BRASILIA: Deforestation in Brazil's rainforest has jumped around 67% in the first seven months of the year, according to preliminary data from Brazil's space research agency, which the government has attacked as misleading and harmful to the national interest.

The National Institute for Space Research (INPE) monitoring system registered destruction of 4,699 square kilometres (1,814 square miles) this year compared to 2,810 square kilometres in the previous period monitored, data on the agency's website showed.

In July alone, 2,255 square kilometres of Amazon forest were lost, more than triple July 2018's 597 square kilometres, according to INPE. That is the largest monthly deforestation registered by the agency in years and nearly the landmass of Luxembourg.

The Amazon is the world's largest tropical rainforest, a bulwark against global warming often called the "lungs of the earth" because of the vast amounts of carbon dioxide it soaks up and recycles into oxygen.

Brazil contains roughly 60% of the rainforest.

Environmentalists and researchers blame President Jair Bolsonaro's rhetoric in favour of economic development in the Amazon for emboldening loggers, ranchers and informal miners since he assumed office in January.

Bolsonaro has vehemently criticized the data from INPE and fired the head of the agency on Friday over what he called "lies" that hurt the country's trade talks.

"News like this that does not match the truth causes great damage to the image of Brazil," Bolsonaro said in a press conference last week.

The country's space research agency, independent scientists and environmentalists, however, have all defended the data as accurate. Fired INPE director Ricardo Galvao told Reuters on Saturday that he continued to defend the figures as showing an "undeniable" spike in deforestation.

A retired Air Force colonel, Darcton Policarpo Damiao, will head the agency, for now, the government said on Monday. Damiao has a doctorate in sustainable development and his thesis was on deforestation in the Amazon, according to the announcement.

Due to cloud cover and other factors, deforestation registered in a certain month may have happened in a prior month, Environment Minister Ricardo Salles said last week. At a news conference with Bolsonaro, the minister suggested that discrepancies of that kind made it impossible to trust the data.

Salles said deforestation should only be measured with more exact annual figures, published in the so-called PRODES data series, instead of the rapid-response DETER data, which is updated almost daily.

Yet comparing longer periods of time - the first seven months of the year, for example - virtually eliminates concerns over when the deforestation actually took place, according to Tasso Azevedo, coordinator of geographic initiative MapBiomas.

MapBiomas is a collaboration between universities, non-profit groups and technology companies to monitor deforestation, drawing from several different sources including INPE data.

Tasso called the government criticism of the DETER data baseless, estimating its accuracy at more than 90%.

Sharp rises in the rapid-response data have consistently corresponded with an increase in the year-end figure, he added.

In fact, the annual PRODES figures have always shown even worse deforestation than detected by the faster DETER data over the past decade.

"Why does (Salles) spend so much time trying to say that the alerts happened earlier or later when he could use the same time to take some action," Azevedo said. "Instead of indicating what they're doing to reduce deforestation, they're criticizing the deforestation data."