Wednesday, September 16, 2009

What we know (and don’t know) Wednesday

I started the Temper-Tantrum Tuesday series because I know a lot of my viewers stop by to keep up to date with the Catspiracy. For those of you that do that I want to say, “Thank You” and stop by tomorrow for the Purrsday edition of the Catspiracy. I figured if I kept my rants confined to one specific day those people would know that if it’s Tuesday it would probably be a rant and would be forewarned.

I really only did it for myself so I could get things off my chest and not chase off my followers. So when I got a positive feedback I was pleasantly surprised. So I figured I could set aside Wednesday to follow up on my Tuesday rant with a closer look at the science and skeptism behind one of the topics I ranted about Tuesday.

Global Warming

That Global Warming is real and provable is very easy. Our Moon doesn’t have an Atmosphere and its average temperature is –67 degrees F, Earth has an Atmosphere and its average temperature is 57 degrees F. Our Atmosphere keeps our planet 124 degrees warmer, a good thing too I don’t have that many sweaters.

As the Sun’s rays hit the ground they warm it up. On the Moon this heat is radiated back into space. On Earth this heat has to warm the lower atmosphere and it travels upward into the upper atmosphere where it is radiated out into space. This process is called Global Warming.

Global temperatures are regulated by two things, how much heat the planet receives from the Sun and how much heat the upper atmosphere radiates back into space.

Most people accept this part of Global Warming.

With that part of Global Warming agreed upon the next question is: Is this changing?

In the last century the average ground temperature has risen by 1.33 degrees F. So yes it is changing.

This change means that either the Sun is heating the planet more, or the atmosphere is radiating less heat back out into space.

Since the 1700’s the Sun has been getting brighter as part of its regular cycle. This means the heat that the Earth receives from the Sun has been increasing, however the temperature variation on Earth has been negligible for the first 200 years of that cycle. Even the most biased (but peer reviewed study) claims that the Sun can’t be responsible for more than 50% of the increase in the last century. Most scientists put that number at about 7%.

The other part of the equation is how much heat is being radiated back into space from the upper atmosphere?

The way to measure that is to look at the temperature of the upper atmosphere, the Stratosphere and the Thermosphere.

The Stratosphere has been cooling off in the last century by about 0.5 degrees C per decade. The temperature in the Thermosphere is best measured indirectly by looking at the overall atmospheric density (cooler air is more dense than warm air). The atmosphere has gotten 2% denser but the Thermosphere has gotten thinner. This means that the upper atmosphere is cooling, radiating less heat into space.

If the 1.33 degree F temperature rise over the last century was caused by the Sun these parts of the atmosphere would be heating up, not cooling down.

To determine what is causing less heat to escape scientists have looked at the reflective properties of different gases in our atmosphere. Some like sulfur dioxide reduce the amount of visible light hitting the ground while letting heat radiate through unhindered. Others like Carbon Dioxide and Methane let light through but don’t let the heat radiate back out. Oxygen and Nitrogen are fairly neutral.

Industrial activity has increased the amount of Carbon Dioxide on the planet. The strong correlation between the increasing temperatures in the lower atmosphere and increasing levels of Carbon Dioxide make it the prime gas to look at.

No, Not that Climate Model

Climate models (mathematical calculations based on the scientific properties of the atmosphere, not scantily dressed females pointing at clouds) show that increasing the amount of Carbon Dioxide in the atmosphere will in fact increase temperatures.

Knowing that is there room for serious debate? Absolutely.

Climate experts in the 1960’s believed that the increasing amount of Carbon Dioxide in our atmosphere would cause a 2-6 degree F increase in ground temperatures over in the 21st century. The current models show a 3-5 degree rise is probable. Most likely there will be a 4-degree rise in temperature over the next century if nothing is done.

Where the there is a huge disagreement is with the Global Warming doomsayers that point out different feedback mechanisms in the atmosphere and claim the 4 degree rise will trigger scenarios that will cause a sudden jump of 18 degrees.

I’ve looked over these claims and the problem I have with them is the statistics used. They are using low probability events to trigger the next low probability event. So while I will admit that our changing the Earth’s climate on such a massive scale is bound to have some things happen that is hard to predict, the piling of low probability events on top of each other is scientifically dishonest.

A 4-degree temperature rise is bad, but will not wipe humans off the planet. Solutions to global warming have to be looked at in that light so we can work on permanent long-term change over the next century to reduce our harm to the planet. Not look at an improbable 18 degree rise and go into panic mode.

I would love some serious comments on this subject, especially from the extremes (Global Warming deniers or Global Warming doomsayers).


Tricia said...

I still find it difficult to believe that people don't think global warming is happening. I learned about this in grade 7 social science class. The basics never change.

