CAIO SILVESTRE DE CARVALHO CORREIA

CAIO SILVESTRE DE CARVALHO CORREIA

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Increased Amazon carbon emissions mainly from decline in law enforcement
2023 - GATTI, LUCIANA V.; CUNHA, CAMILLA L.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; MESSIAS, CASSIANO G.; ARAI, EGIDIO; DENNING, SCOTT A.; SOLER, LUCIANA S.; ALMEIDA, CLAUDIO; SETZER, ALBERTO; DOMINGUES, LUCAS G.; BASSO, LUANA S.; MILLER, JOHN B.; GLOOR, MANUEL; CORREIA, CAIO S.C.; TEJADA, GRACIELA; NEVES, RAIANE A.L.; RAJÃO, RAONI; NUNES, FELIPE; S.FILHO, BRITALDO S.; SCHMITT, JAIR; NOBRE, CARLOS; CORRÊA, SERGIO M.; SANCHES, ALBER H.; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA; VON RANDOW, CELSO; CRISPIM, STEPHANE P.; SILVA, FRANCINE M.; MACHADO, GUILHERME B.M.
The Amazon forest carbon sink is declining, mainly as a result of land-use and climate change1–4. Here we investigate how changes in law enforcement of environmental protection policies may have affected the Amazonian carbon balance between 2010 and 2018 compared with 2019 and 2020, based on atmospheric CO2 vertical profiles5,6, deforestation7 and fire data8, as well as infraction notices related to illegal deforestation9. We estimate that Amazonia carbon emissions increased from a mean of 0.24 ± 0.08 PgC year−1 in 2010–2018 to 0.44 ± 0.10 PgC year−1 in 2019 and 0.52 ± 0.10 PgC year−1 in 2020 (± uncertainty). The observed increases in deforestation were 82% and 77% (94% accuracy) and burned area were 14% and 42% in 2019 and 2020 compared with the 2010–2018 mean, respectively. We find that the numbers of notifications of infractions against flora decreased by 30% and 54% and fines paid by 74% and 89% in 2019 and 2020, respectively. Carbon losses during 2019–2020 were comparable with those of the record warm El Niño (2015–2016) without an extreme drought event. Statistical tests show that the observed differences between the 2010– 2018 mean and 2019–2020 are unlikely to have arisen by chance. The changes in the carbon budget of Amazonia during 2019–2020 were mainly because of western Amazonia becoming a carbon source. Our results indicate that a decline in law enforcement led to increases in deforestation, biomass burning and forest degradation, which increased carbon emissions and enhanced drying and warming of the Amazon forests.
Sixteen years of MOPITT satellite data strongly constrain Amazon CO fire emissions
2022 - NAUS, STIJN; DOMINGUES, LUCAS G.; KROL, MAARTEN; LUIJKX, INGRID T.; GATTI, LUCIANA V.; MILLER, JOHN B.; GLOOR, EMANUEL; BASU, SOURISH; CORREIA, CAIO; KOREN, GERBRAND; WORDEN, HELEN M.; FLEMMING, JOHANNES; PETRON, GABRIELLE; PETERS, WOUTER
Despite the consensus on the overall downward trend in Amazon forest loss in the previous decade, estimates of yearly carbon emissions from deforestation still vary widely. Estimated carbon emissions are currently often based on data from local logging activity reports, changes in remotely sensed biomass, and remote detection of fire hotspots and burned area. Here, we use 16 years of satellite-derived carbon monoxide (CO) columns to constrain fire CO emissions from the Amazon Basin between 2003 and 2018. Through data assimilation, we produce 3 d average maps of fire CO emissions over the Amazon, which we verified to be consistent with a long-term monitoring programme of aircraft CO profiles over five sites in the Amazon. Our new product independently confirms a long-term decrease of 54% in deforestation-related CO emissions over the study period. Interannual variability is large, with known anomalously dry years showing a more than 4-fold increase in basin-wide fire emissions relative to wet years. At the level of individual Brazilian states, we find that both soil moisture anomalies and human ignitions determine fire activity, suggesting that future carbon release from fires depends on drought intensity as much as on continued forest protection. Our study shows that the atmospheric composition perspective on deforestation is a valuable additional monitoring instrument that complements existing bottom-up and remote sensing methods for land-use change. Extension of such a perspective to an operational framework is timely considering the observed increased fire intensity in the Amazon Basin between 2019 and 2021.
