Poster!

Hi all,

I made a poster giving an overview of my blog so far, and I will be uploading it as soon as I can figure out how to.

This is what I've figured out so far. There is a link here to the poster, where you can see it up close in all its academic beauty. I've also included an image of the poster below, where it is probably hard to read but gives a general notion of what it looks like.

People vs. Forest

Historically speaking, widespread deforestation of the Amazon is fairly recent. In 1970, the Brazilian government inaugurated the Transamazon Highway, and with it kicked off the intense deforestation we see today. In an article by Fearnside, he details the history and effects of this practice. As is usually the case, the biggest motivator in clearing the forest is to make space for traditionally lucrative activities. In Brazil, the expansion of land for cattle ranching is the main enemy, but clearing the land for agriculture also plays a major role. Brazil is a major exporter of meat, and this industry is dominated by medium to large landowners, who while destroying the Rainforest are a significant contributor to the region’s and country’s GDP. The same goes for agriculture, particularly for crops like soybeans and corn.

In order to clear the land, the most common practice is to burn the desired sections of forest. Even though Amazonian soil is sandy, poor in nutrients, and overall not fit for crops, there are still attempts at using it for agriculture. What happens is that whatever is planted does not last more than a few years, and a new plot of land needs to be cleared.

The logging industry is another damaging force. Although generally illegal, the sheer size of the forest makes it very difficult to completely stop it from happening. Nowadays, constantly updated satellite images are being used to spot this type of activity. This system of detection is an improvement but still not a perfect solution, because there needs to be noticeable deforestation before the satellite can spot the activity. Nonetheless, a step in the right direction.

Sources: Fearnside, P. 2005. ―Desmatamento na Amazônia Brasileira: História, índices e conseqüências.‖ Megadiversidade 1(1): 113–23.

Beguoci, Leandro. "O tesouro escondido na selva." Veja Sept. 2009: n. pag. Veja.com. Web. 1 Apr. 2011. 

<http://veja.abril.com.br/especiais/amazonia/tesouro-escondido-na-selva-p-072.html>. 

Climate vs. People

The potential harm being done to the Amazon Rainforest by extreme climate fluctuations is only one part of the story. The areas affected by floods and droughts are home to several million people who are forced to deal with and, sometimes, simply survive the effects that too much rain, or lack thereof, has on their lives.

 The droughts in both 2005 and 2010 left “hundreds of riverside settlements cut off from the outside world”, since several tributaries to the Amazon river dried up. This same article states that the Brazilian government tried delivering aid to the hardest-hit areas, and found that the only effective means of transportation were helicopters and planes. While this means that efforts were made to help, it also means that all the people who can only be reached by aircraft were completely stranded, and also little to no means of making a living or obtaining food, water, and medicine.

In 2010, the Negro River (Rio Negro), one of the main tributaries of the Amazon River, almost dried up due to the lack of rainfall. Here is a picture of the Rio Negro when it is flowing:

Courtesy of www.creativecommons.org

             And a picture of the river in 2010, at the peak of the drought:

Link to picture

Needless to say, this kind of situation halts the economic activities related with the river. Fishing and trade via rivers is a staple of the Amazon states’ economies, and without these, a deadly blow is dealt to the livelihoods of those who depend on the river. In order to try and offset some of the hardships brought on by drought, the Brazilian government has no option but to declare a state of calamity in the Amazon regions, and spend millions of pounds in emergency aid.

            The floods seen in 2009 were no better. Whole cities nearly disappeared engulfed in water, leaving only the rooftops of houses visible. While the water is present, the inhabitants of these cities were forced to move away, and in 2009 over 400,000 people were left homeless for the duration of the floods. What makes the situation worse is that, due to the destructive power of the floods, many people did not have homes to return to, and even more had several of their possessions washed away or severely damaged. Once again, the government response was mainly to announce a state of emergency, and spend copious amounts of money on aid.

            However, one more interesting strategy taken by the government was to give lumber seized from illegal logging activities to the poorest residents of the Amazon, so that they could rebuild homes, or build their houses higher to get away from the water. This same article spoke of how the people view floods as a natural part of the Rainforest’s cycle, and they do not have a problem dealing with the regular yearly floods. In fact, they are used to having “the rains usually end like clockwork at the end of March“. The big problem is that in 2009 the floods had more volume, lasted longer, and water levels rose much faster than usual. The exacerbation of seasons seems to be the trend in recent years, and while the effects on the Amazon itself might take a while to be fully understood, there is very little doubt regarding the power of devastation it has on the people who live in or around the forest.

Sources: Rohter, Larry. "Record Drought Cripples Life Along the Amazon ." The New York Times 11 Dec. 2005: n.pag. New York Times. Web. 31 Mar. 2011. <http://www.nytimes.com/2005/12/11/international/ americas/11amazon.html>. 

BBC News. "Severe drought afflicts Brazilian Amazon." BBC News. N.p., 23 Oct. 2010. Web. 3 May 2011.

