April 25 (UPI) -- Tree cover tropics shrank by 30 million acres in 2018, the fourth largest decline since record keeping began in 2001, according to new data compiled by scientists with the World Resources Institute.
The lost trees weren't new growth. According to the new data, released Thursday by Global Forest Watch, an area of old growth -- primary forest -- the size of Belgium was lost last year.
Though some of the trees were lost to fire, most were clear cut to make way for agriculture, infrastructure and other types of human development. The majority of last year's primary forest losses occurred in the Amazon.
Global Forest Watch is an international effort to monitor the loss of primary tropical forest using satellite images and remote sensing.
"It's really tempting to celebrate a second year of decline since peak tree-cover loss in 2016," Frances Seymour, researcher with the World Resources Institute and head of Global Forest Watch, told BBC. "But if you look back over the last 18 years, it is clear that the overall trend is still upwards. We are nowhere near winning this battle."
Maps published by project scientists revealed a number deforestation hot spots, several of which are located near the homes of indigenous groups -- people that depend on the Amazon for their way of life.
"Though Brazil experienced a decline in deforestation in the early 2000s, this has not been true in other parts of South America," researchers wrote in a news release. "Colombia, Bolivia and Peru all experienced rising rates of primary forest loss since the turn of the century, though with quite different drivers."
In Columbia, the peace process has allowed developers to access and clear primary Amazonian forest once occupied by the Armed Revolutionary Forces of Colombia, or FARC. Elsewhere in South America, agriculture, logging and mining have fueled deforestation.
The new data also revealed spikes in deforestation in Africa, especially Ghana and the Ivory Coast, where illegal mining and cocoa farm expansion has driven tree cutting.
The loss of primary forest is bad news for the climate, as older, larger trees store carbon more efficiently.