Numbers refer to items of the original document.
“9. The Amazon River basin and the surrounding tropical forests nourish the soil and regulate, through the recycling of moisture, the cycles of water, energy and carbon at the planetary level. The Amazon River alone sends 15% of the total fresh water of the planet every year into the Atlantic Ocean. The Amazon is essential for the distribution of rainfall in other distant regions of South America and contributes to the great movements of air around the planet. Moreover, it nurtures the nature, life and cultures of thousands of indigenous, peasant, Afro-descendant, river and urban communities. But it should be noted that according to international experts, the Amazon is the second most vulnerable area of the planet, after the Arctic, when it comes to climate change caused by humans.”
Comment: The Amazon is not essential for rain distribution to other remote regions of South America because the Amazon is not a source of moisture to the atmosphere. Concerning the climate, the Amazon has a stable water balance. The main source of humidity for Amazon rain is the North Atlantic Ocean and mainly during the summer of the Southern Hemisphere. In round numbers (see Braga and Molion, 2018) it rains an average 500,000 m3 / s, of which 80% become rain in the region and the remaining 100,000 m3 / s “go straight” over the Amazon. Of the 400,000 m3 / s of rainfall that falls in the basin, half leaves with the Amazon River and the other half is recycled and incorporated into the moisture stream that reaches other regions of South America. In other words, on average, 300,000 m3/s of the 500,000 m3/s coming from the evaporation of the Atlantic reach other regions south of the Amazon, with the remaining 200,000 m3/s being returned to the Atlantic by the river.
Trees and forests do not produce water but only recycle water from previous rains stored in the soil. Although there is a forest-atmosphere interaction, in the long run the forest exists because it rains and not the other way around. If the forest were a source of moisture, the region would have turned into a desert since it stabilized after the end of the last ice age some 15,000 years ago. The key geographic element for directing moisture to other regions of South America is the formidable barrier to moisture flow posed by the Andes.
A direct atmospheric circulation cell, known as the Hadley-Walker Cell exists on average and will always exist because as the sun warms the surface of the South American continent during the southern summer, the air becomes less dense and rises (convection), carrying moisture and producing clouds and rain. The forest can interact with the atmosphere to intensify this circulation cell in certain years. On the other hand, there are years when this cell does not form. It has been observed, for example, that when there is a strong El Niño event such as that of 2014-2016, this circulation cell is inhibited and the Amazon Basin experiences a severe drought. This would not happen if the forest were the main cause of the existence of this atmospheric circulation cell.
The Arctic thaw in 2006-2007 is attributed in a highly misleadingly way to anthropogenic global warming (AGA). In August 1922, the Norwegian Department of Commerce sent an oceanographic expedition to the Arctic Ocean, headed by Dr. Adolf Hoel, to assess the great extent of thaw that had occurred in that region. Surveys conducted down to 3,100 meters deep at 81° latitude found that the ocean waters were warmer than normal. The report concluded that during that period, probably between 1911 and 1922, the Gulf Stream carried more heat from the tropics to the North Pole (Ifft, 1922). The question is: what human carbon emissions back then were capable of almost completely thawing the Arctic?
“10. (…) Its generous natural abundance of water, heat and humidity means that the ecosystems of the Amazon host around 10% to 15% of the terrestrial biodiversity and store between 150 and 200 billion tons of carbon each year.”
Comment: This statement: “store between 150 and 200 billion tons of carbon each year” is completely wrong. There is a carbon stock in the Amazon (note well, stock!) that is about 70 to 80 billion tC – assuming that biomass density is 300 tC per hectare throughout the biome and not 150 to 200 billion tC, as the text says. The Amazon does not “incorporate” 150 to 200 billion tC per year via photosynthesis. According to Fan et al (1990), measurements taken in the Central Amazon revealed an assimilation of 4.4 kgC / ha / hour during the day by photosynthesis and a breath loss of 2.57 kgC / ha / hour during the night. Assuming that these numbers could be generalized to the 550 million hectares (ha) of the Amazon Biome, there would be assimilation of about 4.5 billion tC, which is not a negligible number considering that human activities emit 9 billion tC per year, i.e., a 50% assimilation of current carbon emissions, and therefore, its vegetation cover must be conserved.
“16. At present, climate change and the increase in human intervention (deforestation, fires and changes in land use) are driving the Amazon towards a point of no return, with high rates of deforestation, forced displacement of the population, and pollution. They are putting its ecosystems at risk and exerting pressure on local cultures. Thresholds of 4oC of warming or 40% deforestation are “tipping points” of the Amazon biome towards desertification, which means a transition to a new biological state that is generally irreversible. And it is worrying that today deforestation has already reached between 15 and 20%.”
