Saturday, April 14, 2007

GLOBAL WARMING, pt 1 - Science

"What if the sky really is falling?"

You can hardly turn on your television, pick up a magazine, or have a conversation today without the topic of Global Warming coming up. For an obscure scientific topic, it has become a cultural phenomenon that stretches across the entire planet. People speak of what is happening and what will happen with the authority usually reserved for scientific experts, and make proclamations and predictions of the future that are rare outside of Prophets and Psychics.

The idea of Global Warming is that the entire planet is undergoing a shift in temperature, becoming warmer. Climate specialists have studied historical records and noted a general trend upward, and by studying ice cores can tell some things about the atmosphere in the past. From this it is believed that the planet has for a few centuries been growing warmer. Here is a chart that lays out the overall warming trend for the last 120 years:

Warming Trend
Now, reading this chart is a bit confusing, so just look at the red line: that's the mean (halfway between extremes) for the areas checked over these years. The increase is greatly exaggerated by making the X-axis (up and down) very broad, but it shows an increase of .8 degrees Celsius (just over a degree Fahrenheit) over the 120 years.

This was determined by studying tree rings (which show stress and bad weather trends, narrow rings are hard times for the tree, broad ones are good growth periods), ice core samples, and records of temperature kept in meteorological labs around the world. The trend, as you can see, actually dipped in some periods and raised in others, sometimes faster, sometimes slower, but overall it is upward, to warmer temperatures.

Because of this warming trend, there is some concern among many that we are seeing the beginning of something particularly dangerous, even catastrophic on the horizon that we might be able to prevent by changing our lifestyles. Some warn that we'll see the oceans rise due to melting ice caps, causing coastal areas to be taken over by flooding. Some warn that due to the increased warming, areas that are presently livable will become deserts and thus we will lose cropland and lose food production. Some warn of increased pests as cold winters do not kill as many off, others note that pollution will be worse in hot cities, and that we will see more hurricanes and deadly storms.

Others have more dire warnings. Vice President Gore warns that we have ten years before the trend becomes irreversable and earth becomes steadily unlivable for human beings (he said that about two years ago). Rising Sea levels is the largest area for concern, with some claiming that the sea will rise as much as six meters (about 20 feet) in the next century unless something is done immediately. You can consult Flood Maps to see what the world looks like with various levels of sea level increases. Some suggest crime will increase, as better weather tends to bring out everyone, including criminals.

A report requested by the Pentagon to examine potential strategic concerns that catastrophic global warming (worst-case scenarios) could generate predicted that within 13 years, shortages of water and energy supply will become increasingly harder to overcome. Widespread crop failure, major cities plunged underwater, and increased warfare as resources are battled over are possible outcomes.

The movie The Day After Tomorrow popularized and portrayed some of the more radical and extreme predictions by Whitley Strieber and Art Bell, such as the earth's axis shifting, causing titanic storms, tsunamis that flood all of New York City hundreds of feet in water, then instantly freeze into thick ice. Overnight, the planet turns from what we have today into an instantly unlivable doom.

Some of these reports are contradictory. They predict water shortages due to summer droughts, but increased rainfall in the winter instead of cold weather. They predict ice sheets melting, but ice sheets thickening because of increased snow in the arctic regions. They predict both siberian winters and warmer winters, they predict flooding rivers as winters see more precipitation, but crops unable to get the water needed to grow.

