# Fires Drive Long-Term Environmental Degradation in the Amazon Basin
## 4 Discussion
In particular, the fire foci in the Q1 and Q2 quarters occurred from January to June, a period during which natural fires do not occur in this type of vegetation as well as in the two months of drought equivalent to the period of August-October [92; 93]. The moderately negative Pearson correlations obtained between the SPI and emissions and those obtained between the SPI and fire foci (Figures S2 and S3) indicate that dry periods increase the likelihood of forest burning. High C emissions (989-504 Tg C year\({}^{-1}\)) occurred in the region in 2015 and were associated with extreme fire events. As shown in Figure S2, in 2015, a strong El Nino event occurred, which is consistent with the findings of [PERSON] et al. [94], [PERSON] et al. [95], and [PERSON] et al. [55]. Note that fire incidence is associated with SST anomalies, especially the warm phase of ENSO [21; 33; 55]. In recent decades, some studies have reported a high frequency of droughts and extreme rainfall in some Amazonian areas [38; 82; 86; 92; 96; 97]. Some periods of extreme drought in 1997 and 1998 were related to the occurrence of El Nino events [98], as well as the drought recorded in 2010, which was related to El Nino events from previous years [99]. [PERSON] et al. [100] found that drought severity had the greatest influence on the occurrence of fires. Changes in the duration of the dry season, increase in dry days and delayed onset of the dry season were observed in the southern Amazon and Bolivia [29; 86; 101], all of which have the potential to intensify fires conditions. These areas are largely coincident with the \"deforestation arc\", wherein the largest land use conversions have occurred [21; 87]. Brazil, which contains the largest portion of the Amazon Forest in its territory, set emission reduction targets as part of the Paris Agreement during the 21 st Conference of the Parties in 2015. Despite some initial success, deforestation rates have since increased, especially in 2019, which exhibited an increase of 43.93% (10,123.17 km\({}^{2}\)) compared with 2018 [102]. Although Bolivia also ratified the Paris Agreement, it burned the equivalent of 79.63% of its Amazon Basin area. These countries must adopt stricter policies to contain deforestation and fire foci in order to fulfill their Paris Agreement commitments. The results obtained were also similar for Bolivia, showing that rainfall in its region was not similar to that in other more forested basin areas (Figure S1). This also suggests that decreasing rainfall affects local climates via a feedback process, in which less forest area causes less rain and less rainfall leads to less forest area [40]. In addition, land use change in these areas causes landscape fragmentation by increasing the flammability of forests, which makes them more susceptible to fires than dense forests [94], and substantially alters the region's albedo, itself an important variable that controls climate processes [87]. Our results show that, currently, the incidence of fire foci is the largest threat to the Amazon landscape, already affected by various types of forest disturbance [103]. Between2001 and 2019, the total burned areas in the Amazon Basin corresponded to 23.78% of its total area. These fires not only affected forests in agricultural frontier areas (76.91%), but also those of ILs (17.16%) and CUs (5.93%), which are recognized as biodiversity conservation areas. Furthermore, nearly four-fifths (79.63%) of the Bolivian Amazon Basin area was affected by fire foci; the corresponding values for Guyana and Brazil were 29.58% and 20.77%, respectively. These values are compelling considering the fact that the Amazon rainforest has lost an estimated 20% of its vegetation cover in the last five centuries [104]. These findings demonstrate that fires have advanced beyond deforestation areas and invaded the areas employed as reserves in private properties, such as ILs and CUs, which should be safeguarding the Amazon's natural heritage [8].