Comments: There is no man-made “climate change” or “global warming.” What exists is natural climate variability. Studies using climatic evidence suggest that during the Holocene (last 10,000 years), the climate was at least about 2° C warmer than the current one (Alley, 2000) and that the last 3 Interglacials (130,000, 240,000 and 320,000 years ago) had temperatures of 6° C to 10° C higher than the current interglacial (Sime et al, 2009). There are concrete physical arguments that suggest that global warming between 1916 and 1945 was caused by solar activity, the most intense solar activity recorded in the last 400 years, and that the 1976-2005 warming — attributed to human activities– was caused by a reduction in global cloud coverage by 5% (data from the ISCCP Project) – which resulted in a larger solar radiation stream entering — and the large frequency of strong El Niño events. Warming levels of 4° C are mere speculation, as the numbers are taken from climate simulation models, the so-called global climate models (MCG), which are complex computer codes but do not reproduce the current climate and particularly the hydrological cycle, which is of fundamental importance to the Amazon. The “tipping point,” better translated as “point of no return,” of 40% deforestation (Nobre et al, 2016) is also the result of speculation based on MCG results.
First, let me make it clear that I do not support widespread deforestation. I am only expressing the most rational and likely physical phenomenology. The Amazon Biome constitutes 5.5 million km2, while the surface of Planet Earth is 510 million km2 and its oceans cover 361 million km2. Therefore, the Amazon Biome corresponds to 1% of the surface of Planet Earth and 1.5% of its oceans. In principle, widespread deforestation of the Amazon would not affect the global climate because it is small in proportion to the ocean area (71%), which is one of the global climate controllers. In the case of Brazil it is also necessary to distinguish the “Legal Amazon” – a territory of 5.2 million km2 demarcated for tax incentives – from the Amazon Biome, which covers about 70% of the Legal Amazon. The parts of the Legal Amazon that suffer anthropogenic pressure are the southern and eastern regions, characterized by transitional biomes such as cerradão and cerrados, which are not covered by with tropical rainforests. It is noteworthy that according to data from the Ministry of the Environment, 84% (or more) of the Amazon Biome in Brazilian Territory are preserved, an area equivalent to the territories of Germany, Spain, Finland, France, the Netherlands, Ireland, Norway, Portugal, United Kingdom and Sweden combined.
“45. The native Amazonian peoples have probably never been so threatened on their own lands as they are at present” (Fr.PM). The extractive and agricultural projects that exploit the land with no consideration whatsoever are destroying this territory (cf. LS 4, 146), which runs the risk of turning into savannah.”
Comment: About the risk of savannization, see previous comments. The use of the verb “destroy” is an obvious semantic exaggeration. Assuming, absurdly, that deforestation took place at the current average rate (7,000 km2 per year, INPE / MCTI data, 2019), it would take 780 years to clear the entire Amazon Biome. Most deforestation and fire use occur on private properties and one should remember that the Brazilian Forest Code allows deforestation of up to 20% on properties in the Amazon Biomes and up to 50% in the cerrados.
“54. The massive felling of trees, the extermination of the tropical forest by intentional forest fires, the expansion of the agricultural frontier and monocultures are the cause of the current regional climate imbalances, with obvious effects on the global climate, with planetary dimensions such as great droughts and increasingly frequent floods. Pope Francis refers to the Amazon and Congo basins as “lungs of our planet”, underlining the urgency of protecting them (LS 38).”
Comments: If you consider the biome as a whole, tropical rainforests consume more oxygen than they produce. Rainforest survival depends on nutrient recycling, which results from the degradation of organic matter that falls onto the forest soil (leaves, branches, animals, insects) and is broken down by aerobic microorganisms, oxygen consumers. In other words, the biome consumes more oxygen than it produces. Furthermore, the word “lung” is inappropriate because a lung is just a “bellows,” a “pump” that facilitates gas exchange and produces no oxygen. Oxygen comes primarily from the oceans, produced by marine phytoplankton, and from the photodissociation of the water molecule by high-energy solar radiation. Regarding the global climate, see previous comments.
Alley, R. B. (2000). “The Younger Dryas Cold Interval as Viewed from Central Greenland. Quaternary Science Reviews, 19(1-5), 213-226.
Braga, H. A & Molion, L.C.B. 2018, “A seca de 2013/2014 no Sudeste do Brasil”. Anuário do Instituto de Geociências, UFRJ, ISSN 1982-3908 – Vol. 41 – 1 / 2018 p. 100-107
Fan, S.M., Wofsy, S.C., Bakwin, P.S., Jacob, D.J., 1990. Atmosphere-Biosphere Exchange of CO2 and 03 in the Central Amazon Forest. Jour. Geophys. Res., Vol. 95, D10, p. 16,851-16,864.
Ifft, G. N, 1922. “The Changing Arctic,” Monthly Weather Review, p. 589, November. https://journals.ametsoc.org/toc/mwre/50/11 [cf. e.g.,
Nobre, C. A., Sampaio, G., Borma, L.S., Castilla-Rubio, J.C., Silva, J.S., Cardoso, M., et al. 2016. “The Fate of the Amazon Forests: Land-use and Climate Change Risks and the Need of a Novel Sustainable Development Paradigm.” Proceedings of the National Academy of Sciences, U.S.A., 113 (39).
Sime, L.C, Wolff, E.W., Oliver, K.I.C.& Tindall, J.C., 2009. “Evidence for Warmer Interglacials in East Antarctica Ice Cores.” Nature, Vol.462, p.342-345 (19 November).
Translated by the staff of Pan-Amazon Synod Watch
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