Comments on: Too Late for Global Warming – 450 Parts Per Million is History – Now What?

By: Niobe Lathis

Niobe Lathis — Thu, 25 Oct 2007 16:52:40 +0000

Changes in latitudes, changes in attitudes… haha, sorry

By: Jon Gelbard

Jon Gelbard — Thu, 25 Oct 2007 15:45:51 +0000

With the collapse of the Arctic ice sheet this summer, there will undoubtedly be a tremendous increase in the Earth’s albedo at high altitudes…
High LATITUDES, that is… :-) (that’s what happens to language when trying to do 27 things at once!)

By: Jon Gelbard

Jon Gelbard — Thu, 25 Oct 2007 15:43:58 +0000

As another note, there is the element of “who knows” what feedbacks are kicking in at the moment.
With the collapse of the Arctic ice sheet this summer, there will undoubtedly be a tremendous increase in the Earth’s albedo at high altitudes, compared to when the ice sheet is intact. There is the release of CO2 from warming permafrost, release of methane from warming oceans, and, frankly, who knows what else…
The key word is that we are “destabilizing” the global climate system. Increasing the probability of “Climate Surprises”.

By: Jon Gelbard

Jon Gelbard — Thu, 25 Oct 2007 15:40:30 +0000

One article we’ve seen this week helps to explain this – the oceans are absorbing less CO2. So climate models will have to be revised to account for this unfortunate development.
Then you also have the rapid rise of China and India’s emissions, rampant tropical deforestation reducing those sinks, and the utter failure of world leaders to take key efficiency increases at the policy level – such as boost fuel efficiency standards and make cars such as those unpatriotically gargantuan Hummers, Dodges and Ford 350+’s illegal (of course, the latter would also help stave off Peak Oil, which, according to the folks at theoildrum.com seems to be growing closer on an eerie parallel journey with climate change).
The good news, which we here know well, is that the solutions to these dilemmas – rapid transition to cleaner, more efficient technologies – will benefit our environment, economies, health, security, and quality of life alike!
Here is a piece that I penned a couple of weeks ago about David Orr and others’ take on Climate Change and the next American President: http://conservationvalue.blogspot.com/2007/10/leading-fight-against-climate-change-is.html

By: Jason

Jason — Thu, 25 Oct 2007 12:59:16 +0000

“We thought we’d be at that threshold within about a decade…. We thought we had that much time. But the new data indicates that in about mid-2005 we crossed that threshold…. What the report establishes is that the amount of greenhouse gas in the atmosphere is already above the threshold that could potentially cause dangerous climate change.”
“[A]lso we have really seen an unexpected acceleration in the rate of accumulation of CO2 itself [not just CO2e] , and that’s been beyond the limits of projection … beyond the worst-case scenario. We are already at great risk of dangerous climate change – that’s what the new figures say…. It’s not next year, or next decade; it’s now.”
Semantics or long term strategic planning aside, the two above quotes represent the take-home message from this announcement in my eyes. We’ve seriously underestimated the extent and time frame of the problem.

By: Joey Feinstein

Joey Feinstein — Thu, 25 Oct 2007 10:33:04 +0000

For scenario planning and climate stabilization purposes, the distinction of GHG type is key. The effects CO2 emitted today are suspended by up to 30 years and last much longer, while other GHGs, although more potent in their short terms heat trapping, have more immediate and less enduring effects. Ludicrous as it may be to look for hope in this distinction, it does offer some solace with regards to long terms reductions.
At the same time, I do understand the impatience expressed by Joe as it pertains to semantics: real change is imperative, and that’s something semantics can retard like quicksand.

By: Noam Ross

Noam Ross — Thu, 25 Oct 2007 09:50:54 +0000

RealClimate explains the complexity here pretty well. The 450 number includes more than CO2 and other greenhouse gases but includes other climate forcings (positive and negative): http://www.realclimate.org/index.php/archives/2007/10/co2-equivalents/

By: Nayeon

Nayeon — Thu, 25 Oct 2007 03:46:50 +0000

Very interesting. Would you say that the CSMonitor jumped the gun on this then?

By: Jamais Cascio

Jamais Cascio — Thu, 25 Oct 2007 01:30:08 +0000

The original fear, as discussed by Hansen, et al, is about CO2 (not CO2e) reaching 450ppm, in the context of other greenhouse gases also peaking (the other ghgs have faster atmospheric cycling time, so they aren’t as hard to deal with as CO2). The overall CO2e concentrations in that scenario would be over 500, closer to 550ppm.
We’re seeing atmospheric CO2 rising faster than modeled, and this is a huge problem, but we’re not yet at the 450ppm CO2 tipping point.
This is not a “semantic” debate, btw. It’s a question of getting the science right in our public discussions of this problem.

By: Joe Madden

Joe Madden — Thu, 25 Oct 2007 00:13:32 +0000

CO2 or CO2e, the threshold was 450 PPM…If we now decide to debate semantics while the planet burns, we are in serious shizzle.

By: Nayeon

Nayeon — Wed, 24 Oct 2007 23:43:50 +0000

Yes, it’s not just CO2, it was a variety of greenhouse gases. Was the original fear about CO2 only?

By: Jamais Cascio

Jamais Cascio — Wed, 24 Oct 2007 23:10:54 +0000

Be sure you’re making a distinction between ppm CO2 and ppm CO2E — CO2 plus the various other greenhouse gases translated into CO2 equivalence (e.g., methane x23). The CSM article talks CO2E, not base CO2 — which is up to 380-385ppm.