Counting greenhouse gas emissions

2009-04-24

in Geek stuff, Law, Politics, Science, The environment

Wood frame in a garden

Greenhouse gas emissions figures, as dealt with in the realm of public policy, are often a step or two removed from reality.

For instance, reductions in emissions are often expressed in relation to a ‘business-as-usual’ scenario, by governments wanting to flatter the results of their mitigation efforts. That means, instead of saying that emissions are X% up from last year, you say that they are Y% down from where they would have been in the absence of government action. Since the latter number is based on two hypotheticals (what emissions would have been, and what reductions arose from policy), it is harder to criticize and, arguably, less meaningful.

Of course, the climate system doesn’t care about business-as-usual (BAU) projections. It simply responds to changes in the composition of the atmosphere, as well as the feedback effects those changes induce.

The second major disjoint is between the relentless focus of governments on emissions directly produced by humans, compared with all emissions that affect the climate. For example, drying out rainforests makes them less biologically productive, leading to more greenhouse gasses in the atmosphere. Similarly, when permafrost melts, it releases methane, which is a powerful greenhouse gas. It is understandable why governments don’t generally think about these secondary emissions, largely because of the international political difficulties that would arise if they did. Can Canada miss its greenhouse gas mitigation targets because of permafrost melting? Who is responsible for that melting, Canada or everyone who has ever emitted greenhouse gasses? People who have emitted them since we learned they are dangerous?

While the politics of the situation drive us to focus on emissions caused by voluntary human activities (including deforestation), we need to remain aware of the fact that the thermodynamic balance of the planet only cares about physics and chemistry – not borders and intentionality. When it comes to “avoiding dangerous anthropogenic interference in the climate system” we need to remember to focus on both our absolute level of emissions (not their relation to a BAU estimate) and to take into account the secondary effects our emissions have. Doing otherwise risks setting our emission reduction targets too low, and thus generating climate change damage at an intolerable level.

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{ 6 comments… read them below or add one }

Betula April 25, 2009 at 9:14 am

“Since the latter number is based on two hypotheticals (what emissions would have been, and what reductions arose from policy), it is harder to criticize and, arguably, less meaningful.”

Yet the theory of AGW, which is based on probabilities derived from uncertainties and will lead to all kinds of hypotheticals……..is very meaningful and, arguably, easy to criticize.

Milan April 25, 2009 at 12:20 pm

The key elements of the science of anthropogenic climate change are extremely solid. They are not based on ‘hypotheticals.’ We know that burning fossil fuels and cutting forests add to the level of greenhouse gasses in the atmosphere. Further, we know that higher concentrations of greenhouse gasses warm the planet. Finally, we have extremely good evidence that our emissions are sufficient to produce a very dangerous outcome, if left unchecked.

Most of the ‘debate’ that persists about it is the result of the self-interested actions of organizations and individuals who are opposed to effective government climate policies.

More on the science of climate change

Also recommended:

Weart, Spencer. The Discovery of Global Warming.

Weaver, Andrew. Keeping our Cool: Canada in a Warming World.

Milan April 25, 2009 at 12:21 pm
Milan April 25, 2009 at 12:26 pm
. September 30, 2009 at 11:26 am

“Indonesia’s logging of its rainforests has long been identified as a big contributor to the world’s emissions of greenhouse gases (GHGs), and hence to global warming. This is one reason for the shocking statistic that Indonesia trails only China and America as an emitter of carbon. But now attention is also turning to the soil beneath the trees, and especially to peat. Al Gore, a former American vice-president and a vigorous climate-change campaigner, has pointed to evidence that the top two metres of soil contain three times as much carbon as the entire vegetation on the planet, and that soil degradation, such as the burning of peatland, is the main cause of Indonesia’s high level of emissions.”

. January 23, 2011 at 5:01 pm

Not hot air
A new, private initiative should help show which gases come from where

IN 1955 a young man called David Keeling started to measure the level of carbon dioxide in the Californian air. It seemed of little practical value, but he liked designing and building the equipment—and driving back and forth along the Pacific Coast Highway to his sampling site at Big Sur was fun. Scientists with a new-found interest in the world’s carbon-dioxide levels soon learned of his work and gave him a job setting up monitoring stations in Hawaii and Antarctica for the Scripps Institute of Oceanography, in La Jolla. He continued to work there for almost 50 years, devoting his life to the monitoring effort. His son, Ralph, runs the carbon-dioxide programme at Scripps to this day.

In those 50 years measuring carbon-dioxide levels has gone from being a fun problem for a postdoc to a crucial issue for the planet. But the amount of effort put into it remains surprisingly small. America’s National Oceanic and Atmospheric Administration (NOAA) runs the biggest network of monitoring sites. A dozen other countries run a few here and there as well, with an expanded European effort getting under way. However, the scientists involved have been pointing out for years that it would take a very small investment, in a scientific world of satellites and supercomputers, to make such networks a lot more capable. On January 12th, such an investment was at last revealed—but not by any of the governments to which the pleas had been addressed.

A private company in Maryland, known until recently as AWS Convergence Technologies but now called Earth Networks, has announced that over the next five years it will spend $25m installing 100 state-of-the-art carbon-dioxide and methane monitors around the world. Fifty will be sited in America. According to Pieter Tans, the doyen of the field at NOAA, the country currently has 17 or 18, so that will improve things by a factor of four. In some less-well-covered places things will improve even more.

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