Sunday, September 16, 2007

Roger and Jim

Ethon came back from the library with some interesting reading. Of course we had to clean the liverwurst sandwich crumbs out of the copies, but underneath the stains Eli found this interesting comparison of Roger Revelle's 1990 recommendations for dealing with global climate change with Jim Hansens 2007 recommendations.

Revelle (1990)

Hansen (2007)

1. Changing the mix of fossil fuels to use more methane and less oil and coal

1. Phase out the use of coal and unconventional fossil fuels except where the CO2 is captured and sequestered. Reserve oil and gas for transportation.

2. Energy conservation, i.e., increasing energy efficiency, the benefits obtained per unit of energy used

2. There must be a rising price (tax) on carbon emissions, as well as effective energy efficiency standards, and removal of barriers to efficiency.

3. Substitution of non-fossil energy sources for coal, oil and natural gas

5. Sequestration of carbon in trees and other long lived land plants

4. Steps must be taken to ‘draw down’ atmospheric CO2 via improved farming and forestry practices, including burning of biofuels in power plants with CO2 sequestration.

6. Increasing the earth’s albedo

6. See Crutzen, Paul

4. Sequestration of organic carbon in the deep sea by stimulating spring phytoplankton production in high latitude oceans

3. There should be focused efforts to reduce non-CO2 human-made climate forcings, especially methane, ozone and black carbon.

Revelle was more enthusiastic about geoengineering, but of course 1990 were relatively early and hopeful days. OTOH, Hansen is a great believer in sequestration.

Interested mice can find more on Hansen's POV on his Columbia web site


Anonymous said...

JH's point 3, so important he made it twice (see 7)? Or a c&p error?

Horatio Algeranon said...

Malaisy Americans

EliRabett said...

A late evening C&P error. Corrected

Anonymous said...

Re point 6:

I don't know who has his finger on the knob, but he's turning it the wrong way. Google for Palle/'s presentation on albedo change (there's a recent satellite study which also shows a drop in albedo measured by satellite so this effect looks as if it were real -- looking for it I found a graph of falling global cloud amounts over the twenty years to 2005, well, like, duh!). Following the link, I find no mention of the best way of doing this -- search for Latham and Salter's trimarans and their hygroscopic nuclei production.

re point 4:

The rabbetlab model mentions the biological pump as an afterthought. I suspect that the 70% of the surface which is wet is doing things we haven't measured to a sufficient level of accuracy.

Julian Flood

EliRabett said...

Julian, blogs are at best a skim over what is in a good course, or textbook. The scientific literature concentrates on new stuff, and assumes the textbook.

Eli was too cryptic on increasing the albedo, this is a geo-engineering idea to pump SO2 in the the atmosphere up high and increase the albedo. Problem is once you start, you have to keep it up forever. The most recent person to bring this up was Paul Crutzen (see link) although there is debate about how serious he was. However, with many of Revelle's points what is interesting is that 17 years ago the same ideas were being discussed. Much of the problem and its solutions are obvious.

As I said of my carbon cycle model, it was a toy that I put out there so folk could get an idea of how such a model worked and it was far from complete. The post did point to some more complete models (which themselves were not state of the art) so your conclusion about my believing that the biological pump was a small part of the system is wrong.


Anonymous said...

The problem as I see it with most of geo-engineering methods to counteract global warming is that 1) they are unproven 2) they will have unintended consequences (we know SO2 in the troposphere causes acid rain, for example) or 3) both.

The idea of fertilizing the oceans with iron is a perfect example of number 1 (and perhaps number 2, for all we know). People kept touting that as "The Answer" until someone actually did an experiment to see how well it would work in practice. The result: not very well.

A good example on the "unintended consequences" side of the coin is "pretty much any project the Army Corps of Engineers has ever been involved in" (eg, canal system in Florida which nearly killed the Everglades)

When you start pumping stuff into the atmosphere on a massive scale, you had better have a good idea what is going to happen ahead of time. Otherwise, you could end up causing more problems than you solve.

A lot of geo-engineering amounts to little more than an excuse for not reducing emissions. Some people seem to assume that there is always an easy fix right around the corner. Technology will save the day.

Sometimes, you just have to bite the bullet and actually address the problem rather than put a band-aid on it and/or pawn it off on future generations.