Farming and global warming

The Francis Effect: How Pope Francis Changed the Conversation About Global Warming

Abstract. Understanding the influence of global warming on regional hydroclimatic extremes is challenging. To reduce the potential risk of extremes under future climate states, assessing the change in extreme climate events is important, especially in Asia, due to spatial variability of climate and its seasonal variability. Here, the changes in hydroclimatic extremes are assessed over the Asian monsoon region under global mean temperature warming targets of 1.5 and 2.0 ∘C above preindustrial levels based on representative concentration pathways (RCPs) 4.5 and 8.5. Analyses of the subregions classified using regional climate characteristics are performed based on the multimodel ensemble mean (MME) of five bias-corrected global climate models (GCMs). For runoff extremes, the hydrologic responses to 1.5 and 2.0 ∘C global warming targets are simulated based on the variable infiltration capacity (VIC) model. Changes in temperature extremes show increasing warm extremes and decreasing cold extremes in all climate zones with strong robustness under global warming conditions. However, the hottest extreme temperatures occur more frequently in low-latitude regions with tropical climates. Changes in mean annual precipitation and mean annual runoff and low-runoff extremes represent the large spatial variations with weak robustness based on intermodel agreements. Global warming is expected to consistently intensify maximum extreme precipitation events (usually exceeding a 10 % increase in intensity under 2.0 ∘C of warming) in all climate zones. The precipitation change patterns directly contribute to the spatial extent and magnitude of the high-runoff extremes. Regardless of regional climate characteristics and RCPs, this behavior is expected to be enhanced under the 2.0 ∘C (compared with the 1.5 ∘C) warming scenario and increase the likelihood of flood risk (up to 10 %). More importantly, an extra 0.5 ∘C of global warming under two RCPs will amplify the change in hydroclimatic extremes on temperature, precipitation, and runoff with strong robustness, especially in cold (and polar) climate zones. The results of this study clearly show the consistent changes in regional hydroclimatic extremes related to temperature and high precipitation and suggest that hydroclimatic sensitivities can differ based on regional climate characteristics and type of extreme variables under warmer conditions over Asia.

CLIMATE models suggest that increases in greenhouse-gas concentrations in the atmosphere should have produced a larger global mean warming than has been observed in recent decades, unless the climate is less sensitive than is predicted by the present generation of coupled general circulation models1,2. After greenhouse gases, sulphate aerosols probably exert the next largest anthropogenic radiative forcing of the atmosphere3, but their influence on global mean warming has not been assessed using such models. Here we use a coupled oceana¤-atmosphere general circulation model to simulate past and future climate since the beginning of the near-global instrumental surface-temperature record4, and include the effects of the scattering of radiation by sulphate aerosols. The inclusion of sulphate aerosols significantly improves the agreement with observed global mean and large-scale patterns of temperature in recent decades, although the improvement in simulations of specific regions is equivocal. We predict a future global mean warming of 0.3 K per decade for greenhouse gases alone, or 0.2 K per decade with sulphate aerosol forcing included. By 2050, all land areas have warmed in our simulations, despite strong negative radiative forcing in some regions. These model results suggest that global warming could accelerate as greenhouse-gas forcing begins to dominate over sulphate aerosol forcing.

