Environment

The Clean Air Act, passed in 1970, created programs that lowered the levels of six common pollutants: particulate matter, ozone, lead, carbon monoxide, nitrogen dioxide, and sulfur dioxide. As a result, the combined emissions of these six dropped by 78% over the ensuing 50 years even while the U.S. economy continued to grow. In particular, the reduction of smog and fine particulate matter improved public health nationwide.

Electric cars store large amounts of energy in their battery banks that is used to drive the car. But in principle, parked electric cars could be used as mobile energy storage networks. The energy in cars could be given back to the power grid – a technology known as vehicle-to-grid or V2G. Alternatively, the stored energy in a car could supply electricity directly to a home, for example during a power outage. This is V2H.

The clothing industry accounts for about 10% of global greenhouse gas emissions – more than, for example, air travel. Large amounts of land are used to grow natural materials for clothing, but synthetic materials are more common. Used textiles often end up in landfills, where they take decades to decompose. A fair amount of clothing gets reused, but ultimately very little of it gets recycled. Estimates are less than 1% of used clothing is recycled into new textiles globally. Much of it simply cannot be.

Heat pumps are highly efficient all-in-one heating and cooling systems. Ordinary furnaces burn fuel to produce heat. Heat pumps move existing heat from one place to another using electricity and refrigerant. A heat pump can act as heater in the winter and an air conditioner in the summer.

Five species of sea turtles are found in the Gulf of Mexico. All five were pushed to the brink of extinction due to human activity. The Endangered Species Act of 1973 listed all sea turtles in the United States as threatened or endangered except the flatback turtle. Under the Act, it is illegal to harm or in any way interfere with a sea turtle or its eggs.

Hoover Dam was built in the 1930s during the Great Depression. It is famous for taming the wild Colorado River, providing the power that electrified the American Southwest, and for creating Lake Mead, the largest man-made reservoir in the United States. The dam is as tall as a 60-story building and was the world’s highest dam when it was built. And now, it has real problems.

Cacti are famous for their ability to survive some of the harshest conditions on Earth, making them symbols of resilience in a warming world. But climate change is altering temperatures and rainfall patterns across many desert regions, highlighting the importance of understanding how these plants adapt.

The starry night sky has fascinated humanity for countless millennia. For most of that time, it was an untouchable, immutable and vast expanse that was beyond the influence of anyone. But the present-day commercial space race has created new threats to the relationship between people and the celestial expanse by crowding the night sky and polluting the atmosphere.

The part of the year between the chill of winter and the heat of mid-summer tends to be when renewable energy systems perform best. Longer, milder days when electricity demand is relatively low are when wind and solar power are ramping up and can account for greater shares of grid energy consumption.

Lithium is the key metal for electric vehicle and energy storage batteries. Viewed as a way to strengthen U.S. energy independence, there has been a growing rush for lithium across the country. By 2030, at least six new mining projects are projected to be underway and another 13 will soon follow, mostly in the Southwest. There are more than 100 U.S. projects to which companies have staked claims. Worldwide, there are over 500 proposed lithium mines as the need for batteries skyrockets.