Avaliação da influência climática no balanço de N2O na Amazônia
2020 - CORREIA, CAIO S. de C.
O óxido nitroso (N2O) é o terceiro gás de efeito estufa natural mais importante no planeta Terra, suas emissões são provenientes, principalmente, da atividade bacteriana nos solos em processos de nitrificação e desnitrificação. Este estudo foi desenvolvido com o objetivo de elucidar a contribuição da Amazônia nas emissões de N2O nos anos de 2010 a 2018. A quantificação do N2O foi realizada por meio da coleta do ar atmosférico utilizando aviões de pequeno porte que descreveram um perfil vertical da superfície até 4,4 km de altitude, em quatro locais, posicionados de tal forma na Amazônia, que tornasse possível um estudo que a representasse regionalmente. As amostras são quantificadas em laboratório em um sistema de alta precisão e acurácia. O fluxo de N2O foi estimado utilizando-se o método de integração de coluna, que consiste na subtração da concentração deste gás no perfil vertical concentração de N2O nas massas de ar que entram no continente (BKG), considerando o tempo que as massas de ar levaram da costa brasileira até o local de coleta. Desenvolveu-se um novo método de determinação das BKG. Foi determinada a emissão de N2O pela queima de biomassa, utilizando a razão CO:N2O, determinada nos perfis amostrados que apresentaram comportamento de emissão de ambos os gases. Os fluxos foram comparados com parâmetros climatológicos e queima de biomassa para serem melhor interpretados. A região tem um comportamento emissor como um todo, lançando para a atmosfera 2,43 ± 0,88 TgN2O ano-1, em média neste período estudado. As fontes Biogênicas representam 81% da emissão total da Amazônia, apresentando uma emissão de 1,95± 0,75 TgN2O ano-1 e as emissões oriundas da queima de biomassa representam 19% da emissão total com 0,47±0,13 TgN2O ano-1.
Regional variability in Amazon methane emissions based on lower-troposphere observations
2022 - BASSO, LUANA; GATTI, LUCIANA; MARANI, LUCIANO; MILLER, JOHN; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE; TEJADA, GRACIELA; DOMINGUES, LUCAS; ARAI, EGIDIO; SANCHEZ, ALBER; CORREA, SERGIO; ANDERSON, LIANA; ARAGAO, LUIZ; CORREIA, CAIO; CRISPIM, STEPHANIE; NEVES, RAIANE
After a period where atmospheric methane (CH4) levels were nearly steady, its levels have been rapidly raising since 2007, but the main reasons remains uncertain. Increases in wetlands emissions could be one possible reason, mainly at tropical regions like Amazonia, which host some of the largest wetlands/seasonally flooded areas on the globe. Based on 590 lower troposphere vertical profiles of CH4 and carbon monoxide (CO) observations over four sites at Amazon (at the northeast, southeast, northwest-central and southwest-central regions) we estimated that Amazon region contributes with 8% of global CH4 emissions, and wetlands are the mainly CH4 source to the atmosphere (Basso et al., 2021). Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 and 2018. We observed an unexpected east-west gradient in CH4 emissions, with higher emissions in northeast Amazon region. The higher emissions are mainly from wetlands and are not explained by biomass burning and anthropogenic emissions (like enteric fermentation), but its causes remains unclear. In the other three sites located further downwind along the main air-stream the CH4 emissions represents approximately 24-36% of what is observed in the northeast region. Our wetlands emission estimates of each region were compared to analogous fluxes from the WetCharts wetland model ensemble (Bloom et al., 2017). The estimates were similar except for the northeast region, where WetCharts does show substantial emissions, but still just 40% of our estimates based on the lower troposphere observations (Basso et al., 2021).
