2 . This past summer I set out on a journey to Canada’s Arctic. When I left I was wrapped in a blanket of uncertainty and ______.

But when I first met the group members, I knew I didn’t have anything to ______. The group was amazingly ______ and I was soon part of a big family boarding on an amazing ______!

Approaching the Arctic, I was repeatedly ______ with its unusual largeness and its beauty. There I flew over vast glaciers (冰河) and stood on the frozen Arctic Ocean, ______   polar bears walk in search of seal holes, and _______ wait for a meal.

However, I also learned the pollutants carried by ocean from far away have a negative ______ on all Arctic inhabitants. And global warming has put polar bears at ______ because a warmer climate means that they have a shorter time to ______ seals on the ice.

During the journey, I talked with some ______ scientists about the ruins of homes once ______ by the ancient Thule people. I made good friends with people from different parts of world.

The Arctic is a land of incredible beauty which ______ to be preserved. I’ve learned why it is so important to ______ it. This journey has made me more determined to try to ______ that I do not leave negative or harmful footprints on either Earth or its people.

4 . Meat is crucial for feeding the planet, leading scientists have said, as they warned it is not more environmentally-friendly to go vegan (素食).

Prof. Geoff Simm, Director of Global Academy Agriculture and Food Security at the University of Edinburgh, said, “I think livestock (家畜) farmers do feel they are being demonized (妖魔化).” Often the argument is made that going vegan would minimize land use, but the modelling studies that have been done demonstrate that’s not the case. We feel that while livestock production has a range of economic, social and environmental costs and benefits, the costs have perhaps been receiving far more attention recently than some of the benefits. Meat has massive social benefits. It’s an important source of dietary protein, energy, highly bioavailable micronutrients (微量营养素), even small amounts of animal-sourced food have a really important effect on the development of children, in the developing world on their cognitive and physical development and they are really important.

Prof. Mike Coffey, from Scotland’s Rural College, added, “It’s completely unnecessary to go vegan. If everybody went vegan it would be devastating for the UK environment. Animals bred for food help boost biodiversity.”

Researchers are currently attempting to breed more environmentally friendly cattle, which grow faster and eat less, which could further reduce the sector’s carbon footprint by reducing the amount of methane (甲烷) released by cows.

Prof. Coffey said that the difference in methane emissions from best and worst cattle was about 30 percent and that if all UK farmers used the most efficient animals this could reduce carbon emissions by nearly a third. But Prof. Coffey said the next stage will be trying to measure the methane given off by different breeds of cattle to find which are the lowest emitters. Prof. Coffey said that soon shoppers could be able to check meat labels to find out how much environmental impact their food has had. He added, “My expectation is that at some point in the near future there will be product labels that relates to the efficiency or carbon impact of the food.”

Professor Andrea Wilson, also of Edinburgh University, said more research was needed into the impact of veganism (绝对素食主义). She added, “We know a lot about the livestock sector because people have looked at it. We actually know very little about the vegan sector. The danger is we demonize one and jump too quickly to the other.”

6 . Coming upon a clear - cut in an old forest is a shocking experience. Tees large and small are collapsed one above the other in pile, and the ground is covered with the tracks of heavy machinery. Such was the scene when forest activist Zack Porter and I hiked a newly built logging (伐木) road in Green Mountain National Forest.

Clear - cutting in the American forests has long been widespread. But now, the Forest Habitat Creation Project represents new reasoning which is hotly debated - that clear - cutting benefits native creatures. The thinking is that clear - cutting done wisely can mimic natural disturbances, for example, from insect invasions or from storms overturning older trees that produce what ecologists call Early Successional Habitats - places where young trees and bushes get the upper hand and animals that depend on such habitat thrive.

The project also states that forests “can only be saved by being destroyed” - by keeping them young. Timber (木材) interests are enthusiastic about the approach because it lets them profit from cutting trees while claiming the significance of conservation. Hunting groups favor it because a younger, less thick forest makes it easier to find the game and birds they're tracking.

