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Nations will reaffirm their commitment to reducing greenhouse gas (GHG) emissions during the 26th United Nations Climate Change Conference (COP26; www.ukcop26.org), in Glasgow, Scotland, in November 2021. Revision of the national commitments will play a key role in defining the future of Earth’s climate. In past conferences, the main target of Amazonian nations was to reduce emissions resulting from land-use change and land management by committing to decrease deforestation rates, a well-known and efficient strategy1,2. However, human-induced forest degradation caused by fires, selective logging, and edge effects can also result in large carbon dioxide (CO2) emissions1,2,3,4,5, which are not yet explicitly reported by Amazonian countries. Despite its considerable impact, forest degradation has been largely overlooked in previous policy discussions5. It is vital that forest degradation is considered in the upcoming COP26 discussions and incorporated into future commitments to reduce GHG emissions.

There is a growing interest in Amazonian fires, accompanied by a substantial increase in research in the subject. Here, we list five common misunderstandings about Amazonian climate, vegetation, fires and the deforestation process to help to support future research.

Carbon (C) emissions from forest fires in the Amazon during extreme droughts may correspond to more than half of the global emissions resulting from land cover changes. Despite their relevant contribution, forest fire-related C emissions are not directly accounted for within national-level inventories or carbon budgets. A fundamental condition for quantifying these emissions is to have a reliable estimation of the extent and location of land cover types affected by fires. Here, we evaluated the relative performance of four burned area products (TREES, MCD64A1 c6, GABAM, and Fire_cci v5.0), contrasting their estimates of total burned area, and their influence on the fire-related C emissions in the Amazon biome for the year 2015. In addition, we distinguished the burned areas occurring in forests from non-forest areas. The four products presented great divergence in the total burned area and, consequently, total related C emissions. Globally, the TREES product detected the largest amount of burned area (35,559 km2), and consequently it presented the largest estimate of committed carbon emission (45 Tg), followed by MCD64A1, with only 3% less burned area detected, GABAM (28,193 km2) and Fire_cci (14,924 km2). The use of Fire_cci may result in an underestimation of 29.54 ± 3.36 Tg of C emissions in relation to the TREES product. The same pattern was found for non-forest areas. Considering only forest burned areas, GABAM was the product that detected the largest area (8994 km2), followed by TREES (7985 km2), MCD64A1 (7181 km2) and Fire_cci (1745 km2). Regionally, Fire_cci detected 98% less burned area in Acre state in southwest Amazonia than TREES, and approximately 160 times less burned area in forests than GABAM. Thus, we show that global products used interchangeably on a regional scale could significantly underestimate the impacts caused by fire and, consequently, their related carbon emissions.

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Fire is one of the main anthropogenic drivers that threatens the Amazon. Despite the clear link between rainfall and fire, the spatial and temporal relationship between these variables is still poorly understood in the Amazon. Here, we stratified the Amazon basin according to the dry season onset/end and investigated its relationship with the spatio-temporal variation of fire. We used monthly time series of active fires from 2003 to 2019 to characterize the fire dynamics throughout the year and to identify the fire peak months. More than 50% (32 246) of the annual mean active fires occurred in the peak month. In 52% of the cells, the peaks occurred between August–September and in 48% between October–March, showing well-defined seasonal patterns related to spatio-temporal variation of the dry season. Fire peaks occurred in the last two months of the dry season in 67% of the cells and in 20% in the first month of the rainy season. The shorter the dry season, the more concentrated was the occurrence of active fires in the peak month, with a predominance above 70% in cells with a dry season between one and three months. We defined a Critical Fire Period by identifying the consecutive months that concentrated at least 80% of active fires in the year. This period included two to three months between January and March in the northwest, and in the far north it lasted up to seven months, ending in March–April. In the south, it varied between two and three months, starting in August. In the northeast, it was three to four months, between August and December. By quantifying the role of the dry season in driving fire seasonality across the Amazon basin, we provide recommendations to monitor fire dynamics that can support decision makers in management policies and measures to avoid environmentally or socially harmful fires.

We acessed the efficacy of stirring (ST), high shear dispersion (HSD) and low (LPH) and high (HPH) pressure homogenization to improves the stability of fresh or frozen/ thawed sheep milk (whole and skimmed). After each process, milk samples were evaluated for color, buffering capacity, soluble calcium, pH, particle size distribution and near infrared backscaterring. From the results obtained, we observed that freezing changed the buffering capacity and particle size distribution of whole milk and the buffering capacity, sedimentation and soluble calcium in skimmed one. The physical processes caused changes in milk (mainly in the whole one) and most of them (except HSD) was able to reduced, at least partially, the defects caused by the freezing of the milk, improving the product stability. In addition, the HPH and LPH also improved the stability of fresh milk. In respect to their effectiveness, the processes can be ordered as HPH> LHP> ST. Although less effective, the ST can be an interesting alternative to process previously frozen sheep milk, since it is a cheap, simple and easy to operate technology.

