关于拯救地球环境和有关自然灾害的英文文章

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Counting carbon Jay Gregg Creating national emissions inventories seemed easy: I would simply take the energy consumption of a country, break it down by fuel type, multiply by a carbon-emissions factor and sum the figures. This was years ago, when I first started to determine the seasonal cycles of fossil fuel carbon dioxide (CO2) emissions in an effort to improve scientific understanding of the global carbon cycle. It was a collaborative effort with the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory in the United States, one of the main data warehouses for emissions inventories. However, after spending a jet-lagged afternoon in Indonesia's ministry of petroleum thumbing through coffee-stained reports, searching the shelves for missing pages and volumes and trying to make sense of data that looked like they were created by a random number generator, I realised that I had been a bit naïve. Data from Indonesia has improved considerably since then, though for many developing nations the figures are still spotty at best. Even for more developed countries, data quality varies substantially. While the United Nations Framework Convention on Climate Change (UNFCCC) has created guidelines for reporting emissions inventories, many countries lack the resources to provide reliable and transparent data in a timely manner. Recently, there has been a concerted scientific effort (e.g. here, here and here)to better quantify the level of uncertainty in emissions inventories. And politically, a lot of attention is currently focused on the uncertainty in China's data – which often lacks transparency and reliability. For scientists, uncertainty is a normal part of our work and emissions inventories are no exception. It is clear that the level of uncertainty is currently too high for political and economic purposes, and some improvements should be made. However, we have neither the time to wait, nor the resources to produce perfect inventories, so this should not be an excuse to further stall talks. We should set a goal for an acceptable and realistic level of uncertainty in emissions inventories and create an international action plan to achieve it. Emissions inventories are verified by a panel of international experts at the UNFCCC, but it is often difficult to know how accurate the reported emissions are when national statistics lack transparency. Scientists could quickly recognise if the global total was off the mark, but it would not be easy to determine which countries had incorrectly reported their numbers. Scientists do their best to quantify the uncertainty by looking at the revisions countries have made to their reports and inconsistencies in the underlying statistics. The majority of carbon-dioxide emissions come from fossil-fuel combustion. However, energy statistics are notoriously tricky, because fossil fuels are dug out of the ground, transported, processed and consumed in myriad ways. There are many accounting challenges: private consumers stockpile fuels or obtain them from black markets; military fuel use is usually not reported; some data are withheld because of non-disclosure agreements with private companies; national agencies use different units, statistical techniques and data-collection methods. Even after countries publish energy reports, they still make data revisions, sometimes even decades later. Because of the enormous task in obtaining, processing and making sense of the underlying data, building an inventory can be challenging, time-consuming and expensive. Nevertheless, scientists try to create something as close to reality as possible. Unfortunately, for most countries the scientific uncertainty in their emissions inventories is roughly as large as their proposed reductions under the Kyoto Protocol (this also speaks to the fact that the reduction targets are most likely too modest to keep the globe from warming two degrees Celsius above pre-industrial levels). Even for the United States, which keeps meticulous data, the margin of error for annual fossil fuel carbon-dioxide emissions calculations is 3% to 5%. For China, we estimated the uncertainty to be about 15% to 20%. For some of the less developed countries, it is likely much higher. The majority of the world's carbon emissions come from just a handful of countries, so improving estimates from a few key players can reduce the overall uncertainty in global emissions. For example, the total industrial carbon-dioxide emissions from Africa are roughly equal to the uncertainty in the industrial carbon-dioxide emissions from China, since China's emissions are more than five times ...