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1.
相对于工业化革命前期,全球年平均地表气温上升2℃的时间和相应的气候变化受到了广泛关注,特别是包括欧盟成员国在内的许多国家和国际组织已经将避免2℃全球变暖作为温室气体减排的首要目标.为此,本文作者基于16个气候模式在20世纪气候模拟试验和SRES B1、A1B和A2温室气体和气溶胶排放情景下的数值模拟试验结果,采用多模式集合方法预估研究了2℃全球变暖发生的时间、对应的大气中主要温室气体浓度以及中国气候变化情况.根据模式集合平均结果,三种排放情景下2℃全球变暖分别发生在2064年、2046年和2049年,大气二氧化碳当量浓度分别为625 ppm、645 ppm和669 ppm(1 ppm=10-6).对应着2℃全球变暖,中国气候变暖幅度明显更大.从空间分布形势上看,变暖从南向北加强,在青藏高原地区存在一个升温大值区;就整体而言,中国区域平均的年平均地表气温上升2.7～2.9℃,冬季升温幅度(3.1～3.2℃)要较其他季节更大.年平均降水量在华南大部分地区减少0～5％,而在其余地区增加0～20％,中国区域年平均降水增加3.4％～4.4％,各季节增加量在0.5％～6.6％之间. 相似文献
2.
Using a set of numerical experiments from 39 CMIP5 climate models, we project the emergence time for 4°C global warming with respect to pre-industrial levels and associated climate changes under the RCP8.5 greenhouse gas concentration scenario. Results show that, according to the 39 models, the median year in which 4°C global warming will occur is 2084. Based on the median results of models that project a 4°C global warming by 2100, land areas will generally exhibit stronger warming than the oceans annually and seasonally, and the strongest enhancement occurs in the Arctic, with the exception of the summer season. Change signals for temperature go outside its natural internal variabilities globally, and the signal-to-noise ratio averages 9.6 for the annual mean and ranges from 6.3 to 7.2 for the seasonal mean over the globe, with the greatest values appearing at low latitudes because of low noise. Decreased precipitation generally occurs in the subtropics, whilst increased precipitation mainly appears at high latitudes. The precipitation changes in most of the high latitudes are greater than the background variability, and the global mean signal-to-noise ratio is 0.5 and ranges from 0.2 to 0.4 for the annual and seasonal means, respectively. Attention should be paid to limiting global warming to 1.5°C, in which case temperature and precipitation will experience a far more moderate change than the natural internal variability. Large inter-model disagreement appears at high latitudes for temperature changes and at mid and low latitudes for precipitation changes. Overall, the inter-model consistency is better for temperature than for precipitation. 相似文献
3.
ZHANG Ying 《大气和海洋科学快报》2012,5(6):514-520
The outputs of 17 models in the Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed to investigate the temporal and spatial features of 2.0°C warming of the surface temperature over the globe and China under the Representative Concentration Pathways (RCP) 4.5 scenario. The simulations of the period 1860-1899 in the "historical" experiment are chosen as the baseline. The simulations for the 21st century in the RCP4.5 experiment are chosen as the future project. The multi-model ensemble mean (MME) shows that the global mean temperature would cross the 2.0°C warming threshold in 2047. Warming in most of the models would cross the threshold during 2030-2060. For local warming, high-latitude areas in the Northern Hemisphere show the fastest warming over the globe. Land areas warm substantially faster than the oceans. Most of the southern oceans would not exceed the 2.0°C warming threshold within the 21st century. Over China, surface warming is substantially faster than the global mean. The area-averaged warming would cross the 2.0°C threshold in 2034. Locally, Northwest China shows the fastest warming trend, followed by Central North China and Northeast China. Central China, East China, and South China are the last to cross the 2.0°C warming threshold. The diversity of the models is also estimated in this study. Generally, the spread among the models increases with time, and there is smaller spread among the models for the areas with the faster warming. 相似文献
4.
To clarify the link between existing infrastructure legacy and the 2°C target, we extend the work of Davis et al. (Science 329:1330–1333, 2010) by introducing non-CO2 greenhouse gases and the inertia in transportation-needs drivers. We conclude that climate policies able to maintain climate change below 2°C cannot disregard existing infrastructure. 相似文献
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We used daily maximum temperature data (1986–2100) from the COSMO-CLM (COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events (EMTEs) with the intensity–area–duration method. Between 1986 and 2005 (reference period), the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr–1, 31.4–33.3°C, and 1.76–3.88 million km2, respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and 15.98%–30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73–12.48, 0.64–2.76, and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by 23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C. 相似文献
6.