Balance – as a journalistic norm in the domain of climate change reporting – is measured by analyzing both coverage of the debate over anthropogenic contributions to global warming (i.e., the existence of anthropogenic global warming) and coverage of decisions regarding action on global warming (i.e., actions regarding global warming) (Boykoff & Boykoff, 2004). Field of application/theoretical foundation: Balance is a commonly investigated and internationally agreed-upon journalistic norm that ensures that journalists portray different sides of a story in a neutral and objective way (Westerståhl, 1983). In science reporting, more specifically in reporting on climate change, this journalistic norm can lead to biased reporting in that sense that journalistic coverage does not mirror the scientific understanding (i.e., climate change does exist and action is needed) (Boykoff & Boykoff, 2004). References/combination with other methods of data collection: There are experimental studies that test the effects of differentially balanced news stories (e.g., Clarke et al., 2014; Dixon & Clarke, 2012), largely confirming that balanced coverage reduces confidence in a scientific consensus and heightens uncertainty of science, risks, etc. Example studies: Boykoff & Boykoff (2004); Boykoff (2007); Clarke (2008); Clarke et al. (2014); Dixon & Clarke (2012) Information on Boykoff & Boykoff, 2004 Authors: Maxwell T. Boykoff & Jules M. Boykoff Research question: The prevalence of the norm of balance in reporting on climate change and the degree to what this coverage’s adherence to balance led to biased coverage of both anthropogenic contributions to global warming (i.e., its existence) and resultant action. Object of analysis: A sample (636 articles) of the US prestige-press coverage of global warming, i.e., New York Times, Washington Post, Los Angeles Times, Wall Street Journal Time frame of analysis: between 1988 and 2002 Info about variables Variables: Two measures of balance: (a) Coverage of the debate over anthropogenic contributions to global warming (i.e., existence) (b) Coverage of decisions regarding action on global warming (i.e., action) Level of analysis: Newspaper article Variables and values: (a) First measure: Coverage of the debate over anthropogenic contributions to global warming (i.e., existence) Article only presents argument that anthropogenic global warming exists, clearly distinct from natural variations Article presents both sides, but emphasizes that anthropogenic global warming exists, still distinct from natural variation Article presents a balanced account of debates surrounding existence of anthropogenic global warming Article presents both sides, but emphasizes dubious nature of the claim that anthropogenic global warming exists (b) Second measure: Coverage of decisions regarding action on global warming (i.e., action) Dominant coverage of decisions/assertions regarding immediate/mandatory action to deal with global warming Balanced accounts of various decisions regarding action Dominant coverage of decisions/assertions regarding cautious/voluntary approaches to deal with global warming Reliability: Intercoder reliability rate of 93% Codebook: Table 1 in Boykoff & Boykoff (2004, p. 128)

