(1), the aggravation of the greenhouse effect is mainly due to the excessive burning of coal, oil and natural gas in modern industrial society, which releases a large amount of carbon dioxide gas into the atmosphere after burning these fuels. Carbon dioxide is also called greenhouse gas. The greenhouse effect will lead to global warming and frequent natural disasters. Therefore, we

Advocate "low carbon life".

(2) Carbon dioxide is mainly consumed by plants for photosynthesis. As shown in the figure, process ① refers to that green plants absorb carbon dioxide in the air through photosynthesis, produce organic matter, store energy and release oxygen, which is conducive to maintaining the balance of carbon and oxygen in the atmosphere and is an automatic "air purifier". ② The figure represents the respiration of plants, which decomposes organic matter into carbon dioxide and water. Return to inorganic environment and be used by plants. (3) indicates the respiration of animals, which decomposes organic matter into carbon dioxide and water, and returns to the inorganic environment to be used by plants. (4) means that vehicles burn fuel and release a large amount of carbon dioxide gas into the atmosphere; (5) means that animals feed on plants; (6) means that animal and plant carcasses are formed after death; and (8) means that animal and plant carcasses are decomposed into carbon dioxide and water by microorganisms and returned to the inorganic environment. It can be seen that the ways of carbon returning to the atmosphere are: 2348.

(3) In the ecosystem, matter and energy are transferred along the food chain, so the energy flow is accompanied by the material cycle. The characteristics of energy flow are gradually decreasing along the food chain, unidirectional and non-circulating.

(4) "Low-carbon life" refers to reducing the energy consumed in daily life as much as possible, thereby reducing the emission of carbon, especially carbon dioxide, thus reducing the pollution to the atmosphere and slowing down the ecological deterioration. The details of life mainly change from three aspects: saving electricity, saving solar terms and recycling. For example, save electricity (such as turning off the lights and computers at will), ride bicycles and take buses. Parents are advised to build biogas digesters and use solar water heaters.

So the answer is: (1) carbon dioxide;

(2) photosynthesis; ②③④⑧

(3) One-way flow and gradual decline;

(4) riding a bicycle; Take a bus.