Brasilia - Brazil's government reported on Thursday that annual destruction of its Amazon rainforest jumped by 28% after four straight years of declines, an increase activists said was linked to recent loosening of the nation's environmental law meant to protect the jungle.However, the destruction was still the second-lowest amount of jungle destroyed since Brazil began tracking deforestation in 1988.The increase in deforestation came in the August 2012 through July 2013 period, the time when Brazil annually measures the destruction of the forest by studying satellite images. The country registered its lowest level of Amazon felling the year before.The Amazon rainforest is considered one of the world's most important natural defences against global warming because of its capacity to absorb huge amounts of carbon dioxide. About 75% of Brazil's emissions come from rainforest clearing, as vegetation burns and felled trees rot.That releases an estimated 400 million tons of carbon dioxide into the atmosphere every year, making Brazil at least the sixth-biggest emitter of the gas.Environment Minister Izabella Teixeira said on Thursday that the most recent figures show 5 843 square kilometres of rainforest were felled. That's compared to the 1 571 square kilometres cleared the previous year.Better roadsEnvironmentalists blame the increase on a loosening of Brazil's environmental laws. They also say that the government's push for big infrastructure projects like dams, roads and railways is pushing deforestation.A bill revising the Forest Code law passed Congress last year after more than a decade of efforts by Brazil's powerful agricultural lobby to make changes to what has been one of the world's toughest environmental laws, at least on paper.The changes mostly eased restrictions for landowners with smaller properties, allowing them to clear land closer to riverbanks and other measures. Perhaps the most controversial portion of the new law was what activists say was an amnesty, allowing those who illegally felled land to not face penalties if they signed an agreement to replant trees, which many environmentalists question could be enforced.Paulo Adario, co-ordinator of Greenpeace's Amazon campaign, said that it was scandalous that there was such a spike in the destruction."The government can't be surprised by this increase in deforestation, given that their own action is what's pushing it," he said. "The change in the Forest Code and the resulting amnesty for those who illegally felled the forest sent the message that such crimes have no consequences."Adario also said the Rousseff government's strong push for infrastructure projects in the Amazon region was leading to increased deforestation, and Thursday's government report showed that much of the destruction was centred along a government-improved roadway running through the states of Para and Mato Grosso.Better roads make it easier to illegally extract timber from the jungle and push more soy farmers and ranchers, who clear trees so they can work land and plant pasture, into previously untouched areas.