PDF HTML阅读 XML下载 导出引用 引用提醒 模拟增温条件下接种AMF对夏蜡梅幼苗生长与光合生理特性的影响 DOI: 10.5846/stxb201501220177 作者: 作者单位: 台州学院生态研究所,台州学院生态研究所,台州学院生态研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31400423）；浙江省自然科学基金（LQ14C030001）；台州学院生态学浙江省重点学科开放课题（EKD2013-07） Effects of AMF inoculation on growth and photosynthetic physiological characteristics of Sinocalycanthus chinensis under conditions of simulated warming Author: Affiliation: Taizhou University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:全球变暖已对植物尤其是珍稀濒危植物产生重要影响。AMF对植物应对气候变化具有重要意义，但是在濒危植物应对气候变暖过程中发挥的作用并不清楚。以濒危植物夏蜡梅（Sinocalycanthus chinensis）一年生幼苗为对象，研究人工模拟增温条件下接种AMF对其生长、形态建成、光合生理、抗氧化酶活性和膜脂过氧化程度、营养物质积累和叶绿素相对含量的影响。实验共4个处理：模拟增温条件下添加AMF（AMF+SW）、添加AMF（AMF）、模拟增温（SW）和对照（CK）。结果表明：（1）接种AMF对幼苗株高、叶宽长比、总根长、根平均直径、根尖总数、比根长和比根表面积有显著影响。（2）AMF+SW条件下幼苗光合日进程呈现出明显"双峰"曲线，AMF显著提高叶片日均净光合速率（Pn）；光合有效辐射大于50 μmol m-2 s-1时，AMF+SW和AMF处理的Pn、最大净光合速率Pnmax和呼吸速率Rd显著高于CK；胞间CO2浓度大于100 μmol CO2/mol时，AMF+SW与AMF处理的Pn、AMF+SW处理的初始羧化效率（α）及AMF处理的光合能力（Amax）显著高于CK，而AMF+SW和AMF处理的CO2补偿点均低于CK。（3）AMF处理的叶可溶性糖显著高于其它处理，AMF+SW和AMF处理的叶可溶性蛋白显著高于CK。因此，AMF能显著促进夏蜡梅幼苗的形态建成和光合作用；在模拟增温条件下，接种AMF对夏蜡梅光合生理具有显著影响。 Abstract:The global climate warming is affecting ecosystems, especially endangered plant species whose distribution is mostly restricted to few areas. Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with many plant species, supplying mineral nutrients to their host plants. Sinocalycanthus chinensis is a national second-class protected plant species, distributed in only a few areas in Zhejiang and Anhui provinces in China. Preliminary investigation has revealed higher infection rate of natural populations of S. chinensis by AMF. The role of AMF in S. chinensis under global warming has remained unknown. To reveal the effects of AMF on S. chinensis under the conditions of global climate warming, the pot experiment was conducted with one-year-old S. chinensis seedlings inoculated with AMF (inoculation of rhizosphere soil at a rate of 5%, v/v; soil without AMF was used as control) and temperature increase was simulated by an electric radiant infrared heater (+ 2℃ measured around the leaves; normal temperature was used as control). Growth rate, morphogenesis, photosynthetic physiological characteristics, antioxidant activities, membrane lipid peroxide level, nutrient content of S. chinensis seedlings were compared under four treatments: AMF, simulated warming (SW), both AMF inoculation and simulated warming (AMF + SW), and control (CK). The results showed that: (1) AMF inoculation had a significant positive effect on plant height and average root diameter, and a negative effect on the width-to-length ratio of mature leaves, total root length, total number of root tips, special root length (root length/root biomass), and special root surface area (root surface area/root biomass). Double-factor variance analysis showed that the average root diameter and total number of root tips was significantly correlated with AMF and SW. This showed that symbiotic association between AMF and S. chinensis may modify the nutrient absorption strategy of S. chinensis through modification in root morphology. (2) The diurnal change in net photosynthetic rate (Pn) of leaves in S. chinensis seedlings under AMF + SW treatment had a typical bimodal curve that was determinately regulated by stomatal conductance. AMF affected significantly the daily mean Pn. After fitting the photosynthesis light response using modified models of rectangular hyperbola, we found that Pn in plants with AMF + SW and AMF treatments were distinctly higher than that of CK when light intensity was more than 50 μmol m-2 s-1. The double-factor variance analysis showed that AMF significantly affected the daily mean Pn, maximum net photosynthetic rate, light saturation point (LSP), and dark respiration rate, whereas SW had a significant effect on LSP. Fitting of the CO2 response by using modified models of rectangular hyperbola revealed that Pn in plants under AMF + SW and AMF treatments was significantly higher than that in the CK with increasing the concentration of CO2. Initial carboxylation efficiency under AMF + SW treatment and photosynthetic capacity under AMF treatment were significantly higher than that of the CK. The CO2 compensation point after the treatment by AMF + SW or AMF was significantly lower than that of the CK. (3) The content of soluble sugars in leaves after the treatment with AMF was significantly higher than that in other treatments. The content of soluble proteins in leaves of plants treated with AMF + SW or AMF was distinctly higher than that of the CK. The double-factor variance analysis showed that SW and AMF + SW interaction had significant effect on the content of soluble sugars in leaves, and both AMF and SW had significant effect on the content of soluble proteins in leaves. The results provided the theoretical foundation for conservation and artificial cultivation of S. chinensis under conditions of global climate change. 参考文献 相似文献 引证文献

<p>Understanding the influence of clouds and precipitation on global warming remains an important unsolved research problem. This talk presents an overview of this topic, with a focus on recent observations, theory, and modeling results for polar clouds. After a general introduction, experiments that disable cloud radiative feedbacks or “lock the clouds” within a state‐of‐the‐art,  well‐documented, and observationally vetted climate model will be presented. Through comparison of idealized greenhouse warming experiments with and without cloud locking, the sign and magnitude cloud feedbacks can be quantified. Global cloud feedbacks increase both global and Arctic warming by around 25%. In contrast, disabling Arctic cloud feedbacks has a negligible influence on both Arctic and global surface warming. Do observations and theory support a positive global cloud feedback and a weak Arctic cloud feedback?  How does precipitation affect polar cloud feedbacks? What are the implications especially for climate change in polar regions?  </p>

