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A lot of rainforest cleared farms don't produce very well and have bad erosion problems. Also a lot of forest is lost to human housing which will never be green again, unless you live underground.Originally Posted by arkansasbob
Deep jungle uses waaaaay more CO2 than corn. Look at the mass of plants in a corn field, separated by rows and only so high. Now imagine a couple hundred feet of rain forest thicker a ULM fan's head.
Just in case this isn't Germans....the world experiences warmest winter on record...
http://www.guardian.co.uk/weather/St...035667,00.html
Unfortunately, the records don't go back very far... :icon_wink:
From that article. To be a little more precise.
What was the total global temperature? After all, isn't global warming about the total earth and not just the northern hemisphere? Once again, not trying to disput what is and isn't going on, just don't like to see partial information to prove a point.The world experienced its warmest period on record during this year's northern hemisphere winter, the US government said today.
it's not the mass of the plants, its the mass of plant growth. does an acre of old growth forrest put on as much mass in a year as an acre of corn? an acre of new-growth weeds growing up to replace the failed farm that didn't produce because of excessive erosion and soil leaching? i don't know, but i imagine its about the same.
Just providing a related article...it came as a surprise to me since the winter in the U.S. was mighty cold and a little snowy to boot...
Researchers raise fears of melting ice at North Pole
Yearly disappearance of sea cover would make ocean warmer
Alan Zarembo, Los Angeles Times
Friday, March 16, 2007
A review of existing computer climate models suggests that global warming could transform the North Pole into an ice-free expanse of open ocean at the end of each summer by 2100, scientists are to report today.
The researchers said that out of the 15 models they looked at, about half forecast that the sea-ice cover -- a continent-size expanse that shrinks and regrows with the seasons -- would seasonally vanish by the turn of the century.
"That may be conservative," said lead author Mark Serreze, a senior research scientist at the National Snow and Ice Data Center in Boulder, Colo.
One model predicted the Arctic would be ice-free each September as early as 2040, according to the article in the journal Science. The remaining models showed the presence of some ice beyond 2100, although they agreed there would be significant ice loss if greenhouse gas emissions continue to grow at the current rate.
The computer models were included in a landmark U.N. report last month that blamed human activities for the "runaway train" of global warming.
The disappearance of the ice would lead to a dramatic reshaping of the Arctic that would accelerate warming of the oceans and potentially change precipitation patterns worldwide.
The Arctic's end-of-summer ice expanses already have been declining by about 9 percent each decade since the early 1970s.
It is possible to see the difference from an airplane heading north from Alaska. "You have to fly a lot longer to get to the ice edge than you used to," said Josefino Comiso, a satellite imaging expert at NASA's Goddard Space Flight Center who was not connected to the report.
He and other experts believe the melting will accelerate as more ice disappears and exposes the open ocean, which absorbs heat and melts more ice from below.
"With less and less ice, you have more and more heat," Comiso said, eventually contributing to further warming around the globe.
The computer forecasts do not apply to Antarctica, where ocean and atmospheric currents help maintain a much colder climate. There has been little melting of sea ice there.
At its yearly peak each March, floating Arctic ice grows to an average of 6.2 million square miles, more than 1 1/2 times the area of the United States.
By September, it typically shrinks more than 50 percent. In 2005, it reached its smallest size on record: 2.1 million square miles.
The effects of disappearing ice are already being felt, the authors said.
Alaska and Siberia are more vulnerable to waves that erode coastlines. Indigenous cultures have had to change hunting practices. And polar bear populations have suffered.
Jacob Sewall, a geoscientist at Virginia Tech University, has suggested that declines in Arctic sea-ice cover during the winter months would reduce winter precipitation in the American West.
"It sets up a relatively large high-pressure (zone) off the west coast of Northern California," he said. "That deflects the storms into the north into British Columbia and southern Alaska."
Loss of ice in the Arctic would not contribute to rising sea levels -- one of the most feared predictions of global warming. When floating ice melts, it does not raise the water line.
I don't know why we're comparing corn to trees anyway. Many of the trees being cut or burned take decades before they reach their preferred size. How long does it take corn to grow to maturity? 4 months?
exactly. how much carbon is in a 4-month gowth of corn? it all came from the atmosphere. how much carbon is in the very outer ring of a very old tree in the jungle? that's what we're comparing.
Consider that trees also produce a full crop of leaves and usually something like acorns. Pine trees produce needles and cones almost all the time.
And then you have the understory.
Corn also uses other nutrients besides carbon, namely NPK. Most crops deplete these levels in the soil faster than forests.
I know that corn grows quickly but for being such a short plant compared to high forests I don't think it would equal out. Forests put out more oxygen than cropland so it stands to reason that more CO2 is consumed because plants strip the C and put out the O2.
You have to remember that corn isn't the only crop. It's about the fastest growing I can think of but there are many other crops that can't hold a candle to corn.
Virtually every link I have provided from NOAA was in relation to global surface and ocean temps. Global. Not the USA, not the N. Hemisphere.
Like this one from NOAA from yesterday, which documents that the GLOBAL average temp was the warmest on record for the December-February period
http://www.noaanews.noaa.gov/stories2007/s2819.htm
how do you know that forests put out more oxygen? what study has proven that? if that is the case, then it is worth no more debate -- the oxygen has to be coming from the co2 it consumes. but i would like to see the proof.
regardless, my point is that, though it is counterintuitive, it is possible that there is little difference between the co2 consumption of farmland and forestland. remember, the rainforest canopy does not allow much sunlight through for photosynthesis below. compare the potential carbon mass put on by an acre of corn to the potential carbon mass put on by two or three giant trees.
Bob, clearing rain forests puts 1.5 gigatons of stored carbon into the carbon cycle. That's the crux of the matter, not how much crops or trees take up a year in carbon.
I just asked my parents who both have forestry degrees and additional masters degrees...
My mom was the state forestor of AR for years and recently got promoted to something else.
They both said that forests use up more CO2 than corn. They said another important point of the forest carbon is that it gets trapped if we use it for something like building materials. Corn pretty much just gets put back into the atmosphere every year because after they harvest the corn the plants rot back into the soil/air.
So if you burn down some forest and plant crops that's pretty much the worst thing to do. Using trees for building and then replanting trees is much better. But we do need food so there has to be crops.
No, what we need is more apples, oranges, grapes, stuff like that. Not so much corn, corn syrup, and corn to feed cows. Then maybe everyone wouldn't have such a fat ass and that would save our asses tons of healthcare costs!
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