Amazon suffers extreme drought, raises fear of a critical tipping point being reached.

reply to post by peck420


Deforestation does correlate with CO2 emissions - about one quarter of them. This is outlined right at the beginning of the last IPCC report:

The global mean concentration of CO2 in 2005 was 379 ppm, leading to an RF of +1.66 [±0.17] W m–2. Past emissions of fossil fuels and cement production have likely contributed about three-quarters of the current RF, with the remainder caused by land use changes.

See also:
Deforestation causes 25% of greenhouse gas emissions says FAO

However to those people saying deforestation has been the sole reason for the exceptional drought seen in the Amazon in the last 5 years, take note that deforestation there has actually dropped drastically (~75%) over that time:

[atsimg]http://files.abovetopsecret.com/images/member/678eeb881b19.jpg[/atsimg]

Deforestation in the Amazon
Amazon deforestation 'record low'

reply to post by mc_squared


Does it really matter ? I mean the lower % of deforestation.

I mean unless the forest gets planted back the drought would and will only get worse with every extra square mile of forest that disappears.

Also with a smaller forest the % of deforestation will get smaller even with the same amount of deforestation.
Or.... Do they always take the original forest as a starting point for that calculation ?

reply to post by TheWill

...My point was that - as an uncontested feature of food-chains - if you eat organisms higher up the food chain, more energy has to go in at the bottom to sustain you --> the reason that a lot of agriculture (especially here in the UK - I mean, 60-something million people on an island this size?) is done away from the point of consumption is that the amount of land (usually proportional to the amount of energy you can get into the system) required to sustain current dietary practices would be extremely expensive relative to transport costs. By changing dietary practice to focus more on food from a lower trophic level (i.e. reduce - even without eliminating - meat), we can reduce the area required for food production....

I understand the point you are trying to make, I am a chemist. However that is only one of the factors to be considered.

From what I understand much of Scotland and certainly from my own experience much of New England and States like West Virgina are much more suited to grass than to crops because of steep rocky thin soil. Also, take my farm in North Carolina, according to the old soil survey I use to have two feet of very good top soil. This piece of a much larger tract was sold because it no longer produced even with chemical fertilizers. My first soil test showed 98% clay - NO TOP SOIL - zip, zilch, nada I turned it into grazing land and now, after fifteen years I have about four or five inches of rich black top soil instead of sticky clay.

As far as I am concerned rotation should not only be between crops but also be between crops, fruit trees, pasture and types of animals. To get the best production with the minimum of artificial chemicals applied to the land. Monoculture, requiring heavier and heavier doses of chemicals is just plain bad for the land and ultimately bad for the crops.


I am not an organic farmer. I think there is a place for chemicals but they should not be a substitute for lazy thinking.

Use GOATS not Round-up

reply to post by crimvelvet


Much of the land not suitable for horticulture - certainly across the south of England, Scotland I'm never really sure of - is unsuitable because of past practices: cutting down trees and introducing grazing animals led to wide-scale erosion across the (chalk) downs, and the heathlands are unfarmable because forest clearing by burning, followed by burning to create graze, made them too acid.

But the damage done by long past farming practice aside, I can see why exhausted land is used for grazing. And I have to agree 100% that improved practice is required (hard to see how anyone could disagree), although I have to add that such improved farming practice probably wouldn't involve shipping fodder from overseas to feed the livestock.

reply to post by Sinter Klaas


I was calculating the percentage as a function of the rate itself, not the total forest - i.e. from the 2004 rate (~27000) compared to the 2009 (~7000) = 1/4 of what it was.

Obviously any deforestation is still a bad thing, I'm just saying it makes a very weak argument to try and pinpoint it all on one thing, especially when that one thing is actually stabilizing somewhat while the overall problem seems to be accelerating.

In the end it's like I said before though - everything adds up. Deforestation is of course still a critical issue, but trying to lean on it and ignore the other 75% is not going to solve the problem either. The climateprogress.org article I left in the OP goes into great detail about all the factors involved.