Projected changes in summer water vapor transport over East Asia under the 1.5°C and 2.0°C global warming targets 
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下载免费PDF全文 水汽输送的变化对于降水的变化有重要贡献。基于优选的13个CIV1IP5模式发现:RCP4.5和RCP8.5排放情景下,1.5°C和2.0°C增暖时东亚夏季水汽输送均加强,且2.0°C增暖时模式间一致性更好;水汽含量的增加对东亚南部和北部水汽输送的加强均有贡献,东亚南部水汽输送的加强也与低层环流的加强相联系。0.5°C额外增暖(1.5°C和2.0°C增暖间比较)时,两种排放情景下水汽输送的变化在我国南海与东北地区存在差异,使得两个地区降水变化存在差异;水汽输送的变化与低层环流的变化关系密切,且模式间一致性相对低。 相似文献
7.
Zhongwei YAN Yihui DING Panmao ZHAI Lianchun SONG Lijuan CAO Zhen LI 《Journal of Meteorological Research》2020,(2):243-251
The regional mean surface air temperature(SAT)in China has risen with a rate of 1.3–1.7℃(100 yr)^-1 since 1900,based on the recently developed homogenized observations.This estimate is larger than those[0.5–0.8℃(100 yr)^-1]adopted in the early National Reports of Climate Change in China.The present paper reviews the studies of the longterm SAT series of China,highlighting the homogenization of station observations as the key progress.The SAT series of China in early studies showed a prominent warm peak in the 1940s,mainly due to inhomogeneous records associated with site-moves of a number of stations from urban to outskirts in the early 1950s,thus leading to underestimates of the centennial warming trend.Parts of China were relatively warm around the 1940s but with differentphase interdecadal variations,while some parts were even relatively cool.This fact is supported by proxy data and could partly be explained by interdecadal changes in large-scale circulation.The effect of urbanization should have a minor contribution to the observed warming in China,although the estimates of such contributions for individual urban stations remain controversial.Further studies relevant to the present topic are discussed. 相似文献
8.
In the recent climate change negotiations it was declared that the increase in global temperature should be kept below 2°C by 2100, relative to pre-industrial levels. China's CO2 emissions from energy and cement processes already account for nearly 24% of global emissions, a trend that is expected to keep increasing. Thus the role of China in global GHG mitigation is crucial. A scenario analysis of China's CO2 emissions is presented here and the feasibility of China reaching a low-carbon scenario is discussed. The results suggest that recent and continued technological progress will make it possible for China to limit its CO2 emissions and for these emissions to peak before 2025 and therefore that the global 2°C target can be achieved. Policy relevance In signing the Copenhagen Accord, China agreed to the global 2°C target. Results from this article could be used to justify low-carbon development policies and negotiations. While many still doubt the feasibility of a low-carbon pathway to support the global 2°C target, the results suggest that such a pathway can be realistically achieved. This conclusion should increase confidence and guide the policy framework further to make possible China's low-carbon development. Related policies and measures, such as renewable energy development, energy efficiency, economic structure optimization, technology innovation, low-carbon investment, and carbon capture and storage (CCS) development, should be further enhanced. Furthermore, China can play a larger role in the international negotiations process. In the global context, the 2°C target could be reaffirmed and a global regime on an emissions mitigation protocol could be framed with countries’ emissions target up to 2050. 相似文献
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基于CMIP6的16个全球模式试验数据,多模式集合预估了《巴黎协定》1.5°C/2°C温升目标下“一带一路”倡议的主要陆域未来气温和降水变化。与观测相比较,多模式集合能够比较准确地刻画“一带一路”主要陆域1995～2014年气温和降水的空间结构特征。在SSP2-4.5、SSP3-7.0和SSP5-8.5三种不同路径情景下,相对于工业革命前（1850～1900年）,全球升温1.5°C与2°C分别将发生在2020年代中后期与2040年左右。全球1.5°C与2°C温升目标下,预计“一带一路”陆域平均的气温分别显著升高1.84°C和2.43°C,两者相差0.59°C,模式间标准差分别为0.18°C和0.21°C;区域平均的降水分别显著增加20.14 mm/a和30.02 mm/a,相差9.88 mm/a,模式间标准差分别为10.79 mm/a和13.72 mm/a。两种温升目标下,“一带一路”主要陆域气温空间上均表现为一致性显著增暖,高纬度的增温幅度普遍比低纬度大;降水变化具有明显的空间差异性,地中海与黑海地区、中国南部至中南半岛地区减少,其他地区的降水普遍增加。P-E指数表征的干旱化未来在欧洲地区、中国南部至中南半岛地区、南亚印度东部地区、东南亚和赤道非洲中部地区达到最大。 相似文献
11.
