Yasuní National Park in Amazonian Ecuador

The lungs of Earth. World Rainforest Day

Perhaps no other place on Earth plays a more crucial role in sustaining life as we know it than the Amazon rainforest, the largest in the world. The Amazon spans nine countries in South America including Ecuador, where this pristine ecoregion is protected by the Yasuní National Park, shown here. Today is set aside as World Rainforest Day, to remember the vital role of this and other rainforests and to champion efforts to protect them. The world's rainforests are under threat like never before from deforestation driven by agriculture and cattle ranching. Some studies indicate that humans have degraded or destroyed more than half of the world's rainforests. Fewer trees means warmer temperatures, which increases the risk of drought and wildfire and compounds the damage of deforestation.

The Amazon has been called the lungs of the planet because the estimated 390 billion trees here convert carbon dioxide into oxygen, which humans and other animals need to survive. The Amazon also cools our planet by capturing and storing carbon. It is as much the planet's air conditioner as it is its lungs. For that reason, the health of rainforests is crucial to arresting climate change.

The other gift of rainforests, and of the Amazon in particular, is biodiversity. The number of species of plants, animals, and insects in the Amazon is not in the thousands, but in the millions. Scientists estimate half of the planet's biodiversity exists in the Amazon. In fact, many of our modern pharmaceuticals are derived from Amazon plants. That makes the Amazon not just the Earth's lungs and air conditioning, but also its medicine cabinet.