elwoodblues

The popular idea of what global warming means has changed a few days. The earth was going to dry up. Then we were going to be flooded. Now there's a new idea in vogue, and I'd like to talk about it.

It's called local variability. It roughly means that global warming isn't necessarily indicated by widespread increases in temperature, or widespread changes in climate in general. Rather, global warming creates increased temperature variability in local areas.

Now, there is some science behind this; I'm not saying this is total crap. But there's some danger of perception here, too, and I've already seen plenty of evidence of it. See, there's no disconfirming evidence to be found.

Temperatures higher than usual? Why, that's global warming at work! Temperatures somewhat lower than last year? That's global warming too! Temperature the same as last year? Well, don't be too relieved, there's bound to be some smooth spots.

I'm not saying that this will necessarily effect scientists and their findings. But it can have great impact on individuals with little or no scientific training. Remember a few years ago, when every damn thing that happened in the weather was 'El Nino' at work?

I've seen the same thing happening with this local variability idea. Sometimes it's off-handed, sometimes it's even flippant. But it's an insidious confirmation bias, and it's so damned effective that I have to wonder if that's not entirely accidental.

copernicus

Why do you consider this a change? Climatologists have argued for many years that global warming would lead to extreme weather changes at the local level--both hot and cold. This is not news. I don't recall anyone predicting that the earth would "dry up" soon. The atmosphere will lose water at a greater rate, but the planet won't become a desert in the near future. As for flooding, that has already been increasing. The rise in sea levels is measurable, and it is going to have catastrophic effects in the future. Most of the human race lives close to the sea. Massive migrations inland will cause serious disruptions in agriculture, not to mention other areas of the economy. Treasury Secretary O'Neill has likened global warming to a nuclear holocaust in its effects on the human race.

I don't get your point. Are you saying that global warming is not happening, that it is bogus science? This issue of local variability is one thing. But there is a relative scientific consensus that global warming is taking place and that it is caused by human industrial activity--much of it by the US release of carbon into the atmosphere. Even Bush recognizes that now, after having his fanny kicked by his own hand-picked science panel.

It is true that many people are prone to confusing weather changes with climate changes, and the less knowledgeable ones think that they can prove or disprove global warming by local warm and cold spells. But that is not what climatologists are saying. What they are saying is that some of the extreme weather conditions that we have been observing recently have been the result of global warming, including the El Nino cycles.

elwoodblues

"Why do you consider this a change?"

Because it's now part of what the public thinks. That's what I was describing; not necessarily what scientific bodies were theorizing, but what the public perceived the dangers to be. And this is now the main theory in the public eye, as far as I can tell.

"The rise in sea levels is measurable, and it is going to have catastrophic effects in the future."

Odd, that. How measurable? Where's the water coming from? Because the ice caps are actually accumulating billions of tons of ice each year, from what I've read...

"Are you saying that global warming is not happening, that it is bogus science?"

I'm not saying that. I don't want to debate that here. I'm just concerned about some aspects of this specific theory, especially as it relates to average, non-scientific individuals.

"What they are saying is that some of the extreme weather conditions that we have been observing recently have been the result of global warming, including the El Nino cycles."

I am not arguing with the science of it, per se. I'm just very concerned about this:

As far as the public is concerned, this is a scientific theory that has a plethora of confirming evidence (be it real, or just normal weather fluctuations), and no real way to get disconfirming evidence.

The only way that a scientist could disconfirm this theory would be with reams of data and strict, intense statistical methodology. That's well beyond the vast majority of individuals. The put a lot more creedence in the fact that it snowed in April, or didn't snow in November.

I'm not questioning a global warming theory. I'm questioning a scientific theory that leaves precious little room for disconfirming evidence, especially with the vast majority of average individuals.

Stars In My Eyes

Yes. I understand any scientific theory has to be falsifiable - it should be possible to invalidate it with the right data and two opposing datasets cannot both "prove" a theory is right if they contradict each other. Yet now any warmer OR cooler/wetter OR drier/windier OR calmer/cloudier OR clearer etc than "average" weather event is often reported by the mass media as being linked to global warming. But what is the "average" - the last 150 years out of 4.5 billion? The Earth is warmer than 100 years ago, cooler than 1000 years ago (Medieval Warm Period), warmer than 10,000 years ago (end of Ice Age etc) and so on. What's "normal"?

A good example of the local variability elwoodblues talks about is the Antarctic Peninsula, less than 2% of the total Antarctic landmass, much of which is juts outside the Antarctic Circle. This 2% is experiencing some substantial local warming with melting and treating ice glaciers, "extreme ecological change" etc. Yet this often gets reported as "The Antarctic is melting!" by the mass media when in fact ground and satellite measurements over the last 20 years show over the other 98% there is an average cooling trend with the sea ice pack edging towards the equator and the overall ice mass balance increasing. The layman doesn't get to know this, since conflicting data is often overloooked or ignored by the mainstream media.