<http://www.bbc.co.uk/news/world-latin-america-11610382>. 

USA TODAY. "Amazon hit by climate chaos of floods, drought ." USATODAY.com. N.p., 25 May 2009. Web. 

3 May 2011. <http://www.usatoday.com/weather/2009-05-25-amazon-drought-and-floods_N.htm>.  

And the other extreme…

In order to complement my previous post, I have written this one to deal with the topic of extreme droughts in the Amazon Rainforest. Only a few years ago in 2005, the Amazon experienced an unusually dry season caused in part due to the 2002-2003 El Niño. The El Niño/Southern Oscillation is known to influence the climate of the forest, and as I mention in my previous post, is responsible for magnifying the effects of the flooding season as well as the drought season (I will write more about the ENSO in a future post). The difference in 2005 was that in addition to the ENSO affecting the Amazon from the Pacific Ocean, there was also a warming of the waters in the Atlantic Ocean.

The result was an “extreme drought event in the Amazon river basin, regarded as the worst in over a century”, as outlined by a paper by Chen et al. This is the same Chen from my previous post, and once again he uses GRACE satellite measurements to back his findings. There was in fact a widespread deficit in terrestrial water storage in August/September (apex of the drought) compared to the average TWS changes in the values they had for the years 2002-2007. The regions that were hit the hardest saw a decrease in 20-30 cm of water. Also, the average accumulated precipitation from June to September in 2005 was almost 150mm lower than the previous year.

What does all this mean? First of all, the Brazilian government announced a “state of public calamity” in the populated areas. Significant amounts of crops were lost, access to water was minimal if not nonexistent, and the level of forest fires greatly rose. In fact, the state of Acre noted three times as many forest fires compared to 2004. These forest fires are not only dangerous to the local population for obvious reasons, but are a major threat to the forest itself.

Chen’s paper graphed the water levels of four river gauge stations throughout the length of the Amazon River:

Figure 6. Nonseasonal daily water-level change at 4 selected river gauge stations marked in Figure 5.
Annual and semiannual variations have been removed from these time series using unweighted least
squares fit.

A multiple meter drop in water levels means that several branches of the Amazon River, both those usually intermittent and not, dry up. For the vast majority of the population in the region, the River and its branches are integral to most aspects of daily life, ranging from transport to livelihood.

The Forest itself does not do well with this degree of dryness. Some studies have argued that when the Amazon experiences an extreme drought, there is actually a “greening-up” of the canopy, as in there is an increase in foliage. This is attributed to an increase in sunlight availability, which outweighs the lack of access to water. This claim is widely disputed; for example, a paper by Phillips et al. states there was actually extensive aboveground biomass loss. In fact, there was aboveground biomass loss in most of the monitored regions, outweighing the amount of gains, as the following graph shows:

Fig. 3. Aboveground biomass change in the Amazon Basin

and contiguous lowland moist forests. The 2005 drought reversed a multidecadal biomass carbon sink across Amazonia. Symbols represent magnitude and direction of measured change and approximate location of each plot. (A) Annual aboveground biomass change before 2005. (B) Annual aboveground biomass change during the 2005 interval. (C) Difference in rates of change in aboveground biomass, 2005 versus pre-2005, for those plots monitored throughout. Grayscale shading in (A) and (B) represents proportion of area covered by forests. Colored shading in (C) indicates the intensity of the 2005 drought relative to the 1998–2004 mean as measured from space using radar-derived rainfall data [Tropical Rainfall Measuring Mission (TRMM)].

The process of greening-up does in fact follow periods of decreased rainfall. This is a normal part of the Amazonian climactic cycle, as every year there is a dry and a rainy season. Yet this greening-up only goes to a certain extent, after which the plants begin to die off. As was shown in the case of 2005, the drought pushed the forest to and beyond that point. Another potential problem that researchers fear is that, with extreme droughts and plant death, natural selection will make it so that drought-resistant plants compose more and more of the forest. This not only means a decrease in biodiversity as the drought-susceptible species would cease to exist, but also, the drought-resistant species generally capture less carbon from the atmosphere.

Finally, I would like to bring the reader’s attention to the fact that the 2005 drought, due to the convergence of abnormal temperatures from both the Atlantic and the Pacific, was considered to be a once in a century occurrence. Until it happened again in 2010, for the same reasons, and affected an area larger than the 2005 drought (large rainfall anomalies over 3 million km2 in 2010, and 1.9 million km2 in 2005). Since this happened only last year, data on its full effects are still unknown, but what is clear is that this kind of drought should not be happening this often.

Sources: Chen, J. L., C. R. Wilson, B. D. Tapley, Z. L. Yang, and G. Y. Niu (2009), 2005 drought event in the Amazon River basin as measured by GRACE and estimated by climate models, J. Geophys. Res., 114, B05404, doi:10.1029/2008JB006056. 

