A New Measure of Global Warming from Carbon Emissions

[kristopher]

Damon Matthews, a professor in Concordia University’s Department of Geography, Planning and the Environment has found a direct relationship between carbon dioxide emissions and global warming. Matthews, together with colleagues from Victoria and the U.K., used a combination of global climate models and historical climate data to show that there is a simple linear relationship between total cumulative emissions and global temperature change. These findings will be published in the next edition of Nature, to be released on June 11, 2009.

Until now, it has been difficult to estimate how much climate will warm in response to a given carbon dioxide emissions scenario because of the complex interactions between human emissions, carbon sinks, atmospheric concentrations and temperature change. Matthews and colleagues show that despite these uncertainties, each emission of carbon dioxide results in the same global temperature increase, regardless of when or over what period of time the emission occurs.

These findings mean that we can now say: if you emit that tonne of carbon dioxide, it will lead to 0.0000000000015 degrees of global temperature change. If we want to restrict global warming to no more than 2 degrees, we must restrict total carbon emissions – from now until forever – to little more than half a trillion tonnes of carbon, or about as much again as we have emitted since the beginning of the industrial revolution.

“Most people understand that carbon dioxide emissions lead to global warming,” says Matthews, “but it is much harder to grasp the complexities of what goes on in between these two end points. Our findings allow people to make a robust estimate of their contribution to global warming based simply on total carbon dioxide emissions.”

In light of this study and other recent research, Matthews and a group of international climate scientists have written an open letter calling on participants of December's Conference of the Parties to the U.N. Framework Convention on Climate Change to acknowledge the need to limit cumulative emissions of carbon dioxide so as to avoid dangerous climate change.

http://mediarelations.concordia.ca/pressreleases/archives/2009/06/a_new_measure_of_global_warmin_1.php

[joshcryer]

1. For perspective, assuming *no* increase in emissions, we'd have 17.5 years.

According to Wikipedia we release about 28.5 billion tonnes of CO2 a year into the atmosphere: http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions

However, I can find sites that show numbers as high as 31 billion tonnes in 2008: http://www.pbl.nl/en/publications/2009/Global-CO2-emissions-annual-increase-halves-in-2008.html

Tried to post an image but I didn't like the inline. Google image search for for global CO2 emissions: http://images.google.com/images?q=global%20co2%20emissions

Cumulative CO2 even shows a more scary image (an exponential growth curve): http://images.google.com/images?q=global+co2+cumulative

Damon did a study last year discussing the ramifications of this: http://www.newscientist.com/article/dn13395

His latest study gives the modellers something to go by, and *highly* simplifies the arguments (since we can now say x amount of carbon leads to x amount of warming), trying to find a free copy (darn pay-for websites). No doubt IPCC AR5 is going to be one scary report (especially considering AR4 didn't even take into account Greenland and Antarctic meltoff).

Here's the Nature abstract: http://www.nature.com/nature/journal/v459/n7248/abs/nature08047.html

[joshcryer]

2. Also, the "2 degree" figure is generally considered the "jump off" point in heating.

Some say that if we go over it we are at much bigger risk for absolute catastrophe. A complete phaseout of CO2 in 17 years is arguably impossible. So I'm afraid that the whole "going over 2 degrees" thing is going to happen regardless.

[joshcryer]

3. Only zero emissions can prevent a warmer planet

Greenhouse gas emissions will have to be eliminated completely to stabilise the Earth's climate and prevent temperatures from rising. That's the conclusion of climatologists in the US who say that our current efforts to merely stabilise emissions will not be enough.

Damon Matthews, from Concordia University in Canada, and Ken Caldeira, from the Carnegie Institution for Science, Stanford, USA, used a global climate model to study how greenhouse emissions would need to change in order to stabilise global temperatures over the next few hundred years. Previous studies have only looked at what happens when emissions are stabilised.

Humans have been releasing carbon dioxide into the atmosphere in increasing quantities since the industrial revolution. But to simplify the simulation, Matthews and Caldeira injected a single pulse of carbon dioxide into a pre-industrial atmosphere.

(...)

The lingering carbon dioxide means that global warming persisted for the entire simulation. For the four different emission scenarios, global temperatures stabilised at 0.09, 0.34, 0.88 and 3.6 ºC above pre-industrial levels respectively.

So far industrial emissions total around 450 billion tonnes. "Even if we eliminated carbon dioxide today we are still committed to a global temperature rise of around 0.8 ºC lasting at least 500 years," says Caldeira.

http://www.newscientist.com/article/dn13395

---

Just highlighting Damon's earlier reporting on this subject, he is an expert on cumulative CO2 emissions. I posted the same link upthread.

[kristopher]

4. Josh

Even that alone won't do it. We also need to eliminate the use all heat producing, non-renewable, energy sources.

EOS, TRANSACTIONS AMERICAN GEOPHYSICAL UNION, VOL. 89, NO. 28, PG 253
doi:10.1029/2008EO280001, 2008
Long-Term Global Heating From Energy Usage
Eric J. Chaisson
Wright Center, Tufts University, Medford, Mass., USA
Harvard College Observatory, Cambridge, Mass., USA

Abstract
Even if civilization on Earth stops polluting the biosphere with greenhouse gases, humanity could eventually be awash in too much heat, namely, the dissipated heat by-product generated by any nonrenewable energy source. Apart from the Sun's natural aging—which causes an approximately 1% luminosity rise for each 108 years and thus about 1°C increase in Earth's surface temperature—well within 1000 years our technological society could find itself up against a fundamental limit to growth: an unavoidable global heating of roughly 3°C dictated solely by the second law of thermodynamics, a biogeophysical effect often ignored when estimating future planetary warming scenarios.

The Five Precepts are:
1. Abstain from taking life,
2. Abstain from taking that which is not given,
3. Abstain from misconduct done in lust,
4. Abstain from lying,
5. Abstain from all forms of intoxication.

[joshcryer]

5. I'm well aware of this report. Global warming is happening now.

I'm pretty sure I never stated that waste heat wasn't a contributing factor, merely that it couldn't be the primary factor. But misleading people is your forte.

"Unavoidable global heating" is a bit absolutist, though. Just throw stratospheric sulfur aerosols into the atmosphere: http://en.wikipedia.org/wiki/Stratospheric_sulfur_aerosols_(geoengineering)

Global warming is happening now. And, indeed, the CO2 in the atmosphere will linger for quite some time. We have a warmer earth regardless. Geoengineering will have to be utilized to save future society.