Burning Down the AGW Denialist Billboards
Following on last week’s post I’ve decided to write a little more on climate change. In particular, I want to address in an informal way four issues that come up again and again.
CO2 is not the only greenhouse gas, but it is the most important one, and most of it is put there by humans.
The focus in the global warming discussion is on fossil “carbon” in the form of CO2 gas. There are other global warming related gases, but this is the main one. We often hear people complaining that water vapor is a more important greenhouse gas, or that there are other greenhouse gases, etc. The reason that none of that is important, and that this question is nothing other than a poorly executed canard, is this: Global warming is caused by the atmospheric release of carbon previously trapped in solid or liquid form during ancient times. With that carbon trapped, the earth is a bit cooler, with the carbon in the atmosphere, the earth is a bit warmer. That is the part that matters.
While large climate changes have happened in the past, they are always bad news for the organisms living on the planet.
Have you ever heard about the famous genetic bottlenecks the human species went through? A bottleneck is when almost all the individuals of a species die off. Our recent bottlenecks were caused by climate change.
The earth has been much much warmer (and colder) in the past. In fact, than it is now. It was so warm that dinosaurs lived within the arctic circle! So, given this, why do we care about global warming?
Well, the truth is, global warming probably isn’t that important. If we put all that carbon that was at one time in the atmosphere back, and make a warmer earth, we’ll just have a warmer earth. Life will go on.
Of course, the ecology of the planet will be entirely different, and most living species will have a hard time adapting to that change. There will be a mass extinction. But I wouldn’t worry about that mass extinction as much as other mass extinctions. A mass extinction caused by a cosmic impact could actually kill off ALL life instead of just a whole bunch of species, and could have a much longer recovery time if it happens to not kill everything. But a warming-related mass extinction may not be so bad.
Many humans will die miserable deaths, but in the larger scale, that is of no great consequence.
There is one small problem…if there is enough warming and the warming is fast enough, the cyanobacteria in the ocean could face a major die-off, which in turn would cause oxygen-breathing organisms to die off. But again, lots of other organisms would survive, so life would go on. But, well, whatever.
There is natural variation in climate, but it is easy to see the long-term anthropogenic warming as something added.
Short term natural variation such as El Nino cycles can be fairly intense, and it may be difficult for an individual to understand that over medium and long time scales AGW is occuring. There is also “natural” variation in the direction your car goes as you drive between two distant points…you don’t drive in a perfectly straight line, which might take you through people’s yards and across rivers where there is no bridge, and so on. You drive on roads and there is some back and forth that happens along the way. You don’t go, “OMG, we’re varying back and forth in our exact direction! We’ll never get to where we are going!!! We can’t possibly understand or measure our direction or know or plan where we will end up!!!! OMG!!!”
Well, some people do, but most people get that there are different signals of variation in time-series phenomena and, even so, it is possible to understand longer-term trends. And with respect to climate, we do understand and there is a warming going on now.
The effects of global warming have already started to occur.
People often say that we can’t be sure if the effects of global warming will be severe, but this is one of the most offensive things people say, because it overlooks the things that have already happened, including the moose dying off in Minnesota (for a local example) and the millions of people who have died with desertification in North Africa (to provide one of the more tragic examples). The effects of global warming are not confined to the future.
A related question is about the link between global warming and severe weather events. There is a link, though the link to each kind of weather event is not clearly proven beyond a shadow of a doubt by multiple scientific studies. And never will be, because it is hard to do that and probably not necessary. The link is so impossible to avoid that it is not necessary to work out the proximate mechanisms to the level that would be.
A lot of well-meaning people claim that you can’t connect a particular hurricane or other weather event with global warming “because it does not work that way.” But those well-meaning people are wrong, exactly because it DOES work that way. Weather events are linked to the process of movement of excess tropical heat energy towards the poles and towards the outer atmosphere. With a warmer earth there will be more severe and more extreme weather events. Some specific types of weather events may not increase in magnitude, while others do. But overall, more warming = more “weather,” which will be in the form of more rain in a given rainfall, more wind-related events, and yes, even more snow under certain conditions.
Think of it this way. You can’t blame a given convenience store robbery on poverty during a period of crime rising with worsening economic conditions, but when the business association meets and 14 store owners were robbed since the last meeting (rather than the old average of, say, 1 or 2) then you can blame that phenomenon on the crime rate/poverty connection (assuming there is a connection). We can blame increased severity of weather events on global warming because it makes perfectly good scientific sense to do so.
Can AGW denialists ever be convinced that AGW is real?
I had a global warming denialist on my blog a few months back. He kept pointing out that it was just as warm in Minnesota at one point in the past as it is now, so there is no global warming. I explained that he was cherry picking and misinterpreting the data. He fought back until I posted a couple of items that fully and indubitably proved that he was in fact being intellectually dishonest. He went away and has not been back.
I don’t expect these dyed-in-the-wool cranks to change their minds, but it is appropriate that those of us who do have bits and pieces of the internet in our charge keep the dialog honest and progressive. The denialists are putting up offensive, inaccurate, one-liner billboards. We are burning the billboards down with science. It is worthwhile work, important work, and it can even be fun on occasion.
This entry was posted on Wednesday, December 16th, 2009 at 2:11 pm and is filed under Greg Laden, Science. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.