Anthropogenic Climate Change

Because my first post (Statistics of Terrorism) was utterly discredited and ruined by tropers (along side my research tied to Terrorism, so now I have to start over again), I'm going to ask an interesting question; How serious is global warming?

To start of: Martin Weitzman, an environmental economist in Harvard, argues that there is a 5 percent chance that temperatures will rise significantly enough to effectively destroy planet earth. Compare this to the 'documentary' an Inconvenient Truth, where the the chances of a Global warming apocalypse is inevitable if we continue our current path. 5% vs 100%.

That "destroying planet earth" is bullshit. Global warming is a serious threat because of the high cost associated with it, not because it has the potential to make humanity go extinct. Preventing or limitating the global warming is just much cheaper than letting it happen...

edited 13th Sep '11 5:28:46 AM by Uchuujinsan

Outright apocalypse is unlikely, but serious detrimental effects are a certainty - they've already happened!

Doomsday unlikely. Massive chaos from increased suffering and lost of species: likely.

It is a issue that must be tackled for our future.

Okay, so we established that an apocalypse is unlikely, but let's just say it is inevitable. What are our options? Reducing emissions? Unlikely. I do not believe people are naturally altruistic. Sometimes they are, but most of the times they act in their best interest. Would reducing emissions be profitable? Nope. The entire environmentalist argument for reducing emissions is really 'oh, look, people are awesome! I'm sure they would reduce emissions if we inform them of global warming!'. It's stupid. A real solution would be a Stratoshield. Sure, there are drawbacks, but it can be deactivated once those drawbacks are realized. To put it all in economic perspective: Stratoshield deployment cost: $20 million, Stratoshield maintenance cost: $10 million per year, probability of stopping global warming: Very likely. Al Gore's campaign cost for making people know global warming: $300 million per year, probability of stopping global warming: 0.

The problem is scientists are still figuring out whether anything we can do can reverse the effects at this point. And or whether its mostly our fault or mostly natural.

Either way, th evidence for the existence of global climate change is pretty ridiculously solid, though.

At this point, it's not really possible to prevent. The main concern is mitigation.

Sixth Extinction Event, basically.

Scientists have already determined that it's almost certainly due to human activity. At this point, some degree of global warming is inevitable, but both mitigation and adaptation are still possible. While it's a possibility that we've already passed some sort of tipping point and catastrophic warming (in the range of 5 C° or more) is already impossible to prevent, it's also possible that there's still time to prevent most of it.

Even if it's not possible to entirely prevent climate change, it's still certainly worthwhile to try to mitigate it. Scientists have found that mitigation is less expensive and more effective than adaptation, and also involves less human suffering. Mitigation and adaptation efforts are in people's direct self-interest, since many of the impacts are already occurring or will in a few decades.

The most worrisome effects of climate change aren't rising sea levels or extinction of a few large mammal species like polar bears. The biggest problem is that a 5 C° increase (maybe even less) in global average temperature — which is a definite possibility, especially if no serious efforts are made at mitigation — would turn areas such as the central United States, which are responsible for much of the world's food production, into a permanent Dust Bowl-like climate. This would result in massive, global food shortages, and at the same time, warmer temperatures would allow for the faster and wider spread of many diseases.

There are many different estimates of how bad it would be, but hundreds of millions or even billions of deaths as a result are not that unlikely. Human extinction is highly unlikely; humans are too widespread and too adaptable for that.

Another major concern are positive feedbacks, that is, sources of greenhouse gas emissions that would be triggered by warming, and then cause further warming; these have the potential to cause fairly rapid, out-of-control climate change. Some examples are arctic ice melting (open water reflects less energy than ice), the melting of permafrost (which often has large quantities of methane trapped in it), and ocean acidification (because higher acidity reduces its capacity to hold dissolved CO 2, which could potentially turn it into a carbon source, like what happens when hot water saturated with salt cools down). Ocean acidification in itself could be disastrous, considering how central ocean ecosystems are to the planet's basic ecological cycles.

For sure, anthropogenic climate change is the biggest challenge humanity has faced in recorded history.

edited 13th Sep '11 8:45:44 AM by Enthryn

You don't really need to be altruist to not want to have your economic well-being threatened by the negative effects of climate change. The problem is short-sightedness, where you try to profit today at a significant cost tomorrow. We don't properly calculate the actual cost of... for instance... cutting down a tree. We think, okay you cut down a tree and sell the log and you make some money. You don't think, I cut down a tree causing a release in carbon, decrease in oxygen production, decrease in water filtration, decrease in disease mitigation, decrease in wildlife (healthier eco-system means less taxation of your public infrastructure) and so on. Nobody pays that cost.