The Amazon's sensitivity to the overall changing climate I think can best be summed up in this quote:

the forest will have already experienced three extreme dry spells in just 12 years, two of which occurred during the past five years: 1998, 2005 and 2010.

What a coincidence that those happen to be the 3 hottest years on record eh?

Considering we are well on pace to continue breaking this temperature threshold in the next few years, (let alone how bad it might get in the coming decades!) - it is downright frightening to think what lies ahead for the Amazon, even if we managed to stop deforestation altogether.

reply to post by TheWill

But the damage done by long past farming practice aside, I can see why exhausted land is used for grazing. And I have to agree 100% that improved practice is required (hard to see how anyone could disagree), although I have to add that such improved farming practice probably wouldn't involve shipping fodder from overseas to feed the livestock.

That strikes me as just plain dumb too. (Ship the steak not the hay/grain) Actually I have a major gripe with grain subidies here in the USA because they have made grass-fed non-competitive with confinement/grain fed. A very artificial situation that breeds new diseases. and uses grain that could go to better use. I feed grain as little as possible, mainly in the winter breeding season.

Unfortunately the breeding of animals that reach slaughter weight fast has saddled us here in the USA with animals that require grain and are not thrifty.

reply to post by mc_squared


Ever gave this a thought?

Let's say 'climate change' is making our world hotter. They ( scientists ) say that its due to gasses forming in the atmosphere causing a 'greenhouse effect'. Which in turn heats the planet and melts, dries and cools the planet from that point onwards.

Let's look at it from another angle.

If this is true or part of the cause. Then wouldn't the 'greenhouse' effect only heat the surrounding area of the rainforest that may not get as much heat, causing better tropical conditions for plant life to grow, which may intern cause faster growth of all round plant/tree life in the area that wasn't seen before then. If so, the this would have plants/trees create even more oxygen released into the atmosphere actually repairing the the atmosphere ( as known oxygen repairs atmospheric tears/gases ) Which in turn repairs the very thing that made the forests grow more rapidly and then goes back to square one. I am sure before we came to make cars/planes there was other instances of such chemicals in the atmosphere it is was already here to begin with. I think ( not sure about this ) dung beetles are supposedly the number one contributer to Co2 emisions into our planet.

So with what I wrote in mind, maybe we should not think of ourselves as ''the fixers'' but only another helping hand in making the world go round.

reply to post by DenyStupidity


I think it was termites, not dung beetles, that produce a lot of Methane, not CO2.

You are aware, aren't you, that hotter isn't the only thing that tropical plants need to grow? If it also becomes drier- because, for example, the changing temperature has altered cloud dispersal patterns at a rate faster than seed distributions, the xerophytic plants - a tiny subset of tropical plants and not particularly great carbon fixers - would be the only ones with sufficient adaptations to survive in hot, dry conditions.

Also, most truly tropical plants already have some adapatations to heat - the relatively high temperature of the tropics causes oxygen to bind with intermediate carbohydrates during photosynthesis, which quite rapidly stops photosynthesis and kills the plant. If tropical temperatures are experience long-term outside the tropics, it could for this reason be devastating to plants which have not had millennia to adapt to those conditions.

The issue is the rate at which the CO2 level is rising, not that it is rising. Pretty much all of it that we could release was in the atmosphere during the carboniferous, when modern coal was first set down, but when things change fast - which they are now doing - plant systems can't keep up. This isn't too much of an issue when it's a range expansion without range loss - not many trees went extinct at the end of the last glacial maximum in europe - but as an indication of how much time trees need to shift their ranges, the poleward trend of cold-tolerant species following the retreat of the glaciers is still in motion, and that's 10,000 years that they've had to catch up with the retreating ice.

But yes, it will sort itself out. It should even take less than a hundred thousand years, even if we get it past tipping point, and it's unlikely to be the world's greatest ever mass extinction, so something will survive. Not necessarily us, but something.

reply to post by mc_squared


I didn't mean how much co2 get's released during deforestation.

What I meant was that we are adversly affecting the environment by reducing the carbon recovery cylce by land and vegetation.

Think of it like water usage.

