Why air pollution darkens the sky
Weather is a good thing only when you don't mind it. Once a topic is formed, it is most likely associated with disaster.
The debate over "man-made" global warming
The internationally renowned popular science magazine "Discover" published in January this year put "Katrina" and the resulting concerns The global warming debate ranked as the top technology news story of 2005. Most meteorologists and environmental groups believe that global warming is caused by humans, and that excessive use of petrochemical energy (mainly oil, natural gas and coal) is the main cause of climate warming.
Although this is a commonplace issue, the hurricane and two snow-related photos in 2005 gave ordinary people a more intuitive understanding of this issue. One of these two photos is an aerial shot of the peak of Kilimanjaro Snow Mountain. People can clearly see that the snow on the top of the mountain has begun to melt, exposing dark brown rocks and soil. "USA Today" even listed Kilimanjaro Snow Mountain as the most scenic spot that people should see immediately, because the newspaper predicted that the highest mountain in Africa is likely to turn black forever in the near future. Another photo of snow is a comparison of satellite photos of the Arctic Circle ice cap. As can be seen from the figure, the area of white ice cover in the Arctic in 2005 was significantly reduced compared to 1979. Those who live along the coast, especially those in small island nations, may lose their homes forever due to rising sea levels caused by melting Arctic ice.
The United Nations World Meteorological Organization (WMO), headquartered in Geneva, recently released an annual report stating that the world’s average surface temperature in 2005 was higher than the 30-year average from 1961 to 1990. At 0.48 degrees Celsius, it is the world’s hottest year after 1998 since records began in 1861.
But the debate in the meteorological community is no longer whether the climate is warming, but whether this change is caused by humans. Because like many natural phenomena, the earth's temperature itself changes periodically. To understand the real reasons for the persistent high temperatures in recent years, we must take a closer look at Earth's past.
Fortunately, everything that happened on earth will leave some kind of trace. Tree rings, polar ice cores and coral polyp data can all provide indirect historical data on climate change. Michael Mann, a meteorologist at the University of Virginia, is an expert in this area. In 1998, he and two other meteorologists jointly published a research report, reconstructing a map of Earth's climate changes over the past 600 years. In 1999, they advanced this analysis to 1,000 years ago. Finally, the three people drew the analysis results into a historical graph of temperature changes. From the graph, it can be seen that the earth's average temperature curve was almost flat between 1000 and 1900 AD. After 1900, the arrival of the industrialization era, it began to rise rapidly. Curved upward, the international meteorological community calls this famous temperature chart the "hockey stick" chart.
At the end of 2004, Mann established his own website www. realclimate. org, this website has become an important platform for international meteorology enthusiasts to exchange information. In 2005, Mann recruited nine collaborators to build this website. These people are all senior experts in the field of meteorology. They have written more than 100 meteorological research reports, covering almost all fields and hot spots in meteorology. One of the most eye-catching is an article criticizing novelist Michael Crichton's new book "State of Fear".
Crichton is the author of "Jurassic Park". His "State of Fear" portrays environmentalists who support the "man-made" theory of global warming as a group of environmental terrorists and implies that Global warming is a big conspiracy created by environmental organizations to make huge profits for environmental engineering companies. Interestingly, this accusation was originally the key point for environmental groups to criticize their opponents, but the people behind it were oil companies.
This originally purely scientific debate is becoming beyond recognition due to the intervention of politics and literature. No matter how well-founded the scientific analysis of Mann and others is, their readers are destined to be smaller than those of Crichton’s fans. The novel "State of Fear" sold 1.7 million copies in its first printing and has trained millions of "meteorologists" around the world. On the website of the online bookstore Amazon, you can see more than 800 readers' comments. A considerable number of them support Clenchton's views. They are staunch supporters of Bush's environmental policies. It is precisely because of the Bush administration's change of face that the U.S. government withdrew from the Kyoto Protocol, an agreement established by the United Nations to reduce greenhouse gas emissions. Although this protocol went through many hardships and finally came into effect in early 2005, the actual effect of the Kyoto Protocol was compromised because the United States, which accounts for more than a quarter of the world's greenhouse gas emissions, did not participate.
Hurricane Katrina on August 29, 2005, almost razed New Orleans to the ground, giving environmental groups hope of persuading the U.S. government. In the day after Katrina, reporters and government officials expressed their views on the connection between hurricanes and global warming.
Senior reporter Ross Gerberspan wrote an article in the Boston Globe on August 30: "The National Weather Service calls this hurricane 'Katrina,' but its real name should be global warming." < /p>
Many people suspect that the increase in the frequency of hurricanes in North America in recent years is related to global warming. However, the meteorological community generally believes that the frequency of hurricanes itself has a natural cycle. The northern hemisphere is currently on the rise. This change is related to Global warming has nothing to do with it. However, a group of meteorologists represented by MIT meteorology professor Kelly Emanuel believe that global warming has led to an increase in hurricane intensity. Kelly published a research report in the journal Nature in August last year, claiming that the intensity of North American hurricanes has more than doubled from the 1970s, and this change is directly linked to rising sea surface temperatures. According to Emanuel's early calculations, for every 1 degree Celsius increase in sea surface temperature, hurricane wind speeds will increase by 7%. The intensity of several North American hurricanes in 2005 not only proved his point, but was much stronger than he expected.