Tropical fire activity closely follows the co-occurrence of multiple climate stressors. Yet, it remains challenging to quantify how changes in climate alter the likelihood of fire risks associated with compound events. Recent abrupt changes in fire regimes in iconic landscapes in Brazil (namely the Pantanal and Xingu) provide a key opportunity to evaluate how extremely dry and hot conditions, both together and individually, have influenced the probability of large fires. Here we quantify the relationships between climate and fire across these regions and provide evidence on the extent to which fire risk and the associated impacts could be constrained if anthropogenic global warming is limited. We investigate the burned area, differentiating between fire types according to land use (forest fires, savanna fires, farming fires and grassland and wetland fires), and derive present and future fire risks linked to multiple climate variables. We show that concurrent air dryness (high vapour-pressure deficit (VPD)) and low precipitation have driven fire occurrence in both Xingu and the Pantanal, with VPD playing a dominant role. Historical climatic change has already increased compound event-related (CE-related) fire risks of all fire types (5%–10%), and these risks are likely to increase in the future due to global warming. The likelihood of CE-related increase in fire risk may be reduced by up to 14.4% if global warming is constrained to +1.5 °C instead of +3 °C. Nevertheless, substantially increased CE-related fire risks are still expected even if restricting global mean warming to 1.5 °C, particularly in the Pantanal. We thus conclude that climate action should be coordinated with environmental protection to reduce ignition sources and promote effective conservation measures to preserve these biomes.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 16:51-59 (2000) - doi:10.3354/cr016051 Severe summer rainfall in China associated with enhanced global warming Dao-Yi Gong1,*, Shao-Wu Wang2 1Key Laboratory for Environmental Change and Natural Disaster Research, China Ministry of Education, Institute of Resources Science, Beijing Normal University, 100875 Beijing, China 2Department of Geophysics, Peking University, 100871 Beijing, China *E-mail: gdy@pku.edu.cn ABSTRACT: Trends of extreme wet and dry conditions during recent decades were examined using observed data for eastern China. Mean precipitation for the region has shown a significant downward trend from the 1950s to the mid-1970s, and a positive trend since the late 1970s. The change in trend since the late 1970s, i.e. the period during which enhanced global warming emerged, is most prominent. The linear trend of the mean summer rainfall anomalies over the 4 subregions studied was +7.5% decade-1. Changes in the trend of severe wet and dry events are not symmetrical. During the period 1977-1998, the number of severe wet stations increased at the rate of 20.3 decade-1, but the trend for severe dry events was only -5.4 decade-1. Similar rainfall changes can be found over many global land areas. The summer rainfall in eastern China showed only a negligible secular trend during the period 1880-1998. However, the decadal variations were clear. The mean rainfall in 1990-1998 was higher than for any other decade in the last 100 yr. The linear trend of the 33-station mean during 1977-1998 was +47.5 mm decade-1; such a strong increase is unprecedented in the record since 1880. Decadal variations and global warming may both play important roles in the recent significant increase in summer rainfall. This paper also presents the results of greenhouse and/or aerosol forcing experiments, in which summer precipitation over eastern China is generally estimated to rise. There are many uncertainties, however, in the regional precipitation simulations. For example, the modeled rainfall is sensitive to whether aerosols are included or not. Further research is needed to determine whether there is a substantial relationship between the rainfall changes in China and global greenhouse warming. KEY WORDS: Severe summer rainfall · Global warming · China Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 16, No. 1. Online publication date: November 10, 2000 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2000 Inter-Research.

