tag:blogger.com,1999:blog-5235419263414453422.post4456681941958101620..comments2024-02-23T01:30:06.101-08:00Comments on Early Warning: Global Carbon Sink Not Degrading YetStuart Stanifordhttp://www.blogger.com/profile/07182839827506265860noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-5235419263414453422.post-76372666950247353582011-12-29T07:46:45.069-08:002011-12-29T07:46:45.069-08:00Rob,
Can you provide references for the studies y...Rob,<br /><br />Can you provide references for the studies you refer to? There is at least one study that makes the case that the CO2 fertilization effect on forests is quite real. You can read it at http://www.pnas.org/content/early/2010/02/02/0912376107.abstract) . And there is plenty of data that CO2 enhances plant growth. While there's little chance this enhanced growth will continue to help much in slowing the rise of CO2, it at least offers some hope that if we could significantly slow the dumping of CO2 into the air forest growth might help to eventually stabilize or even reduce CO2 levels, perhaps coupled with wide-scale use of biochar. I discussed this in my blog a while back at http://michaelaucott.blogspot.com/search/label/Climate I agree that drought is a grave worry. Sadly, the tulip tree that I pictured in that blog entry was nearly killed by the severe drought in my area in summer of 2010, and another larger tulip tree did die.Mike Aucotthttps://www.blogger.com/profile/05692592170835103639noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-2372304164030643362011-12-29T01:25:40.591-08:002011-12-29T01:25:40.591-08:00Mike,
yes, increased sink on land, and more impor...Mike,<br /><br />yes, increased sink on land, and more importanty also in the oceans - thus also increasing acidity and global die-off of ocean life (in the long-term)...<br /><br />AlexAlexander Achttps://www.blogger.com/profile/16845172528191878930noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-41181590446333871962011-12-28T23:43:30.507-08:002011-12-28T23:43:30.507-08:00"and likely reflects in part increased growth...<i>"and likely reflects in part increased growth of plants due to higher levels of CO2"</i><br /><br />Actually a few studies in 2011 find no evidence of the CO2 fertilization effect. Much of the drawdown in CO2 is attributable to regrowth in boreal and tropical forests, according to a recent global forest inventory. <br /><br />China and Russia have large areas of forest that are regenerating now that logging has ceased in those (formerly affected) areas. <br /><br />Hard to imagine the mythical 'plant food effect' offsetting continued drying in forest regions. Especially considering tropical forests may in fact be near a heat tolerance threshold, and that a large proportion of global regrowth is occurring in tropical regions.Rob Paintinghttps://www.blogger.com/profile/14198427903627448320noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-89664671437341466882011-12-28T13:01:50.565-08:002011-12-28T13:01:50.565-08:00So you imply that it still makes sense to reduce o...So you imply that it still makes sense to reduce out global carbon footprint ;-)<br /><br />Ok, more seriously, here is one <a href="http://www.atmos-chem-phys-discuss.net/10/9045/2010/acpd-10-9045-2010.pdf" rel="nofollow">recent study:</a><br /><br /><i>Recently several studies have extended the estimation of AF over the last two decades, with a suggestion of a positive trend in AF (Canadell et al., 2007; Raupach et al., 2008; LeQuere et al., 2009). Moreover, this positive trend has been interpreted as evidence for a decreasing trend in the efficiency of the ocean and 15 land carbon sinks. Given the model-based projection of a substantial reduction in the sink strength of the ocean and land in the future (e.g. by a large-scale dieback of the Amazon old-growth forest, Cox et al., 2000), the notion that the sinks have already begun to deviate from a linear response to the atmospheric CO2 perturbation is a<br />source of substantial concern. While there remains discussion about whether this trend in the AF is actually statistically significant (Knorr, 2009), we focus our discussion here on whether the inferred conclusion is possible, i.e. whether an increasing trend in the AF implies a decreasing e ffi ciency of the carbon sinks.</i><br /><br />and I think their conclusion is similar to yours - s S/N ratio is to high to conclude anything robust.<br /><br />AlexAlexander Achttps://www.blogger.com/profile/16845172528191878930noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-85599688347158737542011-12-28T07:28:17.059-08:002011-12-28T07:28:17.059-08:00It's clear the fraction of yearly emissions th...It's clear the fraction of yearly emissions that goes into the sink is not increasing. But, because yearly emissions are increasing, the size of the yearly sink has grown - from about 1.5 gigatons in 1965 to over 3 gigatons today. This is remarkable and likely reflects in part increased growth of plants due to higher levels of CO2, which is food for plants. Of course the sink is not quite keeping with increased dumping of CO2 into the air by humans and is as you note vulnerable.Mike Aucotthttps://www.blogger.com/profile/05692592170835103639noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-7511819832359676482011-12-27T15:42:59.217-08:002011-12-27T15:42:59.217-08:00I take your point Lucas - I was not attempting to ...I take your point Lucas - I was not attempting to imply anything more than that the sink qua sink was not becoming less effective.Stuart Stanifordhttps://www.blogger.com/profile/07182839827506265860noreply@blogger.comtag:blogger.com,1999:blog-5235419263414453422.post-7978796391561793752011-12-27T14:58:13.305-08:002011-12-27T14:58:13.305-08:00Hi Stuart.
Sorry, I feel compelled to quibble ove...Hi Stuart.<br /><br />Sorry, I feel compelled to quibble over the use of the word "degrading" in the title of this post.<br /><br />Though it may be true that the global "carbon sink" is still operating in a fairly normal way, the physical qualities of those sinks may in fact be degrading.<br /><br />For example you mentioned ocean acidification - as much CO2 as ever before may be going into the oceans but, clearly, the quality of this "sink" is degrading as it acidifies.Lucas Durandhttps://www.blogger.com/profile/12978045535093722565noreply@blogger.com