Project Savior said...

It is very basic science. There is a little room in the interpretation of how big a change there will be but the basic science is, well basic.

Stephanie B said...

Apparently, I have to do this in parts.

I'm entirely with you until the last three paragraphs, not because I'm certain a specific bad thing will happen, but because the system is so complex.

You can't work in environmental sciences for any length of time (and I don't but my father did) without realizing that oftimes the tiniest changes have big consequences. Not always, but fare more than a "small" percentage of time.

Do I think people will be wiped from the face of the earth. Not really, but I do think that the poorest groups in the world will suffer the most for our greed. 4 degrees may not destroy humanity, but it can raise the water level for oceans (to a speculated level), which can have devastating effects on coastal areas, worldwide, many of which are some of the most densely populated areas. It can make islands disappear. Warmer oceans/atmosphere can increase the severity and frequency of storms and droughts, the latter, again, having impacts on millions of people in third world nations. Whole nations, even continents can lose their fresh water sources if glaciers erode and don't return (which is already happening in South America). And that's not just third world nations. China and India, the two most populated nations on earth, depend on water that flows from the Himalayas. If the water goes (or melts too quickly), devastation and death for millions of people.

Stephanie B said...

Not the ones who cause the problem, mind you, but people with money and oil they burned with no thought to the future. It's a sad irony that, if even the most benign results come to pass, the ones who will pay hardest are those who have contributed least to the problem and who are the least likely to have the resources to save themselves.

Skeptics like to cite that the earth balances herself. True, to a point, but she has no trouble eradicating life when she does it (remember the tsunami a couple of years back?). And, again, that's speculation on our part as pronounced as the worst doomsayer.

We don't know what will happen. Scientists worry because we don't know what will happen and because putting this genie in the bottle becomes more impossible every month, because, by the time we know conclusively without a doubt, there will be no stopping the juggernaut. And someone will be paying for the excesses to date. We've only seen the tip of the iceberg.

See, if we're right to be worried, doing nothing means horrible (and needless) suffering by people who desperately don't deserve it and doing something keeps some of that from happening. If we're wrong, if we do nothing, we run out of fossil fuels (after continuing to put other combustion related poisons into the environment for the remaining decades we'll have them) and we're unprepared with other energy methods and, if we do something, we stop using our limited fossil fuels to the same extent, along with the other pollution that goes with it, and explore clean technologies that can last, potentially, forever.

Either way, doing nothing is bad and doing something is good.

Two more thoughts. When "An Inconvenient Truth" came out, people blasted it for "exaggerated" short term predictions, but even the worst predictions at that time have not been as bad as the actuality since then. The ice loss has been unprecedented and unexpected. The carbon sequestering of the ocean has not been as significant as expected and the resultant increase in acidity has had adverse effects on coral reefs around the world. Threaten the reefs, you threaten the worlds fish sources (already strained from overfishing) which much of the world (particularly the poor portions) depend on. Then there are the more subtle effects like the impact via viruses of bee populations where colonies died en masse. Only then the general public realized how crucial this one creature was to agriculture.

Secondly, although I don't think people will be destroyed by this, but I can't quite shake an important example few people mention. Another Earthly neighbor, Venus. Venus is our twin, slightly closer to the sun, slightly smaller. Evidence available says it once had water, perhaps once had life. No more. Now it's poisonous and unimaginably hot (900 deg F), presumably through the greenhouse effect. But, here's the thing, we can't figure out why it's so hot because our estimates of worst case greenhouse galloping away don't make it nearly that hot. And yet it is.

Since we don't know the mechanism, we can't rule it out. And wouldn't that be a sad reflection humanity, that we had an example of what could happen and we didn't learn a thing.

Just sayin'.

Project Savior said...

Stephanie, Looking at the problem you had with my post, the spot I lumped rising sea levels, massive droughts, the deaths of millions of people, altering peoples way of life for the worse, etc. as "bad". I can see how you could think my just grouping all that together and just calling it "bad" could be considered a little vague. I did it because the post was getting a little long. It definitely needs a follow up post. The point I was trying to make in those last few paragraphs was we know doing nothing will lead to a 4 degree rise in temperatures, we don't want that.

Project Savior said...

If we work to significantly reduce that, a 2-3 degree rise in the next century, we can build a world where green technology is thought of as natural and economics will take the environmental impact into account. If we do that and we find out later something the doomsayers warn is correct we will already be on the right path. Unfortunately, it took us a century to mess up the environment as much as we have, so it will take a long time to clean it up. I agree with you we need to take more actions, but it needs to be with long-term goals not knee-jerk reactions. Like I said I'll have to do a follow up post soon.