The validity of the manmade global warming alarm requires the support of scientific forecasts of (1) a substantive long-term rise in global mean temperatures in the absence of regulations, (2) serious net harmful effects due to global warming, and (3) cost-effective regulations that would produce net beneficial effects versus alternatives policies, including doing nothing. Without scientific forecasts for all three aspects of the alarm, there is no scientific basis to enact regulations. In effect, the warming alarm is like a three-legged stool: Each leg needs to be strong. Despite repeated appeals to global warming alarmists, we have been unable to find scientific forecasts for any of the three legs. We drew upon scientific (evidence-based) forecasting principles to audit the forecasting procedures used to forecast global mean temperatures by the Intergovernmental Panel on Climate Change (IPCC) — leg “1” of the stool. This audit found that the IPCC procedures violated 81% of the 89 relevant forecasting principles. We also audited forecasting procedures, used in two papers, that were written to support regulation regarding the protection of polar bears from global warming — leg “3” of the stool. On average, the forecasting procedures violated 85% of the 90 relevant principles. The warming alarmists have not demonstrated the predictive validity of their procedures. Instead, their argument for predictive validity is based on their claim that nearly all scientists agree with the forecasts. This count of “votes” by scientists is not only an incorrect tally of scientific opinion, it is also, and most importantly, contrary to the scientific method. We conducted a validation test of the IPCC forecasts that were based on the assumption that there would be no regulations. The errors for the IPCC model long-term forecasts (for 91 to 100 years in the future) were 12.6 times larger than those from an evidence-based “no change” model. Based on our own analyses and the documented unscientific behavior of global warming alarmists, we concluded that the global warming alarm is the product of an anti-scientific political movement. Having come to this conclusion, we turned to the “structured analogies” method to forecast the likely outcomes of the warming alarmist movement. In our ongoing study we have, to date, identified 26 similar historical alarmist movements. None of the forecasts behind the analogous alarms proved correct. Twenty-five alarms involved calls for government intervention and the government imposed regulations in 23. None of the 23 interventions was effective and harm was caused by 20 of them. Our findings on the scientific evidence related to global warming forecasts lead to the following recommendations: End government funding for climate change research. End government funding for research predicated on global warming (e.g., alternative energy; CO 2 reduction; habitat loss). End government programs and repeal regulations predicated on global warming. End government support for organizations that lobby or campaign predicated on global warming.

Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world’s largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10–20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased—particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more immediately pressing for fishes than the consequences of global warming. Limits upon dam construction should therefore be a priority action for conserving fish biodiversity in the Indo-Burma hotspot. This would minimize synergistic impacts attributable to dams plus global warming, and help ensure the continued provision of ecosystem services represented by the Lower Mekong fishery.

Waiting to Exhale?: Global Warming and Tax Policy

Mid-summer surface air temperature and its internal variability over China at 1.5 °C and 2 °C global warming

The goal of this paper is to determine whether there is a correlation between awareness of global warming, and where global warming occurs. This theory is carried out by analyzing maps containing various forms of data that have to do with global warming, such as precipitation and surface temperature, and comparing it with a map of engagement from tweets which mention global warming. This paper found that there is no solid correlation between mentioning global warming in tweets and global warming's effect, although there was a steady increase in both. This is most likely due to Twitter's user base increasing over the years. Therefore it appears that although the effects of global warming have increased, the percentage of people aware of it on major social media sites has not. This then concludes that before trying to find a solution or preventative measure to global warming, an approach must first be made to create awareness for it on social media platforms.

"Climate change" vs. "Global warming": Different public perceptions, sentiments and explanatory factors in China

The study aimed to determine the students’ knowledge, attitudes, and practices towards global warming and their relationships. The researcher utilized a descriptive-correlational design and the systematic sampling technique. The respondents of the study were 340 students from grades 7 to 12 at Sibulan National High School. The researcher used validated questionnaires and employed weighted mean, Spearman’s Rank Correlation Coefficient, mean, and percentage in treating the data. The study revealed that students’ knowledge about global warming is “very satisfactory.” Students’ attitude towards global warming is also “very positive” and their extent of practices to minimize global warming is “high.” Moreover, the study found that there is a significant and positive relationship between the students’ knowledge about global warming and their attitude towards global warming. The student’s attitude towards global warming is also significantly and positively related to their practices to minimize global warming. However, no significant relationship is found between students' knowledge about global warming and their practices to minimize it.