GW fixes - how many trees?

<div class='quotetop'>QUOTE(etyler88 @ Mar 29 2007, 04:54 PM) [snapback]414174[/snapback]</div>

I'm not sure that any new planting in the Sahara could keep up with the cutting down elsewhere. But yes if we put more carbon into storage it would, in general, help.

 

mature forests are carbon neutral. New forests are carbon negative.

 

<div class='quotetop'>QUOTE(etyler88 @ Mar 29 2007, 08:54 AM) [snapback]414174[/snapback]</div>

Per the Arbor Day Foundation:

"Trees counteract global warming in multiple ways. Atmospheric carbon dioxide is the leading contributor to global warming, and as trees grow they remove CO2 from the atmosphere, storing the carbon and releasing oxygen. A single tree can remove more than a ton of CO2 over its lifetime."

"Also, shade provided by trees reduces summer air conditioning needs. According to the USDA, the cooling effect of a healthy tree is equal to 10 room-size air-conditioners operating 20 hours a day. Trees reduce the "heat-island" effect in urban areas, where summer temperatures are generally warmer than the surrounding countryside. According to the U.S. Forest Service, 50 million strategically placed shade trees could eliminate the need for seven 100-megawatt power plants. Additionally, trees around homes and in cities slow cold winter winds, reducing the need for winter heating. This relief on fuel consumption for heating and cooling helps reduce CO2 emissions from burning fossil fuels."

http://www.arborday.org/media/zonechanges2006.cfm

 

<div class='quotetop'>QUOTE(tripp @ Mar 29 2007, 12:02 PM) [snapback]414227[/snapback]</div>

This is largely true, but most people probably don't realize how little carbon sequestration typically occurs in old established forests - not that they aren't good for other reasons.

Another point to make about ecosystems - mixed grasslands/shrublands typically provide a lot of carbon mineralization depending on the species of plants. And I must emphasize the word mineralization, hence, the carbon isn't released into the air upon typical burning patterns.

Irrigating the sahara?? That would require a lot of freshwater especially considering the evaporation rates!

 

<div class='quotetop'>QUOTE(MarkMN @ Mar 29 2007, 12:10 PM) [snapback]414230[/snapback]</div>

http://www.renewableenergyaccess.com/rea/news/story?id=47522

There you go. Counter the rising sea level with the irrigation of the sahara. Let's build a billion of them. Job creation too!

 

<div class='quotetop'>QUOTE(etyler88 @ Mar 29 2007, 10:54 AM) [snapback]414174[/snapback]</div>

I looked this up a while back to figure out how much it would cost me to make my family carbon neutral by planting a new forest somewhere. Turns out to be a nice round number.

The EPA says an acre of fast-growing US southern pine forest can absorb about a ton of carbon a year. That's probably an upper bound, and only occurs at the peak of growth. But take that as a guide.
http://www.epa.gov/sequestration/faq.html#4

The comments about mature forest are correct. By and large carbon is only absorbed as the forest is growing.

In retrospect, realizing that's tons of carbon (not C02), and given the lifestyle and other changes I've made to bring down household C02 release, I'd only need about 5 acres of new forest. That doesn't sound too bad. Sequester your carbon and bequeath it to your kids.

Hmm, actually, that's not too cost-ineffective compared to what I did earlier this year, which was to buy wind power for my electrical service. My calculation is that I avoided 2.5 tons of carbon a year by buying wind power, and it'll cost me maybe $500/year. The net present value of 90 years of $500 payments at 5% is about $10,000. I probably couldn't buy 2.5 suitable acres, plant the forest, and pay the annual taxes on the land for that. But it seems that planting trees is in the ballpark, cost-wise, as a personal strategy. No idea if we have that much potential forest land in the US, but I'd bet this would be totally impractical as a matter of national policy. No data on that though.

Ah, well, if I did the conversion right, the EPA site yields 7x10^9 tons of C02, or maybe 2*10^9 tons of carbon release, net, in the US, each year. Does 2 billion tons of carbon sound right? Yeah, 6 or 7 tons per person is about right. Total US land area is 2.3 billion acres. So, nope, we're not going to find room here to offset that carbon with trees Irrigate the sahara, though, that sounds pretty good.

 

<div class='quotetop'>QUOTE(etyler88 @ Mar 29 2007, 10:54 AM) [snapback]414174[/snapback]</div>

What trees are the best, anyone know? Leafy trees? Pines? Palms? Cacti?

 

We should massively thin all old growth forests and then let 'em grow back. Basically like we did in New England (deforested for farm land and then let it grow back). Take all of the slash and trunks and chip 'em and then bury the chips in stainless steel casks. Of course this 'll decimate the fauna though. I'm joking, of course, but you get your carbon sink.

Here in CO the pine beatles (oops, beetles) are taken a pretty heavy toll on the trees in the mountains. There's been a lot of logging in areas with significant beetle kill to reduce the fire threat. It's actually kind of cool because you can see many new trees shooting up in the areas that have been clear cut. Now if they'd just take the wood and start generating electricity with it or use it for BTL to make gasoline.

 

Interesting article HERE from Scientific American:

There's more, but your new-growth forest in CO is probably not helping ... it is probably warming, rather than reducing the warming. According to this study, it is not just "new growth" that is important, but "new growth" in tropical areas.

 

<div class='quotetop'>QUOTE(fshagan @ Apr 11 2007, 12:29 AM) [snapback]421353[/snapback]</div>

Well, if you deforested the mountains in CO the albedo probably wouldn't change a whole lot because the surface would still be pretty dark. Either way, it's an interesting point that they bring up. Just randomly planting tonnes of trees could actually be worse. Unless... we genetically engineer some kind of faster growing tree that has white leaves.