Amazon methane budget derived from multi-year airborne observations highlights regional variations in emissions
2021 - BASSO, LUANA S.; MARANI, LUCIANO; GATTI, LUCIANA V.; MILLER, JOHN B.; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; DOMINGUES, LUCAS G.; ARAI, EGIDIO; SANCHEZ, ALBER H.; CORREA, SERGIO M.; ANDERSON, LIANA; ARAGAO, LUIZ E.O.C.; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.
Atmospheric methane concentrations were nearly constant between 1999 and 2006, but have been rising since by an average of ~8 ppb per year. Increases in wetland emissions, the largest natural global methane source, may be partly responsible for this rise. The scarcity of in situ atmospheric methane observations in tropical regions may be one source of large disparities between top-down and bottom-up estimates. Here we present 590 lower-troposphere vertical profiles of methane concentration from four sites across Amazonia between 2010 and 2018. We find that Amazonia emits 46.2 ± 10.3 Tg of methane per year (~8% of global emissions) with no temporal trend. Based on carbon monoxide, 17% of the sources are from biomass burning with the remainder (83%) attributable mainly to wetlands. Northwest-central Amazon emissions are nearly aseasonal, consistent with weak precipitation seasonality, while southern emissions are strongly seasonal linked to soil water seasonality. We also find a distinct east-west contrast with large fluxes in the northeast, the cause of which is currently unclear.
Amazonia as a carbon source linked to deforestation and climate change
2021 - GATTI, LUCIANA V.; BASSO, LUANA S.; MILLER, JOHN B.; GLOOR, MANUEL; DOMINGUES, LUCAS G.; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; ARAGAO, LUIZ E.O.C.; NOBRE, CARLOS; PETERS, WOUTER; MARANI, LUCIANO; ARAI, EGIDIO; SANCHES, ALBER H.; CORREA, SERGIO M.; ANDERSON, LIANA; VON RANDOW, CELSO; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.
Amazonia hosts the Earth’s largest tropical forests and has been shown to be an important carbon sink over recent decades. This carbon sink seems to be in decline, however, as a result of factors such as deforestation and climate change. Here we investigate Amazonia’s carbon budget and the main drivers responsible for its change into a carbon source. We performed 590 aircraft vertical profiling measurements of lower-tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in Amazonia from 2010 to 2018. We find that total carbon emissions are greater in eastern Amazonia than in the western part, mostly as a result of spatial differences in carbon-monoxide-derived fire emissions. Southeastern Amazonia, in particular, acts as a net carbon source (total carbon flux minus fire emissions) to the atmosphere. Over the past 40 years, eastern Amazonia has been subjected to more deforestation, warming and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends. We explore the effect of climate change and deforestation trends on carbon emissions at our study sites, and find that the intensification of the dry season and an increase in deforestation seem to promote ecosystem stress, increase in fire occurrence, and higher carbon emissions in the eastern Amazon. This is in line with recent studies that indicate an increase in tree mortality and a reduction in photosynthesis as a result of climatic changes across Amazonia.
Sensitivity of Amazon Carbon Balance to climate and human-driven changes in Amazon
2019 - GATTI, LUCIANA V.; DOMINGUES, LUCAS G.; BASSO, LUANA S.; MILLER, JOHN B.; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO S. de C.; TEJADA, GRACIELA; ARAGAO, LUIZ E.O.C.; ANDERSON, LIANA O.; GLOOR, MANUEL; PETERS, WOUTER; VON RANDOW, CELSO; NEVES, RAIANE A.L.; IPIA, ALBER; CRISPIM, STEPHANE P.; ARAI, EGIDIO
Amazon is the major tropical land region, with critical processes, such as the carbon cycle, not yet fully understood. Only very few long-term greenhouse gas measurements is available in the tropics. The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest carbon pool in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important because the stability of carbon in forests and soils can be disrupted in short time-scales. The main processes releasing C to the atmosphere are deforestation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate. In the last 40 years, Amazon mean temperature increased by 1.1ºC. The length of the dry season is also increasing. We observed a reduction of 50.5mm in the annual mean precipitation during this same 40 years period. Precipitation reduction occurred mainly in the dry season, exacerbating vegetation water stress with consequences for the carbon balance. To understand the consequences of climate and human-driven changes on the C budget of Amazonia, we put in place the first program with regional representativeness, from 2010 onwards, aiming to quantify greenhouse gases based on extensive collection of vertical profiles of CO2 and CO. Regular vertical profiles from the ground up to 4.5 km height were performed at four sites along the main air-stream over the Amazon. Here we will report what these new data tell us about the greenhouse gas balance and its controls during the 2010-2017. Along this period we performed 513 vertical profiles over four strategic regions that represent fluxes over the entire Amazon region. The observed variability of carbon fluxes during these 8 years is correlated with climate variability (Temperature, precipitation, GRACE) and human-driven changes (Biomass Burning). The correlations were performed inside each influenced area for each studied site. It was observed a persistent C source from the Amazon (natural plus anthropogenic sources) to the atmosphere. Amazon was a consistent source of 0.4 ± 0.2 PgC/year on average considering the Amazon area of 7.2 million km2. Fire emission is the main source of carbon to the atmosphere, which is not compensate by the C removal from old-growth Amazon forest.
