the "steroid" effect that is making a drought a little drier, a heat wave that much hotter, a winter slightly less cold.

Waxing philosophical

My mother was a heavy smoker in the 1960s, as a child, I remember seeing white coated scientists that claimed that there was not a definite link between smoking and lung cancer. I lost her to that disease 10 years ago.

My sister spent a lot of time in tanning booths in the 1980s. Again, there were plenty of "experts" that stated the rays from the tanning beds were different and actually "good" for you. She died two years ago from metastatic melanoma.

It is okay to have differing opinions - it is even a good thing, if the motives are purely science based.

Our choice, as Americans and citizens of Earth is to decide what priority we assign to this 5 to 10 percent change in our climate. Where does this fit into the decisions we must make for our future energy and environmental policies?

Our very special planet

When the Soviet Cosmonaut Yuri Gagarin, the first human in outer space, reached the top of our atmosphere and gazed out of his small porthole, he was terrified. He was not worried about his spacecraft, he was shocked by how thin and fragile our atmosphere appeared against the cold blackness of space.

Gagarin later explained that he had always been taught that we lived at the bottom of a "great ocean" of air. From his Vostok 1 spacecraft, the ocean looked more like a shallow puddle.

As far as we know, out of the vastness of the universe, the planet Earth is the only place that harbors life. Someday we may find other worlds that provide an environment gentle enough to enable life to form, but for now, this is it, our lonely outpost in the corner of a galaxy.

It seems prudent, patriotic and reverent that we do what we can to conserve and protect the fragile envelope of air that allows us to live on planet Earth. The legacy we leave future generations depends upon the actions we take in the coming years. Our heirs will be the judges of our success.

In the words of Thomas Jefferson in 1789, "I say the Earth belongs to each generation during its course, fully and in its own right, and no generation can contract debts greater than may be paid during the course of its own existence."

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