Brazil’s Rainfall Remains Healthy: Susceptible to Natural Climatic Events, Not Anthropogenic Global Warming

by Vijay Jayaraj

Brazil has been in the midst of controversy for not acting on climate change. Greta Thunberg and other children have named Brazil as one of the five countries in a lawsuit for climate inaction. Brazil’s President Bolsonaro has also been under heavy fire for being skeptical towards the climate crisis movement.

The biggest news in recent times was the fires in the Amazon rainforest. 60 percent of the rainforest is situated within Brazil’s borders. Rainfall is an important component for the forests within Brazil’s borders and also for Brazil’s highly populated cities.

Proponents of Catastrophic Anthropogenic Global Warming (CAGW) insist that human greenhouse gas emissions have worsened climate change. Some of them say that the CAGW has caused an increase in extreme rainfall events like floods and droughts.

Here we shall take a look at the rainfall pattern in Brazil—both regional and national level—to determine if there are significant negative imprints of anthropogenic global warming and whether the CAGW proponents’ claims are true.

Just as with any big country, Brazil’s geography is diverse, and the rainfall patterns are different in different regions. Nevertheless, some studies analyze the national-level changes in rainfall.

Detailed research in 2014 tried analyzing the annual maximum daily rainfall trends in the Midwest, southeast, and southern Brazil for 71 years. It concluded that “there is a positive trend in the annual maximum daily rainfall data series.”

Figures: Decennial means and reference series for Midwest, Southeast, and South regions; Maximum daily rainfall for the Midwest, Southeast, and South regions
Figure Source:

A 2017 study on the “Historical analysis of interannual rainfall variability and trends in south-eastern Brazil” explained that the rainfall patterns have been largely influenced by weather phenomena in the Atlantic and Pacific oceans, not by CAGW.

Rainfall patterns were highly sensitive to the coupled impact of three major ocean-atmosphere climate variabilities: the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO).

For Southeast Brazil, the precipitation was below normal during the first cold AMO phase (1888–1930) and above normal throughout the second cold AMO phase (1964–1994). During the AMO warm phase, drought periods were extremely severe. Precipitation also seems to follow PDO index trends and El Nino years brought wetter years.

It has also been understood that the climatic changes in Northern Hemisphere such as the Little Ice Age (between approximately 1500 and 1850) and the Medieval Climate Anomaly (between 900 and 1100, also called the Medieval Warm Period), have had a influence on South American rainfall patterns, including Brazil.

The Amazon rainforest (including the 40 percent outside Brazil) has displayed a similar ENSO-influenced positive rainfall trend.

The World Bank’s climate knowledge portal says the Amazon experienced a 5 percent increase in rainfall over the past three decades, and the three most recent droughts (2005, 2010, 2015/16) were due to ENSO weather phenomenon, not CAGW.

A 2010 research report published in the Geophysical Research Letters measured the change in greenness of the Amazon using NASA MODIS satellite data. The study explicitly stated that “Amazon rain forests were remarkably unaffected in the face of once-in-a-century drought in 2005, neither dying nor thriving, contrary to a previously published report and claims by the Intergovernmental Panel on Climate Change.”

A newer study in 2015 analyzed the seasonal rainfall variations in the Northern Amazon between 1979 and 2011 and concluded that there has been a significant increase in rainfall over the Northern Amazon region.

Conclusion: It is very evident that the rainfall patterns over Brazil and the entire Amazon are sensitive to the changes in weather patterns over the ocean. However, the rainfall patterns have not been significantly disrupted or impacted by the supposed CAGW in recent decades. All major droughts in the past two decades were due to periodic ENSO weather patterns, and there has been an overall increase in Amazon rainfall levels.

Vijay Jayaraj (M.Sc., Environmental Science, University of East Anglia, England), Research Contributor for the Cornwall Alliance for the Stewardship of Creation.

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Tony Garcia
October 9, 2019 10:43 pm

A 2017 study on Amazon rainfall , “A rainforest-initiated wet season onset over the southern Amazon.” Wright is the first author. Besides Fu and Worden, additional coauthors are from Google Inc., Mountain View, California; the Dynamic Meteorology Laboratory (LMD), Paris, France; and the University of Texas at Austin, article found here:, appears to link a large part of the Amazon’s rainfall to evapotranspiration from it’s trees. If the number of trees is reduced, it remains to be seen how this effect is affected, and the results may only be noticeable over a period of time; I would therefore expect that it is too soon to analyse the climactic effect, if any, that the recent Amazon fires may have had……..

Reply to  Tony Garcia
October 9, 2019 11:08 pm

That research you mention takes a “might” theory;

“Scientist Rong Fu of UCLA, a leader of the new research efforts, published a paper in 2004 suggesting that increased evaporation of water from leaves — a process known as transpiration — might be the cause.”

Adds in gross assumptions without verifications to proclaim a possibility into firm conclusions…
They are no stronger than the original “might”.

