记得上几周我在温景嵩老师的博文“退休之乐（5）：亮出了批判IPCC错误论断的旗帜”评论里面支持全球变暖，温老师举了北大钱维宏教授得到的一个例子，认为“在年际和年代际的气温实际变化和人类活动排放出的二氧化碳的实际变化呈现出一种反相关的关系”，后来我去查看cctv2“面对面”对钱教授的采访，好像是举得1970年到2000年的温度数据（具体忘了，差不多这么多）。我现在说的这篇文章，恰好可以部分解释这个反例。 这篇我们组的题为“ The Hindcast Skill of the CMIP Ensembles for the Surface Air Temperature Trend ”（ http://www.agu.org/pubs/crossref/2012/2012JD017765.shtml ）的文章刚刚发表在JGR-Atmospheres上，论文的第一作者Koichi（和我合作了两篇文章，还未发表）分析了大概50个IPCC的实验结果，从不同时间（10年~100年）和空间（10°到半球尺度）尺度分析了模式对过去温度趋势的模拟能力，结果证明在洲际以上地理尺度和30年以上的时间尺度上模式表现出了很好的模拟能力，但在地区尺度和时间小于30年的范围内，模式的结果不是很可靠（相关报道见 http://uanews.org/story/ua-climate-scientists-put-predictions-test ）。 回到最开始的争论，钱老师的结果是正确的，前提是在一定的时空尺度下。现在IPCC的实验大概都是30年到100年（或者300年）尺度，虽然CO 2 导致的增温的强度不可能十分精确，但是模式告诉我们地球在未来100年在CO 2 增长的情况下的确会变暖，即使某些地区某个时间段（小于30年）会呈现出降温的趋势。
It's only 73F in my living room at 7:23 am. I have to put socks on. So, I would say it's a cold winter day in Hawaii. However, I will never agree with those people who think burning oil, gas, and coal is ok. It is NOT ok. One third of the CO2 we release into the atmosphere is absorbed by the world ocean. So, the ocean is becoming more acid. Read about ocean acidification, and you will be as worried as most oceanographers about the future of the Earth.
3 June 2011 | By Stephen Harris Carbon dioxide is bad. That’s the common thread in public discourse. We’re constantly told of the need to reduce the amount of CO2 in the atmosphere and that it’s destroying the planet. Of course the reality is that carbon dioxide is a key part of the natural cycle of energy and vital to the survival of all life on this planet. It also has a wide range of commercial uses. So should we see CO2 as more of a resource than a problem? Our supplies of the gas are set to increase massively as carbon-capture power plants become a reality, and scientists and industry are increasingly looking for new ways to use and hopefully monetise it. Carbon dioxide is already used in food preparation and preservation, in drug and chemical processing, in water treatment, welding and pneumatics. None of these applications will soak up all the CO2 we’re going to produce in the next fifty years, though at least CCS power stations could become more cost-effective if they sell the gas on. But what if we could develop a use for carbon dioxides that actually helped the climate change cause and made a big impact on greenhouse gas emissions? Injecting CO2 into oil wells as they dry up keeps it out of the atmosphere but also helps get more oil out, meaning we have more fossil fuels to burn and even more CO2 to deal with. A different idea, as highlighted in our recent feature , is to mineralise CO2 to create products for use in the construction and food industries. If we can make it economical and energy efficient, we could even take the waste materials of existing cement-making processes – ash and carbon dioxide – and combine them to make a stronger form of cement. Nature, as so often is the case, could also provide a solution – photosynthesis. It gives plants their own wonderful use for CO2, but unless we literally go back to living in forests by covering the whole world in trees, there’s really only so much they can do for us. Instead, some scientists are hoping to deliver an artificial version of photosynthesis that effectively turns carbon dioxide into an energy storage medium. If we can efficiently use sunlight to power the reaction, we can transform the pesky gas (and water) into usable fuels. Of course, we are already turning plants into fuel with serious consequences for food prices. Around 40 per cent of corn grown in the US is now used to make ethanol instead of feeding humans and animals, according to the Department of Agriculture. Photosynthesising algae could provide one alternative to this. Another idea is to do the energy conversion ourselves. Scientists at MIT have already developed a ‘practical artificial leaf’ that uses solar energy and inexpensive catalysts to produce hydrogen from water with efficiencies much greater than those of real leaves. Find a way of efficiently adding carbon dioxide to this artificial process and we could create biofuels to use in our existing fuel infrastructure without the need to rely on growing plants (and impacting food production). Though all these ideas are still at the laboratory stage, the business world is taking notice. Spanish research institute MATGAS, which is majority-owned by industrial gas company Air Products, is coming to the end of a Though all these ideas are still at the laboratory stage, the business world is taking notice. Spanish research institute MATGAS, which is majority-owned by industrial gas company Air Products, is coming to the end of a