Which is why we have controversy regarding Global Warming. The warnings run a rather broad gamut of possibilities, and what's worse, they are often presented in a rather forceful, unscientific manner. In 1989, Discover Magazine interviewed atmospheric scientist Stephen Schneider, who said:
On the one hand, as scientists, we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but... On the other hand, we are not just scientists, but human beings as well. And like most people we’d like to see the world a better place... To do that we need to get some broad-based support, to capture the public’s imagination. That, of course, entails getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have... Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.
Pope DarwinWhich means rather than careful (and dull) presentation of data couched in careful language of possibilities and probabilities, we get forceful, absolute statements. Rather than "we might see" instead we get "proof," "consensus," "confirmation," "no longer any dispute" and so on. The predictions, warnings, and guesses of future events are presented as absolute fact, as if science has an unquestioned support of the statements, like some infallible Science Pope issued a Papal Bull with the final word. For example, in 2005, Tim Barnett, a marine physicist at the Scripps Institution of Oceanography in San Diego said this:
'We've got a serious problem. The debate is no longer: 'Is there a global warming signal?' The debate now is what are we going to do about it?'
This effect is compounded by reporters who know little to nothing about climatology and atmospheric science, and further are trying to write something that gets them attention and gets their story carried by their employer. Lacking the understanding to tell what the scientist is saying and interested in "cutting to the chase" reporters will take stories like the Pentagon report and present it as damning data of a coming doom that the Pentagon is trying to warn a stupid and obstinate US president about. When a scientist says "if conditions are right, we might see this happen" the reporter writes "scientists say x, y, and z are in our future." Add to this a certain political component that affects both scientists and reporters, and the information that we get can be a bit fuzzy or even unscientific at times. More on that later.

Some scientists have begun to be alarmed at how climate studies are being presented, and warn that this kind of language is problematic at best, and counterproductive at worst. In a Houston Chronicle article (now no longer on the Internet) earlier this year, Kevin Vranes, a climate scientist at the University of Colorado wondered if they'd created a monster. His concern was that the press and the radical statements were presenting things to a degree that people were speculating far beyond what the science supported.

The truth is, there is no true "consensus" in science on anything; science is not decided by voting and going with the majority view. Science is simply the study of observable, measurable natural events and processes and trying to draw factual conclusions about how and why they occur. There is always a debate and discussion going on in science by its very nature: the constant questioning and examining of data.

Scientists will agree on some basic observable phenomena, called "laws" such as gravity and thermodynamics, they agree that molecular structures are reliable such as water being made of two atoms of hydrogen and one atom of oxygen. It is not, however, accurate to say that scientists are unanimous or even largely in agreement on global warming. The overall trend appears to be with the best data a slow, slight upward trend. This trend appears to be true on the mean for the entire planet. That's as far as any consensus goes. What happens next? What causes this? That's where the speculation begins and "consensus" ends.

Many scientists, such as those who have signed a petition asking for better research and less hysteria, are more cautious in their statements. Many are skeptical that the global warming will even continue, pointing to several trends that show a slowing and even reversal. Some scientists even reject the warming trend entirely, pointing out that the information before the middle 20th century is sketchy at best and guesses based on tree rings and soil samples tell little about temperature and much about other conditions.

Thus, there's controversy. Some claim that the earth is clearly warming, will warm even faster in the future, and it is caused by humans. Others question or deny various aspects of this, and some completely deny the warming trend at all.

Then it gets more controversial. The problem is that in the past, scientists have made various statements and warnings about dire futures which simply did not work out the way they'd predicted. Either their warnings did not take into account future technology or their threats were based on faulty information, or their statements were too dire and exaggerated, so the threat ended up being nothing. Sometimes, the dangers were even reversed by later findings.

Remember the Ozone Layer? The Ozone Layer is one of the various layers in the sky of different kinds of atmosphere that make up our air. This particular layer is one of the most important for blocking some of the sun's more harmful radiation (the sun is little more than a titanic nuclear explosion), such as some Ultraviolet Light. In 1985 scientists (specifically British scientists Joesph Farman, Brian Gardiner, and Jonathan Shanklin of the British Antarctic Survey) studying the weather and sky over Antarctica in 1985 noticed something in the sky. No it wasn't a bird or a plane, it was a hole in the sky: more specifically, the Ozone layer.

This hole is a natural event, every year the hole develops due to the extreme cold and various chemicals that swirl in the upper atmosphere, and then in the summer, it begins to repair. The scientists reported that it was larger than previously seen, and over the years reported on how big it was. They speculated that possibly ChloroFluoroCarbons (CFCs) such as used in aerosol spray cans and air conditioning could contribute to this, as could some other pollutants.