Nevertheless, Porter says, “Allowing some of the oldest standing trees in New England to be removed is equal to dereliction of duty on the part of the government, who sees the forests as commodities (商品).” “Forests can produce clean water, clean air, carbon storage, and biodiversity that we need,” he continues as we walk among lovely mixed hardwoods and evergreens that are cut down for logging. “We shouldn't be removing them for short - term gain.”

In this sense, Zack Porter's description of logging for wildlife for short - term gain - the short - term gain of favoring habitat for species people today want to see and hunt - is reasonable.

9 . Five years ago, we cut nearly every single tree across 19 acres here, piled and burned the branches and left the trunks where they lay. The goal was to restore one of the Ozarks’ rarest ecosystems, a type of dry and rocky grassland.

Logging down trees to bring back grass may seem puzzling in a time of climate change, as forest conservation and tree planting have become popular ways to keep carbon out of the atmosphere. But it is exactly what we should do in some parts of the Southeast. The climate and biodiversity crises are problems to be solved together. We can’t afford to rob biodiversity to pay for the climate. And grasslands are surprisingly good at pulling carbon out of the atmosphere. A single sunflower might not be the carbon grab that an oak tree is, but grass’s deep root systems store the element deep underground, where it can take hundreds or thousands of years to return to the atmosphere.

For the past century, the commonly held belief was that forests once covered most of the region from the Atlantic Ocean to the Mississippi River. But we now know that’s not true. Much of the Southeast was a string of large and small grassland ecosystems with enormous biodiversity. All of these unique grasslands are under threat, but not all by tree invasion. The few remaining grasslands in Arkansas are being converted to grow rice, Virginia grasslands are being flattened by housing developers, and low-lying coastal grassy plain is facing sea-level rise. Because grasslands are so easily navigated (导航) and settled, they may be the most threatened ecosystems in the world.

And it’s obvious that everywhere, grasslands remain undervalued. Many conservation organizations working in the Southeast are still focused on tree planting and preserving existing forests. The Nature Conservancy’s Cumberland Forest Project covers 253, 000 acres of land in Kentucky, Tennessee and Virginia, part of an effort to store carbon and create continuous habitats for species migration during climate change. In fact, recent laws are beginning to lead us in the right direction.

10 . With greater climate catastrophe (气候突变) on Earth, it is natural for us to make every effort to stop the potential floods, snowstorms, and alarming reports from scientists. For many of us (myself included), part of that means running out to buy reusable straws, organic cleaners, and packaging-free products.

However, before you rejoice in “green” purchases, take a second to consider the results of a new study from Arizona University. By comparing the shopping habits, mental health and environmental impact of young people, the researchers reaffirmed a principle: Buying less beats buying “green” stuff without effort. And that is true whether you are looking at the impact that your purchases have on the Earth or on your own happiness.

It should not come as a shock that simply consuming less is better for the planet. After all, every new item a factory yields requires some resources to produce. Take plastic bag bans for instance. If your city is getting rid of single-use shopping bags, it can be tempting to pay for a fashionable organic cotton bag hanging in the check-out line of your local supermarket. However, experts insist that growing cotton is actually no better for the Earth than producing the conventional plastic bags. Your best bet for carrying your groceries if you care about sustainability? Any bag you already own. This is true of many kinds of “green” products.

It is not just the Earth that will be happier if you buy less. You will feel more contented too, according to the new study. “People believe that they might well be self-satisfied about becoming environmentally conscious through green buying patterns, but it doesn't seem to be that way”, said the lead researcher Sabrina Helm. “Reduced consumption has effects on increased well-being and decreased psychological distress, but we don't see that with green consumption.”

“Owning every new green product on the market might make you feel contented, but if you relieve yourself of that burden of ownership, most people report feeling a lot better,” said Helm.