Climate change and the Amazon


in Daily updates, Oxford, Science, The environment

Tonight, I saw a public lecture associated with the Oriel College conference: Climate change and the fate of the Amazon. Notes on Thomas Lovejoy’s presentation have been posted on my wiki. Most of it was stuff that I had heard or read before in multiple places, but it will be useful to have another source to cite on a few issues, for the thesis.

The issue of biodiversity also really drives home the instrumentalist v. inherent value perspectives on nature. If golden toads provide no concrete benefit to human beings, should we be concerned about them going extinct. If we are, what level of resources is it sensible to devote, given the myriad other problems that exist?

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{ 10 comments… read them below or add one }

Anon @ Wadh March 21, 2007 at 2:23 pm

If digging up pharmaceuticals in the Amazon and coral reefs has shown anything, it’s that you can’t tell which species will eventually be useful.

Milan March 21, 2007 at 2:46 pm


While potentially a convincing political argument, that line of reasoning is still fully instrumentalist. We may not know what is useful, but usefulness is still the reason for protecting nature.

Anonymous March 26, 2007 at 5:00 pm

Benjamin Franklin

“There is no kind of dishonesty into which otherwise good people more easily and frequently fall than that of defrauding the government.”

Philip K. Dick

“Sometimes the appropriate response to reality is to go insane.”

Milan January 24, 2008 at 2:50 pm

Brazil vows to stem Amazon loss

Brazil has agreed emergency measures to stem deforestation as government figures revealed a sharp increase in the rate of clearances in the Amazon.

The steps were announced after an emergency cabinet meeting chaired by President Luiz Inacio Lula da Silva.

The measures include sending extra federal police and environmental agents to stop farmers and cattle ranchers illegally felling any more rainforest.

In the last five months of 2007, 3,235 sq km (1,250 sq miles) were lost.

. June 26, 2009 at 11:13 am

Brazil’s Lula signs Amazon bill
By Tim Hirsch
BBC News, Sao Paulo

Brazilian President Luiz Inacio Lula da Silva has approved a controversial bill allowing Amazon farmers to acquire an area of public land larger than France.

But the president vetoed some of the most contentious clauses that would have enabled absentee landlords and companies to benefit from the measure.

Smaller parcels of public land will be handed over for free, and larger ones at reduced or market rates.

Critics say it will amount to an amnesty for illegal land-grabbers.

The law is intended to end the chaotic state of land occupation in the Amazon.

. November 4, 2009 at 1:06 pm

Environmentalists fret over the fate of the Amazon for good reason: It contains more than half of the planet’s remaining tropical rainforest, one-fifth of our global freshwater, and as much as one-third of the world’s biodiversity. Saving all this was once a rallying cry for green activists, and a few early triumphs made that goal seem likely. But attention soon shifted away from the rainforest to issues like climate change and organic agriculture, and now the Amazon is disappearing at about the same rate it was in the 1980s.

The good news is that interest in the Amazon has begun to take off again in recent years. That’s mainly because of the role that forests play in staving off climate change: Scientists estimate that the Amazon itself has between 85 billion and 100 billion tons of CO2 stored in its trees and shrubs, or about 11 years’ worth of U.S. carbon emissions. The dangers aren’t limited to Brazil, of course—deforestation rates in Asia and parts of Africa now rival those seen the Americas. In 2009, the Guinness World Records named Indonesia as the country with the most rapidly disappearing forests—it’s losing about 2 percent per year—although Brazil remains the leader in absolute terms.

Many environmentalists now pin their hopes on a U.N.-sponsored plan to use carbon credits as a means of reducing deforestation in developing nations. The so-called REDD Scheme will be on the table at the climate negotiations in Copenhagen next month. In the lead-up to those talks, Robin Williams, Sting, and a host of other aging celebrities have embarked on a “Rainforest SOS” campaign to stop tropical deforestation and prevent “run-away climate change.” Most of the celebs on the roster are more than a little past their prime, but the destruction of the Amazon is just as timely as it ever was.

. May 25, 2010 at 10:55 am

Brazil environment officials arrested for logging

Police in Brazil have arrested at least 70 people suspected of illegal logging in the Amazon – including officials employed to protect the rainforest.

Several environmental officials in Mato Grosso state are accused of providing false licences for the extraction of timber from protected areas.

Loggers, landowners and forest managers have also been charged.