“the plant sucks water out of the ground like a straw, no matter which isotope the water contains. That means water vapor transpired from plants has more deuterium than water vapor evaporated from the ocean.”

All without on the ground verification.

Nor does it explain how Brazil’s arid regions grow substantial plant/forest populations that depend upon rising mists for their water source. All from humidity laden breezes off the ocean.

The theory as stated by Fu ignores general wind directions and speeds while suggesting that rainfall occurs in very localized spots dependent upon plant transpiration.

The theory that rainfall matching isotope transpiration ignores the fact that transpiration depends upon isotope evaporation; coupled with rainfall provides the initial groundwater and the basic isotope imbalances. Of course it matches, not because the rainforest causes the rain; but because the rainfall provides the isotope imbalance.

Also ignored are the Andes mountains that form Brazil’s western border and strip the normal winds at all seasons of their water content. keeping a large portion of that water within Brazil.

Reply to  ATheoK
October 10, 2019 5:58 am

Increased atmospheric CO2 means LESS water lost by transpiration. Plants are more water-efficient with more CO2.

October 9, 2019 11:45 pm

Greta Thunberg and other children have named Brazil as one of the five countries in a lawsuit for climate inaction.

It is not a “lawsuit”. Go check you facts and try again.

Ferd III
Reply to  Greg
October 10, 2019 12:38 am


“The lawsuit does not seek monetary damages. If the suit is upheld, the UN would be forced to classify the climate change crisis as a human rights crisis.”

The whole point is to cry about the children’s future and make globaloneyclimatewhatevering a human rights principle, punished under human rights ‘laws’.

Jeff Alberts
Reply to  Ferd III
October 10, 2019 6:45 am

And, if you fight it, you’re evil. Because children.

Crispin in Waterloo but really in Beijing
Reply to  Ferd III
October 10, 2019 7:24 am

Human rights are not the result of laws but declarations. A declaration of rights is supposed to be turned into law by each country. Same as a ca bron-free economy.

The reason is jurisdictional. The UN has no actual power. The International Criminal Court does, as far as member countries are concerned. That is the enforcer of “human rights violations”. I don’t see how children can make a case in that court for something that hasn’t happened yet.

October 9, 2019 11:55 pm

Vijay Jayaraj (M.Sc., Environmental Science, University of East Anglia, England)

Amazing. A heretic from the heart of ClimateGate scandal. I can only assume he got his MSc before he realised it was all bogus science.

Thanks for the heads up on the rainfall, not something I’d ever looked into.

Reply to  Greg
October 10, 2019 1:01 am

More likely Vijay’s MSc allowed him to realise how bogus science is now being promoted as reputable science. Thirty years ago climate history was all about natural variability, now unmentionable in woke science circles.

Michael Jankowski
Reply to  Greg
October 10, 2019 10:05 am

Environmental Science is not limited to climate crock.

October 10, 2019 1:12 am

This is an interesting statement:

Brazil’s President Bolsonaro has also been under heavy fire for being skeptical towards the climate crisis movement.

So, does a lawsuit, or any other means of alarmist persuasion, suddenly convert the President into a climate alarmist rather than a sceptic, or does it simply force him to change his political stance on the subject?

I suspect President Bolsonaro’s position really is “I’ll do the best I can for my country and right now that does not mean impoverishing them further to satisfy the political agenda of the wealthy elite”.

Once a sceptic, always a sceptic I guess.

Gerry, England
Reply to  HotScot
October 10, 2019 5:56 am

I am not aware of anyone converting to warmism if they have been sceptical. Going the other way, there are a number of scientists who have done so, usually after actually reading an IPCC report and finding they have been lied to.

Reply to  Gerry, England
October 10, 2019 7:53 am

There have been a couple who have made that claim.
The guy who ran the BEST study for one.
However an examination of his statements prior to his conversion show that he was never a skeptic.

Reply to  HotScot
October 10, 2019 7:56 am

You are absolutely right, except that Bolsonaro’s position really is “I’ll do the best I can for the wealthy elite of my country and right now that does mean impoverishing the working poor of all the big cities and the indigenous populations of the Amazon region and the peasants and workers of the big agro-industrial conglomerates…» And he has been under heavy fire, basically, because of the fraudulent way in which he was elected. As far a the Amzon area is concerned, the overall policies of Lula da Silva were basically the same.
Having said said I want to be clear: On the issues of CAGW I am very much a skeptic.

Reply to  Fonseca-Statter
October 10, 2019 8:09 am


Frankly, I don’t give a monkeys about how Bolsonaro runs the country, and the rest of the world should keep their fat noses out his business.

There’s far too much interference from countries who ‘know best’ how to run another country, and I think Donald Trump is with me on this one.

Mark Broderick
October 10, 2019 1:19 am

“The Stunning Statistical Fraud Behind The Global Warming Scare”