Supermarkets, conservationists and farming groups have shown their concerns about pollution of the Wye, one of the UK’s longest rivers. “The pollution pressures upon the Wye are unacceptable and there was strong enthusiasm for cooperative action to resolve the problem.” said Craig Bennett, head of the Wildlife Trusts.

The pollution referred largely to runoff of the nutrient-rich waste matter produced by the 20 million-plus chickens near the river.

Bennett said: “We discussed how, if the Wye were a school or a hospital, we would be calling for it to be placed into ‘special measures’. We agreed the same level of urgency must be applied.”

Increasing concern led the local government to hold a discussion in May, when they promised to publish a plan for the Wye by the autumn. However, the local government’s push on the river was marred in June when the Department for Environment, Food and Rural Affairs published a Wye video showing sea otters (海獺) rather than the river’s local European otters. The pollution of the Wye was not mentioned at all.

In July Bennett hosted a Wye round table in Powys, Wales, bringing together local groups, the Environment Agency, the chicken produce Avara Foodsr, regional branches of the National Farmers Union and local authorities. They agreed on a plan that included cutting the nutrient pollution “through a reduction in animal numbers” and other measures.

Bennett also wrote to Julie James, the Welsh Climate Change Minister, who said, “I share your concern for the health of the River Wye and other Welsh rivers.”

A supermarket chain said they are committed to protecting the river and engaging with their chicken suppliers to tackle water pollution. They have detailed management plans to make sure their suppliers are farming with care for the environment. A government spokesman said: “We are offering a wide range of support to farmers to speed up their transition to more sustainable practices and help protect this important site.”

In recent years some extreme weather events have arisen from global warming because of human activities, with studies indicating an increasing threat from extreme weather in the future. Scientists were certain that global warming is being caused mostly by increasing concentrations ofgreenhouse gasesand otherhumanactivities.

Its effects include warming global temperature, rising sea levels and expansion of deserts in the subtropics(亚热带). Warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing loss of glaciers, permafrost and sea ice. Other likely changes include more frequent extreme weather events including heat waves, droughts, heavy rainfall with floods, heavy snowfall and species extinction due to great change of temperature. Bad effects on humans include the threat to food security from decreasing crop yields and the loss of populated(住人的) areas because of rising sea levels.

Possible responses to global warming are reduction of emissions(排放), adaptation to its effects, building systems resilient to its effects, and possible future climate engineering. Most countries are parties to the United Nations Framework Convention on Climate Change UNFCCC), whose objective is to prevent dangerous climate change. It has adopted a range of policies designed to reduce greenhouse gas emissions and to assist in adaptation to global warming. It is agreed that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level.

On 12 November 2015, NASA scientists reported that human-made carbon dioxide continues to increase above levels that have not been seen in hundreds of thousands of years: currently, about half of the carbon dioxide released from the burning of fossil fuels remains in the atmosphere and is not absorbed by vegetation and the oceans.

Once considered an optional lifestyle choice, recycling has become a commonplace activity in most areas. One type of recycling, called downcycling, involves re-purposing a material into a new product of lesser quality. 【小题1】

Downcycling is also known as downstream recycling. It is most common in terms of industrial materials. These products lose their value as they are recycled, which limits their capacity for new use. 【小题2】 White writing paper, for example, is often downcycled into cardboard; once downcycled to this new form, it can no longer be used as white paper again. Another example of downcycling includes the use of plastic components.

Giving products a new life is considered a good way to reuse materials and avoid waste. Once downcycled to their full capacity, however, these materials are eventually so degraded that they cannot be reused further. Since downcycled products are considered of lower quality than their original form, they cannot be used in remaking their original product.

【小题3】 Plastic, glass, and aluminium products coded with the number one may be remade into something of equal or greater value. This type of recycling is known as upcycling, and represents the forward compatibility of recycled components. Materials available for downcycling, such as water, juice, and milk bottles, are coded with the number two. 【小题4】

Items available for downcycling often require additional chemicals, energy, and other treatments in order to transform them into something usable. Durable plastic products in particular require much additional treatment. Trash bins, tables, and chairs are also considered materials with a high energy cost to recycle.

When a product reaches a code seven, it is considered no longer recyclable. 【小题5】 Since these products can no longer be made into new ones, they will either have to be reused or discarded, typically in a landfill.