Study shows earth has more trees now than it did in the 1980’s

Contrary to popular belief, a study that covers the tree cover loss/gain has shown that in total more trees have grown than lost. The study, led by Xiao Peng Song and Matthew Hanses of the University of Maryland is based on the analysis of satellite data from 1982-2016.

“Land change is a cause and consequence of global environmental change^1,2. Changes in land use and land cover considerably alter the Earth’s energy balance and biogeochemical cycles, which contributes to climate change and—in turn—affects land surface properties and the provision of ecosystem services^1,2,3,4. However, quantification of global land change is lacking. Here we analyze 35 years’ worth of satellite data and provide a comprehensive record of global land-change dynamics during the period 1982–2016. We show that—contrary to the prevailing view that forest area has declined globally⁵—tree cover has increased by 2.24 million km² (+7.1% relative to the 1982 level). This overall net gain is the result of a net loss in the tropics being outweighed by a net gain in the extratropics. Global bare ground cover has decreased by 1.16 million km² (−3.1%), most notably in agricultural regions in Asia. Of all land changes, 60% are associated with direct human activities and 40% with indirect drivers such as climate change. Land-use change exhibits regional dominance, including tropical deforestation and agricultural expansion, temperate reforestation or afforestation, cropland intensification, and urbanization. Consistently across all climate domains, montane systems have gained tree cover and many arid and semi-arid ecosystems have lost vegetation cover. The mapped land changes and the driver attributions reflect a human-dominated Earth system. The dataset we developed may be used to improve the modeling of land-use changes, biogeochemical cycles, and vegetation–climate interactions to advance our understanding of global environmental change^1,2,3,4,6.”

The research, in short, found that tree cover loss in the tropics was outweighed by tree cover gain in subtropical, temperate, boreal, and polar regions. However, Mongabay points out an important caveat: tree cover is not necessarily forest cover, that these new “green areas” are monocultures.

While this is true to an extent, it does not discard the fact that today, the majority of our tree usage comes from new forests—forests that are planted for the specific purpose of being cut down for lumber. Moreover, forest destruction had been occurring for many years prior to the British Industrial Revolution, where a switch to coal was triggered mainly due to near-complete deforestation, and only in recent times have there been efforts to reverse it.

There are a number of closely related trends that support the notion that this should be viewed as net-positive, namely an increasingly efficient agriculture production that improves the rate at which land is returned to nature and a growing record square-mileage of protected land and water where human interference, like extractive practices, is banned. These, in turn, allow biomass the opportunity to grow again and reconstitute itself.

SOURCE: Nature Journal, Mongabay, YouTube