单项选择题

案例分析题

Scientific consensus is a rare thing.But the experts agree almost unanimously on one thing—humankind is changing the earth’s natural environment，and quickly.As an expanding global population spreads ever further a round the globe，habitats（栖息地）are being destroyed to make room for mushrooming towns and cities，all the while consuming more and more oil and other fossil fuels.
In many ways humans have never had it so good：average global life expectancy has shot up by almost 20years in the past half-century，most countries are getting richer by the day and medical science has beaten scores of previously fatal conditions.And yet there are increasing fears that this human-dominated phase of the earth’s long history docs much harm to the earth.The statistics compiled by the United Nations Environment Programme，or UNEP，can make for depressing reading.Species are becoming extinct at a speed around 100times faster than would happen naturally.Almost half the world’s original forests—the habitat which supports around two-thirds of the wildlife—has disappeared in.the past three decades.Farming land is eaten by deserts around 30times faster than ever before seen，while air pollution is thought to kill 50，000annually in the United States.
Most seriously of all，the climate appears to be changing.The billion of tons of carbon dioxide pumped into the earth’s atmosphere annually，along with other so-called greenhouse gases，is causing the earth to heat up，virtually all environmental scientists agree.Such a change would have a wide range of impacts on the natural world and human society.
Environmental campaigners—joined by increasing numbers of politicians—want urgent action.’We really should be very alarmed as a global community，’says Tony Juniper，director of green group Friends of the Earth，’We still have time to do something about these things，but time is now extremely short.There is an increasingly confident assessment about the likelihood of the consequences of global climate change，and the time scales that we have to deal with it.’
The international response has been mixed.The 1997Kyoto protocol（协议）committed industrialized nations to cut their combined greenhouse gas emissions below 1990levels by 2008-12，but was undermined after the United States，the biggest global polluter，declined to approve the deal.Washington opposed Kyoto’s methods rather than its aims.It acknowledged something needs to be done，calling for the country to cure its addiction to oil.Whatever the consensus on diagnosis，there is little agreement on action，something the UNEP warns must change.To tackle global warming，it warns that only a fundamental change in lifestyle.and economy，with a significant moderation in the consumption of resources，can bring any hope of a solution.

By saying that “humans have never had it so good”(Linel, Para. 2), the author means that people nowadays（）.