NASA: Amazon Wildfire Activity Slightly Below Average This Year
Short summary: We have had wildfires for many years now in the Amazon, even in the tropical rainforest – mainly started by humans for forest clearing and ranching.
It is not enough to impact significantly on the Paris agreement pledges yet, though it is important in the long term if this continues for decades.
This image is being shared even in usually reputable media with captions such as National Geographic’s “The Amazon is burning at record rates – and deforestation is to blame.” Similarly, the BBC is reporting it as a “record.”
But is it? You would not guess from these headlines that NASA’s description for the original photo says that it is burning at less than average rates.
Bit of a big difference there. The BBC did mention this but don’t even link to the NASA page to check and in only two throwaway sentences easy to miss.
Meanwhile, US space agency NASA said that overall fire activity in the Amazon basin was slightly below average this year. The agency said that while activity had increased in Amazonas and Rondonia, it had decreased in the states of Mato Grosso and Pará.
What they do not explain is that this Brazilian DETER data is not intended for fire counts or for deforestation analysis but just for a rapid response alert to regions that are burning.
UPDATE 23rd August: The whole thing has got very politicized, and the BBC have done a second article today that no longer mentions the NASA results at all.
Similarly, articles from other news sources don’t mention them either. Basically, the NASA fire count has disappeared from the news media as far as I can see.
Sometimes they do but just in a short one-line sentence, for instance at the end of this article:
US space agency NASA, meanwhile, has said that overall fire activity across the Amazon basin this year has been close to the average compared to the past 15 years.
The image they share shows smoke from fires in the Amazon region on 13th August 2019. These are not necessarily all forest fires. Some of these will be fires in natural savannah – or in a pasture to stimulate new growth for the cattle.
Here it is again with the original NASA caption:
So, go to the Global Fire Emissions Database. and this is what you see in the “Totals” section:
The green line for 2019 there is a bit hard to make out, so here is a zoom in, as you can see it is way below the top line which is for 2005, with only a few data points and is also below the 2003 line.
Before I go into what happened there I’d like to briefly touch on a few common misunderstandings and urban myths/outdated science that many believe about the Amazon rainforest. I’ll go into in more detail later on.
- Many of the fires you see in the photos are not forest fires, and not all forest fires are illegal deforestation
The ranchers use fire for forest clearing, “slash and burn agriculture” as it is called. That is because it is much easier to convert forest into grassland by burning it than to do it by felling the trees.
Once it is cut, the way they manage the pastures is to re-burn them every few years to clear out the brush and to get the grass to resprout.
So not all the fires you see are burning in a virgin tropical rainforest. Many are controlled grassland fires, to get the grass to resprout. We do something similar in the UK where they do a controlled burning of heather (Muir burn) for grouse, sheep, and deer.
It is illegal to start those fires in Brazil during the driest season because though it is the easiest time to burn the grassland the fires can get out of control too easily.
But they are not always started with the intention to burn down the tropical forest. It’s often just a mistake. The same happens for heather fires in the UK some of our forest fires are due to out of control heather fires.
You can read about how they manage the pastures in Brazil through burning here: Cattle Ranching in the Amazon Region.
- We do not risk losing the Amazon as a whole in any of the climate scenarios through to 2100
That is something they used to think a few years back, that at some future tipping point the entire forest would go, turning to drier savannah. However, that was based on simplifying assumptions that turned out to be misleading.
The research has moved on. A large part of the Amazon rainforest will remain through to 2100 even with high emissions, especially the Western Amazon forest.
This region survived the previous glacial minimum when it was warmer and will survive any anthropogenic warming through to 2100.
- The Amazon rainforest will not disappear rapidly once you get below 59% forest cover
This is based on widely misreported research about the fractal process of fragmentation of forests at 59% forest cover.
- We will not all suffocate if the Amazon rainforest is cut down
Many of the news reports talk about the Amazon rainforest being a major source of oxygen. Actually, most of it comes from the sea, phytoplankton. But we are not going to suffocate if we burn down forests.