I don't actual care about my absolute water resource, I care about my actual yearly recovery rate. If my usage exceeds my recovery rate it is just a mater of time....

Same with the forests, I really don't care about the carbon released when a tree is deforested, I care far more about the yearly rate of absorbtion that is now gone. The further the natural recovery cycle is damaged the more damaging our emissions become.

reply to post by DenyStupidity

Ever gave this a thought? Let's say 'climate change' is making our world hotter. They ( scientists ) say that its due to gasses forming in the atmosphere causing a 'greenhouse effect'. Which in turn heats the planet and melts, dries and cools the planet from that point onwards....

This is the point that really disturbs me.

Woods Hole Oceanographic Institution expresses it better than I in Abrupt Climate Change: Should we be worried?

"Most of the studies and debates on potential climate change, along with its ecological and economic impacts, have focused on the ongoing buildup of industrial greenhouse gases in the atmosphere and a gradual increase in global temperatures. This line of thinking, however, fails to consider another potentially disruptive climate scenario. It ignores recent and rapidly advancing evidence that Earth’s climate repeatedly has shifted abruptly and dramatically in the past, and is capable of doing so in the future.

Fossil evidence clearly demonstrates that Earth vs climate can shift gears within a decade....

But the concept remains little known and scarcely appreciated in the wider community of scientists, economists, policy makers, and world political and business leaders. Thus, world leaders may be planning for climate scenarios of global warming that are opposite to what might actually occur..."

So what about a shift toward glaciation?

Joe Romm over at Climate Progress states:
"Absent human emissions, we’d probably be in a slow long-term cooling trend due primarily by changes in the Earth’s orbit, ... " What Joe is talking about is the Milankovitch Cycle

This peer reviewed paper, also agrees that we are at the point in the earth's Milankovitch Cycle that ushers in an ice age. The biggest question of course is why we are not covered in ice yet.


Lesson from the past: present insolation minimum holds potential for glacial inception (2007)

Because the intensities of the 397 ka BP and present insolation minima are very similar, we conclude that under natural boundary conditions the present insolation minimum holds the potential to terminate the Holocene interglacial. Our findings support the Ruddiman hypothesis [Ruddiman, W., 2003. The Anthropogenic Greenhouse Era began thousands of years ago. Climate Change 61, 261–293], which proposes that early anthropogenic greenhouse gas emission prevented the inception of a glacial that would otherwise already have started....

This paper looked at the Arctic for the entire Holecene: (present interglacial)

Temperature and precipitation history of the Arctic

..Solar energy reached a summer maximum (9% higher than at present) ca 11 ka ago and has been decreasing since then, primarily in response to the precession of the equinoxes. The extra energy elevated early Holocene summer temperatures throughout the Arctic 1-3° C above 20th century averages, enough to completely melt many small glaciers throughout the Arctic, although the Greenland Ice Sheet was only slightly smaller than at present... As summer solar energy decreased in the second half of the Holocene, glaciers reestablished or advanced, sea ice expanded, and the flow of warm Atlantic water into the Arctic Ocean diminished. Late Holocene cooling reached its nadir during the Little Ice Age (about 1250-1850 AD), when sun-blocking volcanic eruptions and perhaps other causes added to the orbital cooling, allowing most Arctic glaciers to reach their maximum Holocene extent...

The biggest problem I have with the CAGW theory, is it assumes no (little) changes in the energy from the sun received by the earth.

During the 20th century the sun has been very active according to this paper but with cycle 24 the sun has now gone into a long minimum with "unusual characteristic"s according to NASA and according to the Solar Dynamics Observatory Mission News

"We want to compare the sun's brightness now to its brightness during previous minima and ask: is the sun getting brighter or dimmer?"

The answer seems to be dimmer. Measurements by a variety of spacecraft indicate a 12-year lessening of the sun's "irradiance" by about 0.02% at visible wavelengths and 6% at EUV wavelengths."

