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Amazon deforestation soars after a decade of stability

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Deforestation in the Amazon has skyrocketed in the past half a year, according to analysis of satellite images issued by Brazil's non-profit research institute, IMAZON.

 

The results compared the deforestation in a particular month with figures from the same month a year before, and the difference ranged from a 136 per cent increase in August to a 467 per cent rise in October.

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Brazil's Amazon is not an isolated case, and a larger global pattern is emerging. A study released last week shows that the rate of loss of tropical forests between the 1990s and 2010 accelerated by 62 per cent, instead of slowing down by 25 per cent as previously claimed by a UN agency.

 

"The message is clear," says lead author Do-Hyung Kim, from the University of Maryland. "The rate of deforestation is way up. If this trend continues, it won't be long before the world's tropical forests are essentially gone."

 

http://www.newscientist.com/article/dn27056-amazon-deforestation-soars-after-a-decade-of-stability.html#.VPS81o42fPT

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Lovejoy says that preserving tropical forests, which take carbon out of the atmosphere

Astonishing incorrect statement.

The Co2 taken up by the trees is broken down rapidly y decay and other processes constantly, and not laid down and sequestrated in sediment.

So the Amazon is not a significant CO2 sink unlike for example peatland.

The soil below is often quite poor and nutrients are aggressively recycled.

Cutting down and burning large areas is hardly desirable though.

I wonder what is being grown on the cleared land or land it is replacing.

I have a suspicion it will be fuel of some kind to meet CO2 targets

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Cattle farming for the likes of McDonald's! they should really put a stop to it fast, but of course this increasingly globalised world is fueling the 'fire', we should preserve the forests as we do with natural wonders.

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Astonishing incorrect statement.

The Co2 taken up by the trees is broken down rapidly y decay and other processes constantly, and not laid down and sequestrated in sediment.

So the Amazon is not a significant CO2 sink unlike for example peatland.

The soil below is often quite poor and nutrients are aggressively recycled.

Cutting down and burning large areas is hardly desirable though.

I wonder what is being grown on the cleared land or land it is replacing.

I have a suspicion it will be fuel of some kind to meet CO2 targets

Don't the trees themselves act as a CO2 reservoir, just by being made of a lot of cellulose - C6H10O5? If they're not there, those elements are in the atmosphere.

 

It will mostly be soya beans and cattle.

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Don't the trees themselves act as a CO2 reservoir, just by being made of a lot of cellulose - C6H10O5? If they're not there, those elements are in the atmosphere.

It will mostly be soya beans and cattle.

Indeed crucial in keeping the balance

Anything with green leaves photosynthesis taking in CO2 and releasing O2, in a chemical reaction in the chloroplast, chlorophyll is a green pigment, which traps the sunlight. Present in green part of leaves.

carbon dioxide + water (+ light energy) → glucose + oxygen

Of course naturally when vegetation dies and decays CO2 which is stored is released and by chopping down forests aggressively massive amounts of stored CO2 is released into atmosphere.

average tree stores 2000kg of CO2 hell of a lot.

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Astonishing incorrect statement.

The Co2 taken up by the trees is broken down rapidly y decay and other processes constantly, and not laid down and sequestrated in sediment.

So the Amazon is not a significant CO2 sink unlike for example peatland.

The soil below is often quite poor and nutrients are aggressively recycled.

Cutting down and burning large areas is hardly desirable though.

I wonder what is being grown on the cleared land or land it is replacing.

I have a suspicion it will be fuel of some kind to meet CO2 targets

 

Actually it's not. It's quite a complicated subject they do act as sinks but deforestation can increase emissions, depending on the land use.

 

 

Tropical rainforests act as global carbon sinks. Inverse modeling of atmospheric CO 2 concentrations indicates that tropical forests contribute a carbon sink of 1-3 gigatonne (1 billion metric tons) per year (Rodenbeck et al. 2003). To provide further evidence of this carbon sequestering activity, several studies that have conducted long-term monitoring plots which define a plot as an area of forest 1 hectare in area, and where all trees above 10 cm diameter in breast height are tracked individually over time. The plots span the Amazonian forests of northern South America, including Bolivia, Brazil, Ecuador, French Guiana, Peru, and Venezuela (Phillips et al. 2007). Results from these studies have shown that forests are increasing in above-ground biomass, by 0.3-0.5% per year over the past two decades (Malhi & Grace 2000). These experimental studies confirm findings from laboratory research and modeling, that rising productivity of tropical forests is due to sequestering of increased CO 2 concentrations in the atmosphere (Phillips et al. 2007). Because of this activity, some research suggests that tropical rainforests may benefit from increased CO 2 characteristic of modern climate change, and may even serve to offset rising atmospheric levels by sequestration.

 

Interactions with nutrient cycling may decrease the proposed benefits of increased atmospheric carbon dioxide

 

At the same time, however, regulation of atmospheric carbon dioxide depends not just on the trees, but also on tropical forest soils. New research in Costa Rica has shown that extra amounts of phosphorus, nitrogen, and other key nutrients in tropical rainforest soils cause an increase in CO 2 emissions by 20% annually (Cleveland & Townsend 2006). Since nutrient cycles are closely linked to terrestrial systems, the impact of climate change on carbon cycling and storage may not be clear-cut. Understanding whether and how climate change affects cycling of nutrients such as phosphorus, sulfur, nitrogen, and potassium would likely alter current predictions about the carbon cycle responses within tropical forests. At present, the causality and feedback effects of these interactions are poorly understood; more research is needed.

 

https://web.duke.edu/nicholas/bio217/jmz28/effects.html

 

 

Carbon Sequestration

Tropical deforestation contributes as much as 90% of the current net release of biotic carbon dioxide into the atmosphere. This change may represent as much as 20% - 30% of the total carbon flux due to humans - i.e., rivaling the carbon release due to fossil fuel burning.  Deforestation thus is an important potential source of carbon.  But what if we allow forests to regenerate?  As they grow, forests will store or sequester carbon, and so carbon sequestration has become part of the global warming debate.  What is the current balance sheet – are the world’s forests a source or a sink for atmospheric CO2?  This is uncertain for three main reasons.  We are not sure how much forest is being burnt, vs the amount of regrowth.  We don’t know enough about the fate of deforested land, ie, how much is reverting to secondary forest.  We don’t know how forest disturbance is affecting soil and forest floor carbon stores. Still, there is good evidence that the regrowth of previously-deforested areas in Europe and North America during the 20th century has sequestered considerable amounts of CO2 from the atmosphere.

 

http://www.globalchange.umich.edu/globalchange2/current/lectures/deforest/deforest.html

 

Tropical Forests Play Huge Role in Inhaling Emissions

http://www.climatecentral.org/news/tropical-forests-fossil-fuel-emissions-18498

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