BRASILIA, Aug 13 (Reuters) - Deforestation in Brazil"s Amazon rainforest fell 10% in July from a year earlier, after four straight monthly increases, preliminary data showed on Friday, but destruction remains far higher than before President Jair Bolsonaro took office. Cleared forest in the month of July totaled 1,498 square km (578 square miles), nearly twice the size of New York City, according to government space research agency INPE. From January to July, deforestation in the Amazon was up 7.8% from a year ago to 5,108 square kilometers, INPE data showed. Last year, deforestation hit a 12-year high under far-right President Bolsonaro, who has weakened environmental enforcement and called for mining and commercial farming in protected areas of the rainforest. In June, Bolsonaro again dispatched the military to protect the forest, repeating an intermittent strategy that has failed to reduce destruction to levels seen before he took office in 2019. Bolsonaro"s office did not immediately respond to a request for comment on the latest deforestation data. The latest INPE figures cap the period for Brazil"s official annual deforestation records, measured from August 2020 to July 2021 to minimize interference from cloud cover. For the 12 months through July, the preliminary data shows a 4.6% decrease in deforestation. Scientists say a decrease in the preliminary numbers generally means there will be a decrease in the final, more accurate measure known as PRODES. Vice President Hamilton Mourao, who leads the government"s Amazon policy, said last week that the figures are now headed in the right direction. "The cycle ended on July 31 ... I think it will be in the range of 4% to 5%, a very small reduction, very inadequate, but it"s on track," Mourao told reporters. But researchers say the destruction is still far higher than before Bolsonaro took office and a single-digit decrease does little to change the vast environmental impact. The Amazon is considered a vital bulwark against climate change and its destruction is the top source of Brazil"s greenhouse gas emissions. "It"s too early to celebrate the reduction in the deforestation rate this year," said Ane Alencar, the science director of the Amazon Environmental Research Institute (IPAM). "It will be quite difficult for the government to change its image with a reduction that small." Alencar said the annual PRODES figure will likely be above 10,000 square km for the third straight year. Before Bolsonaro, that level of destruction was last seen in 2008. She said that Amazon destruction may have plateaued at this high level in part because of uncertainty over whether Bolsonaro will be re-elected and continue his rhetoric signaling to illegal loggers and ranchers that they will not be punished. Bolsonaro has slid in opinion polls and is currently seen losing to former left-wing President Luiz Inácio Lula da Silva in the 2022 election, although neither has declared their candidacies. "It"s a moment where these people that are deforesting the Amazon, in the middle of nowhere, they are just waiting to see what is going to happen," Alencar said.