The video.

The expansion pack.

The science has been settled for a long time. The alternatives to not reducing emissions have not borne fruit. And too much has happened already for us to discount climate change mitigation/geoengineering.

We need to start using less carbon and trying to undo the damage we've already done. Even if you're worried about the economy, you'll want to pursue policies towards that end since the alternative will be far more expensive.

Yes it's serious, and yes something must be done.

EDIT: Oh, and any arguments to the contrary have probably been brought up here, particularly here.

edited 13th Sep '11 10:00:45 AM by RadicalTaoist

It's very hard to get neutral, objective facts and analysis on global warming because the political climate has so strongly polarized the debate on this issue. I will summarize arguments taken from Patrick Michaels and Robert Balling's book "Climate of Extremes". Michaels and Balling are professional climatologists who are semi-controversial because they agree man-made warming is occurring, but disagree that the end result will be catastrophic.

This is from their first chapter "A Global Warming Science Primer"

Quote: "Earth's mean surface temperature is doubtlessly warmer than it was 100 years ago. Get over it.

What matters is 1) how much it has warmed 2) how much of that warming is caused by human activity, and 3) how the relationship between that activity and present temperatures can be translated into a reliable estimate of future warming and it's effects."

They then go into an analysis of historical temperature data, taken from the United Nations Intergovernmental Panel on Climate Change (the IPCC), which they seem to regard as accurate and valid.

Figure 1.1 traces "temperature anomolies" from 1900 to 2006, and demonstrates a clear warming trend. There are in fact two distinct periods of warming, one from 1910 to 1945, and the other from 1975 to about 1998. In both of these warming trends, the actual rate of warming has been extremely steady: .320 degrees F plus or minus .038 per decade. This rate does not appear to be accelerating (and may have dropped off significantly in the last 10 years).

Michaels and Balling conclude that the first warming trend had more to do with changes in the sun, while the second one has resulted largely from human activities. The reason for this is that heating due to solar activity has a very different pattern from that due to greenhouse gases. Computer models predict that solar heating will heat the upper atmosphere as well as the lower atmosphere, while greenhouse gases heat primarily the lower atmosphere. They present data which shows that lower atmospheric heating, and upper atmospheric cooling, is indeed what is currently happening. In addition, models predict that greenhouse gases would warm winter temperatures more than summer temperatures, which is also occurring. They therefore conclude that since 1975, most warming has been due to human activity.

This has had the interesting side effect that the yearly temperature range has been narrowing. Both summer highs and winter lows are increasing over time, but winter lows are increasing faster, which is resulting in less temperature variation over the course of the year: the climate is becoming less variable. Finally, the daily temperature range is also narrowing for the same reason: in most places the daily low is warming faster than the daily highs. These are all signs of the effect of greenhouse gases.

Michaels and Balling then combine the model outputs with observed data and come up with a forecast for warming for the 21st century: 3.1 degrees F. They mention that this forecast should be treated with a great deal of caution, because the computer models are known to be imprecise (they predict more warming that we observe happening, esp. in the upper atmosphere, and also fail to predict the narrowing temperature ranges accurately).

They also mention that technically, global warming has stopped since 1998. They regard this as a temporary aftereffect of the 1998 El Nino, the largest on record. If you look at the century long trend line, it's visually obvious that the lack of warming since 1998 is within other temporary reverses that have frequently occurred. Computer models that assume that the warming trend is still continuing, but have been overlaid by the El Nino are more accurate at predicting monthly temperature variations since 1998. So the assumption is that warming will continue at some point in the near future, but at this point that's only an assumption.

Another interesting implication is that, if it's true that the lower atmosphere is warming faster than the upper, then increased precipitation is likely to occur. We are heading for more tropical conditions, not more drought. This still has the potential to do tremendous damage to the agricultural industry, as well as problems to populated areas due to flooding.

The bottom line is ammunition for both sides of the partisan debate. Global warming due to human activity is almost certainly occurring, yet the extent of the warming, esp. in the last 10 years or so, is somewhat in doubt. This could be considered good news: the worst damage may yet be preventable.

In my perspective, the way people are treating Global Warming is the same way people treated the passenger pigeon when their population reached the billions before their complete extinction in 1914. They were regarded as so common or ubiquitous that even when their numbers reached critical levels and laws were passed to protect the wanton killing of the birds, the numbers continued to decrease until they simply couldn't recover and further efforts to preserve their species were too late. With global warming, no one is immediately doing anything about the situation because it's happening so slowly. As a result no one thinks it's an emergency so they let the problem continue unabated until it reaches levels that human aid can do little to alleviate. The problem with this whole thing is that most people (unfortunatly including myself) think that the global warming problem is no immediate concern and can be solved at any time.

