[ti:Which Technologies Could Help the World Reach its Climate Goals?] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]The United Nations Climate Change Conference, [00:04.20]known as COP26, [00:07.32]is continuing in Glasgow, Scotland. [00:11.44]World leaders, climate experts and activists have gathered [00:17.08]in an effort to negotiate new action plans [00:21.16]to fight the widespread effects of climate change. [00:26.80]Technology is likely to play a big part [00:30.84]in helping the world reach its climate goals in the future. [00:36.80]Here is a closer look at some possible [00:40.24]technology-based solutions. [00:43.24]Fusion is the process that fires the sun. [00:47.80]But some experts say it could someday power our homes. [00:53.60]Fusion happens when the nuclei of two atoms [00:58.52]are subjected to extreme heat. [01:01.52]This leads to the formation of a new larger atom [01:06.76]and large amounts of energy. [01:10.40]One problem is that the process itself [01:14.00]requires a large amount of energy. [01:17.04]Developers of the technology [01:20.32]have not yet performed a fusion reaction [01:24.36]that releases more energy than it requires. [01:29.00]In addition, running an electric power plant off of fusion [01:34.08]would require the resulting heat [01:37.00]to be contained in an economical way. [01:40.84]Still, scientists at Britain's Oxford University, [01:45.96]America's Massachusetts Institute of Technology [01:50.56]and other places say they are making progress. [01:55.24]The British government believes a working model [01:59.68]for producing electricity [02:02.20]can be in place by the year 2040. [02:06.08]Advanced nuclear plants would be smaller [02:10.36]than today's massive nuclear reactors. [02:14.40]Experts say they could be used in rural areas [02:19.60]and could take over for wind and solar power [02:23.96]when the sun goes down or the wind dies. [02:28.20]But advanced nuclear reactors [02:32.08]are difficult and costly to build. [02:35.80]Critics say they would also create more dense waste. [02:41.52]And they would run on uranium, which is far more [02:46.60]enriched than fuel used in today's reactors. [02:51.32]That could make some advanced reactors more [02:55.84]appealing to militants seeking materials to make weapons. [03:02.24]In the United States, Bill Gates has said he aims [03:07.00]to build a reactor that uses advanced nuclear technology [03:12.48]for about $1 billion. [03:15.68]His plans call for many advanced nuclear plants [03:20.40]to be operational by the 2030s. [03:24.20]China, Russia and Japan are also working on the technology. [03:31.80]Last month, a Swiss company announced [03:35.48]it had launched the world's largest [03:38.40]carbon capturing plant in Iceland. [03:42.12]The system captures carbon dioxide (CO2) [03:47.48]directly from the air and puts the gas underground. [03:53.44]Currently, there are 15 direct air capture plants [03:57.88]operating worldwide. [04:00.28]The International Energy Agency (IEA) [04:05.28]estimates the plants capture more than 9,000 [04:09.76]metric tons of CO2 per year. [04:14.56]While that might sound like a lot, it is about equal [04:19.16]to the amount produced by about 2,000 cars [04:23.56]over the same period. [04:26.28]Carbon capturing costs are currently high [04:30.12]-- in the range of $600 per metric ton of CO2 captured. [04:37.00]But supporters say those costs will fall [04:41.80]as the technology improves. [04:45.16]Supporters also say tax breaks for businesses [04:50.04]in the U.S. and other countries [04:52.92]could help the technology. [04:55.20]But critics, including the environmental group Sierra Club, [05:00.76]say offering large credits could actually lead [05:05.16]to more plants continuing to burn fossil fuels. [05:11.08]Hydrogen can be mixed with natural gas [05:14.76]to make a cleaner-burning fuel. [05:17.80]This could power a fuel cell vehicle. [05:21.68]Such a vehicle would release environmentally friendly water vapors. [05:28.40]So-called clean hydrogen can be produced [05:32.96]using energy methods such as wind and solar. [05:37.56]But those methods are more costly [05:40.80]than "grey hydrogen," which is made with fossil fuels. [05:46.96]Another possibility, known as "blue hydrogen," [05:51.48]can be made in natural gas plants that capture carbon. [05:56.40]But some scientists say that process can release methane gas, [06:03.32]which would make hydrogen no cleaner than natural gas itself. [06:09.40]Saudi Arabia, the world's largest oil exporter, [06:14.56]is planning to build a $5-billion plant [06:19.32]to produce clean hydrogen. [06:22.16]Geothermal power plants capture heat [06:26.24]up to 370 degrees Celsius far below the Earth's surface. [06:34.00]The heat creates steam that [06:36.84]can turn turbines to produce electricity. [06:41.64]The United States, Indonesia, the Philippines and Kenya [06:47.32]lead the world in geothermal electricity production. [06:53.04]But the technology would need to greatly expand [06:57.12]to become a major alternative to fossil fuels. [07:02.64]Experts estimate the U.S. has the capacity [07:06.80]to produce 10 percent of the country's current power demand [07:12.24]through geothermal power. [07:14.84]But startup costs to build the technology are high. [07:20.36]This has prevented major investments so far. [07:25.44]Countries lacking in fossil fuel resources, [07:29.88]including Japan and Singapore, [07:32.88]are seeking to develop geothermal power. [07:37.08]I'm Bryan Lynn. 更多听力请访问51VOA.COM