Is There a Link Between Population Growth and Tree Density?

Counting to 3 Trillion: One Study Reveals an Important Link Between Human Population Growth and Declining Tree Density

When it comes to environmental issues, we often cannot see the forests for the trees. We get so bogged down by tiny details at the regional level that we fail to realize just how pervasive many environmental problems are globally. A recent Yale-led study published in Nature, sought to correct this imbalance by evaluating environmental impact at both the micro and macro level. Researchers from 15 countries took on the daunting task of mapping our world’s trees, all 3 trillion of them, in order to make sense of changing patterns in tree cover and how they impact the sustainability of one of our most beloved renewable resources, timber. The study’s findings reflect a thoughtful analysis of the complicated nexus of human, environmental, and economic interaction and are a prefect resource for students submitting a video on the dangers of deforestation to our World of 7 Billion video contest.

Mapping Global Tree Populations Worldwide

Researchers, using a combination of satellite imagery, forest inventories, and supercomputer technologies, were able to map global tree populations at the square kilometer level, allowing them to construct the most refined estimate of global tree cover to date. The study estimates that there are approximately 3 trillion trees in our terrestrial environment – that’s over 420 trees for every person on Earth! The figure, while 7.5 times higher than previous estimates, underscores serious concerns about global deforestation and land use conversion.

Deforestation is the conversion of forest to another land use or the long-term reduction of tree cover and is a major threat to economies ecosystems worldwide. Around 1.6 million people depend on forests for their livelihoods, and more than 80 percent of all terrestrial species of animals, plants, and insects call our forests home. The study used historical land use data, like the clearing trees for agriculture land, to quantify human impact on the environment. Results revealed a strong negative correlation between a growing human population and tree densities and identify human activity is largest driver of tree cover loss worldwide. The total number of trees on Earth has dropped by nearly 46 percent since the start of human civilization. Today, deforestation, changing land use patterns, and unsustainable management of forest resources are responsible for a total loss of over 15 billion trees each year!

The Impacts of Deforestation

The impacts of deforestation and shifting land use trends are universal and bleed into many other pressing environmental concerns like climate change and biodiversity loss. Our forests are the largest terrestrial carbon sink. When we chop down trees, we are reducing the potential to remove harmful CO2 from the atmosphere. Furthermore, the practice of deforestation itself accounts for 15 percent of global greenhouse gas emissions. Increased levels of CO2 in our atmosphere cause climate change and make our world a more vulnerable and potentially unstable place. Reduced forest cover leads to habitat loss and fragmentation. Nearly 80 percent the world’s documented species are found in the tropical rainforest. When we destroy forest ecosystems, we threaten Earth’s biodiversity. Thankfully, there are many things that we can do to reduce loss of tree cover. Responsible forest management, promotion of sustainable consumer products, habitat conservation, and adoption of policies that benefit both forest ecosystems and local communities are all ways that we can create a healthier and more sustainable planet for our generation and generations to come.

Student Videos Tackle Deforestation

Want to do more? Encourage your students to become active participants in our global community by submitting their solutions to deforestation in our student video contest. Follow our Twitter hashtag #W7BForests for the latest information on the environmental and social impacts of deforestation and check out our website, World of 7 Billion.