The problem is that global warming is both an immediate concern and cannot be solved at any time. It's an immediate concern because the initial impacts of global warming are already occurring. Just look at the unprecedented drought in Texas for an example.

Due to positive feedbacks (which I mentioned in my above post), if nothing is done about global warming soon, it will be nearly impossible to prevent further warming. These "tipping points" are the reason why immediate action is necessary; the problem will become worse and harder to do anything about as time goes on.

Global warming... is a problem. How to fix it? Beats me.

Could we go green? Sure. But the Third World couldn't. They have to go dirty to get to our level. So, what is there to be done?

The third world could, with help.

God forbid we spend the resources on them, though. Am I saying that as a whole the developed world is too self-centered to muster the political will to help the developing world become carbon-efficient, even if our survival as a species may depend on it? Yes. I went there.

http://www.independent.co.uk/environment/climate-change/shock-as-retreat-of-arctic-sea-ice-releases-deadly-greenhouse-gas-6276134.html

You know, back in September I didn't think much of global warming.

I live in Wisconsin. It's the 13th of December. As in, winter time in the Northern Hemisphere.

It still hasn't snowed yet.

Yeah, that's the positive feedback effect caused by melting permafrost. Scientists have been warning about this — or at least, about very similar feedbacks — for years now. This is how rapid, irreversible climate change can be triggered: a moderate amount of warming triggers a whole bunch of positive feedbacks that each cause further warming.

edited 13th Dec '11 7:41:41 PM by Enthryn

In the last fifty years, we have raised the Earth's temperature two degrees Celsius, and we are expected to reach five degrees Celsius warmer by the year 2050 (or perhaps even earlier). That might not sound like all that much, until you realize that the last ice age was only five degrees Celsius cooler than it is today. In other words, in fifty years time, the world will be as different climate wise from today as it was during the last ice age. Worse, if global temperatures continue to rise after that, reaching seven or eight degrees Celsius warmer than it is today (as we might expect if current trends are not reversed in the next two hundred years), most mammals will not be able to survive (at that temperature range, most of the planet - from 30 degrees north and south of the Equator - would reach Australian Outback conditions. Humans would have to live underground, or migrate to Antarctica and Siberia). Reptiles, though, might be just fine as they don't have to worry about cooling their bodies down, so we might just be ushering in a new age of reptiles.

As for the 5% chance that the OP was quoting, that is a 5% chance that global warming exacerbates itself (by melting frozen methane deposits and releasing stored carbon from frozen tundra) to the point that we have a runaway greenhouse effect and and up just like the planet Venus. In other words, that is a 5% chance that we turn Earth into the closest thing in the solar system to actual hell. When you put it that way, that 5% seems pretty serious - I wouldn't want to bet my life on 5% odds, let alone the planet.

And as bad as that is, most life on Earth would already be killed long before we reach that threshold. Already many large groups are simply dropping dead worldwide, and the likely cause is global warming. For example, coral reefs can only live in a certain temperature range, and we have already surpassed that range around the tropics. This is the consequences of global warming, not in some long distant future that you will never see, but right here, right now:

It certainly seems that the human race is in for some serious pruning by 2050. Even in the best of scenarios, our population isn't suited for that kind of temperature increase. How do you farm enough food?

And that doesn't factor in the geopolitical concerns, which are even starker than the weather predictions.

edited 13th Dec '11 8:13:44 PM by johnnyfog

You live in Wisconsin and it hasn't snowed yet, boo hoo. Do you remember last year?

Anecdotal evidence doesn't work.

I wasn't really being entirely serious, you know...

An important thing to realize is that a few degrees higher means the ice pack line in the mountains recedes by a lot. Losing that much ice means you don't get irrigation in the summer. We're already seeing the effects of that all over the place. Look at the Andes, the Alps. Hell, Kashmir river sources that feed Pakistan and India are getting pretty damn dry in the summer, and those two really don't need another reason to be at each other's throats.

Allow me to offer counterpoint:

It's December 14th in Colorado, in my neck of the state we've had about 30 inches of snow (normally we have about half that) so far this season, the running temperature average for the last two weeks is about 25 degrees Fahrenheit during the day and less than 15 at night. (30 year average for the same time frame puts the day time temp at around 44F and night average at about 22F.)

Yet this is more typical and traditional of Colorado than global warming would have us believe.