In response, the press reported that we were destroying the ozone layer, that CFCs were to blame, that we'd need sunblock 3000 in a few years to prevent instant sun cancer. UV blocking windshields, sunglasses, and suntan oil became prevalent, the hole in the ozone layer was a reference in late night talk show jokes. CFC's were banned in all western countries, and other chemicals took their place. Movies like Robocop and Demolition Man (they wore robes and covered up their skin as much as possible) assumed this horrible sun-cooking future.

Ozone HoleThe Ozone hole? Over the years, it has fluctuated and each year around December and January (summer over Antarctica) it... closes. Some years it's bigger, some it's very small. Some years it's a record size (although they only have records back to 1977), some years it's smaller than the average. The trend over the last five years has actually been to become smaller. In the future it might get bigger.

In other words: this wasn't the doom that was expected by some and predicted by many. It really didn't turn out to be all that terrible, and as a result it dropped out of the public discussion and newspaper reports. It was just another natural phenomenon, and without being scary or seeming to purport a terrible future, it wasn't very interesting. Naturally, reporting that the Ozone Hole was not that big a deal wasn't interesting to report on either. So it just dropped off the radar.
"In fact, the story wasn't 'wrong' in the journalistic sense of 'inaccurate.'"
Global Warming is fairly recent, it only started to really take hold in the 1980s along side the Ozone Layer and was often combined to present a future of horror and doom. Before that? Well, actually, it was global cooling that was the big scare. At the time, it made sense. For several decades (see that chart up top?) the overall global temperature actually had dropped. This trend was viewed with some concern, even hysteria by a few. Newsweek ran an article in 1975 about the scare, and leading scientists predicted problems with crops growing, harsh winters, climate change, and warfare. Sound familiar? This was based on climate studies and overall world trends at the time.
"There is a finite possibility that a serious worldwide cooling could befall the Earth within the next 100 years"
-(from a U.S. National Academy of Sciences Report, 1975)
The papers picked this up, and reporters talked about it with their usual restraint and deeply informed analysis. Another ice age might be coming! Firebrand billionaire Ross Perot proposed trucking Icebergs south to the equator to slow the cooling process. Then in 1992, Newsweek published a different story: the cooling was due to the greenhouse gasses, in a perverse manner, somehow the increase in greenhouse gasses in the atmosphere were causing cooling, based on the work of writer John Hamaker.
"On the short time scale, If CO2 is augmented by another 10 percent in the next 30 years, the increase in the global temperature may be as small as +0.1 deg."
-(Dr Stephen Schneider, in 1971 paper on the effect of atmospheric aerosols)
Interestingly enough, some scientists, noting the temperature trend for the last few years, are still predicting a future cooling period - even a possible ice age to come. As a result, the picture and the discussion becomes even more muddied. Good science is interested in doubt and question, because the goal is to find out what is really happening, not to end the discussion. Good science understands that extraordinary claims require extraordinary evidence.

Here's what I mean: if I claim that the moon is getting closer to the earth and we're all going to die by 2100 due to the catastrophic effects on tides and gravity, nobody will believe me. In order for anyone to even listen, I'll need some pretty impressive evidence and data to be even considered by anyone with an education. To claim that we're all doomed requires even greater level of proof. This is a basic scientific standard: if you claim something amazing or outrageous, you need amazing evidence. Lacking that, you've simply got an interesting, if a bit outrageous, hypothesis.

Next week, I'll look more closely at specific areas where the controversy rages, but until then, just remember: if someone pretends the discussion is over and the science is certain on this, take their statements with a grain of salt. Especially if they become insulting or condescending toward you for your questions or doubts.

Part Two: Taking the Earth's Temperature
Part Three: Questions and Answers A
Part Four: Questions and Answers B
Part Five: What and Why
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