Police estimate that the illegal logging operation has caused damage amounting to about $500m (£345m).

The arrests followed a two-year investigation in six Amazon states.

. July 6, 2010 at 11:41 am

“But far from “grossly exaggerating” the state of the science in 2007, as North claimed, the IPCC – because it referenced the WWF report, not the peer-reviewed literature – grossly understated it. The two foremost peer-reviewed papers on the subject at the time of the 2007 report were both published in Theoretical and Applied Climatology. They are cited throughout the literature on Amazon dieback.

What do they tell us? That the projection in the IPCC’s report falls far, far short of the predicted impacts on the Amazon.

The first paper, by Cox et al, shows a drop in broadleaf tree cover from approximately 80% of the Amazon region in 2000 to around 28% in 2100 (Figure 6). That is bad enough, involving far more than 40% of the rainforest(1). But the forest, it says, will not be largely replaced by savannah:

“When the forest fraction begins to drop (from about 2040 onwards) C4 grasses initially expand to occupy some of the vacant lands. However, the relentless warming and drying make conditions unfavourable even for this plant functional type, and the Amazon box ends as predominantly baresoil (area fraction >0.5) by 2100.”

In other words, the lushest region on earth is projected by this paper to be mostly replaced by desert as a result of global warming (and the consequent reduction in rainfall) this century. I hope I don’t have to explain the consequences for biodiversity, the people of the Amazon or climate feedbacks, as the carbon the trees and soil contain is oxidised and released to the atmosphere.”

. December 18, 2010 at 5:55 pm

Brazil: Amazon deforestation falls to new low

Deforestation in the Brazilian Amazon has fallen to its lowest rate for 22 years, the government says.

Satellite monitoring showed about 6,450 sq km of (2,490 sq miles) of rainforest were cleared between August 2009 and July 2010, a drop of 14% compared with the previous 12 months.

Brazilian officials said the reduction was due to better monitoring and police control.

Environment minister Izabella Teixeira said the figures were “fantastic”.

She said she would be “proud” to present the results at the UN Climate Change Conference currently taking place in Cancun, Mexico.

She added that Brazil was well on course to reduce deforestation to its target of 5,000 sq km of by 2017.

The latest figure still represents an area more than half the size of Lebanon or Jamaica.

But it is far lower than the peak of 27,772 sq km in 2004.

President Luiz Inacio Lula da Silva said the reduction showed Brazil was “keeping its promises” on tackling global warming.

In 2005 President Lula pledged to reduce deforestation by 80% by 2020.

Peer reviewed science! July 14, 2011 at 9:47 pm

Malhi, Y. et al., 2009, Exploring the likelihood and mechanism of a climate-change-induced dieback of the Amazon Forest, PNAS, 106 (49), 20610-20615.

Surpassing a possible tipping point in the viability of the Amazon rainforest is unlikely during the 21stcentury. However, changes in the rainfall regime could lead to a transition from rainforest to seasonal forest.

A recent issue of the Proceedings of the National Academy of Sciences (PNAS) included a special feature on “tipping elements” in the Earth System. In one of the papers, the question of whether climate change may cause a large dieback or degradation of the Amazon rainforest was explored. Data on the observed rainfall regime for the period 1970-1999 was combined with satellite-derived maps of vegetated areas (evergreen forest, deciduous forest, savanna) to determine the climatic thresholds favouring the presence of forest as opposed to savanna. The authors then examined climate simulations of rainfall regime by 19 global climate models (GCMs) for the period 1970-1999 and for the future (2070-2099), under the emission scenario A2. None of these simulations incorporated feedbacks from changes in vegetation and soils. Their results showed a large mismatch between observed climate and GCM-simulated climate with GCMs tending to underestimate current rainfall regime in Amazonia. Among GCMs, projections of future trends varied considerably. To take these findings into consideration, the authors took the relative change in monthly rainfall predicted by each GCM and applied these to the observed climate for the late 20th century rather than to the GCM-simulated current climate. The resulting projections show longer and more intense dry seasons in east Amazonia over the 21stcentury, conditions they show are more likely to lead to a transition from rainforest to seasonal forest, than to savanna. As for the west Amazonia region, the climate is likely to remain one that will favour rainforest, but there is a possibility (near 10%) of shifting from a generally seasonal moisture regime to a seasonally dry regime.

Summary courtesy of Environment Canada

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