Today, you can buy a pair of sneakers (运动鞋) partially made from carbon dioxide pulled out of the atmosphere. But measuring the carbon-reduction benefits of making that pair of sneakers with carbon dioxide is complex. There’s the carbon dioxide that stayed in the ground, a definite carbon reduction. But what about the energy cost of cooling the carbon dioxide into liquid form and transporting it to a production facility? And what about when your kid outgrows the shoes in six months and they can’t be recycled into a new product because those systems aren’t in place yet?

Researchers are trying to help companies figure out how to account for each step in a product’s life.

As companies try to reduce their carbon footprint, many are doing life cycle assessments to measure the full carbon cost of products, from the obtaining of materials to energy use in manufacturing, from product transport to users’ behavior and end-of-life disposal (处理). It’s an impressively complex measurement, but such bean-counting is needed to hold the planet to a livable temperature, says low-carbon systems expert Andrea Ramirez Ramirez of the Delft University of Technology in the Netherlands.

Carbon use can be reduced at many points along the production chain—by using renewable energy in the manufacturing process, for instance, or by adding atmospheric carbon dioxide to the product. But if other points along the chain like transporting consume more energy or give off more carbon dioxide, Andrea notes, the final record may show a decrease rather than a reduction. A product is carbon-reduction only when its production actually removes carbon from the environment, temporarily or permanently.

In the rush to create products that can fight climate change, however, some companies have been charged with “greenwashing”—making products appear more environmentally friendly than they really are. Examples include labeling (用标签表明) plastic garbage bags as recyclable when their whole purpose is to be thrown away; using labels such as “eco-friendly” or “100% Natural” without official certification; and claiming a better carbon footprint without acknowledging the existence of even better choices.

【小题1】How does the author lead in the topic of the text?

A．By listing specific figures.	B．By putting up questions.
C．By referring to documents.	D．By offering some solutions.

【小题2】What does Andrea think of measuring the carbon cost of products?

A．Difficult but meaningful.	B．Expensive but promising.
C．Energy-saving and affordable.	D．Time-consuming and valueless.

【小题3】What can be defined as reducing carbon use in the production chain?

A．Using renewable energy in production.

B．Changing carbon dioxide into material.

C．Reducing carbon footprint in products’ life.

D．Cutting down carbon dioxide in transporting.

【小题4】What can we know from the last paragraph?

A．Companies are sparing no efforts to reduce carbon use.

B．Plastic garbage bags must be labeled as “eco-friendly”.

C．Most products are less environmentally friendly than before.

D．There is a long way to cut some companies’ ”greenwashing“.