Morat

Is this an argument for the media to get better science staff and to stop sensationalizing anything?

Or an argument about global warming based on media reports?

Seriously, if you want to know normal, ask climatologists. Not Time or Newsweek.

I don't see exactly why the notion that increased average global temperature would lead to massive changes in local climate is all that surprising. Climate is an energy system. A very complex energy system. You've just fed more energy into it. That doesn't mean that energy is distrubted evenly. Not in something as complex as global climate.

Especially given that local climate changes cause feedback into the global system. Increased heat in one area causes an air or water current to move. This drives heat up in another spot, while chilling yet a third.

SteveEvil

I think they mean all of that.

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The problem is that most people don't know any climatologists and they find science websites and magazines far too dull to read. Most people go to Time and Newsweek to find out about what is "normal".

I don't think anyone is disputing that. I think the problem is that most people aren't let in on the idea that global climate is extremely complicated. They see a headline screaming "GLOBAL WARMING ATE MY BABY!" and they take it to heart. This can affect a lot of political decisions based on a sort of panic reflex. The scientific jury is still largely out on the effect of human consumption of fossil fuels on the earth's climate but in the media it is a foregone conclusion that our cars are rapidly turning the earth into another Venus.

EDIT: Stupid frikkin brackets

[ February 15, 2002: Message edited by: SteveEvil ]</p>

copernicus

Nonsense. According to obsolete anti-environmentalist propaganda, the satellite data was counterevidence against the global warming hypothesis. More recently, it was discovered that the original findings made no adjustments for orbital decay. When that information was figured in, the satellite data was consistent with the vast amount of other data that confirms the global warming hypothesis. Furthermore, most climatologists now accept that the recent warming trend (as opposed to earlier warming trends) has been caused by the rapid dumping of carbon into the atmosphere by human activity. (The US is the worst offender, although China will eventually overtake it.) You can read the <a href="http://lwf.ncdc.noaa.gov/oa/climate/globalwarming.html" target="_blank">NOAA FAQ</a> on global warming, if you want to see what the scientific consensus thinks about global warming.

As for the arctic ice sheet, it continues to break up at an alarming rate, with recent studies showing that Antarctic lakes have warmed to unprecedentedly high temperatures. An ice sheet that was roughly the size of Long Island broke off not more than a few weeks ago. The Greenland ice sheet is rapidly retreating, although there is some disputable evidence that it is thickening in the middle. Glaciers have been retreating rapidly all over the world.

No one seriously questions that global warming is real. A handful of scientists, many funded by industry, have argued that the evidence is suggestive, but still inconclusive. Meanwhile, our President has just released a plan for voluntary pollution controls that he thinks will slow the increase in CO2 emissions. The rest of the world is clamoring for a decrease, especially from the US, the world's biggest polluter.

Amalthea

As far as I was aware, global warming was just a term that the media picked up on to describe the theory - I always knew it by the more accurate term "global climate change". This allows for local variablity, such as a decrease in local average temperature.

I have a real bone to pick with science reporting in the popular media, especially when it comes to global "warming". The simplistic way it is portrayed (and I understand that it has to be simplified somewhat for the lay public) allows for complete misunderstanding of the processes involved.

Exactly, climate and weather are two different things, but how many people on the street understand this distinction?

My point exactly. How many people realise that the majority of the rise in sea level will be accounted for by thermal expansion of the seawater, not by the ice caps melting? Or that a slight rise in average global temperature might trigger more accumulation of snow at in the polar regions and that at present there is very little in the way of precipitation in those areas.

I think that the point that I am trying to make is that I wish that the media would not jump to oversimplified conclusions and pass these onto the public, who are not equiped to sort the wheat from the chaf.

[ February 16, 2002: Message edited by: Amalthea ]</p>

Loren Pechtel

Originally posted by Amalthea:
My point exactly. How many people realise that the majority of the rise in sea level will be accounted for by thermal expansion of the seawater, not by the ice caps melting? Or that a slight rise in average global temperature might trigger more accumulation of snow at in the polar regions and that at present there is very little in the way of precipitation in those areas.

So what if it's by the water expanding or by more water coming out of the caps? It still rises. That's like saying that tobacco isn't bad because it's mostly the radioactive contaminants that are the killers, not the tobacco.

Second, you are describing a feedback mechanism that might reduce the severity of the problem. It won't stop it, though.

Amalthea

True. I wasn't trying to diminish the severity of the problem, I was just commenting upon the ease by which misuderstandings promulgate themselves in the press, and the manner in which the subtle complexities of the problem get overlooked. Sorry if that wasn't clear.