Land use and cover change and CO2 atmospheric measurements in the Amazon forests
2019 - TEJADA, GRACIELA; GATTI, LUCIANA V.; BASSO, LUANA S.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; DOMINGUES, LUCAS G.; IPIA, ALBER; CORREIA, CAIO S. de C.; ARAI, EGIDIO; GLOOR, EMANUEL U.; MILLER, JOHN B.; VON RANDOW, CELSO
In the last years, global CO2 concentrations have reach levels never seen before reaching more than 400 ppm. Among the main causes of these emissions are the burning of fossil fuels and the land use and cover change (LUCC) related emissions. In the Amazon region, the main CO2 emissions are related to deforestation. Multitemporal LUCC datasets have been restrict to Brazil, but now has been released a pan-Amazon dataset for all the countries sharing the Amazon, opening the possibility of studying the Amazon forests as a whole. On the other hand, the lower-troposphere greenhouse gas (GHG) monitoring program “Carbam project”, has been collecting biweekly GHGs vertical profiles in four sites of the Amazon since 2010, filling a very important gap in regional GHGs measurements. Our purpose is to understand the relationships between regional LUCC and CO2 aircraft measurements in the Amazon. Here we present the relationships between annual LUCC data from 2010 to 2017 in the Amazon forest and in each mean influence area of Carbam sites comparing them with mean annual CO2 fluxes. Considering the whole Amazon forests and the mean annual CO2 fluxes, the years with more forest loss and agriculture increase are 2010 and 2016, showing relation with CO2 fluxes. On the other hand, 2011 and 2017 also have deforestation (less than 2010 and 2016), but the CO2 fluxes are lower, showing that droughts could also influence the CO2 concentrations. Looking at each influence area, total carbon flux of Alta Floresta and Rio Branco have the same tendency as the forest loss from 2013 to 2017, but no in 2010 and 2012. In Tabantinga, Tefé and Santarem there is no a direct relationship between the carbon fluxes and the forest loss. To understand better the relationships at each site, we have to consider the years of measurements. Also, the temporal scale, carbon fluxes are measure biweekly and the LUCC data is annual. Looking at the potentialities and limitations of this relationship, it will be possible to improve the methodology to better understand the interaction of human activities and CO2 emissions on the carbon balance.
Increasing of carbon emission from biomass burning due to the temperature rising and precipitation reduction in the Amazon
2019 - CASSOL, HENRIQUE L.G.; DOMINGUES, LUCAS G.; BASSO, LUANA S.; GATTI, LUCIANA V.; MARANI, LUCIANO; TEJADA, GRACIELA; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; CORREIA, CAIO S. de C.; ARAI, EGIDIO; GLOOR, MANUEL; MILLER, JOHN B.; ANDERSON, LIANA O.; ARAGAO, LUIZ E.O.C.