Adequate use of whey from sheep's milk cheese in smallholdings is a challenge. The possibility of producing a fermented dairy product manufactured by mixing sheep milk and whey at different concentrations was evaluated. Results showed that fermentation time, gel strength, acid content and difference in colour were proportional to the milk content. Post acidification was observed for almost all the samples for 35 days and resulted in a similar pH drop for the samples, but with different amounts of acid. The gels with 100% and 75%-milk samples remained stable during storage, while a slight (∼11%) or excessive (47%) whey separation was observed for gels with 30% and 15%-milk samples, respectively. In addition, good sensory acceptance was obtained for samples produced with ≥30% milk. Therefore, use of whey from sheep's milk cheese (≤70%) for fermented dairy product manufacture is an interesting use for this sheep cheese waste.

The impacts of stirring and homogenisation processes on the physicochemical and sensory characteristics of stirred yoghurt produced from fresh, refrigerated and frozen/thawed sheep milk were studied. Yoghurt from frozen/thawed milk was more sensitive to post acidification and had a higher Casson yield stress than yoghurt from fresh milk. The main differences caused by stirring and homogenisation were observed in NIR backscattering and in rheological parameters of yoghurt from refrigerated and frozen/thawed milk (Casson yield stress reduced and Casson consistency index increased). These modifications, however, were not able to improve the low scores of sensory evaluation of yoghurt from frozen/thawed milk, probably penalised by their worst textures. Results suggest that sheep milk cold preservation, mainly freezing/thawing, negatively affects the characteristics of yoghurt; although some improvements in physicochemical parameters are observed after stirring and homogenisation, these were not enough to avoid poor sensory evaluation of the samples.

The impact of stirring and homogenization on set yogurt production was assessed for fresh, refrigerated (4 days/7 °C) and frozen/thawed (1 month/-18 °C) sheep milk. Results showed that cold storage increased the fermentation time (>90min) and that yogurt from frozen/thawed milk was more sensitive to post acidification (50% higher pH drop) and had less firmness and adhesiveness (~25% lower). Stirring and homogenization changed the milk structure, reducing the natural creaming occurrence in the first hours of fermentation (10–100%) and increasing the yogurt textural parameters. The overall evaluation of the physical processes made before the milk was fermented showed modifications that were greater for refrigerated and frozen/thawed milk than for fresh milk. After 28 days of storage from production, all yogurt samples showed no additional syneresis, no reduction in the lactic acid bacteria counts and an increase in the adhesiveness and firmness. Therefore, results suggest that both milk refrigeration and freezing alters yogurt fermentation time, buffering capacity and texture, and that stirring and homogenization improved the yogurt texture of all samples due to higher interactions of fat and proteins. This information is useful for sheep milk producers to improve the quality of the yogurt produced, especially when it is obtained from previously cold-stored milk.

We assessed the impact of stirring (ST), high shear dispersing (HSD) and low (LPH, 3.5 MPa) and high pressure homogenization (HPH, 50 MPa) on physicochemical and structural characteristics of whole and skimmed sheep milk fresh or previously frozen and thawed (FT). Freezing affected the size of the fat globules, their interaction with caseins, reduced calcium solubility (10%) and buffering capacity (5–11%). Amongst the studied processes, HSD was the only one unable to improve the milk stability. The other ones reduced the size of the fat globules and increased fat and casein interactions, favoring milk stability and reducing the creaming occurrence (>22%). LPH and HPH also reduced the sedimentation in skimmed milk (>37%). Moreover, all processes recovered the buffering capacity of FT samples. The effectiveness of the processes can be ordered as ST Practical application Sheep milk is normally not homogenized because it has a lower fat globule size than cow milk, which reduces the creaming occurrence. However, creaming happens in some instances and it can be intensified if the milk is preserved frozen (to accumulate enough volume) prior to the dairy production, causing defects in the final products (mainly yogurts). The studied physical processes can be strategically used to solve this problem, increasing the milk emulsion stability, reducing the sedimentation occurrence and changing the buffering capacity to reach the same value of fresh milk.