However, this research report also attracted objections.
William Gray, a meteorologist at Colorado State University, publicly stated: "Emanuel's article is terrible, the worst article I have ever read!" Another senior hurricane expert, Christopher Lancy, pointed out , Emanuel's research is full of loopholes. The main reason is that the method of measuring hurricane wind speed has been improved. The error of the previous measurement method was too large, and the data obtained was not reliable, so it could not be compared with the current data.
Scientific arguments will eventually come to light, but accusations based on morality are not so simple. Lancy, who now works at the National Hurricane Research Center in the United States, publicly announced his withdrawal from the Intergovernmental Panel on Climate Change (IPCC). He felt that the IPCC interfered with serious scientific research. The Keto Institute, an independent think tank in the United States, even published a research report pointing out that the IPCC is not a scientific research institution in the true sense, but a propaganda department influenced by politicians. "Keto" predicts that the United States will allocate US$4 billion to climate research in the next fiscal year. In order to ensure the intensity of funding, the red flag of "global warming" must not fall.
Who is right and who is wrong? It’s not clear yet. But this kind of controversy in the meteorological community gave the Bush administration a very good-sounding excuse to refuse to sign the Kyoto Protocol.
Two latest findings support the theory of "man-made"
Let's put aside politics for a moment and focus on two of the most interesting findings of meteorological research in 2005. One is the latest report from the "European Antarctic Ice Core" (EPICA) project. Scientists drilled ice cores in Antarctica that were 650,000 years old, which is 210,000 years earlier than previously obtained data. This research can be traced back to 1990, when scientists began to mine ice cores from the Greenland ice sheet. Some of these huge icicles are 3,000 meters long, and the bubbles in them completely preserve the climate of the past 110,000 years. Data is more accurate and credible than any indirect analysis. The "European Antarctic Ice Core" project turns its attention to the more ancient Antarctica, pushing humankind's understanding of the earth's conditions in ancient times forward by hundreds of thousands of years. Analysis shows that in the past 650,000 years, the level of carbon dioxide in the atmosphere has never exceeded 300PPM (three hundred parts per million), while the current level of carbon dioxide has reached 380PPM, which is 27% higher than the pre-industrial peak. . The new findings clearly show how human activity affects levels of greenhouse gases.
Another new discovery is not actually new, but it finally attracted public attention last year. As early as the early 1990s, scientists proposed that air pollution caused by burning fossil fuels (especially coal) would reduce the intensity of sunlight hitting the earth's surface. Aircraft exhaust can have the same effect. The "9?11" incident gave meteorologists a golden opportunity, because all civilian aircraft in the United States were grounded for three days. Measurements show that during these three days, the temperature in the United States increased by approximately 1 degree Celsius. This phenomenon called "Global Dimming" has been unknown to the world. It was not until January 2005 that the British BBC Television Discovery Channel broadcast a special program that ordinary people knew about it for the first time. thing.
These two interesting new scientific discoveries are related to each other. The former points out that human overexploitation of fossil fuels has greatly changed surface temperatures in a short period of time. The latter suggests that this change will also trigger global dimming, leading to global cooling. At first glance, one might think that the two cancel each other out and are nothing to worry about. In fact, this is not the case. The air pollution that causes global dimming will bring various diseases to people and must be controlled no matter what. The greenhouse gases that cause global warming are invisible and intangible. They are not air pollution in the ordinary sense, so ordinary people ignore their impact. Many meteorologists believe that the record-breaking heat in Europe in 2003 was caused by Europe's efforts to reduce air pollution and reduce the degree of "global dimming" in recent years, but did not reduce carbon dioxide levels accordingly.
In other words, "global dimming" caused by air pollution is likely to temporarily conceal the truth of global warming, which is more serious than currently observed.
These two new discoveries tell us that meteorology is an extremely complex subject that involves too many factors and is difficult to predict accurately. For example, the severe cold in Europe that started at the end of last year made many people exclaim: Isn’t it about global warming? Why is it so cold this winter! In fact, this severe cold is ultimately caused by global warming, because rising temperatures cause Arctic ice and snow to melt, reducing the salinity of the North Atlantic seawater, thereby slowing down the flow of warm seawater near the equator to the north, and this warm current is Europe's The main reason why the winter in Siberia is not as cold as in Siberia.
Because greenhouse gases can bring about many unexpected consequences, the term "climate change" is popular in the international meteorological community to replace "global warming". As Richard Alley, a professor at Pennsylvania State University, once said, there is a critical point in the balance of climate. When climate change exceeds a certain critical point, drastic changes will occur. Perhaps global warming itself is not enough to cause the hurricanes in the North American summer and the severe winter in Europe in 2005, but global warming is accelerating the Earth's climate toward a critical point. Once the tipping point is exceeded, humanity faces not just a few hurricanes but a true catastrophe.