Recent droughts have increased the magnitude and frequency of the forest fires in the Amazon (Aragão et al. 2018). As a consequence, the Amazon has become a Carbon source due to the rising of the Carbon emission from biomass burned in the El Niño events. Faced with climate change and the likely acceleration of temperature in tropical regions, we hypothesize that Amazon will become a Carbon source even in non-droughts years, due to the increase of forest fires. Therefore, we compared 7 years of atmospheric profiles of CO2 obtained from aircraft overfly at four sites of the Amazon, since 2010, with temperature, precipitation, and fire counts (FC). Carbon emission from fires was obtained by the ratio of CO/CO2 and differs by site and year. The FC and climatic variables were extracted from quarterly influence areas by site and weighted by the amount of trajectories within a cell of one degree resolution. The fire emissions released by the Amazon is about 0.38 ± 0.086 Pg.C.yr-1, which represent roughly 17% of the annual global fires emissions (Werf et al. 2017). However, there are markedly divergences in the Fire emissions across Amazon. For instance, the emission from the Eastern is 400% higher and account of an average 60% more FC than observed in the Western. FC were positively and significantly correlated with Carbon from fires at all sites (ρ = 0.55-0.83, α = 0.05, p-value<0.001), being higher in the Southeastern of Amazon (Alta Floresta and Santarém sites), and lower in the Northwest of Amazon (Tefé site and Rio Branco Sites). This discrepancy may occur due to the Southeastern of Amazon be located inside the “Arc of deforestation” where the dynamic of the Land-Use Land-Cover Change is more pronounced. We also found a strong relationship between FC and temperature and precipitation (r² adj = 0.44-0.67, p-value<0.001). Temperature is positively correlated with FC and explains circa of 90% of their variability in the linear model (r² partial = 0.4-0.59, α = 0.05, p-value<0.001). It means that an increase of one degree (1°C) in the Amazon represents an increase of about 13600 fire counts; and the reduction of 100 mm precipitation means an increase of 315 in the fire counts. In the balance of the Fire emissions, it would add 1.27 Pg Pg.C.yr-1 at each degree celsius of increase and 0.2 Pg.C.yr-1 at each 100 mm of precipitation reduction.
Understanding the seasonality and interannual variability of Amazon CH4 budget and climate feedbacks based on atmospheric data from vertical profiles measurements
2019 - BASSO, LUANA S.; GATTI, LUCIANA V.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; DOMINGUES, LUCAS G.; CORREIA, CAIO S. de C.; IPIA, ALBER; ARAI, EGIDIO; ARAGAO, LUIZ E.O.C.; ANDERSON, LIANA O.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; GLOOR, MANUEL; MILLER, JOHN B.
Currently tropical land regions, like Amazon, are still poorly observed with large-scale integrating in-situ observations although they host some of the largest wetlands/seasonally flooded areas on the globe. The role of these regions in the global CH4 balance and the climate feedbacks have remained uncertain. To help this situation we have started a lower-troposphere greenhouse gas-monitoring program over tropical South America consisting of regular vertical profile greenhouse gas and carbon monoxide (CO) observations at four sites along the main airstream since 2010. Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and carbon monoxide analysis of flask air, fortnightly between 2010 to 2017. Over the full period the Amazon (total area of around 7.2 million km2) was a source of CH4, of approximately 46 ± 6 Tg/year, which represent 8% of the global CH4 flux to the atmosphere. CH4 emissions from different parts of the basin vary markedly. There are comparably high emissions from the eastern part of the basin exhibiting strong variability, with particularly high CH4 fluxes in the early part of the wet season (January to March). A second period of high emissions occurs during the dry season. The cause of the high emissions is unclear. In contrast to the eastern Amazon site a clear seasonality was observed at the other three sites located further downwind along the main sir-stream, with the largest emissions occurring at the beginning of the wet season (January to March). In addition, these data show an interannual variability in emissions magnitude, so we discuss how these data can be correlate to temperature, precipitation, terrestrial water storage anomalies (from GRACE) and Fire counts (human-driven changes) that could be influencing this variability. Using a CO/CH4 emission ratio calculated in this study we find a biomass burning contribution varying between 10 and 23% of the total flux at each site. Also, we discuss what the data tell us about possible ongoing feedbacks to possible changes in temperature, precipitation and biomass burning and indicating what variables can be contributing to CH4 emissions from Amazon.