No doubt that humans have widely changed, developed, and exploited (开发) much of the natural world for our own ends. But how much of the land surface remains free of our often-harmful influence?

In a new study, scientists compared figures from four different sets of data using different kinds of methods and classification (分类) systems to answer this question. On average, the researchers say roughly half (48 to 56 percent) of the world’s land shows “low” influence of humans. While the figures may inspire many—stressing the vast expanse of significantly untouched lands that can still be protected through conservation measures—the study also shows just how much of the Earth has already been occupied and used by humans.

In fact, only about a quarter (20 to 34 percent) of the planet’s ice-free land surface shows “very low” signs of human influence, the researchers say, and the parts of the planet that we have left alone up until now constitute (构成) some of the least livable places on Earth. In other words, whether through urbanization, forestry, agriculture or other means, humans have applied the most influence on biodiverse land that presented ripe and easy opportunities for immediate human needs; in contrast, roasting deserts in the world’s hottest places, or frozen wastelands in its coldest spots, have been ignored.

Even so, the researchers say the results shown here give us a strong, clear marker that we can use to help structure existing and future conservation efforts by preventing disturbance on existing low influenced areas, meanwhile, recovering areas for conservation in land that has already been exploited too much.

“The encouraging takeaway from this study is that if we act quickly and decisively (果断地), there is a slim window in which we can still conserve roughly half of the Earth’s land in a relatively untouched state,” says biologist and lead author of the study, Jason Riggio.

There’s a chance, right now, to draw a line in the sand, and say “no more”.

The Eurotunnel is a tunnel(隧道) which crosses the Channel under the sea, linking France and the UK. It is about 50.5 km long and 38km lies under the seabed. There are trains which carry passengers and cars, and others which carry carriages or other heavier vehicles(车辆), as well as goods.

The construction of the tunnel started in 1986, with a cost of almost 10 billion pounds. It was opened in 1994 but was not financially successful until 2007, because of the high interest rates (利率) the company had to pay the banks, as well as low earnings from passengers and goods.

The Eurotunnel is a very convenient way of traveling between the two countries as the journey is quick (less than one hour), cheap, and comfortable. You can go with your car, motorbike or bike. The tunnel operates every day, round the clock. At the busiest times there are up to three shuttle departures (班次) per hour. There are facilities(设施)for disabled passengers and for babies at the two terminals (终点站).

The Eurotunnel, also commonly known as the Channel Tunnel, Eurochannel and Eurochunnel is environmentally friendly. It perfects its sources of energy through its use of renewable energy with the result that, by 2008, it had reduced its greenhouse gas emissions(排量) by 45%. In addition, 50% of the waste produced is recycled.

The future of the Eurotunnel seems promising, although some people who have the fear of enclosed(与外界隔绝的)spaces will never use this type of transportation. There have been some problems with snow storms like the one in the winter of the 2009 which have made the services stop for a period of time, leaving passengers in the tunnel for more than 15 hours without light, heating, food or drink, inside an unmoving train under the sea. Some of the passengers reacted very badly and decided not to use this means of transport again.

For environmental reasons, Britain will ban all new petro-and diesel-powered vehicles from its roads beginning in 23 years, a government report says.

The plan, expected Wednesday, aims to start removing petrol and diesel engines in 2040. It follows a similar official statement in France and comes after the British government was ordered by the High Court to develop new plans to reduce NO2 in the air. Judges ruled that previous clean-air plans were not enough to meet European Union pollution limits in the coming years.

Britain’s government has said the poor air quality has an unnecessary and avoidable negative effect on citizens’ health, and costs up to $ 3.5 billion in annual lost productivity.

Part of the new plan involves an offer of $ 260 million to local governments to change rules where vehicle emissions(排放) are over EU standards. Ideas so far include changing road layouts, reprogramming traffic lights and charging a fee for the oldest and most polluting cars on the road.

The plan also includes $1.3 billion for government purchase of extreme-low-emission vehicles, nearly $ 130 million to improve infrastructure for electric vehicle charging stations and $ 378 million for remodeling existing vehicles.

Climate change is also a reason for the plan to get these vehicles off the road. “We can’t carry on with petrol and diesel cars,” Environment Secretary Michael Gove said. “It’s important we all prepare for a significant change which deals not just with the problems of health caused by emissions, but the broader problems caused in terms of accelerating climate change.”

Gove added that local communities are partly responsible for coming up with ways to limit emissions, including possible limitations on commuters(上下班往返者) and the addition of cleaner mass transportation options. Local leaders are called on to draw up “appropriate plans” to deal with climate challenges related to emission, he said.