《Climate Policy》2013,13(3):247-260
In order to stabilize long-term greenhouse gas concentrations at 450 ppm CO2-eq or lower, developed countries as a group should reduce emissions by 25–40% below 1990 levels by 2020, while developing countries' emissions need to be reduced by around 15–30%, relative to their baseline levels, according to the IPCC and our earlier work. This study examines 19 other studies on the emission reductions attributed to the developed and developing countries for meeting a 450 ppm target. These studies considered different allocation approaches, according to equity principles. The effect of the assumed global emissions cap in these studies is analysed. For developed countries, the original reduction range of 25–40% by 2020 is still within the average range of all studies, but does not cover it completely. Comparing the studies shows that assuming a global emissions cap of 5–15% above 1990 levels by 2020 generally leads to more stringent reduction targets than when a global emissions cap of 20–30% above 1990 levels is assumed. For developing countries, the reduction range of 15–30% below their baseline levels by 2020 corresponds to an increase on the 1990 level from 70% (about the 2006 level) to 120%. Reducing deforestation emissions by 50% below baseline levels by 2020 may relax the emission reductions for either group of countries; for developing countries by about 7% or for developed countries by about 15% (but not for both). 相似文献
12.
Bruce T. Anderson 《Climatic change》2012,112(2):325-337
Current international efforts to reduce greenhouse gas emissions and limit human-induced global-mean near-surface temperature increases to 2°C, relative to the pre-industrial era, are intended to avoid possibly significant and dangerous impacts to physical, biological, and socio-economic systems. However, it is unknown how these various systems will respond to such a temperature increase because their relevant spatial scales are much different than those represented by numerical global climate models—the standard tool for climate change studies. This deficiency can be addressed by using higher-resolution regional climate models, but at great computational expense. The research presented here seeks to determine how a 2°C global-mean temperature increase might change the frequency of seasonal temperature extremes, both in the United States and around the globe, without necessarily resorting to these computationally-intensive model experiments. Results indicate that in many locations the regional temperature increases that accompany a 2°C increase in global mean temperatures are significantly larger than the interannual-to-decadal variations in seasonal-mean temperatures; in these locations a 2°C global mean temperature increase results in seasonal-mean temperatures that consistently exceed the most extreme values experienced during the second half of the 20th Century. Further, results indicate that many tropical regions, despite having relatively modest overall temperature increases, will have the most substantial increase in number of hot extremes. These results highlight that extremes very well could become the norm, even given the 2°C temperature increase target. 相似文献
13.
Niklas Höhne Christopher Taylor Ramzi Elias Michel Den Elzen Keywan Riahi Claudine Chen 《Climate Policy》2013,13(3):356-377
This article provides further detail on expected global GHG emission levels in 2020, based on the Emissions Gap Report (United Nations Environment Programme, December 2010), assuming the emission reduction proposals in the Copenhagen Accord and Cancun Agreements are met. Large differences are found in the results of individual groups owing to uncertainties in current and projected emission estimates and in the interpretation of the reduction proposals. Regardless of these uncertainties, the pledges for 2020 are expected to deliver emission levels above those that are consistent with a 2°C limit. This emissions gap could be narrowed through implementing the more stringent conditional pledges, minimizing the use of ‘lenient’ credits from forests and surplus emission units, avoiding double-counting of offsets and implementing measures beyond current pledges. Conversely, emission reduction gains from countries moving from their low to high ambition pledges could be more than offset by the use of ‘lenient’ land use, land-use change and forestry (LULUCF) credits and surplus emissions units, if these were used to the maximum. Laying the groundwork for faster emission reduction rates after 2020 appears to be crucial in any case. 相似文献
14.
