Can We Fix It?

(This is a long, semi-boring rant about global warming. The top is a discussion of how we know it's happening. The bottom is what people are trying to do about it.)


Global warming is a fact. It is happening. We can see this in numerous records (both from proxies and actual temperature measurements from instruments over the past couple centuries). It is also our fault. I know there are people out there that will try and tell you that this is a natural process, the Earth is doing it's own thing, as it has done for the past few billion years. Well, in the past it has been natural, and part of this change is probably natural, but we are contributing a great deal to the current climate changes and associated affects.

Not only are we adding CO2, CH4, O3, CFCs, and several other greenhouse gases (thus increasing the inputs) we are also reducing the sinks (deforestation, clear cutting, etc). The junk we are adding to the atmosphere is causing warmer temperatures, which increases the amount of water vapor that the atmosphere can hold. Water vapor is a tremendously powerful greenhouse gas. Here's a quick and dirty discussion of why greenhouse gases cause the planet to warm. We get shortwave radiation (visible light) from the Sun that enters the atmosphere (some of this is reflected back to space and some is absorbed by molecules in the atmosphere), it hits the Earth and the Earth sends back longwave radiation (Infra-red light) that then interacts with molecules in the atmosphere that absorb it and send half of it back down to Earth, trapping that energy in the atmosphere causing increased temperatures. So, different molecules absorb and re-emit different wavelengths of radiation. So CO2 absorbs and re-emits certain wavelengths, as does water, CH4, etc. Now, some of this radiation makes it all the way through the atmosphere and out to space - this is called the atmospheric window. This happens because there isn't a molecule or enough of that molecule in the atmosphere to absorb and re-radiate that wavelength of radiation - so it gets through free and clear. What we are doing is adding molecules to the atmosphere that will interact with wavelengths that before now got through unhindered - basically we are shutting the window. This is bad. Heat/Energy can't get out as well, so it's causing increased temperatures.

Now, if somebody tries to tell you that some natural process is increasing the concentrations of the greenhouse gases in the atmosphere you can either be sure they are lying or they don't know what they are talking about (either because they've been misinformed, which is entirely possible in this political climate, or they are just talking about of their ass). We know this from simple calculations, we know what the concentrations of CO2 and CH4 and all the others are in the atmosphere, and it's not too difficult to calculate how much we've put in. There's also the isotopic signatures of the gases - which can tell something about their sources. It's us. Sad but true.


Why am I talking about this? Well, first off. I study it. Secondly, it seems like there are a lot of people out there that don't believe it (including my Father - but no, I didn't sit down and have this conversation with him, because then he may realize I'm studying climate and nobody wants to go down that road...). Third, we had a really cool discussion about what can be done about it in my biological oceanography class. There were two options dicussed for how to decrease the amount of CO2 in the atmosphere (b/c even if we stop emitting there's already a whole hell of a lot of it in the atmosphere that needs to be dealt with).

1) Iron fertilization. Basically it's taking out ships and dumping nutrients, especially iron, into the oceans to cause phytoplankton blooms which should draw down CO2. This seems like a neat idea, increase the primary productivity of the oceans. Although, there are several drawbacks... We have no idea what effect this will have on higher trophic level organisms or on the ecosystem. Those phytoplankton that bloom can produce some very bad chemicals, by-products, such as demoic acid (toxic) and DMS (dimethyl sulfide).

2) Liquify the CO2 and put it at the bottom of the ocean. STUPID! This is a really terrible idea for several reasons. First off, what about all the organisms that live on the bottom of the ocean? This will kill them. Secondly, what if this changes the chemistry of the seawater making it acidic? If that happens, those little plants we're counting on from #1 to draw down CO2 won't be able to grow, and then what? Or what if somethings disturbs the CO2 on the bottom of the sea and it just comes back out again?

So these leads me to a few conclusions. #1 We're basically screwed. #2 We need better ideas about how to solve the problem. #3 People need to be educated about what is really going on.