近幾年來,全球的氣候環境變化,似乎越來越明顯的突顯出「全球暖化」的徵兆,
從冰山融化、加州海灘飄雪到最近這幾天北美洲東岸的酷寒天候、雅加達的大水,
使得全球暖化不再是一個警語,而是已經開始顯現在我們所身處的環境當中,
這種環境的惡化還會持續多久?人們還能做些什麼?
聯合國秘書長潘基文警告,氣候變遷已讓全世界邁入「關鍵階段」,
將對人類健康與環境造成直接影響。聯合國環境計畫署今天在肯亞首都奈洛比召開會議,
潘基文向會議發表文告說:「世界已邁入關鍵階段,儘管我們懷抱善意,全球環境惡化仍每況愈下。」
除了國際之間的公約制訂外,或許每個人也應該要多想想自己還能為環境多做些什麼吧!
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Global warming is real
(本文轉載自Seattle Times)
Talk about global warming changed this week, from Washington, D.C., to Olympia. A scientific conclusion that the existence of global warming is "unequivocal" has moved discussions from what if to what now?
Debate about the reality of a half-century of rising temperatures was put to rest by the latest report of the Intergovernmental Panel on Climate Change, which found a "very likely" link to human causes. The panel, created in 1988 by the United Nations and the World Meteorological Organization, has paced its pronouncements to cycles of research on the human and natural causes of climate change. In 1990, the case for global warming was said to be serious. By 1995, a balance of evidence cast a longer shadow. In 2001, scientists said the evidence continued to accumulate.
This time, the message was blunt. Global warming has increased markedly since 1750 as a result of human causes, and its impact on shrinking snowpacks, declining sea ice, rising oceans and wetter, hotter weather will persist into the future, even if the causes stopped now.
The choice that exists is to slow the process so the worst will not happen. That is an outcome for which the globe has time and options. The behavior and leadership of the United States — a nation with 5 percent of the world's population and 25 percent of CO2 emissions — will certainly be under scrutiny.
Opportunities for finger-pointing abound, so everyone will have to get that out of their political systems.
Automobile emissions will duel with the coal-burning habits of India, China and Russia for status as the greatest villain. The instinct to protect one's national economy down to the last manhole-cover-sized piece of sea ice will be strong.
Announcements are stirring in Olympia. The willingness to get started and stay focused is as welcome as creative ideas.
Progress will come from unlikely sources. Spending more for Washington State University research on cattle feed could be a big step. Agricultural practices and methane-burping cows are a significant part of the global greenhouse effect.
Realistic solutions for quantifiable problems will be very close to home. Transportation and power generation are big parts of our lives, and primary sources of the environmental dilemma.
Last week's sober news offered a fresh start. Global warming is real. Now move on to coaxing out mitigating solutions.
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Climate change questions answered
(本文轉載自SeattlePI)
Here are climate scientists' responses to some common questions about global warming:
Doesn't climate change occur naturally?
The climate has always changed -- sometimes abruptly, but never before with human help. Carbon dioxide levels and temperatures are now headed higher than human civilization has experienced. Everyone studying the matter -- including so-called climate "skeptics" -- acknowledges that adding carbon dioxide and other greenhouse gases to the atmosphere traps more heat, warming the planet.
Don't some scientists dispute global warming?
Few do anymore. Skeptics dispute whether the heat-trapping properties of greenhouse gases are affecting our climate more than natural variability. The most recent draft of the report released today, however, says, "Warming of the climate is unequivocal" and that heating caused by man-made emissions has outpaced natural warming by at least five times.
So there is no serious disagreement among climate scientists?
Quite the contrary. But arguments among scientists actively researching the issue tend to center on questions such as: How fast is the globe likely to warm? What's the most probable amount of sea level rise? How fast will the ocean absorb the heat?
Didn't scientists say 30 years ago that we were headed for an ice age?
It's true that a small group of scientists speculated that the Earth was likely heading into an ice age. According to fossil records, warm climate periods, such as the one we're in now, usually last about 10,000 years -- and it's been about 12,000 for this one so far. Today's report says that, absent greenhouse gases, most regions in the globe would have seen slight cooling in the past few decades -- though certainly not enough to be called an ice age. Bottom line: the widespread agreement today among climate scientists is a far cry from the speculations of a few in the 1970s.
Couldn't a warmer climate be better?
There are upsides to a warmer planet. As the growing seasons lengthen you can plant your vegetables sooner in the spring. More carbon dioxide, which plants turn to food through photosynthesis, generally makes plants grow faster, but it's unclear how much. Places too cold for agriculture could become fertile. But those benefits could easily be outweighed by droughts, flooding, more intense and frequent forest fires and more insects.
Isn't key global warming research like the "hockey stick" wrong?
The "hockey stick" refers to a 1998 temperature graph spanning the past 1,000 years showing a rise in the 20th century (the upward bend of the hockey stick). A 2003 critique by an economist and a mining executive said the climate scientists' earlier analysis relied too heavily on reading tree rings in the American West, skewing the recent temperature trend upward. A National Academy of Sciences review deemed some of the criticisms valid but said the original study's basic conclusions were "supported by an array of evidence." At least seven subsequent studies agreed. Finally, the hockey stick was not the foundation of modern climate-change science -- just one of many pieces of evidence.
Isn't it too late to fix it?
Over the past 300 years, people have burned a lot of oil and coal, emitting carbon dioxide. The gas stays in the atmosphere for possibly hundreds of years, so warming already under way will last centuries. Already 3.2 billion metric tons of CO2 is added to the atmosphere annually, and the number is climbing rapidly. Scientists debate when the tipping points will be reached where warming and damage become uncontrollable. But virtually all agree it will help matters to control the release of greenhouse gases.
Scientists blew their earlier projections of sea-level rise, so why should we believe this one?
Actually, the new report only slightly revises the probabilities of some of the most harmful scenarios regarding sea-level rise. The median projection is basically the same as in the last report.
Sources: International Panel on Climate Change; Realclimate.org; University of Washington Climate Impacts Group; National Academy of Sciences; University of Guelph, Ontario; Climateaudit.org; Geophysical Research Letters; Woods Hole Oceanographic Institute; U.S. Department of Energy.
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