Some of the deadliest new diseases—including COVID-19, Ebola, SARS, and HIV—have arisen when the natural barriers between human and animal populations are breached. Dangerous close contact and prolonged exposure occurs when people encroach on wildlife habitat or bring wild animals into human communities.

The United States has lost the equivalent of nine Grand Canyon national parks, or 24 million acres (9712455.41 hectares) of natural area, between 2001 and 2017 due to agriculture, energy development, housing sprawl and other human factors, making the country more vulnerable to the impacts of climate change, according to a report.

The Center for American Progress proposes that federal agencies and state governments adopt the private-sector practice of proxy carbon pricing when evaluating long-term government decisions and investments.

Achievable gains in energy efficiency, renewable energy, forest conservation, and sustainable land use worldwide could achieve up to 75 percent of needed global emissions reductions in 2020 at a net savings of $14 billion.