Using a set of numerical experiments from 39 CMIP5 climate models, we project the emergence time for 4?C global warming with respect to pre-industrial levels and associated climate changes under the RCP8.5 greenhouse gas concentration scenario. Results show that, according to the 39 models, the median year in which 4?C global warming will occur is 2084.Based on the median results of models that project a 4?C global warming by 2100, land areas will generally exhibit stronger warming than the oceans annually and seasonally, and the strongest enhancement occurs in the Arctic, with the exception of the summer season. Change signals for temperature go outside its natural internal variabilities globally, and the signal-tonoise ratio averages 9.6 for the annual mean and ranges from 6.3 to 7.2 for the seasonal mean over the globe, with the greatest values appearing at low latitudes because of low noise. Decreased precipitation generally occurs in the subtropics, whilst increased precipitation mainly appears at high latitudes. The precipitation changes in most of the high latitudes are greater than the background variability, and the global mean signal-to-noise ratio is 0.5 and ranges from 0.2 to 0.4 for the annual and seasonal means, respectively. Attention should be paid to limiting global warming to 1.5?C, in which case temperature and precipitation will experience a far more moderate change than the natural internal variability. Large inter-model disagreement appears at high latitudes for temperature changes and at mid and low latitudes for precipitation changes. Overall, the intermodel consistency is better for temperature than for precipitation. 相似文献
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Abstract This article presents a set of multi-gas emission pathways for different CO2-equivalent concentration stabilization levels, i.e. 400, 450, 500 and 550 ppm CO2-equivalent, along with an analysis of their global and regional reduction implications and implied probability of achieving the EU climate target of 2°C. For achieving the 2°C target with a probability of more than 60%, greenhouse gas concentrations need to be stabilized at 450 ppm CO2-equivalent or below, if the 90% uncertainty range for climate sensitivity is believed to be 1.5–4.5°C. A stabilization at 450 ppm CO2-equivalent or below (400 ppm) requires global emissions to peak around 2015, followed by substantial overall reductions of as much as 25% (45% for 400 ppm) compared to 1990 levels in 2050. In 2020, Annex I emissions need to be approximately 15% (30%) below 1990 levels, and non-Annex I emissions also need to be reduced by 15–20% compared to their baseline emissions. A further delay in peaking of global emissions by 10 years doubles maximum reduction rates to about 5% per year, and very probably leads to high costs. In order to keep the option open of stabilizing at 400 and 450 ppm CO2-equivalent, the USA and major advanced non-Annex I countries will have to participate in the reductions within the next 10–15 years. 相似文献
17.
Climate sensitivity is an important index that measures the relationship between the increase in greenhouse gases and the magnitude of global warming. Uncertainties in climate change projection and climate modeling are mostly related to the climate sensitivity. The climate sensitivities of coupled climate models determine the magnitudes of the projected global warming. In this paper, the authors thoroughly review the literature on climate sensitivity, and discuss issues related to climate feedback processes and the methods used in estimating the equilibrium climate sensitivity and transient climate response (TCR), including the TCR to cumulative CO2 emissions. After presenting a summary of the sources that affect the uncertainty of climate sensitivity, the impact of climate sensitivity on climate change projection is discussed by addressing the uncertainties in 2°C warming. Challenges that call for further investigation in the research community, in particular the Chinese community, are discussed. 相似文献
18.
N. Ranger L. K. Gohar J. A. Lowe S. C. B. Raper A. Bowen R. E. Ward 《Climatic change》2012,111(3-4):973-981
This study explores the feasibility of limiting increases in global temperature to 1.5°C above pre-industrial levels. A probabilistic simple climate model is used to identify emissions paths that offer at least a 50% chance of achieving this goal. We conclude that it is more likely than not that warming would exceed 1.5°C, at least temporarily, under plausible mitigation scenarios. We have identified three criteria of emissions paths that could meet the 1.5°C goal with a temporary overshoot of no more than 50 years: early and strong reductions in emissions, with global emissions peaking in 2015 and falling to at most 44–48 GtCO2e in 2020; rapid reductions in annual global emissions after 2020 (of at least 3–4% per year); very low annual global emissions by 2100 (less than 2–4 GtCO2e) and falling to zero (or below) in the 22nd century. The feasibility of these characteristics is uncertain. We conclude that the proposed date of review of the 1.5°C goal, set at 2015, may be too late to achieve the necessary scaling up of emissions cuts to achieve this goal. 相似文献
