环境问题为托福常考话题以及独立写作常常可以转化到的一个论证方向，那么就让我们来积累一些时尚新鲜的语言素材吧。从奥巴马总统呼吁应对气候变化威胁的电视讲话中，我们无疑能够得到许多可用的素材哟，一起来积累学习吧！

　　Hi， everybody.This Monday， I'm heading to Alaska for a three-day tour of the state.

　　I've been looking forward to this for a long time.Not only because Alaska is one of the most beautiful places in a country that's full of beautiful places-but because I'll have several opportunities to meet with everyday Alaskans about what's going on in their lives.I'll travel throughout the state， meeting with Alaskans who live above the Arctic Circle， with Alaska natives， and with folks who earn their livelihoods through fishing and tourism.And I expect to learn a lot.

　　One thing I've learned so far is that a lot of these conversations begin with climate change.And that's because Alaskans are already living with its effects.More frequent and extensive wildfires.Bigger storm surges as sea ice melts faster.Some of the swiftest shoreline erosion in the world-in some places， more than three feet a year.

　　Alaska's glaciers are melting faster too， threatening tourism and adding to rising seas.And if we do nothing， Alaskan temperatures are projected to rise between six and twelve degrees by the end of the century， changing all sorts of industries forever.

　　语言素材：1.谋生： earn/seek one’s livelihood/living2.渔业和旅游业： fishing and tourism3.气候变化：climate change4.承受…影响： live with + adj+ effects5.越来越频繁和严重的森林火灾：more frequent and extensive wildfires6.随着海冰融化速度加快，风暴更加汹涌：bigger storm surges as sea ice melts faster7.最快速的海岸线腐蚀：the swiftest shoreline erosion8.导致海平面上升：adding to rising seas

　　This is all real.This is happening to our fellow Americans right now.In fact， Alaska's governor recently told me that four villages are in “imminent danger” and have to be relocated.Already， rising sea levels are beginning to swallow one island community.

　　Think about that.If another country threatened to wipe out an American town， we'd do everything in our power to protect ourselves.Climate change poses the same threat， right now.

　　That's why one of the things I'll do while I'm in Alaska is to convene other nations to meet this threat.Several Arctic nations have already committed to action.Since the United States and China worked together to set ambitious climate targets last year， leading by example， many of the world's biggest emitters have come forward with new climate plans of their own.And that's a good sign as we approach this December's global climate negotiations in Paris.

　　语言素材：

　　9. 发生到... happen to…

　　10. 即将来临的威胁：imminent threat

　　11. 吞没一个一个有居民的小岛：swallow one island community

　　12. 产生…威胁：pose... threat

　　13. 召集其他国家共同面对威胁：convene other nations to meet this threat

　　14. 制定宏伟的气候应对目标：set ambitious climate targets

　　15. 碳排放大国：many of the world’s biggest emitters

　　Now， one of the ways America is leading is by transitioning away from dirty energy sources that threaten our health and our environment， and by going all-in on clean， renewable energy sources like wind and solar.And Alaska has the natural resources to be a global leader in this effort.

　　Now even as we accelerate this transition， our economy still has to rely on oil and gas.As long as that's the case， I believe we should rely more on domestic production than on foreign imports， and we should demand the highest safety standards in the industry-our own.Still， I know there are Americans who are concerned about oil companies drilling in environmentally sensitive waters.Some are also concerned with my administration's decision to approve Shell's application to drill a well off the Alaskan coast， using leases they purchased before I took office.I share people's concerns about offshore drilling.I remember the BP spill in the Gulf of Mexico all too well.

　　语言素材：

　　16. 从威胁健康和环境的污染能源向全面的清洁，可再生能源如风能太阳能转变： transition away from dirty energy sources that threaten our health and our environment and go all-in on clean， renewable energy sources like wind and solar

　　17. 更依靠国内生产而不是进口： rely more on domestic production than foreign imports

　　18. 坚持最高安全标准： demand the highest safety standards

　　19. 关注：be concerned about…

　　20. 批准壳牌公司在阿拉斯加近海钻井： approve Shell’s application to drill a well off the Alaskan coast

　　21. BP公司在墨西哥海岸的石油泄漏事故：the BP spill in the Gulf of Mexico

　　That's precisely why my administration has worked to make sure that our oil exploration conducted under these leases is done at the highest standards possible， with requirements specifically tailored to the risks of drilling off Alaska.We don't rubber-stamp permits.We made it clear that Shell has to meet our high standards in how they conduct their operations-and it's a testament to how rigorous we've applied those standards that Shell has delayed and limited its exploration off Alaska while trying to meet them.The bottom line is， safety has been and will continue to be my administration's top priority when it comes to oil and gas exploration off America's precious coasts-even as we push our economy and the world to ultimately transition off of fossil fuels.

　　语言素材：

　　22. 石油勘探工作：conduct the oil exploration

　　23. 量身制定的要求去避免阿拉斯加近海钻井的风险： the requirements specifically tailored to the risks of drilling off Alaska

　　24. 不经审查就批准： rubber-stamp permits

　　25. 满足最高标准： meet our highest standards

　　26. 测试多么严格的执行那些标准： it is testament to how rigorous we’ve applied those standards.

　　So I'm looking forward to talking with Alaskans about how we can work together to make America the global leader on climate change around the globe.And we're going to offer unique and engaging ways for you to join me on this trip all week at WhiteHouse.gov/Alaska.Because what's happening in Alaska is happening to us.It's our wakeup call.And as long as I'm President， America will lead the world to meet the threat of climate change before it's too late.

　　Thanks， and have a great weekend.