What was happening in the solar cycles before cycle 24.
2003 - Solar Activity Reaches New High

Geophysicists in Finland and Germany have calculated that the Sun is more magnetically active now than it has been for over a 1000 years. Ilya Usoskin and colleagues at the University of Oulu and the Max-Planck Institute for Aeronomy say that their technique – which relies on a radioactive dating technique - is the first direct quantitative reconstruction of solar activity based on physical, rather than statistical, models (I G Usoskin et al. 2003 Phys. Rev. Lett. 91 211101)

... the Finnish team was able to extend data on solar activity back to 850 AD. The researchers found that there has been a sharp increase in the number of sunspots since the beginning of the 20th century. They calculated that the average number was about 30 per year between 850 and 1900, and then increased to 60 between 1900 and 1944, and is now at its highest ever value of 76.

“We need to understand this unprecedented level of activity,” Usoskin told PhysicsWeb."

There are also the changes in albedo from cloud cover as measured by the Earthshine Project


“.....The earthshine observations reveal a large decadal variability in the Earth's reflectance [7], which is yet not fully understood, but which is in line with other satellite and ground-based global radiation data...."

Climate Scientists really do not know what actually is going to happen and the unhealthy focus on just one variable, CO2, could leave mankind unprepared for a very nasty surprise. This is especially true if we have a large volcanic eruption in the right place during a solar grand minimum, a cool ocean cycle and during the wrong point of the precession of the equinoxes.

The Pacific Ocean cycle (PDO) has turned cold click The Arctic Oscillation (AO) click may have also turned cold. The Barents Sea and the AMO index look like they may be headed toward a cold cycle soon. click And the Southern and Indian oceans are headed towards cooling. click

This all adds up to the global sea temperatures FALLING!

reply to post by crimvelvet

The biggest problem I have with the CAGW theory, is it assumes no (little) changes in the energy from the sun received by the earth.

And this is pretty much the biggest problem I have with the anti-CAGW non-theory.

Nobody "assumes" these changes. They measure them. And the overwhelming majority of the evidence points to the fact that solar activity has been decreasing over the last 30 years. Meanwhile when you talk about the 20th century you are talking about a 100 year period where the first half is largely attributed to the Sun. It is only in the last 50 years that man's role (both through GHG emissions and aerosols) becomes significant as the dominant forcing.

So if the Sun begins acting up again - and thus piggybacking on top of anthropogenic warming, this would only make the case for a "catastrophic" warming that much stronger.


And the idea that we're about to enter some sudden global ice age is based on what exactly?
You're taking one climate report out of context - the WHOI is clearly talking about dramatic regional coolings associated with overall global warming - i.e. a concept completely in line with the whole climate change/disruption/imbalance lingo. And then you're superimposing that over a quote from Joe Romm that clearly states "we'd probably be in a slow long-term cooling trend".

So you seem to believe that what amounts to little more than cherry-picking quotes and baseless speculation over some as yet unforeseen global cooling phenomenon should be taken on par with all the hard physical science we have that backs up AGW.

It seems everytime I post on this topic I need to remind someone that AGW isn't just some crackpot theory that was invented on the fly to fill in the holes and explain this mysterious warming we're seeing after the fact.

AGW is based on fundamental physics that predicted it over 100 years ago.

You say you are a chemist - do you understand anything about what makes a CO2 molecule a known greenhouse gas? It is simply it's shape and dynamics, and the fact that it's molecular bonds allow it to function as a temporary dipole, absorbing and re-emitting IR radiation.

This is pure chemistry, math and physics - and it is well understood at this point. Everything we know about CO2 says increasing it's concentration in the atmosphere should trap energy and therefore should lead to an overall warming. What happens amongst the cracks is a lot more complicated, and your WHOI link only supports the overall idea - it doesn't detract from it. Because in the end it all adds up exactly in line with the prevalent theory behind increasing GHGs: e.g. it leads to overall global warming, with regional climate SHTF.


And as for things like changes in albedo: these are once again completely factored into the bigger picture. Something like ice-albedo feedback is pretty self-explanatory as a positive amplifying effect: warming = less ice = lower albedo = more warming. Meanwhile others like clouds are more complicated. This in fact is where the bulk of the uncertainty over climate change lies.