This is an urban myth and science fiction trope used in dystopian futures – but it is not true at all.
We have plenty of oxygen in the atmosphere for thousands of years even if somehow magically all photosynthesis stopped producing oxygen and all the animals continued to use it.
- The burnt areas do not become desert and with global warming, the Amazon will not turn into a desert region
Rather, if there is a forest fire and it is not immediately followed up by ranching activity to convert it to pasture, the trees regrow quickly as lower mass drier forests.
Given enough time over many decades and perhaps centuries, these drier forests would restore to tropical rainforest again.
In a warmer world, some of them will turn to savannah with scattered trees, a habitat known as the Cerrada.
This is another article I’m writing to support people we help in the Facebook Doomsday Debunked group, that find us because they get scared, sometimes to the point of feeling suicidal about it, by such stories.
Do share this with your friends if you find it useful, as they may be panicking too.
SO WHAT HAPPENED – DO WE BELIEVE NASA OR INPE
Here INPE is the Brazilian National Institute for Space Research. They run a program called DETER that does rapid assessments of wildfires by satellite.
It needs to be validated using PRODES which is yearly and far more accurate. The DETER website says the data should not be relied on.
UNICEF reports that the data from satellite images show that Brazil lost 2,254 square kilometers (870 square miles) of forest in July, between three and five times the amount lost in the same month for each of the previous four years.
Bolsonaro questions those figures:
During a recent public appearance, Bolsonaro joked that if the “absurd” deforestation numbers were true, “then I am Captain Chainsaw!”
So what happened? Outside of Brazil, everyone is siding with the INPE. But – it turns out on this particular matter, it may be Bolsorano who is right!
The media reports should never have been leaked to the public without explaining that the science is not validated.
DETER can’t see through clouds. It is designed as a rapid alert system not a fire count system. It can count the same fire multiple times.
When it detects deforestation it has no way of knowing when it happened and may record it for one month when it actually happened years before but the area was covered by cloud and couldn’t be spotted earlier.
More details here (in Spanish)
They differ from the NASA results because they use different satellites and different analysis methods. I’ll describe how they work in a bit more detail in the next two sections.
HOW THE NASA FIRE COUNT WORKS
They are in polar orbits and Terra passes north-south over the equator in the morning, and Aqua in the afternoon. Between them, they view the entire surface of Earth every 1 to 2 days and acquire data in 36 spectral bands.
You can browse their active fire maps here, which detects fires in 1 km pixels that are burning during relatively cloud-free conditions.
The project to count the fires is based on a series of papers by Louis Giglio et al, funded by NASA, and two other organizations.
The methods used are explained in the introduction to their article:
Here, we present the Global Fire Atlas of individual fires based on a new methodology for identifying the location and timing of fire ignitions and estimating fire size and duration, and daily expansion, fire line length, speed, and direction of spread. The Global Fire Atlas is derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 (Col. 6) burned-area dataset (Giglio et al., 2018), which includes an estimated day-of-burn data layer at a 500 m resolution. Individual fire data were generated starting in 2003, when combined data from the Terra and Aqua satellites began to provide greater burn date certainty. The algorithm for the Global Fire Atlas tracks the daily progression of individual fires at a 500 m resolution to produce a set of metrics on individual fire behavior in standard raster and vector data formats. Together, these Global Fire Atlas data layers provide an unprecedented look at global fire behavior and changes in fire dynamics during 2003–2016.
From that paper, they use combined visual and infrared observations.
It works best with clear skies, with an uncertainty of one day either way, and as the cloud cover increases there is more and more uncertainty about when the fire started, 5 days either way if clouds cover 75% of the daily scenes and an uncertainty of 20 days or more if only 15% of scenes are cloud-free, and no mapping possible at all with higher cloud cover.