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E. Kuhlbrodt 《Meteorology and Atmospheric Physics》1954,7(1):170-187
Zusammenfassung Für die inneren Tropen läßt sich die Kenntnis der Höhenströmungen nur durch direkte Beobachtungen gewinnen. Für den Golf von Guinea liegen Messungen innerhalb der Breite 5° N bis 9° S von drei Profilen der Meteor-Expedition und von zwei Studienfahrten der Deutschen Seewarte vor. Eine Voruntersuchung der mittleren Windwerte für die einzelnen benachbarten 5°-Felder einer Breitenzone (gleicher Jahreszeit) ergibt weigehende Übereinstimmung. Deshalb wird die zusammengefaßte Länge 10° W bis 5° E (für jede Breitenzone) der statistischen Bearbeitung zugrunde gelegt. Ziel der Untersuchung ist, die sich bei der Höhenwind-Statistik deutlich heraushebenden, charakteristischen Hauptströmungen zu beiden Seiten des Äquators und im jahreszeitlichen Unterschied zu erkennen und zahlenmäßig zu diskutieren. Nach einer Darstellung der Schichtung der mittleren Komponenten für 0 bis 19 km Höhe werden die einzelnen Strömungssysteme an Hand von Tabellen und Abbildungen näher beschrieben. Untere Troposphäre: Monsun, Antimonsun; Passat. Mittlere Troposphäre: Ostströmung (Urpassat). Hohe Troposphäre: Hohe Westströmung (Anti-Urpassat). Tropopausen-Schicht: Übergang von W in hohen Ost (Oberpassat). Hierbei wird für Test-Höhen die Streuung der beobachteten Einzelwinde besprochen. Größte gemessene Einzelgeschwindigkeit nahe dem Äquator: in der E-Strömung: SE 20 m/s (9 bis 10 km), in der hohen W-Strömung: SW 21 m/s (15 bis 16 km, nördlich vom Äquator), NW 21 m/s (13 bis 14 km, südlich vom Äquator). Die Rolle des Äquators bei den Höhenströmungen (meridionale Komponente) wird zusammenfassend betrachtet.
Mit 5 Textabbildungen. 相似文献
Summary Knowledge on the currents of the upper atmosphere in the inner tropics can be obtained only by direct observations. In the Gulf of Guinea, between the latitudes 5° N and 9° S, three profiles were determined by the Meteor expedition and measurements carried out by two expeditions of the Deutsche Seewarte. A preliminary test of the average wind values gives good agreement for all adjoining 5°-fields of a zone of latitude (during the same season). Therefore, the longitude 10° W-5° E as a whole (for every zone of latitude) could be applied to statistical evaluation. Purpose of this investigation is to establish and discuss quantitatively the characteristic mean currents on both sides of the equator such as result from the wind statistics of the upper atmosphere in their seasonal variations. The distribution of the mean components is given for 0–19 km altitude; the different systems of currents are described in detail by tables and illustrations. Lower troposphere: monsoon, anti-monsoon; trade-wind. Medium troposphere: easterlies (Urpassat). High troposphere: high west-wind (Anti-Urpassat). Tropopause: transition from west to high east-wind (Oberpassat). For certain test heights the dispersion of the different observed winds is discussed. Measured maximum velocities near equator: in the eastern current: SE 20 m/s (9–10 km), in the western current: SW 21 m/s (15–16 km, north of equator), NW 21 m/s (13–14 km, south of equator). The rôle of the equator in connection with high currents (meridional component) is discussed comprehensively.
Résumé On ne peut connaître l'allure de la circulation dans la haute atmosphère de la zone tropicale que par des observations directes. Dans le Golfe de Guinée on dispose de trois profils obtenus entre 5° N et 9° S par l'expédition du «Meteor» et de deux croisières d'étude de la Deutsche Seewarte. Une étude préalable des valeurs moyennes de vent relatives aux diverses surfaces de 5° d'une zone (mêmes saisons) aboutit à des résultats très concordants; aussi a-t-on soumis à l'examen statistique chaque bande zonale de 5° allant de 10° W à 5° E de longitude. Le but de cette recherche est de mettre en évidence les principaux courants en altitude de part et d'autre de l'équateur et d'examiner leurs valeurs numériques dans leurs variations saisonnières. Après avoir représenté la stratification des composantes moyennes entre 0 et 19 km, on décrit les différents systèmes de courants à l'aide de tableaux et de croquis et qui sont les suivants. Troposphère inférieure: mousson et contre-mousson; alizés. Troposphère moyenne: courant d'Est (Urpassat). Troposphère supérieure: courant d'Ouest supérieur (Anti-Urpassat). Tropopause: transition du courant d'Ouest à celui d'Est (Oberpassat). A cet effet on discute la dispersion des vents observés pour des niveaux choisis. Vitesse maximum observée près de l'équateur: dans le courant d'Est SE 20 m/s (à 9–10 km), et dans le courant d'Ouest supérieur SW 21 m/s (à 15–16 km au Nord de l'équateur), NW 21 m/s (à 13–14 km au Sud de l'équateur). On considère en résumé le rôle de l'équateur dans les courants en altitude (composante méridienne).
Mit 5 Textabbildungen. 相似文献