Thousands of fires are ravaging the Amazon rainforest in Brazil - the most intense blazes for almost a decade.
The northern states of Roraima, Acre, Rondônia and Amazonas have been particularly badly affected.
Huge fires have also been burning across the border in Bolivia, devastating swaths of the country's tropical forest and savannah.
So what's happening exactly and how bad are the fires
There have been a lot of fires this year
Brazil - home to more than half the Amazon rainforest - has seen a high number of fires in 2019, Brazilian space agency data suggests.
The National Institute for Space Research (Inpe) says its satellite data shows an 76% increase on the same period in 2018.
Activists say the anti-environment rhetoric of Brazilian President Jair Bolsonaro has encouraged such tree-clearing activities since he came into power in January.
In response to criticism at home and abroad, Mr Bolsonaro announced he was banning setting fires to clear land for 60 days.
The president has also accepted an offer of four planes to fight the fires from the Chilean government and has deployed 44,000 soldiers to seven states to combat the fires.
However, he has refused a G7 offer of $22m (£18m) following a dispute with French President Emmanuel Macron.
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The north of Brazil has been badly affected
Most of the worst-affected regions are in the north of the country.
Roraima, Acre, Rondônia and Amazonas all saw a large percentage increase in fires when compared with the average across the last four years (2015-2018).
Deliberate deforestation
The recent increase in the number of fires in the Amazon is directly related to intentional deforestation and not the result of an extremely dry season, according to the Amazon Environmental Research Institute (Ipam).
Ipam's director Ane Alencar said fires were often used as a way of clearing land for cattle ranches after deforesting operations.
They cut the trees, leave the wood to dry and later put fire to it, so that the ashes can fertilise the soil," she told the Mongabay website.
While the exact scale of deforestation in the rainforest will only be certain when 2019 figures are published at the end of the year, preliminary data suggests there has been a significant rise already this year.
Monthly data shows the scale of the areas cleared has been creeping up since January, but with a spike in July this year - almost 278% higher than in July 2018, according to Inpe.
Inpe tracks suspected deforestation in real-time using satellite data, sending out alerts to flag areas that may have been cleared.
More than 10,000 alerts were sent out in July alone.
The record number of fires also coincides with a sharp drop in fines being handed out for environmental violations, BBC analysis has found.
The fires are emitting large amounts of smoke and carbon
Plumes of smoke from the fires have spread across the Amazon region and beyond.
According to the Copernicus Atmosphere Monitoring Service (Cams), a part of the European Union's Earth observation programme, the smoke has been travelling as far as the Atlantic coast.
The fires have been releasing a large amount of carbon dioxide, the equivalent of 228 megatonnes so far this year, according to Cams, the highest since 2010.
They are also emitting carbon monoxide - a gas released when wood is burned and does not have much access to oxygen.
Maps from Cams show this carbon monoxide - a pollutant that is toxic at high levels - being carried beyond South America's coastlines.