 Rohter, Larry. "Record Drought Cripples Life Along the Amazon ." New York Times. N.p., 11 Dec. 2005 Web. 3 May 2011. <http://www.nytimes.com/2005/12/11/international/americas/11amazon.html>. 

Amazon Forests Green-Up During 2005 Drought Scott R. Saleska, Kamel Didan, Alfredo R. Huete, and Humberto R. da Rocha Science 26 October 2007: 612.Published online 20 September 2007 [DOI:10.1126/science.1146663]

 Drought Sensitivity of the Amazon Rainforest Oliver L. Phillips, et al., Science 6 March 2009: 1344-1347. [DOI:10.1126/science.1164033]

The 2010 Amazon Drought Simon L. Lewis et al., Science 4 February 2011: Vol. 331 no. 6017 p.554 DOI:10.1126/science.1200807

 

So what’s going on?

    The Amazon Rainforest has a dry and a wet season, so the fact that there are large variations in rainfall throughout the year is a natural part of the region’s climate. However, what has been happening in recent years is that, while there are still the two seasons, they are becoming more intense. In other words, the dry season can turn into a full-on drought, and the wet season can have floods that become destructive to both the rainforest itself and the areas surrounding the forest.
    According to a paper by Chen et al. in 2009, the northern and central parts of the Amazon rainforest experienced the worst floods in over half a century, and left nearly 400,000 people homeless. The paper details the results of a study carried out over 7 years using the GRACE (Gravity Recovery and Climate Experiment) satellite. The GRACE satellite measures levels of gravity change, and in the case of this experiment the data collected allowed the researchers to calculate the terrestrial water storage of the Amazon Rainforest. They found that from 2002-2009 there was an increase in how much water was stored in the forest, culminating with the 2009 floods.

Figure 5. The evolution of yearly TWS anomalies (in cm of equivalent water thickness change) in the Amazon basin and surrounding regions during the 7 year period from August 2002 to June 2009. Yearly averages are mean TWS changes from July of the previous year through June of the current year; for example, the 2004 TWS anomalies are the mean during July 2003 through June of 2004. Seasonal (annual and semiannual) signals and the 161 day S2 alias error have been removed through unweighted least squares fit as well as the mean field for the 7 year period.

    One shocking comparison is that the surplus water stored in 2009 was “roughly equal to U.S. water consumption for a year”. Besides the effect this had on the people who were left without a home, excessive flooding can put the ecosystem at risk simply because it is not meant to withstand this kind of weather.
    This study also points to the link between extreme climate variability in the Amazonian Rainforest and El Niño/Southern Oscillation (ENSO). An exceptionally dry season in 2002-2003 is linked to El Niño, and the 2009 flood with La Niña. In fact, the paper has a great comparison between two graphs, one showing precipitation anomalies and the other showing sea surface temperature anomalies i.e. presence of El Niño/La Niña.

Figure 8. (a) Monthly precipitation anomalies for 1997–2009 in the lower Amazon basin (the area encircled by the magenta contour in Figure 3). Each monthly precipitation anomaly is computed by removing the mean monthly precipitation (for that month), estimated for 1997–2008. (b) The NINO3.4 index over the period 1997–2009. NINO3.4 is the average sea surface temperature (SST) anomaly in the region bounded by 5°N–5°S, 170°W–120°W. This region has large variability on El Niño time scales and is close to the region where changes in local sea surface temperature are important for shifting the large region of rainfall typically located in the far western Pacific. The NINO3.4 index time series is provided by the Royal Netherlands Meteorological Institute (http://www.knmi.nl).

    I think that the most important thing to take from this paper is that, while the Amazon Rainforest is by definition subject to intense weather shifts, the climactic extremes are becoming too much, even by Rainforest standards.

Sources: Myneni R.B, et al. 2007 Large seasonal swings in leaf area of Amazon rainforests. Proc. Natl Acad. Sci. USA. 104, 4820–4823. doi:10.1073/pnas.0611338104.

Chen, J. L., C. R. Wilson, and B. D. Tapley (2010), The 2009 exceptional Amazon flood and interannual terrestrial water storage change observed by GRACE, Water Resour. Res., 46, W12526, doi:10.1029/2010WR009383.

Welcome!

    The title of this blog, “Can’t Stop the Waters of March”, is a reference to the song “Waters of March” composed by Bossa Nova legend Tom Jobim. Through imagery and metaphors, the song speaks of the rainfall that accompanies seasonal change in Brazil. However, recent droughts and floods in Brazil show how this previously stable cycle is becoming more and more disrupted. In this blog, I hope to provide an interesting look at the effects of climate change on one of Brazil’s (and the world’s) greatest treasures, the Amazonian Rainforest.

   Luckily for my blog, Tom Jobim wrote lyrics to this song in both Portuguese and English, so any interested readers can take a look at what they say and not just take my word for it.
Song in English, Portuguese, and lyrics in English, Portuguese.