HOW THE INPE FIRE COUNT WORKS – DETER AND PRODES
The INPE used to use the Terra and Aqua satellites to estimate the fire count similarly to NASA, see NASA Satellite Data Used by INPE Provides Rapid Analysis of Amazon.
However, starting from 2015 they now use much higher resolution satellites, Sino-Brazilian Land Resources Satellite (CBERS-4) part of mutual scientific cooperation with China, the China-Brazil Earth Resources Satellite program and the Indian Remote Sensing Satellite (IRS).
These have a resolution of 64 and 56 meters respectively. The data is aggregated to a minimum size of 6.25 hectares for the general public
This is only meant as an alert system so that the authorities can respond quickly to fires in the region. It is not meant to be used in this way to estimate deforestation or fire counts. It’s just not intended for that.
DETER is a quick survey of evidence of changes in forest cover in the Amazon made by INPE. DETER was developed as an alert system to support the supervision and control of deforestation and forest degradation carried out by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) and other agencies related to this theme.
For this purpose we use images from the WFI [Wide field] sensors, from the Sino-Brazilian Land Resources Satellite (CBERS-4) and AWiFS [Advanced wide field sensors], from the Indian Remote Sensing Satellite (IRS), with 64 and 56 meters of spatial resolution respectively. Data are sent daily to the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) without restriction of the minimum mapped area, however, for the general public the polygons are available with a minimum size of 6.25 ha, thus allowing the establishment of a comparison criterion with the data generated by the PRODES project .
INPE emphasizes that DETER is an expedient Alert system developed methodologically to support enforcement. Information on areas is for prioritization by enforcement agencies and should not be construed as a monthly deforestation rate. The official INPE number to measure the annual rate of clearcut deforestation in the Brazilian Legal Amazon has been provided since 1988 by the PRODES project.
DETER (using Google auto translate).
The PRODES project is reliable, based on LANDSAT and other satellites comparing before and after images, and shows deforestation for 2018 of 7,536 square kilometers, similar to previous years. However, it won’t produce the figures for 2019 until next year.
It is possible that the DETER data is correct and the NASA data is mistaken. However, given that DETER is not even designed to do this job, it seems unlikely.
It seems best to wait until the PRODES update for 2019 and then see if the deforested area for 2019 is indeed larger than for 2018. It is far too soon to know, we just don’t have the scientific data to assess this yet.
POLITICIZATION OF SCIENCE
To my mind, this politicization of science is quite shocking. To take the INPE DETER observations which are known to be NOT reliable for this and released with a big warning and publishing their figures and not even mentioning the NASA figures.
This is clearly not done because of any concern about the science behind the NASA figures. It is just because the NASA ones don’t fit the political objective of getting Bolsorano to do something about deforestation.
This is especially clear when, e.g. the BBC, reporters show that they know about the NASA figures having published them with one or two line mentions in some of the articles.
Political leaders are all responding to this, apparently totally unaware that the NASA figures do not support the INPE ones. They are threatening to withdraw from the Mercosur-EU trade deal if he doesn’t do something about this.
European leaders have also expressed dismay over the fires, with UK Prime Minister Boris Johnson saying he is “deeply concerned” about “the impact of the tragic loss of these precious habitats”.
German Chancellor Angela Merkel has called the fire an “acute emergency… shocking and threatening not only for Brazil and the other affected countries but also for the whole world”.
It is great to see more pressure on Brazil to preserve the rainforests. Also, it’s good to see Bolsonaro responding to the pressure.
He is contemplating deploying the military to fight the fires. Since the fires are often started in order to do illegal deforestation, this could well reduce the levels of illegal deforestation if he does do this.
I am of course no fan of Boslorano and care deeply about the Amazon rainforest. I will be glad of the outcome if he fights the fires and acts to stop illegal deforestation. But I also care a lot for truth and I don’t like to see bad science being used for a “good” political objective.
Hopefully, [I] can do a bit to draw attention to it with my article.
Read rest at Science 2.0