In order to slow down or even avoid the coming of catastrophe, humans must take action immediately. The annual United Nations climate conference held in Montreal, Canada, at the end of November 2005 was a good start. The meeting discussed new emission reduction plans after the expiration of the Kyoto Protocol in 2012. Although no substantive agreement was (and could not) be signed, at least this meeting brought leaders of various countries back to the negotiating table and formulated a framework for future negotiations. This is the biggest victory. China sent a large delegation to attend this meeting, but unfortunately very few people from the Chinese media attended. This conference has a great relationship with China. Whether Chinese companies can absorb hundreds of millions of dollars in environmental protection investment after 2012 will largely depend on the outcome of the negotiations at this conference.
China will become the largest beneficiary of the "Kyoto Protocol" due to the CDM mechanism
The "Kyoto Protocol" is essentially an environmental protection law specifically targeted at developed countries and does not provide benefits to developing countries. The country sets emission limits, and even the new version of the XX Protocol after 2012 is unlikely to do so. However, China still has a close relationship with the Kyoto Protocol because of a flexible mechanism called CDM. The full name of CDM (Clean Development Mechanism) is "Clean Development Mechanism", which means developed countries pay for emission reduction projects in developing countries. Of course, developed countries do this because the CDM mechanism allows them to use the emission reductions obtained in developing countries to offset their own emission reduction targets, because the cost of emission reductions in developed countries is generally higher than that in developing countries.
This CDM is the result of many years of hard negotiations. According to Professor Zou Ji, one of the negotiators of the Chinese delegation and deputy dean of the School of Environment at Renmin University, the Kyoto Protocol and the CDM are the wealth left to us by the older generation of Chinese negotiators. In particular, Mr. Zhong Shukong, the first chief negotiator of the Chinese delegation, once served as an interpreter for Premier Zhou Enlai and was a master of diplomacy. He once said that international negotiations on global warming are not climate negotiations, but climate negotiations. political negotiations. This seems very profound today. Because it is closely related to the energy strategies of various countries around the world, this negotiation has become a stage for politicians from various countries to compete.
Some people say that the Kyoto Protocol is a competition between developed and developing countries. Professor Zou Ji disagrees with this statement. He believes that this negotiation is essentially a competition between developed countries, especially the EU and the United States. The EU does better than the United States in the field of environmental protection, and they want to use this advantage to compete with the United States economically. The reason why the United States has a tough attitude on this issue is not because American scientists do not believe in the dangers of global warming, but because it does not want to lose to the EU economically.
The withdrawal of the United States from the "Kyoto Protocol" will cause China to lose a lot in CDM projects, because the United States accounts for 1/4 of the world's greenhouse gas emissions. If the United States joins, the total funds for CDM projects will be more than Now there are several times more. In order to compete for limited funds, developing countries secretly compete with each other and compete fiercely with each other. In order to prevent China from benefiting too much, some countries have set up obstacles in the rules and obstructed China's CDM projects. Thanks to the efforts of Chinese negotiators and scientists, the United Nations recently passed the "Emission Reduction Verification Baseline Methodology" for coal-bed methane projects. From then on, emission reduction mechanisms that rationally utilize coal-bed methane can be included in CDM projects. As we all know, China is a major coal-producing country. If coalbed methane projects are included, China will become the largest beneficiary of international environmental protection funds in CDM projects. Therefore, some people call CDM "Chinese Development Mechanism".
However, Professor Zou Ji believes that climate change is, after all, a problem for the entire planet, and it transcends the concept of a country.
The Chinese delegation is not wrong in emphasizing the interests of developing countries in international negotiations, because the population of developing countries accounts for 80% of the world's total population. Defending the interests of developing countries is equivalent to defending the interests of the entire world.
China’s sunlight has weakened by 10% in the past 50 years
Researchers at the Pacific Northwest National Laboratory in Washington recently published research results saying that through nearly 500 ground-based sunlight receiving and recording instruments spread across China , they found that since 1954, the solar radiation on the ground has dropped by about 2% every decade. Compared with 50 years ago, the sunlight in China has weakened by 10% on average.
At the same time, the rate of water evaporation across China is also declining, by about 1.5 inches every 10 years. Corresponding to the decline in evaporation rate, the amount of cloud cover in China's sky has been decreasing over the past 50 years, by approximately 0.78% every 10 years.
Because the cloud cover is also decreasing, it can be ruled out that cloud obstruction causes the light to weaken. Researchers say it is the massive emissions caused by the burning of coal and petroleum fuels that form the smog that covers China. This layer of smog absorbs and reflects sunlight, causing China to become darker.
The smog formed by this pollutant not only blocks sunlight but also brings acid rain and respiratory diseases