But of course what the CAGW soothsayers completely refuse to ever recognize is that uncertainty works in both directions. True, it might not end up as bad as some say - but it could also in fact be worse. I already left a link in the OP pointing specifically to recent research showing cloud feedbacks resulting in high climate sensitivity.

And meanwhile this whole thread is yet another testament to the mounting physical evidence that says this uncertainty is quickly moving more and more towards the direction of worse. Much worse.

Originally posted by peck420
reply to post by mc_squared

 

I didn't mean how much co2 get's released during deforestation.

What I meant was that we are adversly affecting the environment by reducing the carbon recovery cylce by land and vegetation.

Think of it like water usage.

I don't actual care about my absolute water resource, I care about my actual yearly recovery rate. If my usage exceeds my recovery rate it is just a mater of time....

Same with the forests, I really don't care about the carbon released when a tree is deforested, I care far more about the yearly rate of absorbtion that is now gone. The further the natural recovery cycle is damaged the more damaging our emissions become.

It's one and the same though really.

The reason you're releasing a net amount of CO2 through deforestation/land-use change is because you're simultaneously discharging that embodied carbon and taking away the mechanism that would normally suck it all back in.

In contrast - the reason why dedicated biofuels are at least in theory (practice is a whole other story) environmentally friendly and "renewable" is because they are constantly recycling the CO2 they emit (i.e. they reabsorb it when you grow them back). So in essence you are only lending and borrowing CO2 rather than digging it up and blasting it into the atmosphere faster than the Earth can make up for.

reply to post by TheWill

You are aware, aren't you

Considering he's trying to use the "global warming is good for plants" meme on a thread that is all about how global warming is quickly deteriorating the world's largest rainforest through drought - no, I don't think he's very aware of much at all lol

reply to post by TheWill

I think it was termites, not dung beetles, that produce a lot of Methane, not CO2. You are aware, aren't you, that hotter isn't the only thing that tropical plants need to grow? If it also becomes drier- because, for example, the changing temperature has altered cloud dispersal patterns at a rate faster than seed distributions...

Actually hot is wetter. It is cold, especially glaciation that makes for a very dry climate.


After reading the Thermostat Hypothesis (see below) I did a bit of research myself.

I noticed that when I lived in South Carolina we seemed to get a thunderstorm every afternoon but in northern North Carolina I do not. So I looked at cities along the east coast of the USA (summer)
In Florida it rains 20 times a month. As you head north it drops to 10 times a month and some where north of Fayettville North Carolina it drops to about once a week or so.

Willis Eschenbach on negative feedback and "The Thermostat Hypothesis"


“Abstract

The Thermostat Hypothesis is that tropical clouds and thunderstorms actively regulate the temperature of the earth. This keeps the earth at a equilibrium temperature.

Several kinds of evidence are presented to establish and elucidate the Thermostat Hypothesis – historical temperature stability of the Earth, theoretical considerations, satellite photos, and a description of the equilibrium mechanism. …
www.heliogenic.net...

reply to post by crimvelvet


Good point hotness =(no proportional sign so it'll have to do) wetness. I got a little bit peeved at the whole "global warming will make everything fix itself" because while it is technically true, long term, it's not so much for the reasons that the poster in question suggested, and it's not really within an appreciable timescale. So my brain dropped out and I overlooked that bit.

But as much as increased heat increases humidity - and rainfall - globally, on a local level I do believe that it would effect cloud formation and dispersal - consider a warmer overall temperature, geographic features that introduce warm, humid air to cold weatherfronts and lead to clouds and rain will need to be taller, and I think (but I can't remember for certain) that it's when the continents are closely grouped (read Pangaea here) that higher temperature equalises global humidity - the spread out continents, interrupting the flow of currents, allows greater variability of overall climate, which would mean that while wetness was higher overall, without the forests to generate widespread rainfall, the current wet bits could still be the bits that end up dry (especially as they're inland).

