Q+A

The National Environmental Policy Act, enacted in 1970, is widely viewed as a keystone U.S. environmental law. For any major federal action that affects the environment, such as building an interstate highway or licensing a nuclear power plant, NEPA requires relevant agencies to analyze environmental impacts, consider reasonable alternatives and accept public input. It also allows citizens to sue if they believe government has not complied. Critics argue that NEPA reviews delay projects and drive up costs. In May 2023 negotiations over raising the federal debt ceiling, President Joe Biden agreed to certain changes to NEPA reviews, which both the White House and congressional Republicans said would streamline permitting for infrastructure projects. Legal scholars J.B. Ruhl and James Salzman explain these changes and what they mean for protecting the environment and expanding clean energy production. What kinds of projects typically require NEPA reviews? The statutory text of NE...

The Biden administration has agreed to provide Ukraine with depleted uranium shells to equip M1A1 Abrams tanks that the U.S. is sending there. Britain has already delivered tanks to Ukraine equipped with depleted-uranium shells. DU munitions, developed in the 1970s, are not nuclear weapons and do not produce a nuclear explosion. But soldiers or civilians can be exposed to the uranium, either in combat or afterward. Health physicist Kathryn Higley explains what depleted uranium is and what’s known about potential health and environmental risks. What is depleted uranium? Uranium, symbolized by the letter U, is a naturally occurring element that is radioactive. Natural uranium is composed primarily of three isotopes: U-234, U-235 and U-238. These isotopes are all uranium and have the same chemical characteristics, but they have slightly different masses, as indicated by the numbers 234, 235 and 238. Depleted uranium is mainly U-238, with small amounts of other isotopes, in...

An outbreak of highly pathogenic avian influenza has spread through chicken and turkey flocks in 46 states since it was first detected in Indiana on Feb. 8, 2022. The outbreak is also taking a heavy toll in Canada and Europe. Better known as bird flu, avian influenza is a family of highly contagious viruses that are not typically harmful to most wild birds that transmit it, but are deadly to domesticated birds. The virus spreads quickly through poultry flocks and almost always causes severe disease or death, so when it is detected, officials quarantine the site and cull all the birds in the infected flock. As of early November, this outbreak had led to the culling of over 50 million birds from Maine to Oregon, driving up prices for eggs and poultry – including holiday turkeys. This matches the toll from a 2014-2015 bird flu outbreak that previously was considered the most significant animal disease event in U.S. history. Yuko Sato, an associate professor of veterinary me...

As part of its effort to reduce air pollution and cut greenhouse gas emissions that contribute to climate change, California is pursuing aggressive policies to promote clean trucks. The state already requires that by 2035, all new cars and other light-duty vehicles sold in the state must be zero emission. Its powerful Air Resources Board has adopted rules requiring that most trucks be zero emission by 2035, and is now proposing that all trucks sold by 2040 must be zero emission. The Conversation asked a panel of transportation experts from the University of California, Davis what’s involved in such a rapid transition. 1. Why is California targeting medium- and heavy-duty trucks? Although diesel engines are valuable for moving heavy loads, they also are major polluters. Diesel trucks account for one-fourth of greenhouse gas emissions and about half of conventional air pollution from transportation in U.S. cities. Pollutants in diesel exhaust include nitrogen oxides, fine...