THIS POST IS A CRITICAL REVIEW OF “Amazon Deforestation and Climate Change” J.Shukla, C. Nobre, P. Sellers, Science 16 Mar 1990: Vol. 247, Issue 4948, pp. 1322-1325
DOI: 10.1126/science.247.4948.1322, [LINK]  

RELATED POST ON AMAZONIA LUNGS OF THE EARTH:  [LINK]

PART-1: WHAT THE PAPER SAYS

1. ABSTRACT:  A coupled numerical model of the global atmosphere and biosphere has been used to assess the effects of Amazon deforestation on the regional and global climate. When the tropical forests in the model were replaced by degraded grass (pasture), there was a significant increase in surface temperature and a decrease in evapo-transpiration and precipitation over Amazonia. In the simulation, the length of the dry season also increased; such an increase could make re-establishment of the tropical forests after massive deforestation particularly difficult.
2. FULL TEXT:  The full text of this paper is available in pdf format at this site. Here is the download link for the full text: SHUKLA1990PDF  …. WARNING: clicking on this link will cause a large pdf file to be downloaded to your device.

PART-2: CRITICAL COMMENTARY

1. Since 1980, Amazonia has warmed at a steady rate of 0.0135C per year. No acceleration of the warming rate is evident in the data. Over the same period, land areas in the Southern Hemisphere warmed at a rate of 0.0171C per year with the highest decadal warming seen in decade ending in 1998 with a warming rate of 0.045C per year. 
2. For land in the Tropics, the overall warming rate is 0.0165C per year with the highest decadal warming rate of 0.08C per year seen for the same decade ending in 1998. The warming rate in Amazonia of 0.0135C per year does not seem high in this context. 
3. As for precipitation in Amazonia over this period, rainfall increased by 5% over this period but with three annual droughts in 2005, 2010, and 2015.
4. In a comparison of the temperature data for Amazonia with the Tropics and the Southern Hemisphere, the warming in Amazonia does not appear to be anomalous. The USAID precipitation data do not indicate a drying trend that risks drought conditions. Therefore there does not appear to be a climate impact of deforestation as claimed in the research paper presented above. 
5. The climate data for Brazil and Amazonia are provided by the USAID [LINK] . The source USAID document is also available at this site. Here is the link usaid . Warning….. clicking on this link will cause a large PDF file to be downloaded to your device. 
6. An additional consideration in the interpretation of Amazonia climate anomalies in terms of anthropogenic global warming (AGW) is that AGW is a theory about long term trends in global mean temperature and its interpretation in terms of data for short term weather events or for regional climate is not possible because in these cases, internal climate variability overrides AGW impacts and makes it impossible to interpret the data in terms of AGW. Details of the internal climate variability issue may be found in a related post on this site [LINK]  .
7. Yet another issue in the continued insistence of rich industrialized Western nations that Amazonia must remain a forest and Amazonians must remain a stone age people and that therefore they must not be allowed the same kind of economic and human welfare development enjoyed by the West, is cruel and racist. Details of this issue may be found in a related post [LINK]  where we note:   “That the Global North’s needs are often served at great cost to the Global South is seen in the effects of Rachel Carson’s {Silent Spring} that may or may not have saved some birds in the North but that need of the Global North came at great cost and suffering from the ban on DDT in the Global South. Similarly, the planet saving interpretation of AGW constructs the attitude of the Global North towards the primitive stone age forest dwellers of Amazonia in the Global South. It is claimed that the AGW anti-industrialization priority of the Global North must guide the future of the people of the Amazon forest such that they must remain primitive so that their lands can remain a forest and serve the needs of the Global North by continuing to be The Lungs of the Planet. That Europe was once a forest and the Lungs of the Planet that was cleared by the Europeans on the way to their wealth, power, and Industrial Economy must be considered to be a purely historical detail and irrelevant in terms of the urgency of climate action to Save the Planet from climate change by ensuring that the Amazon remains a stone age museum of forest dwellers so that The Lungs of the Planet are preserved. 

DECADAL WARMING RATES IN LAND AREAS OF THE SOUTHERN HEMISPHERE

DECADAL WARMING RATES IN LAND AREAS OF THE TROPICS

USAID CLIMATE CHART FOR BRAZIL