I'm about to start blathering, so I'm going to distract myself with the Snow, in November, in Nottingham - a city where, apparently, it never snows, but it has snowed heavily for the past three years. Good old North Atlantic current failure...

reply to post by mc_squared

Bumping this thread for an update.
It seems it is worse MC.
Just read this link below and it seems worse.

Two recent severe droughts in the Amazon region, one in 2005 and one in 2010 may cause the rainforest to change from a carbon sink into a net emitter says a recent study.

Read more: www.economicvoice.com...

The forest usually soaks up 1.5 billion tons of carbon a year but the team involved in the study written in 2010 believe that this would not be achievable in 2010 and 2011. The study should be seen as an initial estimate said one of the co-authors as more research was needed to evaluate the number of trees killed off by the drought. The impact of forest fires had also not been included in the study.

Read more: www.economicvoice.com...

I wonder if the recent floods will change things. I hope so. This is troubling information IMHO, two severe drought so close together. The 2005 one was considered once in 100 years!
How many of those "once in a hundred year events " have we had lately? Seems a lot.

reply to post by atlasastro


Yup, I've noticed quite a few articles have popped up since this report was released.

e.g.

Mass tree deaths prompt fears of Amazon 'climate tipping point'

Bear in mind this isn't just 2 droughts in the last 5 years either - there was also another extreme drought in 1997-98, and a major one in the south-east Amazon in 2007. So the world's largest rainforest has experienced 4 significant droughts in the last 12 years.

Meanwhile in 2010/early 2011 we've had:

- record Amazon drought
- record heatwave/forest fires in Russia that killed over 10,000 people and shut down crop exports
- record floods in Pakistan that left 1/5th of the entire country underwater
- "biblical" flooding in Queensland
- ditto for Rio de Janeiro
- massive coral bleaching all over the world
- record Arctic (winter) temperature anomalies that saw some places sustain levels of +21 C above average for an entire month.

...
I think when all is said and done, 2010 will be looked back upon as the year climate change slapped us all in the face. And yet so many people continue to turn the other cheek.

It's crazy to think all this is also happening while the temperature anomaly is still "only" about +0.7-0.8 C. I don't even want to think about what the world could look like when that level reaches 3-4 times this amount, never mind beyond if we don't get off BAU scenarios. The Guardian link above also points out the numerous climate tipping points we might expect to encounter on the road ahead:

Climate tipping points

Scientists know from the geological record that the Earth's climate can change rapidly. They have identified a number of potential tipping points where relatively small amounts of global warming caused by human activities could cause large changes in climate. Some tipping points, like the losses to the Amazon forests, involve positive feedback loops and could lead to runaway climate change.

Arctic ice cap: The white ice cap is good at reflecting the Sun's warming light back into space. But when it melts, the dark ocean uncovered absorbs this heat. This leads to more melting, and so on.

Tundra: The high north is warming particularly fast, melting the permafrost that has locked up vast amounts of carbon in soils for thousands of years. Bacteria digesting the unfrozen soils generate methane, a potent greenhouse gas, leading to more warming.

Gas hydrates: Also involving methane, this tipping point involves huge reservoirs of methane frozen on or just below the ocean floor. The methane-water crystals are close to their melting point and highly unstable. A huge release could be triggered by a little warming.

West Antarctic ice sheet: Some scientists think this enormous ice sheet, much of which is below sea level, is vulnerable to small amounts of warming. If it all eventually melted, sea level would rise by six metres.

reply to post by mc_squared


I think the problems of the Amazon have more to do with Brazil destroying the rain forest for cropland instead of taking care of the land through crop rotations.

It is similar to the Dust Bowl.

So no need to begin advocating global marxism and your failed attempt at stirring up white guilt is over with.

Originally posted by korathin
reply to post by mc_squared

 

I think the problems of the Amazon have more to do with Brazil destroying the rain forest for cropland instead of taking care of the land through crop rotations.

It is similar to the Dust Bowl.

So no need to begin advocating global marxism and your failed attempt at stirring up white guilt is over with.

In all fairness the deforestation of America and Europe is a bad thing, but what Brazil and other Tropical nations are doing is far, far worse.