1 . The national movement to get rid of plastic bags is gaining steam — with more than 240 cities and counties passing laws that ban or tax them since 2007 in the US. But these bans may be hurting the environment more than helping it.
University of Sydney economist Rebecca Taylor and colleagues compared bag use in cities with bans with those without them. For six months, they spent weekends in grocery stores recording the types of bags people carried out.
Taylor found these bag bans did what they were supposed to: People in the cities with the bans used fewer plastic bags, which led to about 40 million fewer pounds of plastic garbage per year. But people who used to reuse their shopping bags for other purposes, like picking up dog waste, still needed bags. "What I found was that sales of garbage bags actually grew sharply after plastic grocery bags were banned," she says.
Garbage bags are thick and use more plastic than typical shopping bags. "So about 30 percent of the plastic that was reduced by the ban comes back in the form of thicker garbage bags," Taylor says. On top of that, cities that banned plastic bags saw a surge in the use of paper bags, which she estimates（估计）resulted in about 80 million pounds of extra paper garbage per year.
A bunch of studies find that paper bags are actually worse for the environment. They require cutting down and processing trees, which involves lots of water, toxic chemicals and fuel. While paper is biodegradable(可生物降解的) and avoids some of the problems of plastic, Taylor says, the huge increase of paper means banning plastic shopping bags increases greenhouse gas emissions(排放).
The Danish government recently did a study that took into account environmental impacts（影响）beyond simply greenhouse gas emissions, including water use, damage to ecosystems and air pollution. These factors make cloth bags even worse. They estimate you would have to use an organic cotton bag 20,000 times more than a plastic grocery bag to make using it better for the environment.
1. What is main idea of the passage?| A．Banning plastic bags is gaining popularity worldwide. |
| B．Banning plastic has great influence on people’s life. |
| C．Banning plastic increases the use of pager and cloth bags. |
| D．Banning plastic may harm rather than help the environment. |
| A．Plastic bags are no longer needed. |
| B．People began to reuse their plastic bags. |
| C．The amount of garbage is even greater. |
| D．Most of the reduced plastic returns in garbage bags. |
| A．They are not as biodegradable as plastic bags. |
| B．It hurts the environment more to make them. |
| C．They can’t be reused as many times as plastic bags. |
| D．They are much thicker than plastic bags. |
| A．Sharp increase. | B．Fast development. |
| C．Tight control. | D．Sharp decrease. |