Ward began to study the effects of rising carbon dioxide levels on plant physiology and development as a graduate student at Duke University with Boyd Strain. “We would expose plants to high CO2 and measure what happened. CO2 is the substrate for photosynthesis, so with high CO2 you often see stimulation of photosynthesis and reproduction. But we also know that in the field, rising CO2 also causes warming. And as you warm plants up, they have higher respiration rates, which can actually reduce some of the gain in carbon they accumulated from the high carbon dioxide.” So the effects of CO2 can be positive and negative—and even unexpected. Ward conducted a study to examine how plants might evolve to adapt to conditions of elevated CO2. She grew Arabidopsis in concentrations of CO2 that were either as high as predicted for the future or as low as has been measured in the past. She then selected and bred the individuals that produced the most seeds. After five generations, she found that the plants that were most fecund under high-CO2 conditions had sped up their life cycle. As a result, they actually produced less biomass than plants that were picked from the population at random. “That was not what I expected,” says Ward. “I thought that plants selected for high seed number under high CO2 would be much larger. But they weren’t. That suggests that genetic change is possible even in a relatively short amount of time —and that the way plants respond to rising CO2 can be surprising.” Read more: Harvesting Ideas - The Scie ntist - Magazine of the Life Sciences http://www.the-scientist.com/article/display/58072/#ixzz1K6zSxO28
GRL Eitors Highlight Temporary acceleration of the hydrological cycle in response to a CO2 rampdown Peili Wu Met Office Hadley Centre, Exeter, UK Richard Wood Met Office Hadley Centre, Exeter, UK Jeff Ridley Met Office Hadley Centre, Exeter, UK Jason Lowe Met Office Hadley Centre, Exeter, UK Current studies of the impact of climate change mitigation options tend to scale patterns of precipitation change linearly with surface temperature. Using climate model simulations, we show a nonlinear hydrological response to transient global warming and a substantial side effect of climate mitigation. In an idealised representation of mitigation action, where we reverse the trend of global warming, the precipitation response shows significant hysteresis behaviour due to heat previously accumulated in the ocean. Stabilising or reducing CO2 concentrations in the atmosphere is found temporarily to strengthen the global hydrological cycle, while reducing rainfall over some tropical and subtropical regions. The drying trend under global warming over The Amazon, Australia and western Africa may intensify for decades after CO2 reductions. The inertia due to accumulated heat in the ocean implies a commitment to hydrological cycle changes long after stabilisation or reduction of atmospheric CO2 concentration. Received 26 April 2010; accepted 17 May 2010; published 23 June 2010. Citation: Wu, P., R. Wood, J. Ridley, and J. Lowe (2010), Temporary acceleration of the hydrological cycle in response to a CO2 rampdown, Geophys. Res. Lett., 37, L12705, doi:10.1029/2010GL043730.
Steven D. Allison, Matthew D. Wallenstein, Mark A. Bradford. Soil-carbon response to warming dependent on microbial physiology . Nature Geoscience , 2010; DOI: 10.1038/ngeo846 全球变暖的情况下，微生物的生理活动可能决定了土壤中向大气释放CO2的量。 多数生态系统模型都预测，随着全球温度的升高将会刺激微生物对土壤C的分解活动，从而形成一个正反馈。但是来自UC Irvine, Colorado State University and the Yale School of Forestry Environmental Studies 等单位的科学家发现随着全球温度的升高，土壤微生物在将土壤中的C转变为CO2的过程的效率将随时间的推移而降低。 以前的模型中都没有考虑到酶的活性的问题，而这些研究者的模型中考虑了酶活性在温度升高过程的变化情况。微生物产生的酶在土壤有机碳转变为CO2的过程中发挥着重要作用。
标签: CO2
