It’s estimated that roughly 20 percent of the Amazon Rainforest has disappeared during the past 50 years.

Deforestation due to agriculture, urbanization, and illegal logging is not only threatening the millions of unique plant and animal species native to the Amazon River region, it’s affecting humans worldwide. Whether it’s extreme drought in São Paulo, Brazil, the multibillion-dollar illegal wildlife trade, or the catastrophic impacts of climate change, threats to the Amazon are having a very tangible ripple effect around the globe.

The good news is that some of the world’s most accomplished scientists are backing a big push to save the forest. We sat down with one of those scientists—National Geographic Explorer Dr. Thomas Lovejoy—to talk about the state of the Amazon and why conservation matters.

NG: You’ve worked in the Amazon for more than 50 years. How have you seen the region change?

TL: In the 1960s, there was only one highway in the entire Amazon Basin. That’s an area as large as the continental United States with one highway and three million people. Today, there are between 30 million to 40 million people, countless roads, and it’s about 20 percent deforested.

But on the plus side, 50 years ago there were only two national parks in Venezuela, and a national forest and an Indigenous reserve in Brazil. Today, more than 50 percent of the Amazon is under some form of protection. The real challenge is to move toward a much more integrated approach to planning and managing the Amazon.

When we talk about conservation of the Amazon, it’s hard for many people to relate because they don’t feel connected to the region. How can we change that?

There are actually a lot of direct connections between our daily lives and the Amazon, no matter how far away we are.

For example, there’s a big, nasty viper called the bushmaster that lives in the Amazon. This snake kills its prey with venom that causes the prey’s blood pressure to go to zero. Scientists in São Paulo discovered that this venom actually works by affecting a previously unknown system in the body called the angiotensin system. This discovery then allowed pharmaceutical chemists to design the first ACE inhibitor medicines. Today, millions of people use these medicines to treat high blood pressure. They have longer, fuller, and more productive lives, and they have the venom of a nasty snake far away in the Amazon to thank for it.

A connection that affects everyone on the planet is climate change. Reforestation is essentially a way of removing excess carbon dioxide from the atmosphere. The existing forest is absorbing some carbon dioxide already. In terms of the global carbon cycle, tropical forests have a carbon sink roughly equal to half of what is in the atmosphere. About half of that is in the Amazon. This means to lose the Amazon would dramatically increase climate change.

And there are some extraordinary local connections as well. The Amazon basically makes half of its own rainfall. Moisture comes in off the Atlantic Ocean, falls as rain in the Amazon forest, and about three-quarters of it evaporates back into the atmosphere. This then gets carried west and most of it turns into rain again closer to the Andes Mountains, where it falls and feeds the Amazon river system. This system holds about 20 percent of the world’s river water, which is huge. What isn’t rained out of the Andes disperses north and south, with the southern portion being really important for agriculture in Brazil and Argentina. So, São Paulo’s current drought—possibly the worst in its history—is happening partly because the region is getting less rainfall from the Amazon.

What is your vision for the future of the Amazon?

There’s been a lot of damage done and forest lost, but nothing is gone until it’s gone. A lot of the negative buzz out there—like the initial projection of species extinctions that I made in 1980—is made in the hope that it will in fact turn out to be a lot less because you’ve gotten people’s attention.

Ideally what we hope is for the Amazon to return to be about 90% of the extent of its original forest, and for it to be managed collectively by the nine Amazon nations (Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana). We want to see more integrated planning between the people in charge of transportation, energy, agriculture, and the other industries in the region. We think Amazon cities can have higher quality of life and keep people in existing cities so there’s less reason to deforest.